LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* [PATCH] powerpc/powernv: remove dead npu-dma code
@ 2018-10-30 13:31 Christoph Hellwig
  2018-11-01  4:41 ` Alexey Kardashevskiy
  0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2018-10-30 13:31 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: James Bottomley, Paul E. McKenney, Andrew Morton, Linus Torvalds,
	linuxppc-dev, linux-kernel

This code has never been unused in the kernel since it was merged, and
there has been no attempt that I could find to even submit users for
it.  Besides the general policy of not keep 1000+ lines of dead
code, it helps cleaning up the DMA code and making powerpc user common
infrastructure.

This effectively reverts commit 5d2aa710 ("powerpc/powernv: Add support
for Nvlink NPUs").

Signed-off-by: Christoph Hellwig <hch@lst.de>
---

[this is a follow up to the brief maintainer summit discussion]

 arch/powerpc/include/asm/pci.h            |   3 -
 arch/powerpc/include/asm/powernv.h        |  23 -
 arch/powerpc/platforms/powernv/Makefile   |   2 +-
 arch/powerpc/platforms/powernv/npu-dma.c  | 989 ----------------------
 arch/powerpc/platforms/powernv/pci-ioda.c | 243 ------
 arch/powerpc/platforms/powernv/pci.h      |  11 -
 6 files changed, 1 insertion(+), 1270 deletions(-)
 delete mode 100644 arch/powerpc/platforms/powernv/npu-dma.c

diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index 2af9ded80540..a01d2e3d6ff9 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -127,7 +127,4 @@ extern void pcibios_scan_phb(struct pci_controller *hose);
 
 #endif	/* __KERNEL__ */
 
-extern struct pci_dev *pnv_pci_get_gpu_dev(struct pci_dev *npdev);
-extern struct pci_dev *pnv_pci_get_npu_dev(struct pci_dev *gpdev, int index);
-
 #endif /* __ASM_POWERPC_PCI_H */
diff --git a/arch/powerpc/include/asm/powernv.h b/arch/powerpc/include/asm/powernv.h
index 2f3ff7a27881..4848a6b3c6b2 100644
--- a/arch/powerpc/include/asm/powernv.h
+++ b/arch/powerpc/include/asm/powernv.h
@@ -11,33 +11,10 @@
 #define _ASM_POWERNV_H
 
 #ifdef CONFIG_PPC_POWERNV
-#define NPU2_WRITE 1
 extern void powernv_set_nmmu_ptcr(unsigned long ptcr);
-extern struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
-			unsigned long flags,
-			void (*cb)(struct npu_context *, void *),
-			void *priv);
-extern void pnv_npu2_destroy_context(struct npu_context *context,
-				struct pci_dev *gpdev);
-extern int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
-				unsigned long *flags, unsigned long *status,
-				int count);
-
 void pnv_tm_init(void);
 #else
 static inline void powernv_set_nmmu_ptcr(unsigned long ptcr) { }
-static inline struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
-			unsigned long flags,
-			struct npu_context *(*cb)(struct npu_context *, void *),
-			void *priv) { return ERR_PTR(-ENODEV); }
-static inline void pnv_npu2_destroy_context(struct npu_context *context,
-					struct pci_dev *gpdev) { }
-
-static inline int pnv_npu2_handle_fault(struct npu_context *context,
-					uintptr_t *ea, unsigned long *flags,
-					unsigned long *status, int count) {
-	return -ENODEV;
-}
 
 static inline void pnv_tm_init(void) { }
 static inline void pnv_power9_force_smt4(void) { }
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index b540ce8eec55..2b13e9dd137c 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -6,7 +6,7 @@ obj-y			+= opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
 obj-y			+= opal-kmsg.o opal-powercap.o opal-psr.o opal-sensor-groups.o
 
