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From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v6 10/20] powerpc/8xx: Temporarily disable 16k pages and 512k hugepages
Date: Fri, 19 Oct 2018 06:55:12 +0000 (UTC)	[thread overview]
Message-ID: <4d14168ad502bbad2e11e2df9162f81e50bb6cb0.1539931702.git.christophe.leroy@c-s.fr> (raw)
In-Reply-To: <cover.1539931702.git.christophe.leroy@c-s.fr>

In preparation of making use of hardware assistance in TLB handlers,
this patch temporarily disables 16K pages and 512K pages. The reason
is that when using HW assistance in 4K pages mode, the linux model
fit with the HW model for 4K pages and 8M pages.

However for 16K pages and 512K mode some additional work is needed
to get linux model fit with HW model.

Therefore the 4K pages mode will be implemented first and without
support for 512k hugepages. Then the 512k hugepages will be brought
back. And the 16K pages will be implemented in further steps.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/Kconfig           |  2 +-
 arch/powerpc/kernel/head_8xx.S | 36 ------------------------------------
 arch/powerpc/mm/tlb_nohash.c   |  3 ---
 3 files changed, 1 insertion(+), 40 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3d008115fe18..287befcf37ab 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -690,7 +690,7 @@ config PPC_4K_PAGES
 
 config PPC_16K_PAGES
 	bool "16k page size"
-	depends on 44x || PPC_8xx
+	depends on 44x
 
 config PPC_64K_PAGES
 	bool "64k page size"
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index c203defe49a4..9b31721b522c 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -363,7 +363,6 @@ InstructionTLBMiss:
 #ifdef CONFIG_HUGETLB_PAGE
 	mtcr	r11
 	bt-	28, 10f		/* bit 28 = Large page (8M) */
-	bt-	29, 20f		/* bit 29 = Large page (8M or 512k) */
 #endif
 	rlwimi	r10, r11, 0, 0, 32 - PAGE_SHIFT - 1	/* Add level 2 base */
 	lwz	r10, 0(r10)	/* Get the pte */
@@ -414,23 +413,8 @@ InstructionTLBMiss:
 
 #ifdef CONFIG_HUGETLB_PAGE
 10:	/* 8M pages */
-#ifdef CONFIG_PPC_16K_PAGES
-	/* Extract level 2 index */
-	rlwinm	r10, r10, 32 - (PAGE_SHIFT_8M - PAGE_SHIFT), 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1), 29
-	/* Add level 2 base */
-	rlwimi	r10, r11, 0, 0, 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1) - 1
-#else
 	/* Level 2 base */
 	rlwinm	r10, r11, 0, ~HUGEPD_SHIFT_MASK
-#endif
-	lwz	r10, 0(r10)	/* Get the pte */
-	b	4b
-
-20:	/* 512k pages */
-	/* Extract level 2 index */
-	rlwinm	r10, r10, 32 - (PAGE_SHIFT_512K - PAGE_SHIFT), 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1), 29
-	/* Add level 2 base */
-	rlwimi	r10, r11, 0, 0, 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1) - 1
 	lwz	r10, 0(r10)	/* Get the pte */
 	b	4b
 #endif
@@ -475,7 +459,6 @@ DataStoreTLBMiss:
 #ifdef CONFIG_HUGETLB_PAGE
 	mtcr	r11
 	bt-	28, 10f		/* bit 28 = Large page (8M) */
-	bt-	29, 20f		/* bit 29 = Large page (8M or 512k) */
 #endif
 	rlwimi	r10, r11, 0, 0, 32 - PAGE_SHIFT - 1	/* Add level 2 base */
 	lwz	r10, 0(r10)	/* Get the pte */
@@ -537,22 +520,8 @@ DataStoreTLBMiss:
 #ifdef CONFIG_HUGETLB_PAGE
 10:	/* 8M pages */
 	/* Extract level 2 index */
-#ifdef CONFIG_PPC_16K_PAGES
-	rlwinm	r10, r10, 32 - (PAGE_SHIFT_8M - PAGE_SHIFT), 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1), 29
-	/* Add level 2 base */
-	rlwimi	r10, r11, 0, 0, 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1) - 1
-#else
 	/* Level 2 base */
 	rlwinm	r10, r11, 0, ~HUGEPD_SHIFT_MASK
-#endif
-	lwz	r10, 0(r10)	/* Get the pte */
-	b	4b
-
-20:	/* 512k pages */
-	/* Extract level 2 index */
-	rlwinm	r10, r10, 32 - (PAGE_SHIFT_512K - PAGE_SHIFT), 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1), 29
-	/* Add level 2 base */
-	rlwimi	r10, r11, 0, 0, 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1) - 1
 	lwz	r10, 0(r10)	/* Get the pte */
 	b	4b
 #endif
@@ -773,12 +742,7 @@ FixupDAR:/* Entry point for dcbx workaround. */
 
