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authorIwona Winiarska <iwona.winiarska@intel.com>2022-02-08 18:36:33 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-02-09 10:04:44 +0300
commit42bed52b2e9cda0d5e2de50f10478c0bcedcdb95 (patch)
tree760f1e4540b51352365516cbba1909a44885c73b /drivers/peci/sysfs.c
parent52857e6828e260b16ac569578705f83cf2a71ac1 (diff)
downloadlinux-42bed52b2e9cda0d5e2de50f10478c0bcedcdb95.tar.xz
peci: Add sysfs interface for PECI bus
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. Acked-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com> Link: https://lore.kernel.org/r/20220208153639.255278-8-iwona.winiarska@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/peci/sysfs.c')
-rw-r--r--drivers/peci/sysfs.c82
1 files changed, 82 insertions, 0 deletions
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
+};