 obj-$(CONFIG_SMP)	+= smp.o subcore.o subcore-asm.o
-obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o npu-dma.o pci-ioda-tce.o
+obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o pci-ioda-tce.o
 obj-$(CONFIG_CXL_BASE)	+= pci-cxl.o
 obj-$(CONFIG_EEH)	+= eeh-powernv.o
 obj-$(CONFIG_PPC_SCOM)	+= opal-xscom.o
diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
deleted file mode 100644
index 6f60e0931922..000000000000
--- a/arch/powerpc/platforms/powernv/npu-dma.c
+++ /dev/null
@@ -1,989 +0,0 @@
-/*
- * This file implements the DMA operations for NVLink devices. The NPU
- * devices all point to the same iommu table as the parent PCI device.
- *
- * Copyright Alistair Popple, IBM Corporation 2015.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- */
-
-#include <linux/slab.h>
-#include <linux/mmu_notifier.h>
-#include <linux/mmu_context.h>
-#include <linux/of.h>
-#include <linux/export.h>
-#include <linux/pci.h>
-#include <linux/memblock.h>
-#include <linux/iommu.h>
-#include <linux/sizes.h>
-
-#include <asm/debugfs.h>
-#include <asm/tlb.h>
-#include <asm/powernv.h>
-#include <asm/reg.h>
-#include <asm/opal.h>
-#include <asm/io.h>
-#include <asm/iommu.h>
-#include <asm/pnv-pci.h>
-#include <asm/msi_bitmap.h>
-#include <asm/opal.h>
-
-#include "powernv.h"
-#include "pci.h"
-
-#define npu_to_phb(x) container_of(x, struct pnv_phb, npu)
-
-/*
- * spinlock to protect initialisation of an npu_context for a particular
- * mm_struct.
- */
-static DEFINE_SPINLOCK(npu_context_lock);
-
-/*
- * Other types of TCE cache invalidation are not functional in the
- * hardware.
- */
-static struct pci_dev *get_pci_dev(struct device_node *dn)
-{
-	struct pci_dn *pdn = PCI_DN(dn);
-
-	return pci_get_domain_bus_and_slot(pci_domain_nr(pdn->phb->bus),
-					   pdn->busno, pdn->devfn);
-}
-
-/* Given a NPU device get the associated PCI device. */
-struct pci_dev *pnv_pci_get_gpu_dev(struct pci_dev *npdev)
-{
-	struct device_node *dn;
-	struct pci_dev *gpdev;
-
-	if (WARN_ON(!npdev))
-		return NULL;
-
-	if (WARN_ON(!npdev->dev.of_node))
-		return NULL;
-
-	/* Get assoicated PCI device */
-	dn = of_parse_phandle(npdev->dev.of_node, "ibm,gpu", 0);
-	if (!dn)
-		return NULL;
-
-	gpdev = get_pci_dev(dn);
-	of_node_put(dn);
-
-	return gpdev;
-}
-EXPORT_SYMBOL(pnv_pci_get_gpu_dev);
-
-/* Given the real PCI device get a linked NPU device. */
-struct pci_dev *pnv_pci_get_npu_dev(struct pci_dev *gpdev, int index)
-{
-	struct device_node *dn;
-	struct pci_dev *npdev;
-
-	if (WARN_ON(!gpdev))
-		return NULL;
-
-	/* Not all PCI devices have device-tree nodes */
-	if (!gpdev->dev.of_node)
-		return NULL;
-
-	/* Get assoicated PCI device */
-	dn = of_parse_phandle(gpdev->dev.of_node, "ibm,npu", index);
-	if (!dn)
-		return NULL;
-
-	npdev = get_pci_dev(dn);
-	of_node_put(dn);
-
-	return npdev;
-}
-EXPORT_SYMBOL(pnv_pci_get_npu_dev);
-
-#define NPU_DMA_OP_UNSUPPORTED()					\
-	dev_err_once(dev, "%s operation unsupported for NVLink devices\n", \
-		__func__)
-
-static void *dma_npu_alloc(struct device *dev, size_t size,
-			   dma_addr_t *dma_handle, gfp_t flag,
-			   unsigned long attrs)
-{
-	NPU_DMA_OP_UNSUPPORTED();
-	return NULL;
-}
-
-static void dma_npu_free(struct device *dev, size_t size,
-			 void *vaddr, dma_addr_t dma_handle,
-			 unsigned long attrs)
-{
-	NPU_DMA_OP_UNSUPPORTED();
-}
-
-static dma_addr_t dma_npu_map_page(struct device *dev, struct page *page,
-				   unsigned long offset, size_t size,
-				   enum dma_data_direction direction,
-				   unsigned long attrs)
-{
-	NPU_DMA_OP_UNSUPPORTED();
-	return 0;
-}
-
-static int dma_npu_map_sg(struct device *dev, struct scatterlist *sglist,
-			  int nelems, enum dma_data_direction direction,
-			  unsigned long attrs)
-{
-	NPU_DMA_OP_UNSUPPORTED();
-	return 0;
-}
-
-static int dma_npu_dma_supported(struct device *dev, u64 mask)
-{
-	NPU_DMA_OP_UNSUPPORTED();
-	return 0;
-}
-
-static u64 dma_npu_get_required_mask(struct device *dev)
-{
-	NPU_DMA_OP_UNSUPPORTED();
-	return 0;
-}
-
-static const struct dma_map_ops dma_npu_ops = {
-	.map_page		= dma_npu_map_page,
-	.map_sg			= dma_npu_map_sg,
-	.alloc			= dma_npu_alloc,
-	.free			= dma_npu_free,
-	.dma_supported		= dma_npu_dma_supported,
-	.get_required_mask	= dma_npu_get_required_mask,
-};
-
-/*
- * Returns the PE assoicated with the PCI device of the given
- * NPU. Returns the linked pci device if pci_dev != NULL.
- */
-static struct pnv_ioda_pe *get_gpu_pci_dev_and_pe(struct pnv_ioda_pe *npe,
-						  struct pci_dev **gpdev)
-{
-	struct pnv_phb *phb;
-	struct pci_controller *hose;
-	struct pci_dev *pdev;
-	struct pnv_ioda_pe *pe;
-	struct pci_dn *pdn;
-
-	pdev = pnv_pci_get_gpu_dev(npe->pdev);
-	if (!pdev)
-		return NULL;
-
-	pdn = pci_get_pdn(pdev);
-	if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
-		return NULL;
-
-	hose = pci_bus_to_host(pdev->bus);
-	phb = hose->private_data;
-	pe = &phb->ioda.pe_array[pdn->pe_number];
-
-	if (gpdev)
-		*gpdev = pdev;
-
-	return pe;
-}
-
-long pnv_npu_set_window(struct pnv_ioda_pe *npe, int num,
-		struct iommu_table *tbl)
-{
-	struct pnv_phb *phb = npe->phb;
-	int64_t rc;
-	const unsigned long size = tbl->it_indirect_levels ?
-		tbl->it_level_size : tbl->it_size;
-	const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
-	const __u64 win_size = tbl->it_size << tbl->it_page_shift;
-
-	pe_info(npe, "Setting up window %llx..%llx pg=%lx\n",
-			start_addr, start_addr + win_size - 1,
-			IOMMU_PAGE_SIZE(tbl));
-
-	rc = opal_pci_map_pe_dma_window(phb->opal_id,
-			npe->pe_number,
-			npe->pe_number,
-			tbl->it_indirect_levels + 1,
-			__pa(tbl->it_base),
-			size << 3,
-			IOMMU_PAGE_SIZE(tbl));
-	if (rc) {
-		pe_err(npe, "Failed to configure TCE table, err %lld\n", rc);
-		return rc;
-	}
-	pnv_pci_ioda2_tce_invalidate_entire(phb, false);
-
-	/* Add the table to the list so its TCE cache will get invalidated */
-	pnv_pci_link_table_and_group(phb->hose->node, num,
-			tbl, &npe->table_group);
-
-	return 0;
-}
-
-long pnv_npu_unset_window(struct pnv_ioda_pe *npe, int num)
-{
-	struct pnv_phb *phb = npe->phb;
-	int64_t rc;
-
-	pe_info(npe, "Removing DMA window\n");
-
-	rc = opal_pci_map_pe_dma_window(phb->opal_id, npe->pe_number,
-			npe->pe_number,
-			0/* levels */, 0/* table address */,
-			0/* table size */, 0/* page size */);
-	if (rc) {
-		pe_err(npe, "Unmapping failed, ret = %lld\n", rc);
-		return rc;
-	}
-	pnv_pci_ioda2_tce_invalidate_entire(phb, false);
-
-	pnv_pci_unlink_table_and_group(npe->table_group.tables[num],
-			&npe->table_group);
-
-	return 0;
-}
-
-/*
- * Enables 32 bit DMA on NPU.
- */
-static void pnv_npu_dma_set_32(struct pnv_ioda_pe *npe)
-{
-	struct pci_dev *gpdev;
-	struct pnv_ioda_pe *gpe;
-	int64_t rc;
-
-	/*
-	 * Find the assoicated PCI devices and get the dma window
-	 * information from there.
-	 */
-	if (!npe->pdev || !(npe->flags & PNV_IODA_PE_DEV))
-		return;
-
-	gpe = get_gpu_pci_dev_and_pe(npe, &gpdev);
-	if (!gpe)
-		return;
-
-	rc = pnv_npu_set_window(npe, 0, gpe->table_group.tables[0]);
-
-	/*
-	 * We don't initialise npu_pe->tce32_table as we always use
-	 * dma_npu_ops which are nops.
-	 */
-	set_dma_ops(&npe->pdev->dev, &dma_npu_ops);
-}
-
-/*
- * Enables bypass mode on the NPU. The NPU only supports one
- * window per link, so bypass needs to be explicitly enabled or
- * disabled. Unlike for a PHB3 bypass and non-bypass modes can't be
- * active at the same time.
- */
-static int pnv_npu_dma_set_bypass(struct pnv_ioda_pe *npe)
-{
-	struct pnv_phb *phb = npe->phb;
-	int64_t rc = 0;
-	phys_addr_t top = memblock_end_of_DRAM();
-
-	if (phb->type != PNV_PHB_NPU_NVLINK || !npe->pdev)
-		return -EINVAL;
-
-	rc = pnv_npu_unset_window(npe, 0);
-	if (rc != OPAL_SUCCESS)
-		return rc;
-
-	/* Enable the bypass window */
-
-	top = roundup_pow_of_two(top);
-	dev_info(&npe->pdev->dev, "Enabling bypass for PE %x\n",
-			npe->pe_number);
-	rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
-			npe->pe_number, npe->pe_number,
-			0 /* bypass base */, top);
-
-	if (rc == OPAL_SUCCESS)
-		pnv_pci_ioda2_tce_invalidate_entire(phb, false);
-
-	return rc;
-}
-
-void pnv_npu_try_dma_set_bypass(struct pci_dev *gpdev, bool bypass)
-{
-	int i;
-	struct pnv_phb *phb;
-	struct pci_dn *pdn;
-	struct pnv_ioda_pe *npe;
-	struct pci_dev *npdev;
-
-	for (i = 0; ; ++i) {
-		npdev = pnv_pci_get_npu_dev(gpdev, i);
-
-		if (!npdev)
-			break;
-
-		pdn = pci_get_pdn(npdev);
-		if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
-			return;
-
-		phb = pci_bus_to_host(npdev->bus)->private_data;
-
-		/* We only do bypass if it's enabled on the linked device */
-		npe = &phb->ioda.pe_array[pdn->pe_number];
-
-		if (bypass) {
-			dev_info(&npdev->dev,
-					"Using 64-bit DMA iommu bypass\n");
-			pnv_npu_dma_set_bypass(npe);
-		} else {
-			dev_info(&npdev->dev, "Using 32-bit DMA via iommu\n");
-			pnv_npu_dma_set_32(npe);
-		}
-	}
-}
-
-/* Switch ownership from platform code to external user (e.g. VFIO) */
-void pnv_npu_take_ownership(struct pnv_ioda_pe *npe)
-{
-	struct pnv_phb *phb = npe->phb;
-	int64_t rc;
-
-	/*
-	 * Note: NPU has just a single TVE in the hardware which means that
-	 * while used by the kernel, it can have either 32bit window or
-	 * DMA bypass but never both. So we deconfigure 32bit window only
-	 * if it was enabled at the moment of ownership change.
-	 */
-	if (npe->table_group.tables[0]) {
-		pnv_npu_unset_window(npe, 0);
-		return;
-	}
-
-	/* Disable bypass */
-	rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
-			npe->pe_number, npe->pe_number,
-			0 /* bypass base */, 0);
-	if (rc) {
-		pe_err(npe, "Failed to disable bypass, err %lld\n", rc);
-		return;
-	}
-	pnv_pci_ioda2_tce_invalidate_entire(npe->phb, false);
-}
-
-struct pnv_ioda_pe *pnv_pci_npu_setup_iommu(struct pnv_ioda_pe *npe)
-{
-	struct pnv_phb *phb = npe->phb;
-	struct pci_bus *pbus = phb->hose->bus;
-	struct pci_dev *npdev, *gpdev = NULL, *gptmp;
-	struct pnv_ioda_pe *gpe = get_gpu_pci_dev_and_pe(npe, &gpdev);
-
-	if (!gpe || !gpdev)
-		return NULL;
-
-	list_for_each_entry(npdev, &pbus->devices, bus_list) {
-		gptmp = pnv_pci_get_gpu_dev(npdev);
-
-		if (gptmp != gpdev)
-			continue;
-
-		pe_info(gpe, "Attached NPU %s\n", dev_name(&npdev->dev));
-		iommu_group_add_device(gpe->table_group.group, &npdev->dev);
-	}
-
-	return gpe;
-}
-
-/* Maximum number of nvlinks per npu */
-#define NV_MAX_LINKS 6
-
-/* Maximum index of npu2 hosts in the system. Always < NV_MAX_NPUS */
-static int max_npu2_index;
-
-struct npu_context {
-	struct mm_struct *mm;
-	struct pci_dev *npdev[NV_MAX_NPUS][NV_MAX_LINKS];
-	struct mmu_notifier mn;
-	struct kref kref;
-	bool nmmu_flush;
-
-	/* Callback to stop translation requests on a given GPU */
-	void (*release_cb)(struct npu_context *context, void *priv);
-
-	/*
-	 * Private pointer passed to the above callback for usage by
-	 * device drivers.
-	 */
-	void *priv;
-};
-
-struct mmio_atsd_reg {
-	struct npu *npu;
-	int reg;
-};
-
-/*
- * Find a free MMIO ATSD register and mark it in use. Return -ENOSPC
- * if none are available.
- */
-static int get_mmio_atsd_reg(struct npu *npu)
-{
-	int i;
-
-	for (i = 0; i < npu->mmio_atsd_count; i++) {
-		if (!test_bit(i, &npu->mmio_atsd_usage))
-			if (!test_and_set_bit_lock(i, &npu->mmio_atsd_usage))
-				return i;
-	}
-
-	return -ENOSPC;
-}
-
-static void put_mmio_atsd_reg(struct npu *npu, int reg)
-{
-	clear_bit_unlock(reg, &npu->mmio_atsd_usage);
-}
-
-/* MMIO ATSD register offsets */
-#define XTS_ATSD_LAUNCH 0
-#define XTS_ATSD_AVA    1
-#define XTS_ATSD_STAT   2
-
-static unsigned long get_atsd_launch_val(unsigned long pid, unsigned long psize)
-{
-	unsigned long launch = 0;
-
-	if (psize == MMU_PAGE_COUNT) {
-		/* IS set to invalidate entire matching PID */
-		launch |= PPC_BIT(12);
-	} else {
-		/* AP set to invalidate region of psize */
-		launch |= (u64)mmu_get_ap(psize) << PPC_BITLSHIFT(17);
-	}
-
-	/* PRS set to process-scoped */
-	launch |= PPC_BIT(13);
-
-	/* PID */
-	launch |= pid << PPC_BITLSHIFT(38);
-
-	/* Leave "No flush" (bit 39) 0 so every ATSD performs a flush */
-
-	return launch;
-}
-
-static void mmio_atsd_regs_write(struct mmio_atsd_reg
-			mmio_atsd_reg[NV_MAX_NPUS], unsigned long offset,
-			unsigned long val)
-{
-	struct npu *npu;
-	int i, reg;
-
-	for (i = 0; i <= max_npu2_index; i++) {
-		reg = mmio_atsd_reg[i].reg;
-		if (reg < 0)
-			continue;
-
-		npu = mmio_atsd_reg[i].npu;
-		__raw_writeq_be(val, npu->mmio_atsd_regs[reg] + offset);
-	}
-}
-
-static void mmio_invalidate_pid(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS],
-				unsigned long pid)
-{
-	unsigned long launch = get_atsd_launch_val(pid, MMU_PAGE_COUNT);
-
-	/* Invalidating the entire process doesn't use a va */
-	mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch);
-}
-
-static void mmio_invalidate_range(struct mmio_atsd_reg
-			mmio_atsd_reg[NV_MAX_NPUS], unsigned long pid,
-			unsigned long start, unsigned long psize)
-{
-	unsigned long launch = get_atsd_launch_val(pid, psize);
-
-	/* Write all VAs first */
-	mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_AVA, start);
-
-	/* Issue one barrier for all address writes */
-	eieio();
-
-	/* Launch */
-	mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch);
-}
-
-#define mn_to_npu_context(x) container_of(x, struct npu_context, mn)
-
-static void mmio_invalidate_wait(
-	struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
-{
-	struct npu *npu;
-	int i, reg;
-
-	/* Wait for all invalidations to complete */
-	for (i = 0; i <= max_npu2_index; i++) {
-		if (mmio_atsd_reg[i].reg < 0)
-			continue;
-
-		/* Wait for completion */
-		npu = mmio_atsd_reg[i].npu;
