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From: Iwona Winiarska <iwona.winiarska@intel.com>
To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org
Cc: x86@kernel.org, devicetree@vger.kernel.org,
	linux-aspeed@lists.ozlabs.org,
	linux-arm-kernel@lists.infradead.org,
	linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh+dt@kernel.org>, Joel Stanley <joel@jms.id.au>,
	Andrew Jeffery <andrew@aj.id.au>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Jonathan Corbet <corbet@lwn.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Yazen Ghannam <yazen.ghannam@amd.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>,
	Iwona Winiarska <iwona.winiarska@intel.com>
Subject: [PATCH 08/14] peci: Add device detection
Date: Tue, 13 Jul 2021 00:04:41 +0200	[thread overview]
Message-ID: <20210712220447.957418-9-iwona.winiarska@intel.com> (raw)
In-Reply-To: <20210712220447.957418-1-iwona.winiarska@intel.com>

Since PECI devices are discoverable, we can dynamically detect devices
that are actually available in the system.

This change complements the earlier implementation by rescanning PECI
bus to detect available devices. For this purpose, it also introduces the
minimal API for PECI requests.

Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 drivers/peci/Makefile   |   2 +-
 drivers/peci/core.c     |  13 ++++-
 drivers/peci/device.c   | 111 ++++++++++++++++++++++++++++++++++++++++
 drivers/peci/internal.h |  15 ++++++
 drivers/peci/request.c  |  74 +++++++++++++++++++++++++++
 drivers/peci/sysfs.c    |  34 ++++++++++++
 6 files changed, 246 insertions(+), 3 deletions(-)
 create mode 100644 drivers/peci/device.c
 create mode 100644 drivers/peci/request.c

diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile
index 621a993e306a..917f689e147a 100644
--- a/drivers/peci/Makefile
+++ b/drivers/peci/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 # Core functionality
-peci-y := core.o sysfs.o
+peci-y := core.o request.o device.o sysfs.o
 obj-$(CONFIG_PECI) += peci.o
 
 # Hardware specific bus drivers
diff --git a/drivers/peci/core.c b/drivers/peci/core.c
index 0ad00110459d..ae7a9572cdf3 100644
--- a/drivers/peci/core.c
+++ b/drivers/peci/core.c
@@ -31,7 +31,15 @@ struct device_type peci_controller_type = {
 
 int peci_controller_scan_devices(struct peci_controller *controller)
 {
-	/* Just a stub, no support for actual devices yet */
+	int ret;
+	u8 addr;
+
+	for (addr = PECI_BASE_ADDR; addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX; addr++) {
+		ret = peci_device_create(controller, addr);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -106,7 +114,8 @@ EXPORT_SYMBOL_NS_GPL(peci_controller_add, PECI);
 
 static int _unregister(struct device *dev, void *dummy)
 {
-	/* Just a stub, no support for actual devices yet */
+	peci_device_destroy(to_peci_device(dev));
+
 	return 0;
 }
 
diff --git a/drivers/peci/device.c b/drivers/peci/device.c
new file mode 100644
index 000000000000..1124862211e2
--- /dev/null
+++ b/drivers/peci/device.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/peci.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static int peci_detect(struct peci_controller *controller, u8 addr)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_request_alloc(NULL, 0, 0);
+	if (!req)
+		return -ENOMEM;
+
+	mutex_lock(&controller->bus_lock);
+	ret = controller->xfer(controller, addr, req);
+	mutex_unlock(&controller->bus_lock);
+
+	peci_request_free(req);
+
+	return ret;
+}
+
+static bool peci_addr_valid(u8 addr)
+{
+	return addr >= PECI_BASE_ADDR && addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX;
+}
+
+static int peci_dev_exists(struct device *dev, void *data)
+{
+	struct peci_device *device = to_peci_device(dev);
+	u8 *addr = data;
+
+	if (device->addr == *addr)
+		return -EBUSY;
+
+	return 0;
+}
+
+int peci_device_create(struct peci_controller *controller, u8 addr)
+{
+	struct peci_device *device;
+	int ret;
+
+	if (WARN_ON(!peci_addr_valid(addr)))
+		return -EINVAL;
+
+	/* Check if we have already detected this device before. */
+	ret = device_for_each_child(&controller->dev, &addr, peci_dev_exists);
+	if (ret)
+		return 0;
+
+	ret = peci_detect(controller, addr);
+	if (ret) {
+		/*
+		 * Device not present or host state doesn't allow successful
+		 * detection at this time.
+		 */
+		if (ret == -EIO || ret == -ETIMEDOUT)
+			return 0;
+
+		return ret;
+	}
+
+	device = kzalloc(sizeof(*device), GFP_KERNEL);
+	if (!device)
+		return -ENOMEM;
+
+	device->controller = controller;
+	device->addr = addr;
+	device->dev.parent = &device->controller->dev;
+	device->dev.bus = &peci_bus_type;
+	device->dev.type = &peci_device_type;
+
+	ret = dev_set_name(&device->dev, "%d-%02x", controller->id, device->addr);
+	if (ret)
+		goto err_free;
+
+	ret = device_register(&device->dev);
+	if (ret)
+		goto err_put;
+
+	return 0;
+
+err_put:
+	put_device(&device->dev);
+err_free:
+	kfree(device);
+
+	return ret;
+}
+
+void peci_device_destroy(struct peci_device *device)
+{
+	device_unregister(&device->dev);
+}
+
+static void peci_device_release(struct device *dev)
+{
+	struct peci_device *device = to_peci_device(dev);
+
+	kfree(device);
+}
+
+struct device_type peci_device_type = {
+	.groups		= peci_device_groups,
+	.release	= peci_device_release,
+};
diff --git a/drivers/peci/internal.h b/drivers/peci/internal.h
index 80c61bcdfc6b..6b139adaf6b8 100644
--- a/drivers/peci/internal.h
+++ b/drivers/peci/internal.h
@@ -9,6 +9,21 @@
 
