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From: Iwona Winiarska <iwona.winiarska@intel.com>
To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.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,
	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>, Arnd Bergmann <arnd@arndb.de>,
	Olof Johansson <olof@lixom.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>,
	Dan Williams <dan.j.williams@intel.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Zev Weiss <zweiss@equinix.com>,
	David Muller <d.mueller@elsoft.ch>,
	Iwona Winiarska <iwona.winiarska@intel.com>
Subject: [PATCH v2 09/15] peci: Add sysfs interface for PECI bus
Date: Tue,  3 Aug 2021 13:31:28 +0200	[thread overview]
Message-ID: <20210803113134.2262882-10-iwona.winiarska@intel.com> (raw)
In-Reply-To: <20210803113134.2262882-1-iwona.winiarska@intel.com>

PECI devices may not be discoverable at the time when PECI controller is
being added (e.g. BMC can boot up when the Host system is still in S5).
Since we currently don't have the capabilities to figure out the Host
system state inside the PECI subsystem itself, we have to rely on
userspace to do it for us.

In the future, PECI subsystem may be expanded with mechanisms that allow
us to avoid depending on userspace interaction (e.g. CPU presence could
be detected using GPIO, and the information on whether it's discoverable
could be obtained over IPMI).
Unfortunately, those methods may ultimately not be available (support
will vary from platform to platform), which means that we still need
platform independent method triggered by userspace.

Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
---
 Documentation/ABI/testing/sysfs-bus-peci | 16 +++++
 drivers/peci/Makefile                    |  2 +-
 drivers/peci/core.c                      |  3 +-
 drivers/peci/device.c                    |  1 +
 drivers/peci/internal.h                  |  5 ++
 drivers/peci/sysfs.c                     | 82 ++++++++++++++++++++++++
 6 files changed, 107 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-peci
 create mode 100644 drivers/peci/sysfs.c

diff --git a/Documentation/ABI/testing/sysfs-bus-peci b/Documentation/ABI/testing/sysfs-bus-peci
new file mode 100644
index 000000000000..56c2b2216bbd
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-peci
@@ -0,0 +1,16 @@
+What:		/sys/bus/peci/rescan
+Date:		July 2021
+KernelVersion:	5.15
+Contact:	Iwona Winiarska <iwona.winiarska@intel.com>
+Description:
+		Writing a non-zero value to this attribute will
+		initiate scan for PECI devices on all PECI controllers
+		in the system.
+
+What:		/sys/bus/peci/devices/<controller_id>-<device_addr>/remove
+Date:		July 2021
+KernelVersion:	5.15
+Contact:	Iwona Winiarska <iwona.winiarska@intel.com>
+Description:
+		Writing a non-zero value to this attribute will
+		remove the PECI device and any of its children.
diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile
index c5f9d3fe21bb..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 request.o device.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 d143f1a7fe98..c473acb3c2a0 100644
--- a/drivers/peci/core.c
+++ b/drivers/peci/core.c
@@ -34,7 +34,7 @@ struct device_type peci_controller_type = {
 	.release	= peci_controller_dev_release,
 };
 
-static int peci_controller_scan_devices(struct peci_controller *controller)
+int peci_controller_scan_devices(struct peci_controller *controller)
 {
 	int ret;
 	u8 addr;
@@ -159,6 +159,7 @@ EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, PECI);
 
 struct bus_type peci_bus_type = {
 	.name		= "peci",
+	.bus_groups	= peci_bus_groups,
 };
 
 static int __init peci_init(void)
diff --git a/drivers/peci/device.c b/drivers/peci/device.c
index 32811248997b..d77d9dabd51e 100644
--- a/drivers/peci/device.c
+++ b/drivers/peci/device.c
@@ -110,5 +110,6 @@ static void peci_device_release(struct device *dev)
 }
 
 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 57d11a902c5d..978e12c8e1d3 100644
--- a/drivers/peci/internal.h
+++ b/drivers/peci/internal.h
@@ -8,6 +8,7 @@
 #include <linux/types.h>
 
 struct peci_controller;
+struct attribute_group;
 struct peci_device;
 struct peci_request;
 
@@ -19,12 +20,16 @@ struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u
 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[];
 
 extern struct device_type peci_controller_type;
 