-		reg = mmio_atsd_reg[i].reg;
-		while (__raw_readq(npu->mmio_atsd_regs[reg] + XTS_ATSD_STAT))
-			cpu_relax();
-	}
-}
-
-/*
- * Acquires all the address translation shootdown (ATSD) registers required to
- * launch an ATSD on all links this npu_context is active on.
- */
-static void acquire_atsd_reg(struct npu_context *npu_context,
-			struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
-{
-	int i, j;
-	struct npu *npu;
-	struct pci_dev *npdev;
-	struct pnv_phb *nphb;
-
-	for (i = 0; i <= max_npu2_index; i++) {
-		mmio_atsd_reg[i].reg = -1;
-		for (j = 0; j < NV_MAX_LINKS; j++) {
-			/*
-			 * There are no ordering requirements with respect to
-			 * the setup of struct npu_context, but to ensure
-			 * consistent behaviour we need to ensure npdev[][] is
-			 * only read once.
-			 */
-			npdev = READ_ONCE(npu_context->npdev[i][j]);
-			if (!npdev)
-				continue;
-
-			nphb = pci_bus_to_host(npdev->bus)->private_data;
-			npu = &nphb->npu;
-			mmio_atsd_reg[i].npu = npu;
-			mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu);
-			while (mmio_atsd_reg[i].reg < 0) {
-				mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu);
-				cpu_relax();
-			}
-			break;
-		}
-	}
-}
-
-/*
- * Release previously acquired ATSD registers. To avoid deadlocks the registers
- * must be released in the same order they were acquired above in
- * acquire_atsd_reg.
- */
-static void release_atsd_reg(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
-{
-	int i;
-
-	for (i = 0; i <= max_npu2_index; i++) {
-		/*
-		 * We can't rely on npu_context->npdev[][] being the same here
-		 * as when acquire_atsd_reg() was called, hence we use the
-		 * values stored in mmio_atsd_reg during the acquire phase
-		 * rather than re-reading npdev[][].
-		 */
-		if (mmio_atsd_reg[i].reg < 0)
-			continue;
-
-		put_mmio_atsd_reg(mmio_atsd_reg[i].npu, mmio_atsd_reg[i].reg);
-	}
-}
-
-/*
- * Invalidate a virtual address range
- */
-static void mmio_invalidate(struct npu_context *npu_context,
-			unsigned long start, unsigned long size)
-{
-	struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS];
-	unsigned long pid = npu_context->mm->context.id;
-	unsigned long atsd_start = 0;
-	unsigned long end = start + size - 1;
-	int atsd_psize = MMU_PAGE_COUNT;
-
-	/*
-	 * Convert the input range into one of the supported sizes. If the range
-	 * doesn't fit, use the next larger supported size. Invalidation latency
-	 * is high, so over-invalidation is preferred to issuing multiple
-	 * invalidates.
-	 *
-	 * A 4K page size isn't supported by NPU/GPU ATS, so that case is
-	 * ignored.
-	 */
-	if (size == SZ_64K) {
-		atsd_start = start;
-		atsd_psize = MMU_PAGE_64K;
-	} else if (ALIGN_DOWN(start, SZ_2M) == ALIGN_DOWN(end, SZ_2M)) {
-		atsd_start = ALIGN_DOWN(start, SZ_2M);
-		atsd_psize = MMU_PAGE_2M;
-	} else if (ALIGN_DOWN(start, SZ_1G) == ALIGN_DOWN(end, SZ_1G)) {
-		atsd_start = ALIGN_DOWN(start, SZ_1G);
-		atsd_psize = MMU_PAGE_1G;
-	}
-
-	if (npu_context->nmmu_flush)
-		/*
-		 * Unfortunately the nest mmu does not support flushing specific
-		 * addresses so we have to flush the whole mm once before
-		 * shooting down the GPU translation.
-		 */
-		flush_all_mm(npu_context->mm);
-
-	/*
-	 * Loop over all the NPUs this process is active on and launch
-	 * an invalidate.
-	 */
-	acquire_atsd_reg(npu_context, mmio_atsd_reg);
-
-	if (atsd_psize == MMU_PAGE_COUNT)
-		mmio_invalidate_pid(mmio_atsd_reg, pid);
-	else
-		mmio_invalidate_range(mmio_atsd_reg, pid, atsd_start,
-					atsd_psize);
-
-	mmio_invalidate_wait(mmio_atsd_reg);
-
-	/*
-	 * The GPU requires two flush ATSDs to ensure all entries have been
-	 * flushed. We use PID 0 as it will never be used for a process on the
-	 * GPU.
-	 */
-	mmio_invalidate_pid(mmio_atsd_reg, 0);
-	mmio_invalidate_wait(mmio_atsd_reg);
-	mmio_invalidate_pid(mmio_atsd_reg, 0);
-	mmio_invalidate_wait(mmio_atsd_reg);
-
-	release_atsd_reg(mmio_atsd_reg);
-}
-
-static void pnv_npu2_mn_release(struct mmu_notifier *mn,
-				struct mm_struct *mm)
-{
-	struct npu_context *npu_context = mn_to_npu_context(mn);
-
-	/* Call into device driver to stop requests to the NMMU */
-	if (npu_context->release_cb)
-		npu_context->release_cb(npu_context, npu_context->priv);
-
-	/*
-	 * There should be no more translation requests for this PID, but we
-	 * need to ensure any entries for it are removed from the TLB.
-	 */
-	mmio_invalidate(npu_context, 0, ~0UL);
-}
-
-static void pnv_npu2_mn_change_pte(struct mmu_notifier *mn,
-				struct mm_struct *mm,
-				unsigned long address,
-				pte_t pte)
-{
-	struct npu_context *npu_context = mn_to_npu_context(mn);
-	mmio_invalidate(npu_context, address, PAGE_SIZE);
-}
-
-static void pnv_npu2_mn_invalidate_range(struct mmu_notifier *mn,
-					struct mm_struct *mm,
-					unsigned long start, unsigned long end)
-{
-	struct npu_context *npu_context = mn_to_npu_context(mn);
-	mmio_invalidate(npu_context, start, end - start);
-}
-
-static const struct mmu_notifier_ops nv_nmmu_notifier_ops = {
-	.release = pnv_npu2_mn_release,
-	.change_pte = pnv_npu2_mn_change_pte,
-	.invalidate_range = pnv_npu2_mn_invalidate_range,
-};
-
-/*
- * Call into OPAL to setup the nmmu context for the current task in
- * the NPU. This must be called to setup the context tables before the
- * GPU issues ATRs. pdev should be a pointed to PCIe GPU device.
- *
- * A release callback should be registered to allow a device driver to
- * be notified that it should not launch any new translation requests
- * as the final TLB invalidate is about to occur.
- *
- * Returns an error if there no contexts are currently available or a
- * npu_context which should be passed to pnv_npu2_handle_fault().
- *
- * mmap_sem must be held in write mode and must not be called from interrupt
- * context.
- */
-struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
-			unsigned long flags,
-			void (*cb)(struct npu_context *, void *),
-			void *priv)
-{
-	int rc;
-	u32 nvlink_index;
-	struct device_node *nvlink_dn;
-	struct mm_struct *mm = current->mm;
-	struct pnv_phb *nphb;
-	struct npu *npu;
-	struct npu_context *npu_context;
-
-	/*
-	 * At present we don't support GPUs connected to multiple NPUs and I'm
-	 * not sure the hardware does either.
-	 */
-	struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
-
-	if (!firmware_has_feature(FW_FEATURE_OPAL))
-		return ERR_PTR(-ENODEV);
-
-	if (!npdev)
-		/* No nvlink associated with this GPU device */
-		return ERR_PTR(-ENODEV);
-
-	nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0);
-	if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index",
-							&nvlink_index)))
-		return ERR_PTR(-ENODEV);
-
-	if (!mm || mm->context.id == 0) {
-		/*
-		 * Kernel thread contexts are not supported and context id 0 is
-		 * reserved on the GPU.
-		 */
-		return ERR_PTR(-EINVAL);
-	}
-
-	nphb = pci_bus_to_host(npdev->bus)->private_data;
-	npu = &nphb->npu;
-
-	/*
-	 * Setup the NPU context table for a particular GPU. These need to be
-	 * per-GPU as we need the tables to filter ATSDs when there are no
-	 * active contexts on a particular GPU. It is safe for these to be
-	 * called concurrently with destroy as the OPAL call takes appropriate
-	 * locks and refcounts on init/destroy.
-	 */
-	rc = opal_npu_init_context(nphb->opal_id, mm->context.id, flags,
-				PCI_DEVID(gpdev->bus->number, gpdev->devfn));
-	if (rc < 0)
-		return ERR_PTR(-ENOSPC);
-
-	/*
-	 * We store the npu pci device so we can more easily get at the
-	 * associated npus.
-	 */
-	spin_lock(&npu_context_lock);
-	npu_context = mm->context.npu_context;
-	if (npu_context) {
-		if (npu_context->release_cb != cb ||
-			npu_context->priv != priv) {
-			spin_unlock(&npu_context_lock);
-			opal_npu_destroy_context(nphb->opal_id, mm->context.id,
-						PCI_DEVID(gpdev->bus->number,
-							gpdev->devfn));
-			return ERR_PTR(-EINVAL);
-		}
-
-		WARN_ON(!kref_get_unless_zero(&npu_context->kref));
-	}
-	spin_unlock(&npu_context_lock);
-
-	if (!npu_context) {
-		/*
-		 * We can set up these fields without holding the
-		 * npu_context_lock as the npu_context hasn't been returned to
-		 * the caller meaning it can't be destroyed. Parallel allocation
-		 * is protected against by mmap_sem.
-		 */
-		rc = -ENOMEM;
-		npu_context = kzalloc(sizeof(struct npu_context), GFP_KERNEL);
-		if (npu_context) {
-			kref_init(&npu_context->kref);
-			npu_context->mm = mm;
-			npu_context->mn.ops = &nv_nmmu_notifier_ops;
-			rc = __mmu_notifier_register(&npu_context->mn, mm);
-		}
-
-		if (rc) {
-			kfree(npu_context);
-			opal_npu_destroy_context(nphb->opal_id, mm->context.id,
-					PCI_DEVID(gpdev->bus->number,
-						gpdev->devfn));
-			return ERR_PTR(rc);
-		}
-
-		mm->context.npu_context = npu_context;
-	}
-
-	npu_context->release_cb = cb;
-	npu_context->priv = priv;
-
-	/*
-	 * npdev is a pci_dev pointer setup by the PCI code. We assign it to
-	 * npdev[][] to indicate to the mmu notifiers that an invalidation
-	 * should also be sent over this nvlink. The notifiers don't use any
-	 * other fields in npu_context, so we just need to ensure that when they
-	 * deference npu_context->npdev[][] it is either a valid pointer or
-	 * NULL.
-	 */
-	WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], npdev);
-
-	if (!nphb->npu.nmmu_flush) {
-		/*
-		 * If we're not explicitly flushing ourselves we need to mark
-		 * the thread for global flushes
-		 */
-		npu_context->nmmu_flush = false;
-		mm_context_add_copro(mm);
-	} else
-		npu_context->nmmu_flush = true;
-
-	return npu_context;
-}
-EXPORT_SYMBOL(pnv_npu2_init_context);
-
-static void pnv_npu2_release_context(struct kref *kref)
-{
-	struct npu_context *npu_context =
-		container_of(kref, struct npu_context, kref);
-
-	if (!npu_context->nmmu_flush)
-		mm_context_remove_copro(npu_context->mm);
-
-	npu_context->mm->context.npu_context = NULL;
-}
-
-/*
- * Destroy a context on the given GPU. May free the npu_context if it is no
- * longer active on any GPUs. Must not be called from interrupt context.
- */
-void pnv_npu2_destroy_context(struct npu_context *npu_context,
-			struct pci_dev *gpdev)
-{
-	int removed;
-	struct pnv_phb *nphb;
-	struct npu *npu;
-	struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
-	struct device_node *nvlink_dn;
-	u32 nvlink_index;
-
-	if (WARN_ON(!npdev))
-		return;
-
-	if (!firmware_has_feature(FW_FEATURE_OPAL))
-		return;
-
-	nphb = pci_bus_to_host(npdev->bus)->private_data;
-	npu = &nphb->npu;
-	nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0);
-	if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index",
-							&nvlink_index)))
-		return;
-	WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], NULL);
-	opal_npu_destroy_context(nphb->opal_id, npu_context->mm->context.id,
-				PCI_DEVID(gpdev->bus->number, gpdev->devfn));
-	spin_lock(&npu_context_lock);
-	removed = kref_put(&npu_context->kref, pnv_npu2_release_context);
-	spin_unlock(&npu_context_lock);
-
-	/*
-	 * We need to do this outside of pnv_npu2_release_context so that it is
-	 * outside the spinlock as mmu_notifier_destroy uses SRCU.
-	 */
-	if (removed) {
-		mmu_notifier_unregister(&npu_context->mn,
-					npu_context->mm);
-
-		kfree(npu_context);
-	}
-
-}
-EXPORT_SYMBOL(pnv_npu2_destroy_context);
-
-/*
- * Assumes mmap_sem is held for the contexts associated mm.
- */
-int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
-			unsigned long *flags, unsigned long *status, int count)
-{
-	u64 rc = 0, result = 0;
-	int i, is_write;
-	struct page *page[1];
-
-	/* mmap_sem should be held so the struct_mm must be present */
-	struct mm_struct *mm = context->mm;
-
-	if (!firmware_has_feature(FW_FEATURE_OPAL))
-		return -ENODEV;
-
-	WARN_ON(!rwsem_is_locked(&mm->mmap_sem));
-
-	for (i = 0; i < count; i++) {
-		is_write = flags[i] & NPU2_WRITE;
-		rc = get_user_pages_remote(NULL, mm, ea[i], 1,
-					is_write ? FOLL_WRITE : 0,
-					page, NULL, NULL);
-
-		/*
-		 * To support virtualised environments we will have to do an
-		 * access to the page to ensure it gets faulted into the
-		 * hypervisor. For the moment virtualisation is not supported in
-		 * other areas so leave the access out.
-		 */
-		if (rc != 1) {
-			status[i] = rc;
-			result = -EFAULT;
-			continue;
-		}
-
-		status[i] = 0;
-		put_page(page[0]);
-	}
-
-	return result;
-}
-EXPORT_SYMBOL(pnv_npu2_handle_fault);
-
-int pnv_npu2_init(struct pnv_phb *phb)
-{
-	unsigned int i;
-	u64 mmio_atsd;
-	struct device_node *dn;
-	struct pci_dev *gpdev;
-	static int npu_index;
-	uint64_t rc = 0;
-
-	phb->npu.nmmu_flush =
-		of_property_read_bool(phb->hose->dn, "ibm,nmmu-flush");
-	for_each_child_of_node(phb->hose->dn, dn) {
-		gpdev = pnv_pci_get_gpu_dev(get_pci_dev(dn));
-		if (gpdev) {
-			rc = opal_npu_map_lpar(phb->opal_id,
-				PCI_DEVID(gpdev->bus->number, gpdev->devfn),
-				0, 0);
-			if (rc)
-				dev_err(&gpdev->dev,
-					"Error %lld mapping device to LPAR\n",
-					rc);
-		}
-	}
-
-	for (i = 0; !of_property_read_u64_index(phb->hose->dn, "ibm,mmio-atsd",
-							i, &mmio_atsd); i++)
-		phb->npu.mmio_atsd_regs[i] = ioremap(mmio_atsd, 32);
-
-	pr_info("NPU%lld: Found %d MMIO ATSD registers", phb->opal_id, i);
-	phb->npu.mmio_atsd_count = i;
-	phb->npu.mmio_atsd_usage = 0;
-	npu_index++;
-	if (WARN_ON(npu_index >= NV_MAX_NPUS))
-		return -ENOSPC;
-	max_npu2_index = npu_index;
-	phb->npu.index = npu_index;
-
-	return 0;
-}
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index cde710297a4e..f480e3fc9ebb 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1203,75 +1203,6 @@ static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
 	return pe;
 }
 
