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Message-ID: <20231013060850.424929-4-abhijit.gangurde@amd.com>
Date: Fri, 13 Oct 2023 11:38:47 +0530
From: Abhijit Gangurde <abhijit.gangurde@....com>
To: <gregkh@...uxfoundation.org>, <masahiroy@...nel.org>,
<linux-kernel@...r.kernel.org>
CC: <Nipun.Gupta@....com>, <nikhil.agarwal@....com>,
<puneet.gupta@....com>, <git@....com>, <michal.simek@....com>,
Abhijit Gangurde <abhijit.gangurde@....com>
Subject: [PATCH v6 3/6] cdx: Register cdx bus as a device on cdx subsystem
While scanning for CDX devices, register newly discovered bus as a
cdx device. CDX device attributes are visible based on device type.
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@....com>
---
Changes in v6:
- New patch in the series
- Register cdx bus as a device on cdx subsystem
drivers/cdx/cdx.c | 77 +++++++++++++++++++++++--
drivers/cdx/cdx.h | 14 ++++-
drivers/cdx/controller/cdx_controller.c | 7 +++
include/linux/cdx/cdx_bus.h | 2 +
4 files changed, 93 insertions(+), 7 deletions(-)
diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
index 75760388f5e7..18da06e0babe 100644
--- a/drivers/cdx/cdx.c
+++ b/drivers/cdx/cdx.c
@@ -125,8 +125,13 @@ static int cdx_unregister_device(struct device *dev,
{
struct cdx_device *cdx_dev = to_cdx_device(dev);
- kfree(cdx_dev->driver_override);
- cdx_dev->driver_override = NULL;
+ if (cdx_dev->is_bus) {
+ device_for_each_child(dev, NULL, cdx_unregister_device);
+ } else {
+ kfree(cdx_dev->driver_override);
+ cdx_dev->driver_override = NULL;
+ }
+
/*
* Do not free cdx_dev here as it would be freed in
* cdx_device_release() called from within put_device().
@@ -201,6 +206,9 @@ static int cdx_bus_match(struct device *dev, struct device_driver *drv)
const struct cdx_device_id *found_id = NULL;
const struct cdx_device_id *ids;
+ if (cdx_dev->is_bus)
+ return false;
+
ids = cdx_drv->match_id_table;
/* When driver_override is set, only bind to the matching driver */
@@ -265,10 +273,11 @@ static int cdx_dma_configure(struct device *dev)
{
struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
struct cdx_device *cdx_dev = to_cdx_device(dev);
+ struct cdx_controller *cdx = cdx_dev->cdx;
u32 input_id = cdx_dev->req_id;
int ret;
- ret = of_dma_configure_id(dev, dev->parent->of_node, 0, &input_id);
+ ret = of_dma_configure_id(dev, cdx->dev->of_node, 0, &input_id);
if (ret && ret != -EPROBE_DEFER) {
dev_err(dev, "of_dma_configure_id() failed\n");
return ret;
@@ -374,6 +383,18 @@ static ssize_t driver_override_show(struct device *dev,
}
static DEVICE_ATTR_RW(driver_override);
+static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct cdx_device *cdx_dev;
+
+ cdx_dev = to_cdx_device(dev);
+ if (!cdx_dev->is_bus)
+ return a->mode;
+
+ return 0;
+}
+
static struct attribute *cdx_dev_attrs[] = {
&dev_attr_remove.attr,
&dev_attr_reset.attr,
@@ -382,7 +403,16 @@ static struct attribute *cdx_dev_attrs[] = {
&dev_attr_driver_override.attr,
NULL,
};
-ATTRIBUTE_GROUPS(cdx_dev);
+
+static const struct attribute_group cdx_dev_group = {
+ .attrs = cdx_dev_attrs,
+ .is_visible = cdx_dev_attrs_are_visible,
+};
+
+static const struct attribute_group *cdx_dev_groups[] = {
+ &cdx_dev_group,
+ NULL,
+};
static ssize_t rescan_store(const struct bus_type *bus,
const char *buf, size_t count)
@@ -479,7 +509,6 @@ static void cdx_device_release(struct device *dev)
int cdx_device_add(struct cdx_dev_params *dev_params)
{
struct cdx_controller *cdx = dev_params->cdx;
- struct device *parent = cdx->dev;
struct cdx_device *cdx_dev;
int ret;
@@ -503,7 +532,7 @@ int cdx_device_add(struct cdx_dev_params *dev_params)
/* Initialize generic device */
device_initialize(&cdx_dev->dev);
- cdx_dev->dev.parent = parent;
+ cdx_dev->dev.parent = dev_params->parent;
cdx_dev->dev.bus = &cdx_bus_type;