+int peci_controller_scan_devices(struct peci_controller *controller);
+
 #endif /* __PECI_INTERNAL_H */
diff --git a/drivers/peci/sysfs.c b/drivers/peci/sysfs.c
new file mode 100644
index 000000000000..db9ef05776e3
--- /dev/null
+++ b/drivers/peci/sysfs.c
@@ -0,0 +1,82 @@
+// 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"
+
+static int rescan_controller(struct device *dev, void *data)
+{
+	if (dev->type != &peci_controller_type)
+		return 0;
+
+	return peci_controller_scan_devices(to_peci_controller(dev));
+}
+
+static ssize_t rescan_store(struct bus_type *bus, const char *buf, size_t count)
+{
+	bool res;
+	int ret;
+
+	ret = kstrtobool(buf, &res);
+	if (ret)
+		return ret;
+
+	if (!res)
+		return count;
+
+	ret = bus_for_each_dev(&peci_bus_type, NULL, NULL, rescan_controller);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static BUS_ATTR_WO(rescan);
+
+static struct attribute *peci_bus_attrs[] = {
+	&bus_attr_rescan.attr,
+	NULL
+};
+
+static const struct attribute_group peci_bus_group = {
+	.attrs = peci_bus_attrs,
+};
+
+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:[~2021-08-03 11:35 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-03 11:31 [PATCH v2 00/15] Introduce PECI subsystem Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 01/15] x86/cpu: Move intel-family to arch-independent headers Iwona Winiarska
2021-10-04 19:03   ` Borislav Petkov
2021-10-11 19:21     ` Winiarska, Iwona
2021-10-11 19:40       ` Dave Hansen
2021-10-11 20:53         ` Winiarska, Iwona
2021-10-11 23:12           ` Dave Hansen
2021-10-11 20:06       ` Borislav Petkov
2021-10-11 20:38         ` Winiarska, Iwona
2021-10-11 21:31           ` Borislav Petkov
2021-10-12 23:15             ` Winiarska, Iwona
2021-10-13  6:42               ` Borislav Petkov
2021-08-03 11:31 ` [PATCH v2 02/15] x86/cpu: Extract cpuid helpers to arch-independent Iwona Winiarska
2021-10-04 19:08   ` Borislav Petkov
2021-10-11 19:32     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 03/15] dt-bindings: Add generic bindings for PECI Iwona Winiarska
2021-08-11 18:11   ` Rob Herring
2021-08-03 11:31 ` [PATCH v2 04/15] dt-bindings: Add bindings for peci-aspeed Iwona Winiarska
2021-08-11 18:11   ` Rob Herring
2021-08-03 11:31 ` [PATCH v2 05/15] ARM: dts: aspeed: Add PECI controller nodes Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 06/15] peci: Add core infrastructure Iwona Winiarska
2021-08-25 22:58   ` Dan Williams
2021-08-26 22:40     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 07/15] peci: Add peci-aspeed controller driver Iwona Winiarska
2021-08-26  1:35   ` Dan Williams
2021-08-26 23:54     ` Winiarska, Iwona
2021-08-27 16:24       ` Dan Williams
2021-08-29 19:42         ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 08/15] peci: Add device detection Iwona Winiarska
2021-08-27 19:01   ` Dan Williams
2021-11-15 22:18     ` Winiarska, Iwona
2021-08-03 11:31 ` Iwona Winiarska [this message]
2021-08-27 19:11   ` [PATCH v2 09/15] peci: Add sysfs interface for PECI bus Dan Williams
2021-11-15 22:19     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 10/15] peci: Add support for PECI device drivers Iwona Winiarska
2021-08-27 21:19   ` Dan Williams
2021-11-15 22:20     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 11/15] peci: Add peci-cpu driver Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 12/15] hwmon: peci: Add cputemp driver Iwona Winiarska
2021-08-03 15:24   ` Guenter Roeck
2021-08-04 10:43     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 13/15] hwmon: peci: Add dimmtemp driver Iwona Winiarska
2021-08-03 15:39   ` Guenter Roeck
2021-08-04 10:46     ` Winiarska, Iwona
2021-08-04 17:33       ` Guenter Roeck
2021-08-05 21:48         ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 14/15] docs: hwmon: Document PECI drivers Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 15/15] docs: Add PECI documentation Iwona Winiarska
2021-08-05 12:17 ` [PATCH v2 00/15] Introduce PECI subsystem Greg Kroah-Hartman

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