-static struct pnv_ioda_pe *pnv_ioda_setup_npu_PE(struct pci_dev *npu_pdev)
-{
-	int pe_num, found_pe = false, rc;
-	long rid;
-	struct pnv_ioda_pe *pe;
-	struct pci_dev *gpu_pdev;
-	struct pci_dn *npu_pdn;
-	struct pci_controller *hose = pci_bus_to_host(npu_pdev->bus);
-	struct pnv_phb *phb = hose->private_data;
-
-	/*
-	 * Due to a hardware errata PE#0 on the NPU is reserved for
-	 * error handling. This means we only have three PEs remaining
-	 * which need to be assigned to four links, implying some
-	 * links must share PEs.
-	 *
-	 * To achieve this we assign PEs such that NPUs linking the
-	 * same GPU get assigned the same PE.
-	 */
-	gpu_pdev = pnv_pci_get_gpu_dev(npu_pdev);
-	for (pe_num = 0; pe_num < phb->ioda.total_pe_num; pe_num++) {
-		pe = &phb->ioda.pe_array[pe_num];
-		if (!pe->pdev)
-			continue;
-
-		if (pnv_pci_get_gpu_dev(pe->pdev) == gpu_pdev) {
-			/*
-			 * This device has the same peer GPU so should
-			 * be assigned the same PE as the existing
-			 * peer NPU.
-			 */
-			dev_info(&npu_pdev->dev,
-				"Associating to existing PE %x\n", pe_num);
-			pci_dev_get(npu_pdev);
-			npu_pdn = pci_get_pdn(npu_pdev);
-			rid = npu_pdev->bus->number << 8 | npu_pdn->devfn;
-			npu_pdn->pe_number = pe_num;
-			phb->ioda.pe_rmap[rid] = pe->pe_number;
-
-			/* Map the PE to this link */
-			rc = opal_pci_set_pe(phb->opal_id, pe_num, rid,
-					OpalPciBusAll,
-					OPAL_COMPARE_RID_DEVICE_NUMBER,
-					OPAL_COMPARE_RID_FUNCTION_NUMBER,
-					OPAL_MAP_PE);
-			WARN_ON(rc != OPAL_SUCCESS);
-			found_pe = true;
-			break;
-		}
-	}
-
-	if (!found_pe)
-		/*
-		 * Could not find an existing PE so allocate a new
-		 * one.
-		 */
-		return pnv_ioda_setup_dev_PE(npu_pdev);
-	else
-		return pe;
-}
-
-static void pnv_ioda_setup_npu_PEs(struct pci_bus *bus)
-{
-	struct pci_dev *pdev;
-
-	list_for_each_entry(pdev, &bus->devices, bus_list)
-		pnv_ioda_setup_npu_PE(pdev);
-}
-
 static void pnv_pci_ioda_setup_PEs(void)
 {
 	struct pci_controller *hose, *tmp;
@@ -1281,13 +1212,6 @@ static void pnv_pci_ioda_setup_PEs(void)
 
