bus: fsl-mc: add bus rescan attribute

Introduce the rescan attribute as a bus attribute to
synchronize the fsl-mc bus objects and the MC firmware.

To rescan the fsl-mc bus, e.g.,
echo 1 > /sys/bus/fsl-mc/rescan

Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20210114170752.2927915-5-ciorneiioana@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/ABI/stable/sysfs-bus-fsl-mc b/Documentation/ABI/stable/sysfs-bus-fsl-mc
new file mode 100644 (file)
index 0000000..a4d384d
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-fsl-mc
@@ -0,0 +1,9 @@
+What:          /sys/bus/fsl-mc/rescan
+Date:          January 2021
+KernelVersion: 5.12
+Contact:       Ioana Ciornei <ioana.ciornei@nxp.com>
+Description:   Writing a non-zero value to this attribute will
+               force a rescan of fsl-mc bus in the system and
+               synchronize the objects under fsl-mc bus and the
+               Management Complex firmware.
+Users:         Userspace drivers and management tools

diff --git a/MAINTAINERS b/MAINTAINERS
index 1284558..1d9d112 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14649,6 +14649,7 @@ M:      Stuart Yoder <stuyoder@gmail.com>
 M:     Laurentiu Tudor <laurentiu.tudor@nxp.com>
 L:     linux-kernel@vger.kernel.org
 S:     Maintained
+F:     Documentation/ABI/stable/sysfs-bus-fsl-mc
 F:     Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
 F:     Documentation/networking/device_drivers/ethernet/freescale/dpaa2/overview.rst
 F:     drivers/bus/fsl-mc/

diff --git a/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index ccec375..4adb6f3 100644 (file)
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -237,8 +237,8 @@ static void dprc_add_new_devices(struct fsl_mc_device *mc_bus_dev,
  * populated before they can get allocation requests from probe callbacks
  * of the device drivers for the non-allocatable devices.
  */
-static int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
-                           bool alloc_interrupts)
+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+                     bool alloc_interrupts)
 {
        int num_child_objects;
        int dprc_get_obj_failures;

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 5a8fc68..ee3e625 100644 (file)
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -208,12 +208,53 @@ static struct attribute *fsl_mc_dev_attrs[] = {
 
 ATTRIBUTE_GROUPS(fsl_mc_dev);
 
+static int scan_fsl_mc_bus(struct device *dev, void *data)
+{
+       struct fsl_mc_device *root_mc_dev;
+       struct fsl_mc_bus *root_mc_bus;
+
+       if (!fsl_mc_is_root_dprc(dev))
+               goto exit;
+
+       root_mc_dev = to_fsl_mc_device(dev);
+       root_mc_bus = to_fsl_mc_bus(root_mc_dev);
+       mutex_lock(&root_mc_bus->scan_mutex);
+       dprc_scan_objects(root_mc_dev, NULL);
+       mutex_unlock(&root_mc_bus->scan_mutex);
+
+exit:
+       return 0;
+}
+
+static ssize_t rescan_store(struct bus_type *bus,
+                           const char *buf, size_t count)
+{
+       unsigned long val;
+
+       if (kstrtoul(buf, 0, &val) < 0)
+               return -EINVAL;
+
+       if (val)
+               bus_for_each_dev(bus, NULL, NULL, scan_fsl_mc_bus);
+
+       return count;
+}
+static BUS_ATTR_WO(rescan);
+
+static struct attribute *fsl_mc_bus_attrs[] = {
+       &bus_attr_rescan.attr,
+       NULL,
+};
+
+ATTRIBUTE_GROUPS(fsl_mc_bus);
+
 struct bus_type fsl_mc_bus_type = {
        .name = "fsl-mc",
        .match = fsl_mc_bus_match,
        .uevent = fsl_mc_bus_uevent,
        .dma_configure  = fsl_mc_dma_configure,
        .dev_groups = fsl_mc_dev_groups,
+       .bus_groups = fsl_mc_bus_groups,
 };
 EXPORT_SYMBOL_GPL(fsl_mc_bus_type);
 

diff --git a/drivers/bus/fsl-mc/fsl-mc-private.h b/drivers/bus/fsl-mc/fsl-mc-private.h
index 6293a24..42bdb86 100644 (file)
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -594,6 +594,9 @@ int __init dprc_driver_init(void);
 
 void dprc_driver_exit(void);
 
+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+                     bool alloc_interrupts);
+
 int __init fsl_mc_allocator_driver_init(void);
 
 void fsl_mc_allocator_driver_exit(void);