 struct peci_controller;
 struct attribute_group;
+struct peci_device;
+struct peci_request;
+
+/* PECI CPU address range 0x30-0x37 */
+#define PECI_BASE_ADDR		0x30
+#define PECI_DEVICE_NUM_MAX		8
+
+struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len);
+void peci_request_free(struct peci_request *req);
+
+extern struct device_type peci_device_type;
+extern const struct attribute_group *peci_device_groups[];
+
+int peci_device_create(struct peci_controller *controller, u8 addr);
+void peci_device_destroy(struct peci_device *device);
 
 extern struct bus_type peci_bus_type;
 extern const struct attribute_group *peci_bus_groups[];
diff --git a/drivers/peci/request.c b/drivers/peci/request.c
new file mode 100644
index 000000000000..78cee51dfae1
--- /dev/null
+++ b/drivers/peci/request.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Intel Corporation
+
+#include <linux/export.h>
+#include <linux/peci.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "internal.h"
+
+/**
+ * peci_request_alloc() - allocate &struct peci_request with buffers with given lengths
+ * @device: PECI device to which request is going to be sent
+ * @tx_len: requested TX buffer length
+ * @rx_len: requested RX buffer length
+ *
+ * Return: A pointer to a newly allocated &struct peci_request on success or NULL otherwise.
+ */
+struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len)
+{
+	struct peci_request *req;
+	u8 *tx_buf, *rx_buf;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return NULL;
+
+	req->device = device;
+
+	/*
+	 * PECI controllers that we are using now don't support DMA, this
+	 * should be converted to DMA API once support for controllers that do
+	 * allow it is added to avoid an extra copy.
+	 */
+	if (tx_len) {
+		tx_buf = kzalloc(tx_len, GFP_KERNEL);
+		if (!tx_buf)
+			goto err_free_req;
+
+		req->tx.buf = tx_buf;
+		req->tx.len = tx_len;
+	}
+
+	if (rx_len) {
+		rx_buf = kzalloc(rx_len, GFP_KERNEL);
+		if (!rx_buf)
+			goto err_free_tx;
+
+		req->rx.buf = rx_buf;
+		req->rx.len = rx_len;
+	}
+
+	return req;
+
+err_free_tx:
+	kfree(req->tx.buf);
+err_free_req:
+	kfree(req);
+
+	return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_alloc, PECI);
+
+/**
+ * peci_request_free() - free peci_request
+ * @req: the PECI request to be freed
+ */
+void peci_request_free(struct peci_request *req)
+{
+	kfree(req->rx.buf);
+	kfree(req->tx.buf);
+	kfree(req);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_free, PECI);
diff --git a/drivers/peci/sysfs.c b/drivers/peci/sysfs.c
index 36c5e2a18a92..db9ef05776e3 100644
--- a/drivers/peci/sysfs.c
+++ b/drivers/peci/sysfs.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-only
 // Copyright (c) 2021 Intel Corporation
 
+#include <linux/device.h>
+#include <linux/kernel.h>
 #include <linux/peci.h>
 
 #include "internal.h"
@@ -46,3 +48,35 @@ const struct attribute_group *peci_bus_groups[] = {
 	&peci_bus_group,
 	NULL
 };
+
+static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct peci_device *device = to_peci_device(dev);
+	bool res;
+	int ret;
+
+	ret = kstrtobool(buf, &res);
+	if (ret)
+		return ret;
+
+	if (res && device_remove_file_self(dev, attr))
+		peci_device_destroy(device);
+
+	return count;
+}
+static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0200, NULL, remove_store);
+
+static struct attribute *peci_device_attrs[] = {
+	&dev_attr_remove.attr,
+	NULL
+};
+
+static const struct attribute_group peci_device_group = {
+	.attrs = peci_device_attrs,
+};
+
+const struct attribute_group *peci_device_groups[] = {
+	&peci_device_group,
+	NULL
+};
-- 
2.31.1