 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
 		phb = hose->private_data;
-		if (phb->type == PNV_PHB_NPU_NVLINK) {
-			/* PE#0 is needed for error reporting */
-			pnv_ioda_reserve_pe(phb, 0);
-			pnv_ioda_setup_npu_PEs(hose->bus);
-			if (phb->model == PNV_PHB_MODEL_NPU2)
-				pnv_npu2_init(phb);
-		}
 		if (phb->type == PNV_PHB_NPU_OCAPI) {
 			bus = hose->bus;
 			list_for_each_entry(pdev, &bus->devices, bus_list)
@@ -1895,9 +1819,6 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
 	}
 	*pdev->dev.dma_mask = dma_mask;
 
-	/* Update peer npu devices */
-	pnv_npu_try_dma_set_bypass(pdev, bypass);
-
 	return 0;
 }
 
@@ -2143,14 +2064,6 @@ static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
 	}
 }
 
-void pnv_pci_ioda2_tce_invalidate_entire(struct pnv_phb *phb, bool rm)
-{
-	if (phb->model == PNV_PHB_MODEL_NPU || phb->model == PNV_PHB_MODEL_PHB3)
-		pnv_pci_phb3_tce_invalidate_entire(phb, rm);
-	else
-		opal_pci_tce_kill(phb->opal_id, OPAL_PCI_TCE_KILL, 0, 0, 0, 0);
-}
-
 static int pnv_ioda2_tce_build(struct iommu_table *tbl, long index,
 		long npages, unsigned long uaddr,
 		enum dma_data_direction direction,
@@ -2639,137 +2552,6 @@ static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
 	.take_ownership = pnv_ioda2_take_ownership,
 	.release_ownership = pnv_ioda2_release_ownership,
 };
-
-static int gpe_table_group_to_npe_cb(struct device *dev, void *opaque)
-{
-	struct pci_controller *hose;
-	struct pnv_phb *phb;
-	struct pnv_ioda_pe **ptmppe = opaque;
-	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
-	struct pci_dn *pdn = pci_get_pdn(pdev);
-
-	if (!pdn || pdn->pe_number == IODA_INVALID_PE)
-		return 0;
-
-	hose = pci_bus_to_host(pdev->bus);
-	phb = hose->private_data;
-	if (phb->type != PNV_PHB_NPU_NVLINK)
-		return 0;
-
-	*ptmppe = &phb->ioda.pe_array[pdn->pe_number];
-
-	return 1;
-}
-
-/*
- * This returns PE of associated NPU.
- * This assumes that NPU is in the same IOMMU group with GPU and there is
- * no other PEs.
- */
-static struct pnv_ioda_pe *gpe_table_group_to_npe(
-		struct iommu_table_group *table_group)
-{
-	struct pnv_ioda_pe *npe = NULL;
-	int ret = iommu_group_for_each_dev(table_group->group, &npe,
-			gpe_table_group_to_npe_cb);
-
-	BUG_ON(!ret || !npe);
-
-	return npe;
-}
-
-static long pnv_pci_ioda2_npu_set_window(struct iommu_table_group *table_group,
-		int num, struct iommu_table *tbl)
-{
-	struct pnv_ioda_pe *npe = gpe_table_group_to_npe(table_group);
-	int num2 = (num == 0) ? 1 : 0;
-	long ret = pnv_pci_ioda2_set_window(table_group, num, tbl);
-
-	if (ret)
-		return ret;
-
-	if (table_group->tables[num2])
-		pnv_npu_unset_window(npe, num2);
-
-	ret = pnv_npu_set_window(npe, num, tbl);
-	if (ret) {
-		pnv_pci_ioda2_unset_window(table_group, num);
-		if (table_group->tables[num2])
-			pnv_npu_set_window(npe, num2,
-					table_group->tables[num2]);
-	}
-
-	return ret;
-}
-
-static long pnv_pci_ioda2_npu_unset_window(
-		struct iommu_table_group *table_group,
-		int num)
-{
-	struct pnv_ioda_pe *npe = gpe_table_group_to_npe(table_group);
-	int num2 = (num == 0) ? 1 : 0;
-	long ret = pnv_pci_ioda2_unset_window(table_group, num);
-
-	if (ret)
-		return ret;
-
-	if (!npe->table_group.tables[num])
-		return 0;
-
-	ret = pnv_npu_unset_window(npe, num);
-	if (ret)
-		return ret;
-
-	if (table_group->tables[num2])
-		ret = pnv_npu_set_window(npe, num2, table_group->tables[num2]);
-
-	return ret;
-}
-
-static void pnv_ioda2_npu_take_ownership(struct iommu_table_group *table_group)
-{
-	/*
-	 * Detach NPU first as pnv_ioda2_take_ownership() will destroy
-	 * the iommu_table if 32bit DMA is enabled.
-	 */
-	pnv_npu_take_ownership(gpe_table_group_to_npe(table_group));
-	pnv_ioda2_take_ownership(table_group);
-}
-
-static struct iommu_table_group_ops pnv_pci_ioda2_npu_ops = {
-	.get_table_size = pnv_pci_ioda2_get_table_size,
-	.create_table = pnv_pci_ioda2_create_table_userspace,
-	.set_window = pnv_pci_ioda2_npu_set_window,
-	.unset_window = pnv_pci_ioda2_npu_unset_window,
-	.take_ownership = pnv_ioda2_npu_take_ownership,
-	.release_ownership = pnv_ioda2_release_ownership,
-};
-
-static void pnv_pci_ioda_setup_iommu_api(void)
-{
-	struct pci_controller *hose, *tmp;
-	struct pnv_phb *phb;
-	struct pnv_ioda_pe *pe, *gpe;
-
-	/*
-	 * Now we have all PHBs discovered, time to add NPU devices to
-	 * the corresponding IOMMU groups.
-	 */
-	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
-		phb = hose->private_data;
-
-		if (phb->type != PNV_PHB_NPU_NVLINK)
-			continue;
-
-		list_for_each_entry(pe, &phb->ioda.pe_list, list) {
-			gpe = pnv_pci_npu_setup_iommu(pe);
-			if (gpe)
-				gpe->table_group.ops = &pnv_pci_ioda2_npu_ops;
-		}
-	}
-}
-#else /* !CONFIG_IOMMU_API */
-static void pnv_pci_ioda_setup_iommu_api(void) { };
 #endif
 
 static unsigned long pnv_ioda_parse_tce_sizes(struct pnv_phb *phb)
@@ -3266,7 +3048,6 @@ static void pnv_pci_enable_bridges(void)
 static void pnv_pci_ioda_fixup(void)
 {
 	pnv_pci_ioda_setup_PEs();
-	pnv_pci_ioda_setup_iommu_api();
 	pnv_pci_ioda_create_dbgfs();
 
 	pnv_pci_enable_bridges();
@@ -3713,27 +3494,6 @@ static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
 	.shutdown		= pnv_pci_ioda_shutdown,
 };
 
-static int pnv_npu_dma_set_mask(struct pci_dev *npdev, u64 dma_mask)
-{
-	dev_err_once(&npdev->dev,
-			"%s operation unsupported for NVLink devices\n",
-			__func__);
-	return -EPERM;
-}
-
-static const struct pci_controller_ops pnv_npu_ioda_controller_ops = {
-	.dma_dev_setup		= pnv_pci_dma_dev_setup,
-#ifdef CONFIG_PCI_MSI
-	.setup_msi_irqs		= pnv_setup_msi_irqs,
-	.teardown_msi_irqs	= pnv_teardown_msi_irqs,
-#endif
-	.enable_device_hook	= pnv_pci_enable_device_hook,
-	.window_alignment	= pnv_pci_window_alignment,
-	.reset_secondary_bus	= pnv_pci_reset_secondary_bus,
-	.dma_set_mask		= pnv_npu_dma_set_mask,
-	.shutdown		= pnv_pci_ioda_shutdown,
-};
-
 static const struct pci_controller_ops pnv_npu_ocapi_ioda_controller_ops = {
 	.enable_device_hook	= pnv_pci_enable_device_hook,
 	.window_alignment	= pnv_pci_window_alignment,
@@ -3955,9 +3715,6 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 	ppc_md.pcibios_fixup = pnv_pci_ioda_fixup;
 
 	switch (phb->type) {
-	case PNV_PHB_NPU_NVLINK:
-		hose->controller_ops = pnv_npu_ioda_controller_ops;
-		break;
 	case PNV_PHB_NPU_OCAPI:
 		hose->controller_ops = pnv_npu_ocapi_ioda_controller_ops;
 		break;
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 8b37b28e3831..54f2935b7ac5 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -231,17 +231,6 @@ extern void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
 #define pe_info(pe, fmt, ...)					\
 	pe_level_printk(pe, KERN_INFO, fmt, ##__VA_ARGS__)
 
-/* Nvlink functions */
-extern void pnv_npu_try_dma_set_bypass(struct pci_dev *gpdev, bool bypass);
-extern void pnv_pci_ioda2_tce_invalidate_entire(struct pnv_phb *phb, bool rm);
-extern struct pnv_ioda_pe *pnv_pci_npu_setup_iommu(struct pnv_ioda_pe *npe);
-extern long pnv_npu_set_window(struct pnv_ioda_pe *npe, int num,
-		struct iommu_table *tbl);
-extern long pnv_npu_unset_window(struct pnv_ioda_pe *npe, int num);
-extern void pnv_npu_take_ownership(struct pnv_ioda_pe *npe);
-extern void pnv_npu_release_ownership(struct pnv_ioda_pe *npe);
-extern int pnv_npu2_init(struct pnv_phb *phb);
-
 /* pci-ioda-tce.c */
 #define POWERNV_IOMMU_DEFAULT_LEVELS	1
 #define POWERNV_IOMMU_MAX_LEVELS	5
-- 
2.19.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] powerpc/powernv: remove dead npu-dma code
  2018-10-30 13:31 [PATCH] powerpc/powernv: remove dead npu-dma code Christoph Hellwig
@ 2018-11-01  4:41 ` Alexey Kardashevskiy
  2018-11-02 10:18   ` Michael Ellerman
  0 siblings, 1 reply; 3+ messages in thread
From: Alexey Kardashevskiy @ 2018-11-01  4:41 UTC (permalink / raw)
  To: Christoph Hellwig, Benjamin Herrenschmidt, Paul Mackerras,
	Michael Ellerman
  Cc: James Bottomley, Paul E. McKenney, Andrew Morton, Linus Torvalds,
	linuxppc-dev, linux-kernel