cdx_dev->dev.dma_mask = &cdx_dev->dma_mask;
cdx_dev->dev.release = cdx_device_release;
@@ -532,6 +561,42 @@ int cdx_device_add(struct cdx_dev_params *dev_params)
}
EXPORT_SYMBOL_GPL(cdx_device_add);
+struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num)
+{
+ struct cdx_device *cdx_dev;
+ int ret;
+
+ cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
+ if (!cdx_dev)
+ return NULL;
+
+ device_initialize(&cdx_dev->dev);
+ cdx_dev->cdx = cdx;
+
+ cdx_dev->dev.parent = cdx->dev;
+ cdx_dev->dev.bus = &cdx_bus_type;
+ cdx_dev->dev.release = cdx_device_release;
+ cdx_dev->is_bus = true;
+ cdx_dev->bus_num = bus_num;
+
+ dev_set_name(&cdx_dev->dev, "cdx-%02x",
+ ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (bus_num & CDX_BUS_NUM_MASK)));
+
+ ret = device_add(&cdx_dev->dev);
+ if (ret) {
+ dev_err(&cdx_dev->dev, "cdx bus device add failed: %d\n", ret);
+ goto device_add_fail;
+ }
+
+ return &cdx_dev->dev;
+
+device_add_fail:
+ put_device(&cdx_dev->dev);
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(cdx_bus_add);
+
int cdx_register_controller(struct cdx_controller *cdx)
{
int ret;
diff --git a/drivers/cdx/cdx.h b/drivers/cdx/cdx.h
index c436ac7ac86f..1f593deb4c9e 100644
--- a/drivers/cdx/cdx.h
+++ b/drivers/cdx/cdx.h
@@ -13,7 +13,7 @@
/**
* struct cdx_dev_params - CDX device parameters
* @cdx: CDX controller associated with the device
- * @parent: Associated CDX controller
+ * @parent: Associated CDX Bus device
* @vendor: Vendor ID for CDX device
* @device: Device ID for CDX device
* @bus_num: Bus number for this CDX device
@@ -24,6 +24,7 @@
*/
struct cdx_dev_params {
struct cdx_controller *cdx;
+ struct device *parent;
u16 vendor;
u16 device;
u8 bus_num;
@@ -59,4 +60,15 @@ void cdx_unregister_controller(struct cdx_controller *cdx);
*/
int cdx_device_add(struct cdx_dev_params *dev_params);
+/**
+ * cdx_bus_add - Add a CDX bus. This function adds a bus on the CDX bus
+ * subsystem. It creates a CDX device for the corresponding bus and
+ * also registers an associated Linux generic device.
+ * @cdx: Associated CDX controller
+ * @us_num: Bus number
+ *
+ * Return: associated Linux generic device pointer on success or NULL on failure.
+ */
+struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num);
+
#endif /* _CDX_H_ */
diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c
index bb4ae7970e21..d1d4606f6c1a 100644
--- a/drivers/cdx/controller/cdx_controller.c
+++ b/drivers/cdx/controller/cdx_controller.c
@@ -79,8 +79,14 @@ static int cdx_scan_devices(struct cdx_controller *cdx)
num_cdx_bus = (u8)ret;
for (bus_num = 0; bus_num < num_cdx_bus; bus_num++) {
+ struct device *bus_dev;
u8 num_cdx_dev;
+ /* Add the bus on cdx subsystem */
+ bus_dev = cdx_bus_add(cdx, bus_num);
+ if (!bus_dev)
+ continue;
+
/* MCDI FW Read: Fetch the number of devices present */
ret = cdx_mcdi_get_num_devs(cdx_mcdi, bus_num);
if (ret < 0) {
@@ -103,6 +109,7 @@ static int cdx_scan_devices(struct cdx_controller *cdx)
continue;
}
dev_params.cdx = cdx;
+ dev_params.parent = bus_dev;
/* Add the device to the cdx bus */
ret = cdx_device_add(&dev_params);
diff --git a/include/linux/cdx/cdx_bus.h b/include/linux/cdx/cdx_bus.h
index 82c27b8c94e1..b5e4b7e05666 100644
--- a/include/linux/cdx/cdx_bus.h
+++ b/include/linux/cdx/cdx_bus.h
@@ -88,6 +88,7 @@ struct cdx_controller {
* @dma_mask: Default DMA mask
* @flags: CDX device flags
* @req_id: Requestor ID associated with CDX device
+ * @is_bus: Is this bus device
* @driver_override: driver name to force a match; do not set directly,
* because core frees it; use driver_set_override() to
* set or clear it.
@@ -104,6 +105,7 @@ struct cdx_device {
u64 dma_mask;
u16 flags;
u32 req_id;
+ bool is_bus;
const char *driver_override;
};
--
2.34.1
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