  parent reply	other threads:[~2021-07-12 22:10 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-12 22:04 [PATCH 00/14] Introduce PECI subsystem Iwona Winiarska
2021-07-12 22:04 ` [PATCH 01/14] x86/cpu: Move intel-family to arch-independent headers Iwona Winiarska
2021-07-14 16:54   ` Williams, Dan J
2021-07-15 16:47     ` Winiarska, Iwona
2021-07-15 18:13       ` Dan Williams
2021-07-15 18:29         ` Luck, Tony
2021-07-12 22:04 ` [PATCH 02/14] x86/cpu: Extract cpuid helpers to arch-independent Iwona Winiarska
2021-07-14 16:58   ` Williams, Dan J
2021-07-15 16:51     ` Winiarska, Iwona
2021-07-15 16:58       ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 03/14] dt-bindings: Add generic bindings for PECI Iwona Winiarska
2021-07-12 22:04 ` [PATCH 04/14] dt-bindings: Add bindings for peci-aspeed Iwona Winiarska
2021-07-15 16:28   ` Rob Herring
2021-07-16 21:22     ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 05/14] ARM: dts: aspeed: Add PECI controller nodes Iwona Winiarska
2021-07-12 22:04 ` [PATCH 06/14] peci: Add core infrastructure Iwona Winiarska
2021-07-14 17:19   ` Williams, Dan J
2021-07-16 21:08     ` Winiarska, Iwona
2021-07-16 21:50       ` Dan Williams
2021-07-17  6:12         ` gregkh
2021-07-17 20:54           ` Dan Williams
2021-07-12 22:04 ` [PATCH 07/14] peci: Add peci-aspeed controller driver Iwona Winiarska
2021-07-13  5:02   ` Randy Dunlap
2021-07-15 16:42     ` Winiarska, Iwona
2021-07-14 17:39   ` Williams, Dan J
2021-07-16 21:17     ` Winiarska, Iwona
2021-07-27  8:49   ` Zev Weiss
2021-07-29 14:03     ` Winiarska, Iwona
2021-07-29 18:15       ` Zev Weiss
2021-07-12 22:04 ` Iwona Winiarska [this message]
2021-07-14 21:05   ` [PATCH 08/14] peci: Add device detection Williams, Dan J
2021-07-16 21:20     ` Winiarska, Iwona
2021-07-27 17:49   ` Zev Weiss
2021-07-29 18:55     ` Winiarska, Iwona
2021-07-29 20:50       ` Zev Weiss
2021-07-30 20:10         ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 09/14] peci: Add support for PECI device drivers Iwona Winiarska
2021-07-27 20:10   ` Zev Weiss
2021-07-27 21:23     ` Guenter Roeck
2021-07-29 21:17     ` Winiarska, Iwona
2021-07-29 23:22       ` Zev Weiss
2021-07-30 20:13         ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 10/14] peci: Add peci-cpu driver Iwona Winiarska
2021-07-27 11:16   ` David Müller (ELSOFT AG)
2021-07-30 20:14     ` Winiarska, Iwona
2021-07-27 21:33   ` Zev Weiss
2021-07-30 21:21     ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 11/14] hwmon: peci: Add cputemp driver Iwona Winiarska
2021-07-15 17:45   ` Guenter Roeck
2021-07-19 20:12     ` Winiarska, Iwona
2021-07-19 20:35       ` Guenter Roeck
2021-07-27  7:06   ` Zev Weiss
2021-07-30 21:51     ` Winiarska, Iwona
2021-07-30 22:04       ` Guenter Roeck
2021-07-12 22:04 ` [PATCH 12/14] hwmon: peci: Add dimmtemp driver Iwona Winiarska
2021-07-15 17:56   ` Guenter Roeck
2021-07-19 20:31     ` Winiarska, Iwona
2021-07-19 20:36       ` Guenter Roeck
2021-07-26 22:08   ` Zev Weiss
2021-07-30 22:48     ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 13/14] docs: hwmon: Document PECI drivers Iwona Winiarska
2021-07-27 22:58   ` Zev Weiss
2021-07-28  0:49     ` Guenter Roeck
2021-08-02 11:39       ` Winiarska, Iwona
2021-08-02 11:37     ` Winiarska, Iwona
2021-08-04 17:52       ` Zev Weiss
2021-08-04 18:05         ` Guenter Roeck
2021-08-05 21:42           ` Winiarska, Iwona
2021-07-12 22:04 ` [PATCH 14/14] docs: Add PECI documentation Iwona Winiarska
2021-07-14 16:51 ` [PATCH 00/14] Introduce PECI subsystem Williams, Dan J
2021-07-15 17:33   ` Winiarska, Iwona
2021-07-15 19:34     ` Dan Williams

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