[PATCH v3 4/4] bus: fsl-mc: add bus rescan attribute

Ioana Ciornei
2018-11-20T15:39:59Z

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

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
---
Changes in v2:
- none
Changes in v3:
- none

Documentation/ABI/stable/sysfs-bus-fsl-mc | 10 ++++++++
drivers/bus/fsl-mc/dprc-driver.c | 4 +--
drivers/bus/fsl-mc/fsl-mc-bus.c | 41 +++++++++++++++++++++++++++++++
drivers/bus/fsl-mc/fsl-mc-private.h | 2 ++
4 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/Documentation/ABI/stable/sysfs-bus-fsl-mc b/Documentation/ABI/stable/sysfs-bus-fsl-mc
index 9f3a95e..e5c7f7f 100644
--- a/Documentation/ABI/stable/sysfs-bus-fsl-mc
+++ b/Documentation/ABI/stable/sysfs-bus-fsl-mc
@@ -7,3 +7,13 @@ Description: Writing a non-zero value to this attribute will
synchronize the objects under dprc.X and the
Management Complex firmware.
Users: Userspace drivers and management tools
+
+What: /sys/bus/fsl-mc/rescan
+Date: November 2018
+KernelVersion: 5.0
+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/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index 2f94aba..cac2dfc 100644
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -214,8 +214,8 @@ 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,
- unsigned int *total_irq_count)
+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+ unsigned int *total_irq_count)
{
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 f0404c6..ea8991d 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -154,12 +154,53 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,

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 07f00f8..ca71275 100644
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -543,6 +543,8 @@ int __must_check fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,

void dprc_driver_exit(void);

+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+ unsigned int *total_irq_count);
int __init fsl_mc_allocator_driver_init(void);

void fsl_mc_allocator_driver_exit(void);
--
1.9.1