On 31/10/2018 00:31, Christoph Hellwig wrote:
> This code has never been unused in the kernel since it was merged, and
> there has been no attempt that I could find to even submit users for
> it.  Besides the general policy of not keep 1000+ lines of dead
> code, it helps cleaning up the DMA code and making powerpc user common
> infrastructure.
> 
> This effectively reverts commit 5d2aa710 ("powerpc/powernv: Add support
> for Nvlink NPUs").
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> 
> [this is a follow up to the brief maintainer summit discussion]
> 
>  arch/powerpc/include/asm/pci.h            |   3 -
>  arch/powerpc/include/asm/powernv.h        |  23 -
>  arch/powerpc/platforms/powernv/Makefile   |   2 +-
>  arch/powerpc/platforms/powernv/npu-dma.c  | 989 ----------------------
>  arch/powerpc/platforms/powernv/pci-ioda.c | 243 ------
>  arch/powerpc/platforms/powernv/pci.h      |  11 -
>  6 files changed, 1 insertion(+), 1270 deletions(-)
>  delete mode 100644 arch/powerpc/platforms/powernv/npu-dma.c
> 
> diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
> index 2af9ded80540..a01d2e3d6ff9 100644
> --- a/arch/powerpc/include/asm/pci.h
> +++ b/arch/powerpc/include/asm/pci.h
> @@ -127,7 +127,4 @@ extern void pcibios_scan_phb(struct pci_controller *hose);
>  
>  #endif	/* __KERNEL__ */
>  
> -extern struct pci_dev *pnv_pci_get_gpu_dev(struct pci_dev *npdev);
> -extern struct pci_dev *pnv_pci_get_npu_dev(struct pci_dev *gpdev, int index);
> -
>  #endif /* __ASM_POWERPC_PCI_H */
> diff --git a/arch/powerpc/include/asm/powernv.h b/arch/powerpc/include/asm/powernv.h
> index 2f3ff7a27881..4848a6b3c6b2 100644
> --- a/arch/powerpc/include/asm/powernv.h
> +++ b/arch/powerpc/include/asm/powernv.h
> @@ -11,33 +11,10 @@
>  #define _ASM_POWERNV_H
>  
>  #ifdef CONFIG_PPC_POWERNV
> -#define NPU2_WRITE 1
>  extern void powernv_set_nmmu_ptcr(unsigned long ptcr);
> -extern struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
> -			unsigned long flags,
> -			void (*cb)(struct npu_context *, void *),
> -			void *priv);
> -extern void pnv_npu2_destroy_context(struct npu_context *context,
> -				struct pci_dev *gpdev);
> -extern int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
> -				unsigned long *flags, unsigned long *status,
> -				int count);
> -
>  void pnv_tm_init(void);
>  #else
>  static inline void powernv_set_nmmu_ptcr(unsigned long ptcr) { }
> -static inline struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
> -			unsigned long flags,
> -			struct npu_context *(*cb)(struct npu_context *, void *),
> -			void *priv) { return ERR_PTR(-ENODEV); }
> -static inline void pnv_npu2_destroy_context(struct npu_context *context,
> -					struct pci_dev *gpdev) { }
> -
> -static inline int pnv_npu2_handle_fault(struct npu_context *context,
> -					uintptr_t *ea, unsigned long *flags,
> -					unsigned long *status, int count) {
> -	return -ENODEV;
> -}
>  
>  static inline void pnv_tm_init(void) { }
>  static inline void pnv_power9_force_smt4(void) { }
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index b540ce8eec55..2b13e9dd137c 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -6,7 +6,7 @@ obj-y			+= opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
>  obj-y			+= opal-kmsg.o opal-powercap.o opal-psr.o opal-sensor-groups.o
>  
>  obj-$(CONFIG_SMP)	+= smp.o subcore.o subcore-asm.o
> -obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o npu-dma.o pci-ioda-tce.o
> +obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o pci-ioda-tce.o
>  obj-$(CONFIG_CXL_BASE)	+= pci-cxl.o
>  obj-$(CONFIG_EEH)	+= eeh-powernv.o
>  obj-$(CONFIG_PPC_SCOM)	+= opal-xscom.o
> diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
> deleted file mode 100644
> index 6f60e0931922..000000000000
> --- a/arch/powerpc/platforms/powernv/npu-dma.c
> +++ /dev/null
> @@ -1,989 +0,0 @@
> -/*
> - * This file implements the DMA operations for NVLink devices. The NPU
> - * devices all point to the same iommu table as the parent PCI device.
> - *
> - * Copyright Alistair Popple, IBM Corporation 2015.
> - *
> - * This program is free software; you can redistribute it and/or
> - * modify it under the terms of version 2 of the GNU General Public
> - * License as published by the Free Software Foundation.
> - */
> -
> -#include <linux/slab.h>
> -#include <linux/mmu_notifier.h>
> -#include <linux/mmu_context.h>
> -#include <linux/of.h>
> -#include <linux/export.h>
> -#include <linux/pci.h>
> -#include <linux/memblock.h>
> -#include <linux/iommu.h>
> -#include <linux/sizes.h>
> -
> -#include <asm/debugfs.h>
> -#include <asm/tlb.h>
> -#include <asm/powernv.h>
> -#include <asm/reg.h>
> -#include <asm/opal.h>
> -#include <asm/io.h>
> -#include <asm/iommu.h>
> -#include <asm/pnv-pci.h>
> -#include <asm/msi_bitmap.h>
> -#include <asm/opal.h>
> -
> -#include "powernv.h"
> -#include "pci.h"
> -
> -#define npu_to_phb(x) container_of(x, struct pnv_phb, npu)
> -
> -/*
> - * spinlock to protect initialisation of an npu_context for a particular
> - * mm_struct.
> - */
> -static DEFINE_SPINLOCK(npu_context_lock);
> -
> -/*
> - * Other types of TCE cache invalidation are not functional in the
> - * hardware.
> - */
> -static struct pci_dev *get_pci_dev(struct device_node *dn)
> -{
> -	struct pci_dn *pdn = PCI_DN(dn);
> -
> -	return pci_get_domain_bus_and_slot(pci_domain_nr(pdn->phb->bus),
> -					   pdn->busno, pdn->devfn);
> -}
> -
> -/* Given a NPU device get the associated PCI device. */
> -struct pci_dev *pnv_pci_get_gpu_dev(struct pci_dev *npdev)
> -{
> -	struct device_node *dn;
> -	struct pci_dev *gpdev;
> -
> -	if (WARN_ON(!npdev))
> -		return NULL;
> -
> -	if (WARN_ON(!npdev->dev.of_node))
> -		return NULL;
> -
> -	/* Get assoicated PCI device */
> -	dn = of_parse_phandle(npdev->dev.of_node, "ibm,gpu", 0);
> -	if (!dn)
> -		return NULL;
> -
> -	gpdev = get_pci_dev(dn);
> -	of_node_put(dn);
> -
> -	return gpdev;
> -}
> -EXPORT_SYMBOL(pnv_pci_get_gpu_dev);
> -
> -/* Given the real PCI device get a linked NPU device. */
> -struct pci_dev *pnv_pci_get_npu_dev(struct pci_dev *gpdev, int index)
> -{
> -	struct device_node *dn;
> -	struct pci_dev *npdev;
> -
> -	if (WARN_ON(!gpdev))
> -		return NULL;
> -
> -	/* Not all PCI devices have device-tree nodes */
> -	if (!gpdev->dev.of_node)
> -		return NULL;
> -
> -	/* Get assoicated PCI device */
> -	dn = of_parse_phandle(gpdev->dev.of_node, "ibm,npu", index);
> -	if (!dn)
> -		return NULL;
> -
> -	npdev = get_pci_dev(dn);
> -	of_node_put(dn);
> -
> -	return npdev;
> -}
> -EXPORT_SYMBOL(pnv_pci_get_npu_dev);
> -
> -#define NPU_DMA_OP_UNSUPPORTED()					\
> -	dev_err_once(dev, "%s operation unsupported for NVLink devices\n", \
> -		__func__)
> -
> -static void *dma_npu_alloc(struct device *dev, size_t size,
> -			   dma_addr_t *dma_handle, gfp_t flag,
> -			   unsigned long attrs)
> -{
> -	NPU_DMA_OP_UNSUPPORTED();
> -	return NULL;
> -}
> -
> -static void dma_npu_free(struct device *dev, size_t size,
> -			 void *vaddr, dma_addr_t dma_handle,
> -			 unsigned long attrs)
> -{
> -	NPU_DMA_OP_UNSUPPORTED();
> -}
> -
> -static dma_addr_t dma_npu_map_page(struct device *dev, struct page *page,
> -				   unsigned long offset, size_t size,
> -				   enum dma_data_direction direction,
> -				   unsigned long attrs)
> -{
> -	NPU_DMA_OP_UNSUPPORTED();
> -	return 0;
> -}
> -
> -static int dma_npu_map_sg(struct device *dev, struct scatterlist *sglist,
> -			  int nelems, enum dma_data_direction direction,
> -			  unsigned long attrs)
> -{
> -	NPU_DMA_OP_UNSUPPORTED();
> -	return 0;
> -}
> -
> -static int dma_npu_dma_supported(struct device *dev, u64 mask)
> -{
> -	NPU_DMA_OP_UNSUPPORTED();
> -	return 0;
> -}
> -
> -static u64 dma_npu_get_required_mask(struct device *dev)
> -{
> -	NPU_DMA_OP_UNSUPPORTED();
> -	return 0;
> -}
> -
> -static const struct dma_map_ops dma_npu_ops = {
> -	.map_page		= dma_npu_map_page,
> -	.map_sg			= dma_npu_map_sg,
> -	.alloc			= dma_npu_alloc,
> -	.free			= dma_npu_free,
> -	.dma_supported		= dma_npu_dma_supported,
> -	.get_required_mask	= dma_npu_get_required_mask,
> -};
> -
> -/*
> - * Returns the PE assoicated with the PCI device of the given
> - * NPU. Returns the linked pci device if pci_dev != NULL.
> - */
> -static struct pnv_ioda_pe *get_gpu_pci_dev_and_pe(struct pnv_ioda_pe *npe,
> -						  struct pci_dev **gpdev)
> -{
> -	struct pnv_phb *phb;
> -	struct pci_controller *hose;
> -	struct pci_dev *pdev;
> -	struct pnv_ioda_pe *pe;
> -	struct pci_dn *pdn;
> -
> -	pdev = pnv_pci_get_gpu_dev(npe->pdev);
> -	if (!pdev)
> -		return NULL;
> -
> -	pdn = pci_get_pdn(pdev);
> -	if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
> -		return NULL;
> -
> -	hose = pci_bus_to_host(pdev->bus);
> -	phb = hose->private_data;
> -	pe = &phb->ioda.pe_array[pdn->pe_number];
> -
> -	if (gpdev)
> -		*gpdev = pdev;
> -
> -	return pe;
> -}
> -
> -long pnv_npu_set_window(struct pnv_ioda_pe *npe, int num,
> -		struct iommu_table *tbl)
> -{
> -	struct pnv_phb *phb = npe->phb;
> -	int64_t rc;
> -	const unsigned long size = tbl->it_indirect_levels ?
> -		tbl->it_level_size : tbl->it_size;
> -	const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
> -	const __u64 win_size = tbl->it_size << tbl->it_page_shift;
> -
> -	pe_info(npe, "Setting up window %llx..%llx pg=%lx\n",
> -			start_addr, start_addr + win_size - 1,
> -			IOMMU_PAGE_SIZE(tbl));
> -
> -	rc = opal_pci_map_pe_dma_window(phb->opal_id,
> -			npe->pe_number,
> -			npe->pe_number,
> -			tbl->it_indirect_levels + 1,
> -			__pa(tbl->it_base),
> -			size << 3,
> -			IOMMU_PAGE_SIZE(tbl));
> -	if (rc) {
> -		pe_err(npe, "Failed to configure TCE table, err %lld\n", rc);
> -		return rc;
> -	}
> -	pnv_pci_ioda2_tce_invalidate_entire(phb, false);
> -
> -	/* Add the table to the list so its TCE cache will get invalidated */
> -	pnv_pci_link_table_and_group(phb->hose->node, num,
> -			tbl, &npe->table_group);
> -
> -	return 0;
> -}
> -
> -long pnv_npu_unset_window(struct pnv_ioda_pe *npe, int num)
> -{
> -	struct pnv_phb *phb = npe->phb;
> -	int64_t rc;
> -
> -	pe_info(npe, "Removing DMA window\n");
> -
> -	rc = opal_pci_map_pe_dma_window(phb->opal_id, npe->pe_number,
> -			npe->pe_number,
> -			0/* levels */, 0/* table address */,
> -			0/* table size */, 0/* page size */);
> -	if (rc) {
> -		pe_err(npe, "Unmapping failed, ret = %lld\n", rc);
> -		return rc;
> -	}
> -	pnv_pci_ioda2_tce_invalidate_entire(phb, false);
> -
> -	pnv_pci_unlink_table_and_group(npe->table_group.tables[num],
> -			&npe->table_group);
> -
> -	return 0;
> -}
> -
> -/*
> - * Enables 32 bit DMA on NPU.
> - */
> -static void pnv_npu_dma_set_32(struct pnv_ioda_pe *npe)
> -{
> -	struct pci_dev *gpdev;
> -	struct pnv_ioda_pe *gpe;
> -	int64_t rc;
> -
> -	/*
> -	 * Find the assoicated PCI devices and get the dma window
> -	 * information from there.
> -	 */
> -	if (!npe->pdev || !(npe->flags & PNV_IODA_PE_DEV))
> -		return;
> -
> -	gpe = get_gpu_pci_dev_and_pe(npe, &gpdev);
> -	if (!gpe)
> -		return;
> -
> -	rc = pnv_npu_set_window(npe, 0, gpe->table_group.tables[0]);
> -
> -	/*
> -	 * We don't initialise npu_pe->tce32_table as we always use
> -	 * dma_npu_ops which are nops.
> -	 */
> -	set_dma_ops(&npe->pdev->dev, &dma_npu_ops);
> -}
> -
> -/*
> - * Enables bypass mode on the NPU. The NPU only supports one
> - * window per link, so bypass needs to be explicitly enabled or
> - * disabled. Unlike for a PHB3 bypass and non-bypass modes can't be
> - * active at the same time.
> - */
> -static int pnv_npu_dma_set_bypass(struct pnv_ioda_pe *npe)
> -{
> -	struct pnv_phb *phb = npe->phb;
> -	int64_t rc = 0;
> -	phys_addr_t top = memblock_end_of_DRAM();
> -
> -	if (phb->type != PNV_PHB_NPU_NVLINK || !npe->pdev)
> -		return -EINVAL;
> -
> -	rc = pnv_npu_unset_window(npe, 0);
> -	if (rc != OPAL_SUCCESS)
> -		return rc;
> -
> -	/* Enable the bypass window */
> -
> -	top = roundup_pow_of_two(top);
> -	dev_info(&npe->pdev->dev, "Enabling bypass for PE %x\n",
> -			npe->pe_number);
> -	rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
> -			npe->pe_number, npe->pe_number,
> -			0 /* bypass base */, top);
> -
> -	if (rc == OPAL_SUCCESS)
> -		pnv_pci_ioda2_tce_invalidate_entire(phb, false);
> -
> -	return rc;
> -}
> -
> -void pnv_npu_try_dma_set_bypass(struct pci_dev *gpdev, bool bypass)
> -{
> -	int i;
> -	struct pnv_phb *phb;
> -	struct pci_dn *pdn;
> -	struct pnv_ioda_pe *npe;
> -	struct pci_dev *npdev;
> -
> -	for (i = 0; ; ++i) {
> -		npdev = pnv_pci_get_npu_dev(gpdev, i);
> -
> -		if (!npdev)
> -			break;
> -
> -		pdn = pci_get_pdn(npdev);
> -		if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
> -			return;
> -
> -		phb = pci_bus_to_host(npdev->bus)->private_data;
> -
> -		/* We only do bypass if it's enabled on the linked device */
> -		npe = &phb->ioda.pe_array[pdn->pe_number];
> -
> -		if (bypass) {
> -			dev_info(&npdev->dev,
> -					"Using 64-bit DMA iommu bypass\n");
> -			pnv_npu_dma_set_bypass(npe);
> -		} else {
> -			dev_info(&npdev->dev, "Using 32-bit DMA via iommu\n");
> -			pnv_npu_dma_set_32(npe);
> -		}
> -	}
> -}
> -
> -/* Switch ownership from platform code to external user (e.g. VFIO) */
> -void pnv_npu_take_ownership(struct pnv_ioda_pe *npe)
> -{
> -	struct pnv_phb *phb = npe->phb;
> -	int64_t rc;
> -
> -	/*
> -	 * Note: NPU has just a single TVE in the hardware which means that
> -	 * while used by the kernel, it can have either 32bit window or
> -	 * DMA bypass but never both. So we deconfigure 32bit window only
> -	 * if it was enabled at the moment of ownership change.
> -	 */
> -	if (npe->table_group.tables[0]) {
> -		pnv_npu_unset_window(npe, 0);
> -		return;
> -	}
> -
> -	/* Disable bypass */
> -	rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
> -			npe->pe_number, npe->pe_number,
> -			0 /* bypass base */, 0);
> -	if (rc) {
> -		pe_err(npe, "Failed to disable bypass, err %lld\n", rc);
> -		return;
> -	}
> -	pnv_pci_ioda2_tce_invalidate_entire(npe->phb, false);
> -}
> -
> -struct pnv_ioda_pe *pnv_pci_npu_setup_iommu(struct pnv_ioda_pe *npe)
> -{
> -	struct pnv_phb *phb = npe->phb;
> -	struct pci_bus *pbus = phb->hose->bus;
> -	struct pci_dev *npdev, *gpdev = NULL, *gptmp;
> -	struct pnv_ioda_pe *gpe = get_gpu_pci_dev_and_pe(npe, &gpdev);
> -
> -	if (!gpe || !gpdev)
> -		return NULL;
> -
> -	list_for_each_entry(npdev, &pbus->devices, bus_list) {
> -		gptmp = pnv_pci_get_gpu_dev(npdev);
> -
> -		if (gptmp != gpdev)
> -			continue;
> -
> -		pe_info(gpe, "Attached NPU %s\n", dev_name(&npdev->dev));
> -		iommu_group_add_device(gpe->table_group.group, &npdev->dev);
> -	}
> -
> -	return gpe;
> -}
> -
> -/* Maximum number of nvlinks per npu */
> -#define NV_MAX_LINKS 6
> -
> -/* Maximum index of npu2 hosts in the system. Always < NV_MAX_NPUS */
> -static int max_npu2_index;
> -
> -struct npu_context {
> -	struct mm_struct *mm;
> -	struct pci_dev *npdev[NV_MAX_NPUS][NV_MAX_LINKS];
> -	struct mmu_notifier mn;
> -	struct kref kref;
> -	bool nmmu_flush;
> -
> -	/* Callback to stop translation requests on a given GPU */
> -	void (*release_cb)(struct npu_context *context, void *priv);
> -
> -	/*
> -	 * Private pointer passed to the above callback for usage by
> -	 * device drivers.
> -	 */
> -	void *priv;
> -};
> -
> -struct mmio_atsd_reg {
> -	struct npu *npu;
> -	int reg;
> -};
> -
> -/*
> - * Find a free MMIO ATSD register and mark it in use. Return -ENOSPC
> - * if none are available.
> - */
> -static int get_mmio_atsd_reg(struct npu *npu)
> -{
> -	int i;
> -
> -	for (i = 0; i < npu->mmio_atsd_count; i++) {
> -		if (!test_bit(i, &npu->mmio_atsd_usage))
> -			if (!test_and_set_bit_lock(i, &npu->mmio_atsd_usage))
> -				return i;
> -	}
> -
> -	return -ENOSPC;
> -}
> -
> -static void put_mmio_atsd_reg(struct npu *npu, int reg)
> -{
> -	clear_bit_unlock(reg, &npu->mmio_atsd_usage);
> -}
> -
> -/* MMIO ATSD register offsets */
> -#define XTS_ATSD_LAUNCH 0
> -#define XTS_ATSD_AVA    1
> -#define XTS_ATSD_STAT   2
> -
> -static unsigned long get_atsd_launch_val(unsigned long pid, unsigned long psize)
> -{
> -	unsigned long launch = 0;
> -
> -	if (psize == MMU_PAGE_COUNT) {
> -		/* IS set to invalidate entire matching PID */
> -		launch |= PPC_BIT(12);
> -	} else {
> -		/* AP set to invalidate region of psize */
> -		launch |= (u64)mmu_get_ap(psize) << PPC_BITLSHIFT(17);
> -	}
> -
> -	/* PRS set to process-scoped */
> -	launch |= PPC_BIT(13);
> -
> -	/* PID */
> -	launch |= pid << PPC_BITLSHIFT(38);
> -
> -	/* Leave "No flush" (bit 39) 0 so every ATSD performs a flush */
> -
> -	return launch;
> -}
> -
> -static void mmio_atsd_regs_write(struct mmio_atsd_reg
> -			mmio_atsd_reg[NV_MAX_NPUS], unsigned long offset,
> -			unsigned long val)
> -{
> -	struct npu *npu;
> -	int i, reg;
> -
> -	for (i = 0; i <= max_npu2_index; i++) {
> -		reg = mmio_atsd_reg[i].reg;
> -		if (reg < 0)
> -			continue;
> -
> -		npu = mmio_atsd_reg[i].npu;
> -		__raw_writeq_be(val, npu->mmio_atsd_regs[reg] + offset);
> -	}
> -}
> -
> -static void mmio_invalidate_pid(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS],
> -				unsigned long pid)
> -{
> -	unsigned long launch = get_atsd_launch_val(pid, MMU_PAGE_COUNT);
> -
> -	/* Invalidating the entire process doesn't use a va */
> -	mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch);
> -}
> -
> -static void mmio_invalidate_range(struct mmio_atsd_reg
> -			mmio_atsd_reg[NV_MAX_NPUS], unsigned long pid,
> -			unsigned long start, unsigned long psize)
> -{
> -	unsigned long launch = get_atsd_launch_val(pid, psize);
> -
> -	/* Write all VAs first */
> -	mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_AVA, start);
> -
> -	/* Issue one barrier for all address writes */
> -	eieio();
> -
> -	/* Launch */
> -	mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch);
> -}
> -
> -#define mn_to_npu_context(x) container_of(x, struct npu_context, mn)
> -
> -static void mmio_invalidate_wait(
> -	struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
> -{
> -	struct npu *npu;
> -	int i, reg;
> -
> -	/* Wait for all invalidations to complete */
> -	for (i = 0; i <= max_npu2_index; i++) {
> -		if (mmio_atsd_reg[i].reg < 0)
> -			continue;
> -
> -		/* Wait for completion */
> -		npu = mmio_atsd_reg[i].npu;
> -		reg = mmio_atsd_reg[i].reg;
> -		while (__raw_readq(npu->mmio_atsd_regs[reg] + XTS_ATSD_STAT))
> -			cpu_relax();
> -	}
> -}
> -
> -/*
> - * Acquires all the address translation shootdown (ATSD) registers required to
> - * launch an ATSD on all links this npu_context is active on.
> - */
> -static void acquire_atsd_reg(struct npu_context *npu_context,
> -			struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
> -{
> -	int i, j;
> -	struct npu *npu;
> -	struct pci_dev *npdev;
> -	struct pnv_phb *nphb;
> -
> -	for (i = 0; i <= max_npu2_index; i++) {
> -		mmio_atsd_reg[i].reg = -1;
> -		for (j = 0; j < NV_MAX_LINKS; j++) {
> -			/*
> -			 * There are no ordering requirements with respect to
> -			 * the setup of struct npu_context, but to ensure
> -			 * consistent behaviour we need to ensure npdev[][] is
> -			 * only read once.
> -			 */
> -			npdev = READ_ONCE(npu_context->npdev[i][j]);
> -			if (!npdev)
> -				continue;
> -
> -			nphb = pci_bus_to_host(npdev->bus)->private_data;
> -			npu = &nphb->npu;
> -			mmio_atsd_reg[i].npu = npu;
> -			mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu);
> -			while (mmio_atsd_reg[i].reg < 0) {
> -				mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu);
> -				cpu_relax();
> -			}
> -			break;
> -		}
> -	}
> -}
> -
> -/*
> - * Release previously acquired ATSD registers. To avoid deadlocks the registers
> - * must be released in the same order they were acquired above in
> - * acquire_atsd_reg.
> - */
> -static void release_atsd_reg(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
> -{
> -	int i;
> -
> -	for (i = 0; i <= max_npu2_index; i++) {
> -		/*
> -		 * We can't rely on npu_context->npdev[][] being the same here
> -		 * as when acquire_atsd_reg() was called, hence we use the
> -		 * values stored in mmio_atsd_reg during the acquire phase
> -		 * rather than re-reading npdev[][].
> -		 */
> -		if (mmio_atsd_reg[i].reg < 0)
> -			continue;
> -
> -		put_mmio_atsd_reg(mmio_atsd_reg[i].npu, mmio_atsd_reg[i].reg);
> -	}
> -}
> -
> -/*
> - * Invalidate a virtual address range
> - */
> -static void mmio_invalidate(struct npu_context *npu_context,
> -			unsigned long start, unsigned long size)
> -{
> -	struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS];
> -	unsigned long pid = npu_context->mm->context.id;
> -	unsigned long atsd_start = 0;
> -	unsigned long end = start + size - 1;
> -	int atsd_psize = MMU_PAGE_COUNT;
> -
> -	/*
> -	 * Convert the input range into one of the supported sizes. If the range
> -	 * doesn't fit, use the next larger supported size. Invalidation latency
> -	 * is high, so over-invalidation is preferred to issuing multiple
> -	 * invalidates.
> -	 *
> -	 * A 4K page size isn't supported by NPU/GPU ATS, so that case is
> -	 * ignored.
> -	 */
> -	if (size == SZ_64K) {
> -		atsd_start = start;
> -		atsd_psize = MMU_PAGE_64K;
> -	} else if (ALIGN_DOWN(start, SZ_2M) == ALIGN_DOWN(end, SZ_2M)) {
> -		atsd_start = ALIGN_DOWN(start, SZ_2M);
> -		atsd_psize = MMU_PAGE_2M;
> -	} else if (ALIGN_DOWN(start, SZ_1G) == ALIGN_DOWN(end, SZ_1G)) {
> -		atsd_start = ALIGN_DOWN(start, SZ_1G);
> -		atsd_psize = MMU_PAGE_1G;
> -	}
> -
> -	if (npu_context->nmmu_flush)
> -		/*
> -		 * Unfortunately the nest mmu does not support flushing specific
> -		 * addresses so we have to flush the whole mm once before
> -		 * shooting down the GPU translation.
> -		 */
> -		flush_all_mm(npu_context->mm);
> -
> -	/*
> -	 * Loop over all the NPUs this process is active on and launch
> -	 * an invalidate.
> -	 */
> -	acquire_atsd_reg(npu_context, mmio_atsd_reg);
> -
> -	if (atsd_psize == MMU_PAGE_COUNT)
> -		mmio_invalidate_pid(mmio_atsd_reg, pid);
> -	else
> -		mmio_invalidate_range(mmio_atsd_reg, pid, atsd_start,
> -					atsd_psize);
> -
> -	mmio_invalidate_wait(mmio_atsd_reg);
> -
> -	/*
> -	 * The GPU requires two flush ATSDs to ensure all entries have been
> -	 * flushed. We use PID 0 as it will never be used for a process on the
> -	 * GPU.
> -	 */
> -	mmio_invalidate_pid(mmio_atsd_reg, 0);
> -	mmio_invalidate_wait(mmio_atsd_reg);
> -	mmio_invalidate_pid(mmio_atsd_reg, 0);
> -	mmio_invalidate_wait(mmio_atsd_reg);
> -
> -	release_atsd_reg(mmio_atsd_reg);
> -}
> -
> -static void pnv_npu2_mn_release(struct mmu_notifier *mn,
> -				struct mm_struct *mm)
> -{
> -	struct npu_context *npu_context = mn_to_npu_context(mn);
> -
> -	/* Call into device driver to stop requests to the NMMU */
> -	if (npu_context->release_cb)
> -		npu_context->release_cb(npu_context, npu_context->priv);
> -
> -	/*
> -	 * There should be no more translation requests for this PID, but we
> -	 * need to ensure any entries for it are removed from the TLB.
> -	 */
> -	mmio_invalidate(npu_context, 0, ~0UL);
> -}
> -
> -static void pnv_npu2_mn_change_pte(struct mmu_notifier *mn,
> -				struct mm_struct *mm,
> -				unsigned long address,
> -				pte_t pte)
> -{
> -	struct npu_context *npu_context = mn_to_npu_context(mn);
> -	mmio_invalidate(npu_context, address, PAGE_SIZE);
> -}
> -
> -static void pnv_npu2_mn_invalidate_range(struct mmu_notifier *mn,
> -					struct mm_struct *mm,
> -					unsigned long start, unsigned long end)
> -{
> -	struct npu_context *npu_context = mn_to_npu_context(mn);
> -	mmio_invalidate(npu_context, start, end - start);
> -}
> -
> -static const struct mmu_notifier_ops nv_nmmu_notifier_ops = {
> -	.release = pnv_npu2_mn_release,
> -	.change_pte = pnv_npu2_mn_change_pte,
> -	.invalidate_range = pnv_npu2_mn_invalidate_range,
> -};
> -
> -/*
> - * Call into OPAL to setup the nmmu context for the current task in
> - * the NPU. This must be called to setup the context tables before the
> - * GPU issues ATRs. pdev should be a pointed to PCIe GPU device.
> - *
> - * A release callback should be registered to allow a device driver to
> - * be notified that it should not launch any new translation requests
> - * as the final TLB invalidate is about to occur.
> - *
> - * Returns an error if there no contexts are currently available or a
> - * npu_context which should be passed to pnv_npu2_handle_fault().
> - *
> - * mmap_sem must be held in write mode and must not be called from interrupt
> - * context.
> - */
> -struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
> -			unsigned long flags,
> -			void (*cb)(struct npu_context *, void *),
> -			void *priv)