 	/* concat physical page address(r11) and page offset(r10) */
 200:
-#ifdef CONFIG_PPC_16K_PAGES
-	rlwinm	r11, r11, 0, 0, 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1) - 1
-	rlwimi	r11, r10, 32 - (PAGE_SHIFT_8M - 2), 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1), 29
-#else
 	rlwinm	r11, r10, 0, ~HUGEPD_SHIFT_MASK
-#endif
 	lwz	r11, 0(r11)	/* Get the pte */
 	/* concat physical page address(r11) and page offset(r10) */
 	rlwimi	r11, r10, 0, 32 - PAGE_SHIFT_8M, 31
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index ae5d568e267f..8ad7aab150b7 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -97,9 +97,6 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
 		.shift	= 14,
 	},
 #endif
-	[MMU_PAGE_512K] = {
-		.shift	= 19,
-	},
 	[MMU_PAGE_8M] = {
 		.shift	= 23,
 	},
-- 
2.13.3


  parent reply	other threads:[~2018-10-19  6:55 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-19  6:54 [PATCH v6 00/20] Implement use of HW assistance on TLB table walk on 8xx Christophe Leroy
2018-10-19  6:54 ` [PATCH v6 01/20] Revert "powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP" Christophe Leroy
2018-10-31  5:42   ` [v6, " Michael Ellerman
2018-10-19  6:54 ` [PATCH v6 02/20] powerpc/mm: Move pte_fragment_alloc() to a common location Christophe Leroy
2018-10-19  6:54 ` [PATCH v6 03/20] powerpc/mm: Avoid useless lock with single page fragments Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 04/20] powerpc/mm: move platform specific mmu-xxx.h in platform directories Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 05/20] powerpc/mm: Move pgtable_t into platform headers Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 06/20] powerpc/code-patching: add a helper to get the address of a patch_site Christophe Leroy
2018-10-31  5:42   ` [v6, " Michael Ellerman
2018-10-19  6:55 ` [PATCH v6 07/20] powerpc/8xx: Use patch_site for memory setup patching Christophe Leroy
2018-10-31  5:42   ` [v6,07/20] " Michael Ellerman
2018-10-19  6:55 ` [PATCH v6 08/20] powerpc/8xx: Use patch_site for perf counters setup Christophe Leroy
2018-10-31  5:42   ` [v6,08/20] " Michael Ellerman
2018-10-19  6:55 ` [PATCH v6 09/20] powerpc/8xx: Move SW perf counters in first 32kb of memory Christophe Leroy
2018-10-19  6:55 ` Christophe Leroy [this message]
2018-10-19  6:55 ` [PATCH v6 11/20] powerpc/mm: Use hardware assistance in TLB handlers on the 8xx Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 12/20] powerpc/mm: Enable 512k hugepage support with HW assistance " Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 13/20] powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 14/20] powerpc/8xx: regroup TLB handler routines Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 15/20] powerpc/mm: don't use pte_alloc_one_kernel() before slab is available Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 16/20] powerpc/mm: inline pte_alloc_one() and pte_alloc_one_kernel() in PPC32 Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 17/20] powerpc/book3s32: Remove CONFIG_BOOKE dependent code Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 18/20] powerpc/mm: Extend pte_fragment functionality to nohash/32 Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 19/20] powerpc/8xx: Remove PTE_ATOMIC_UPDATES Christophe Leroy
2018-10-19  6:55 ` [PATCH v6 20/20] powerpc/mm: reintroduce 16K pages with HW assistance on 8xx Christophe Leroy

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