> -{
> -	int rc;
> -	u32 nvlink_index;
> -	struct device_node *nvlink_dn;
> -	struct mm_struct *mm = current->mm;
> -	struct pnv_phb *nphb;
> -	struct npu *npu;
> -	struct npu_context *npu_context;
> -
> -	/*
> -	 * At present we don't support GPUs connected to multiple NPUs and I'm
> -	 * not sure the hardware does either.
> -	 */
> -	struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
> -
> -	if (!firmware_has_feature(FW_FEATURE_OPAL))
> -		return ERR_PTR(-ENODEV);
> -
> -	if (!npdev)
> -		/* No nvlink associated with this GPU device */
> -		return ERR_PTR(-ENODEV);
> -
> -	nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0);
> -	if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index",
> -							&nvlink_index)))
> -		return ERR_PTR(-ENODEV);
> -
> -	if (!mm || mm->context.id == 0) {
> -		/*
> -		 * Kernel thread contexts are not supported and context id 0 is
> -		 * reserved on the GPU.
> -		 */
> -		return ERR_PTR(-EINVAL);
> -	}
> -
> -	nphb = pci_bus_to_host(npdev->bus)->private_data;
> -	npu = &nphb->npu;
> -
> -	/*
> -	 * Setup the NPU context table for a particular GPU. These need to be
> -	 * per-GPU as we need the tables to filter ATSDs when there are no
> -	 * active contexts on a particular GPU. It is safe for these to be
> -	 * called concurrently with destroy as the OPAL call takes appropriate
> -	 * locks and refcounts on init/destroy.
> -	 */
> -	rc = opal_npu_init_context(nphb->opal_id, mm->context.id, flags,
> -				PCI_DEVID(gpdev->bus->number, gpdev->devfn));
> -	if (rc < 0)
> -		return ERR_PTR(-ENOSPC);
> -
> -	/*
> -	 * We store the npu pci device so we can more easily get at the
> -	 * associated npus.
> -	 */
> -	spin_lock(&npu_context_lock);
> -	npu_context = mm->context.npu_context;
> -	if (npu_context) {
> -		if (npu_context->release_cb != cb ||
> -			npu_context->priv != priv) {
> -			spin_unlock(&npu_context_lock);
> -			opal_npu_destroy_context(nphb->opal_id, mm->context.id,
> -						PCI_DEVID(gpdev->bus->number,
> -							gpdev->devfn));
> -			return ERR_PTR(-EINVAL);
> -		}
> -
> -		WARN_ON(!kref_get_unless_zero(&npu_context->kref));
> -	}
> -	spin_unlock(&npu_context_lock);
> -
> -	if (!npu_context) {
> -		/*
> -		 * We can set up these fields without holding the
> -		 * npu_context_lock as the npu_context hasn't been returned to
> -		 * the caller meaning it can't be destroyed. Parallel allocation
> -		 * is protected against by mmap_sem.
> -		 */
> -		rc = -ENOMEM;
> -		npu_context = kzalloc(sizeof(struct npu_context), GFP_KERNEL);
> -		if (npu_context) {
> -			kref_init(&npu_context->kref);
> -			npu_context->mm = mm;
> -			npu_context->mn.ops = &nv_nmmu_notifier_ops;
> -			rc = __mmu_notifier_register(&npu_context->mn, mm);
> -		}
> -
> -		if (rc) {
> -			kfree(npu_context);
> -			opal_npu_destroy_context(nphb->opal_id, mm->context.id,
> -					PCI_DEVID(gpdev->bus->number,
> -						gpdev->devfn));
> -			return ERR_PTR(rc);
> -		}
> -
> -		mm->context.npu_context = npu_context;
> -	}
> -
> -	npu_context->release_cb = cb;
> -	npu_context->priv = priv;
> -
> -	/*
> -	 * npdev is a pci_dev pointer setup by the PCI code. We assign it to
> -	 * npdev[][] to indicate to the mmu notifiers that an invalidation
> -	 * should also be sent over this nvlink. The notifiers don't use any
> -	 * other fields in npu_context, so we just need to ensure that when they
> -	 * deference npu_context->npdev[][] it is either a valid pointer or
> -	 * NULL.
> -	 */
> -	WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], npdev);
> -
> -	if (!nphb->npu.nmmu_flush) {
> -		/*
> -		 * If we're not explicitly flushing ourselves we need to mark
> -		 * the thread for global flushes
> -		 */
> -		npu_context->nmmu_flush = false;
> -		mm_context_add_copro(mm);
> -	} else
> -		npu_context->nmmu_flush = true;
> -
> -	return npu_context;
> -}
> -EXPORT_SYMBOL(pnv_npu2_init_context);
> -
> -static void pnv_npu2_release_context(struct kref *kref)
> -{
> -	struct npu_context *npu_context =
> -		container_of(kref, struct npu_context, kref);
> -
> -	if (!npu_context->nmmu_flush)
> -		mm_context_remove_copro(npu_context->mm);
> -
> -	npu_context->mm->context.npu_context = NULL;
> -}
> -
> -/*
> - * Destroy a context on the given GPU. May free the npu_context if it is no
> - * longer active on any GPUs. Must not be called from interrupt context.
> - */
> -void pnv_npu2_destroy_context(struct npu_context *npu_context,
> -			struct pci_dev *gpdev)
> -{
> -	int removed;
> -	struct pnv_phb *nphb;
> -	struct npu *npu;
> -	struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
> -	struct device_node *nvlink_dn;
> -	u32 nvlink_index;
> -
> -	if (WARN_ON(!npdev))
> -		return;
> -
> -	if (!firmware_has_feature(FW_FEATURE_OPAL))
> -		return;
> -
> -	nphb = pci_bus_to_host(npdev->bus)->private_data;
> -	npu = &nphb->npu;
> -	nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0);
> -	if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index",
> -							&nvlink_index)))
> -		return;
> -	WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], NULL);
> -	opal_npu_destroy_context(nphb->opal_id, npu_context->mm->context.id,
> -				PCI_DEVID(gpdev->bus->number, gpdev->devfn));
> -	spin_lock(&npu_context_lock);
> -	removed = kref_put(&npu_context->kref, pnv_npu2_release_context);
> -	spin_unlock(&npu_context_lock);
> -
> -	/*
> -	 * We need to do this outside of pnv_npu2_release_context so that it is
> -	 * outside the spinlock as mmu_notifier_destroy uses SRCU.
> -	 */
> -	if (removed) {
> -		mmu_notifier_unregister(&npu_context->mn,
> -					npu_context->mm);
> -
> -		kfree(npu_context);
> -	}
> -
> -}
> -EXPORT_SYMBOL(pnv_npu2_destroy_context);
> -
> -/*
> - * Assumes mmap_sem is held for the contexts associated mm.
> - */
> -int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
> -			unsigned long *flags, unsigned long *status, int count)
> -{
> -	u64 rc = 0, result = 0;
> -	int i, is_write;
> -	struct page *page[1];
> -
> -	/* mmap_sem should be held so the struct_mm must be present */
> -	struct mm_struct *mm = context->mm;
> -
> -	if (!firmware_has_feature(FW_FEATURE_OPAL))
> -		return -ENODEV;
> -
> -	WARN_ON(!rwsem_is_locked(&mm->mmap_sem));
> -
> -	for (i = 0; i < count; i++) {
> -		is_write = flags[i] & NPU2_WRITE;
> -		rc = get_user_pages_remote(NULL, mm, ea[i], 1,
> -					is_write ? FOLL_WRITE : 0,
> -					page, NULL, NULL);
> -
> -		/*
> -		 * To support virtualised environments we will have to do an
> -		 * access to the page to ensure it gets faulted into the
> -		 * hypervisor. For the moment virtualisation is not supported in
> -		 * other areas so leave the access out.
> -		 */
> -		if (rc != 1) {
> -			status[i] = rc;
> -			result = -EFAULT;
> -			continue;
> -		}
> -
> -		status[i] = 0;
> -		put_page(page[0]);
> -	}
> -
> -	return result;
> -}
> -EXPORT_SYMBOL(pnv_npu2_handle_fault);
> -
> -int pnv_npu2_init(struct pnv_phb *phb)
> -{
> -	unsigned int i;
> -	u64 mmio_atsd;
> -	struct device_node *dn;
> -	struct pci_dev *gpdev;
> -	static int npu_index;
> -	uint64_t rc = 0;
> -
> -	phb->npu.nmmu_flush =
> -		of_property_read_bool(phb->hose->dn, "ibm,nmmu-flush");
> -	for_each_child_of_node(phb->hose->dn, dn) {
> -		gpdev = pnv_pci_get_gpu_dev(get_pci_dev(dn));
> -		if (gpdev) {
> -			rc = opal_npu_map_lpar(phb->opal_id,
> -				PCI_DEVID(gpdev->bus->number, gpdev->devfn),
> -				0, 0);

I heavily hacked on these (draft):
https://patchwork.ozlabs.org/project/kvm-ppc/list/?series=70791

and the result is going to be used for VFIO purposes (draft too):
https://patchwork.ozlabs.org/project/kvm-ppc/list/?series=70793

Other bits can go away from npu-dma but I still need some to make
KVM+VFIO work for GPUs, this is without any vendor driver on the host
side whatsoever.



> -			if (rc)
> -				dev_err(&gpdev->dev,
> -					"Error %lld mapping device to LPAR\n",
> -					rc);
> -		}
> -	}
> -
> -	for (i = 0; !of_property_read_u64_index(phb->hose->dn, "ibm,mmio-atsd",
> -							i, &mmio_atsd); i++)
> -		phb->npu.mmio_atsd_regs[i] = ioremap(mmio_atsd, 32);
> -
> -	pr_info("NPU%lld: Found %d MMIO ATSD registers", phb->opal_id, i);
> -	phb->npu.mmio_atsd_count = i;
> -	phb->npu.mmio_atsd_usage = 0;
> -	npu_index++;
> -	if (WARN_ON(npu_index >= NV_MAX_NPUS))
> -		return -ENOSPC;
> -	max_npu2_index = npu_index;
> -	phb->npu.index = npu_index;
> -
> -	return 0;
> -}
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index cde710297a4e..f480e3fc9ebb 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -1203,75 +1203,6 @@ static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>  	return pe;
>  }
>  
> -static struct pnv_ioda_pe *pnv_ioda_setup_npu_PE(struct pci_dev *npu_pdev)
> -{
> -	int pe_num, found_pe = false, rc;
> -	long rid;
> -	struct pnv_ioda_pe *pe;
> -	struct pci_dev *gpu_pdev;
> -	struct pci_dn *npu_pdn;
> -	struct pci_controller *hose = pci_bus_to_host(npu_pdev->bus);
> -	struct pnv_phb *phb = hose->private_data;
> -
> -	/*
> -	 * Due to a hardware errata PE#0 on the NPU is reserved for
> -	 * error handling. This means we only have three PEs remaining
> -	 * which need to be assigned to four links, implying some
> -	 * links must share PEs.
> -	 *
> -	 * To achieve this we assign PEs such that NPUs linking the
> -	 * same GPU get assigned the same PE.
> -	 */
> -	gpu_pdev = pnv_pci_get_gpu_dev(npu_pdev);
> -	for (pe_num = 0; pe_num < phb->ioda.total_pe_num; pe_num++) {
> -		pe = &phb->ioda.pe_array[pe_num];
> -		if (!pe->pdev)
> -			continue;
> -
> -		if (pnv_pci_get_gpu_dev(pe->pdev) == gpu_pdev) {
> -			/*
> -			 * This device has the same peer GPU so should
> -			 * be assigned the same PE as the existing
> -			 * peer NPU.
> -			 */
> -			dev_info(&npu_pdev->dev,
> -				"Associating to existing PE %x\n", pe_num);
> -			pci_dev_get(npu_pdev);
> -			npu_pdn = pci_get_pdn(npu_pdev);
> -			rid = npu_pdev->bus->number << 8 | npu_pdn->devfn;
> -			npu_pdn->pe_number = pe_num;
> -			phb->ioda.pe_rmap[rid] = pe->pe_number;
> -
> -			/* Map the PE to this link */
> -			rc = opal_pci_set_pe(phb->opal_id, pe_num, rid,
> -					OpalPciBusAll,
> -					OPAL_COMPARE_RID_DEVICE_NUMBER,
> -					OPAL_COMPARE_RID_FUNCTION_NUMBER,
> -					OPAL_MAP_PE);
> -			WARN_ON(rc != OPAL_SUCCESS);
> -			found_pe = true;
> -			break;
> -		}
> -	}
> -
> -	if (!found_pe)
> -		/*
> -		 * Could not find an existing PE so allocate a new
> -		 * one.
> -		 */
> -		return pnv_ioda_setup_dev_PE(npu_pdev);
> -	else
> -		return pe;
> -}
> -
> -static void pnv_ioda_setup_npu_PEs(struct pci_bus *bus)
> -{
> -	struct pci_dev *pdev;
> -
> -	list_for_each_entry(pdev, &bus->devices, bus_list)
> -		pnv_ioda_setup_npu_PE(pdev);
> -}
> -
>  static void pnv_pci_ioda_setup_PEs(void)
>  {
>  	struct pci_controller *hose, *tmp;
> @@ -1281,13 +1212,6 @@ static void pnv_pci_ioda_setup_PEs(void)
>  
>  	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
>  		phb = hose->private_data;
> -		if (phb->type == PNV_PHB_NPU_NVLINK) {
> -			/* PE#0 is needed for error reporting */
> -			pnv_ioda_reserve_pe(phb, 0);
> -			pnv_ioda_setup_npu_PEs(hose->bus);
> -			if (phb->model == PNV_PHB_MODEL_NPU2)
> -				pnv_npu2_init(phb);
> -		}
>  		if (phb->type == PNV_PHB_NPU_OCAPI) {
>  			bus = hose->bus;
>  			list_for_each_entry(pdev, &bus->devices, bus_list)
> @@ -1895,9 +1819,6 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
>  	}
>  	*pdev->dev.dma_mask = dma_mask;
>  
> -	/* Update peer npu devices */
> -	pnv_npu_try_dma_set_bypass(pdev, bypass);
> -
>  	return 0;
>  }
>  
> @@ -2143,14 +2064,6 @@ static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
>  	}
>  }
>  
> -void pnv_pci_ioda2_tce_invalidate_entire(struct pnv_phb *phb, bool rm)
> -{
> -	if (phb->model == PNV_PHB_MODEL_NPU || phb->model == PNV_PHB_MODEL_PHB3)
> -		pnv_pci_phb3_tce_invalidate_entire(phb, rm);
> -	else
> -		opal_pci_tce_kill(phb->opal_id, OPAL_PCI_TCE_KILL, 0, 0, 0, 0);
> -}
> -
>  static int pnv_ioda2_tce_build(struct iommu_table *tbl, long index,
>  		long npages, unsigned long uaddr,
>  		enum dma_data_direction direction,
> @@ -2639,137 +2552,6 @@ static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
>  	.take_ownership = pnv_ioda2_take_ownership,
>  	.release_ownership = pnv_ioda2_release_ownership,
>  };
> -
> -static int gpe_table_group_to_npe_cb(struct device *dev, void *opaque)
> -{
> -	struct pci_controller *hose;
> -	struct pnv_phb *phb;
> -	struct pnv_ioda_pe **ptmppe = opaque;
> -	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
> -	struct pci_dn *pdn = pci_get_pdn(pdev);
> -
> -	if (!pdn || pdn->pe_number == IODA_INVALID_PE)
> -		return 0;
> -
> -	hose = pci_bus_to_host(pdev->bus);
> -	phb = hose->private_data;
> -	if (phb->type != PNV_PHB_NPU_NVLINK)
> -		return 0;
> -
> -	*ptmppe = &phb->ioda.pe_array[pdn->pe_number];
> -
> -	return 1;
> -}
> -
> -/*
> - * This returns PE of associated NPU.
> - * This assumes that NPU is in the same IOMMU group with GPU and there is
> - * no other PEs.
> - */
> -static struct pnv_ioda_pe *gpe_table_group_to_npe(
> -		struct iommu_table_group *table_group)
> -{
> -	struct pnv_ioda_pe *npe = NULL;
> -	int ret = iommu_group_for_each_dev(table_group->group, &npe,
> -			gpe_table_group_to_npe_cb);
> -
> -	BUG_ON(!ret || !npe);
> -
> -	return npe;
> -}
> -
> -static long pnv_pci_ioda2_npu_set_window(struct iommu_table_group *table_group,
> -		int num, struct iommu_table *tbl)
> -{
> -	struct pnv_ioda_pe *npe = gpe_table_group_to_npe(table_group);
> -	int num2 = (num == 0) ? 1 : 0;
> -	long ret = pnv_pci_ioda2_set_window(table_group, num, tbl);
> -
> -	if (ret)
> -		return ret;
> -
> -	if (table_group->tables[num2])
> -		pnv_npu_unset_window(npe, num2);
> -
> -	ret = pnv_npu_set_window(npe, num, tbl);
> -	if (ret) {
> -		pnv_pci_ioda2_unset_window(table_group, num);
> -		if (table_group->tables[num2])
> -			pnv_npu_set_window(npe, num2,
> -					table_group->tables[num2]);
> -	}
> -
> -	return ret;
> -}
> -
> -static long pnv_pci_ioda2_npu_unset_window(
> -		struct iommu_table_group *table_group,
> -		int num)
> -{
> -	struct pnv_ioda_pe *npe = gpe_table_group_to_npe(table_group);
> -	int num2 = (num == 0) ? 1 : 0;
> -	long ret = pnv_pci_ioda2_unset_window(table_group, num);
> -
> -	if (ret)
> -		return ret;
> -
> -	if (!npe->table_group.tables[num])
> -		return 0;
> -
> -	ret = pnv_npu_unset_window(npe, num);
> -	if (ret)
> -		return ret;
> -
> -	if (table_group->tables[num2])
> -		ret = pnv_npu_set_window(npe, num2, table_group->tables[num2]);
> -
> -	return ret;
> -}
> -
> -static void pnv_ioda2_npu_take_ownership(struct iommu_table_group *table_group)
> -{
> -	/*
> -	 * Detach NPU first as pnv_ioda2_take_ownership() will destroy
> -	 * the iommu_table if 32bit DMA is enabled.
> -	 */
> -	pnv_npu_take_ownership(gpe_table_group_to_npe(table_group));
> -	pnv_ioda2_take_ownership(table_group);
> -}
> -
> -static struct iommu_table_group_ops pnv_pci_ioda2_npu_ops = {
> -	.get_table_size = pnv_pci_ioda2_get_table_size,
> -	.create_table = pnv_pci_ioda2_create_table_userspace,
> -	.set_window = pnv_pci_ioda2_npu_set_window,
> -	.unset_window = pnv_pci_ioda2_npu_unset_window,
> -	.take_ownership = pnv_ioda2_npu_take_ownership,
> -	.release_ownership = pnv_ioda2_release_ownership,


These are called from the VFIO SPAPR TCE IOMMU subdriver when certain
GPUs are passed through with VFIO:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/vfio/vfio_iommu_spapr_tce.c



> -};
> -
> -static void pnv_pci_ioda_setup_iommu_api(void)
> -{
> -	struct pci_controller *hose, *tmp;
> -	struct pnv_phb *phb;
> -	struct pnv_ioda_pe *pe, *gpe;
> -
> -	/*
> -	 * Now we have all PHBs discovered, time to add NPU devices to
> -	 * the corresponding IOMMU groups.
> -	 */
> -	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
> -		phb = hose->private_data;
> -
> -		if (phb->type != PNV_PHB_NPU_NVLINK)
> -			continue;
> -
> -		list_for_each_entry(pe, &phb->ioda.pe_list, list) {
> -			gpe = pnv_pci_npu_setup_iommu(pe);
> -			if (gpe)
> -				gpe->table_group.ops = &pnv_pci_ioda2_npu_ops;
> -		}
> -	}
> -}
> -#else /* !CONFIG_IOMMU_API */
> -static void pnv_pci_ioda_setup_iommu_api(void) { };
>  #endif
>  
>  static unsigned long pnv_ioda_parse_tce_sizes(struct pnv_phb *phb)
> @@ -3266,7 +3048,6 @@ static void pnv_pci_enable_bridges(void)
>  static void pnv_pci_ioda_fixup(void)
>  {
>  	pnv_pci_ioda_setup_PEs();
> -	pnv_pci_ioda_setup_iommu_api();
>  	pnv_pci_ioda_create_dbgfs();
>  
>  	pnv_pci_enable_bridges();
> @@ -3713,27 +3494,6 @@ static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
>  	.shutdown		= pnv_pci_ioda_shutdown,
>  };
>  
> -static int pnv_npu_dma_set_mask(struct pci_dev *npdev, u64 dma_mask)
> -{
> -	dev_err_once(&npdev->dev,
> -			"%s operation unsupported for NVLink devices\n",
> -			__func__);
> -	return -EPERM;
> -}
> -
> -static const struct pci_controller_ops pnv_npu_ioda_controller_ops = {
> -	.dma_dev_setup		= pnv_pci_dma_dev_setup,
> -#ifdef CONFIG_PCI_MSI
> -	.setup_msi_irqs		= pnv_setup_msi_irqs,
> -	.teardown_msi_irqs	= pnv_teardown_msi_irqs,
> -#endif
> -	.enable_device_hook	= pnv_pci_enable_device_hook,
> -	.window_alignment	= pnv_pci_window_alignment,
> -	.reset_secondary_bus	= pnv_pci_reset_secondary_bus,
> -	.dma_set_mask		= pnv_npu_dma_set_mask,
> -	.shutdown		= pnv_pci_ioda_shutdown,
> -};
> -
>  static const struct pci_controller_ops pnv_npu_ocapi_ioda_controller_ops = {
>  	.enable_device_hook	= pnv_pci_enable_device_hook,
>  	.window_alignment	= pnv_pci_window_alignment,
> @@ -3955,9 +3715,6 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>  	ppc_md.pcibios_fixup = pnv_pci_ioda_fixup;
>  
>  	switch (phb->type) {
> -	case PNV_PHB_NPU_NVLINK:
> -		hose->controller_ops = pnv_npu_ioda_controller_ops;
> -		break;
>  	case PNV_PHB_NPU_OCAPI:
>  		hose->controller_ops = pnv_npu_ocapi_ioda_controller_ops;
>  		break;
> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
> index 8b37b28e3831..54f2935b7ac5 100644
> --- a/arch/powerpc/platforms/powernv/pci.h
> +++ b/arch/powerpc/platforms/powernv/pci.h
> @@ -231,17 +231,6 @@ extern void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
>  #define pe_info(pe, fmt, ...)					\
>  	pe_level_printk(pe, KERN_INFO, fmt, ##__VA_ARGS__)
>  
> -/* Nvlink functions */
> -extern void pnv_npu_try_dma_set_bypass(struct pci_dev *gpdev, bool bypass);
> -extern void pnv_pci_ioda2_tce_invalidate_entire(struct pnv_phb *phb, bool rm);
> -extern struct pnv_ioda_pe *pnv_pci_npu_setup_iommu(struct pnv_ioda_pe *npe);
> -extern long pnv_npu_set_window(struct pnv_ioda_pe *npe, int num,
> -		struct iommu_table *tbl);
> -extern long pnv_npu_unset_window(struct pnv_ioda_pe *npe, int num);
> -extern void pnv_npu_take_ownership(struct pnv_ioda_pe *npe);
> -extern void pnv_npu_release_ownership(struct pnv_ioda_pe *npe);
> -extern int pnv_npu2_init(struct pnv_phb *phb);
> -
>  /* pci-ioda-tce.c */
>  #define POWERNV_IOMMU_DEFAULT_LEVELS	1
>  #define POWERNV_IOMMU_MAX_LEVELS	5
> 


-- 
Alexey

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] powerpc/powernv: remove dead npu-dma code
  2018-11-01  4:41 ` Alexey Kardashevskiy
@ 2018-11-02 10:18   ` Michael Ellerman
  0 siblings, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2018-11-02 10:18 UTC (permalink / raw)
  To: Alexey Kardashevskiy, Christoph Hellwig, Benjamin Herrenschmidt,
	Paul Mackerras
  Cc: James Bottomley, Paul E. McKenney, Andrew Morton, Linus Torvalds,
	linuxppc-dev, linux-kernel

Alexey Kardashevskiy <aik@ozlabs.ru> writes:
> On 31/10/2018 00:31, Christoph Hellwig wrote:
>> This code has never been unused in the kernel since it was merged, and
>> there has been no attempt that I could find to even submit users for
>> it.  Besides the general policy of not keep 1000+ lines of dead
>> code, it helps cleaning up the DMA code and making powerpc user common
>> infrastructure.
>> 
>> This effectively reverts commit 5d2aa710 ("powerpc/powernv: Add support
>> for Nvlink NPUs").
>> 
>> Signed-off-by: Christoph Hellwig <hch@lst.de>
>> ---
...
>> diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
>> deleted file mode 100644
>> index 6f60e0931922..000000000000
>> --- a/arch/powerpc/platforms/powernv/npu-dma.c
>> +++ /dev/null
>> @@ -1,989 +0,0 @@
...
>> -int pnv_npu2_init(struct pnv_phb *phb)
>> -{
>> -	unsigned int i;
>> -	u64 mmio_atsd;
>> -	struct device_node *dn;
>> -	struct pci_dev *gpdev;
>> -	static int npu_index;
>> -	uint64_t rc = 0;
>> -
>> -	phb->npu.nmmu_flush =
>> -		of_property_read_bool(phb->hose->dn, "ibm,nmmu-flush");
>> -	for_each_child_of_node(phb->hose->dn, dn) {
>> -		gpdev = pnv_pci_get_gpu_dev(get_pci_dev(dn));
>> -		if (gpdev) {
>> -			rc = opal_npu_map_lpar(phb->opal_id,
>> -				PCI_DEVID(gpdev->bus->number, gpdev->devfn),
>> -				0, 0);
>
> I heavily hacked on these (draft):
> https://patchwork.ozlabs.org/project/kvm-ppc/list/?series=70791
>
> and the result is going to be used for VFIO purposes (draft too):
> https://patchwork.ozlabs.org/project/kvm-ppc/list/?series=70793
>
> Other bits can go away from npu-dma but I still need some to make
> KVM+VFIO work for GPUs, this is without any vendor driver on the host
> side whatsoever.

OK, so to be clear we will need at least some of this code so that a KVM
host can pass through a GPU to a guest, and that requires no binary
driver on the host.

I don't think anyone's arguing that we should prevent passing through
devices that might need a binary driver in a guest?

Christoph I think that establishes that this is not all dead code, and
so I'm nacking this patch in its current form. If you have other
objections to this code please raise them specifically.

I'll merge Alistair's patch to remove the NPU dma_ops, because they're
not really necessary and might legitimately be getting in the way of
dma_ops cleanups.

  https://patchwork.ozlabs.org/patch/990721/


cheers

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-11-02 10:18 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-10-30 13:31 [PATCH] powerpc/powernv: remove dead npu-dma code Christoph Hellwig
2018-11-01  4:41 ` Alexey Kardashevskiy
2018-11-02 10:18   ` Michael Ellerman

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).