[PATCH v7 01/14] dmaengine: idxd: add wq driver name support for accel-config user tool

Tom Zanussi
2023-07-10T19:07:07Z

From: Dave Jiang <dave.jiang@intel.com>

With the possibility of multiple wq drivers that can be bound to the wq,
the user config tool accel-config needs a way to know which wq driver to
bind to the wq. Introduce per wq driver_name sysfs attribute where the user
can indicate the driver to be bound to the wq. This allows accel-config to
just bind to the driver using wq->driver_name.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
.../ABI/stable/sysfs-driver-dma-idxd | 6 ++++
drivers/dma/idxd/cdev.c | 7 +++++
drivers/dma/idxd/dma.c | 6 ++++
drivers/dma/idxd/idxd.h | 9 ++++++
drivers/dma/idxd/sysfs.c | 28 +++++++++++++++++++
include/uapi/linux/idxd.h | 1 +
6 files changed, 57 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index 534b7a3d59fc..0e577209bee2 100644
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -270,6 +270,12 @@ Description: Shows the operation capability bits displayed in bitmap format
correlates to the operations allowed. It's visible only
on platforms that support the capability.

+What: /sys/bus/dsa/devices/wq<m>.<n>/driver_name
+Date: Mar 27, 2023
+KernelVersion: 6.6.0
+Contact: dmaengine@vger.kernel.org
+Description: Name of driver to be bounded to the wq.
+
What: /sys/bus/dsa/devices/engine<m>.<n>/group_id
Date: Oct 25, 2019
KernelVersion: 5.6.0
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index ecbf67c2ad2b..b1ecfb71d95e 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -510,6 +510,7 @@ void idxd_wq_del_cdev(struct idxd_wq *wq)

static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
{
+ struct device *dev = &idxd_dev->conf_dev;
struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
struct idxd_device *idxd = wq->idxd;
int rc;
@@ -537,6 +538,12 @@ static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)

mutex_lock(&wq->wq_lock);

+ if (!idxd_wq_driver_name_match(wq, dev)) {
+ idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
+ rc = -ENODEV;
+ goto wq_err;
+ }
+
wq->wq = create_workqueue(dev_name(wq_confdev(wq)));
if (!wq->wq) {
rc = -ENOMEM;
diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index eb35ca313684..8bb7e7ff8d6a 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -305,6 +305,12 @@ static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
return -ENXIO;

mutex_lock(&wq->wq_lock);
+ if (!idxd_wq_driver_name_match(wq, dev)) {
+ idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
+ rc = -ENODEV;
+ goto err;
+ }
+
wq->type = IDXD_WQT_KERNEL;

rc = drv_enable_wq(wq);
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 5428a2e1b1ec..c62c78e1c9fa 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -159,6 +159,8 @@ struct idxd_cdev {
int minor;
};

+#define DRIVER_NAME_SIZE 128
+
#define IDXD_ALLOCATED_BATCH_SIZE 128U
#define WQ_NAME_SIZE 1024
#define WQ_TYPE_SIZE 10
@@ -227,6 +229,8 @@ struct idxd_wq {
/* Lock to protect upasid_xa access. */
struct mutex uc_lock;
struct xarray upasid_xa;
+
+ char driver_name[DRIVER_NAME_SIZE + 1];
};

struct idxd_engine {
@@ -637,6 +641,11 @@ static inline void idxd_wqcfg_set_max_batch_shift(int idxd_type, union wqcfg *wq
wqcfg->max_batch_shift = max_batch_shift;
}

+static inline int idxd_wq_driver_name_match(struct idxd_wq *wq, struct device *dev)
+{
+ return (strncmp(wq->driver_name, dev->driver->name, strlen(dev->driver->name)) == 0);
+}
+
int __must_check __idxd_driver_register(struct idxd_device_driver *idxd_drv,
struct module *module, const char *mod_name);
#define idxd_driver_register(driver) \
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 293739ac5596..6caad044f506 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1266,6 +1266,33 @@ static ssize_t wq_op_config_store(struct device *dev, struct device_attribute *a
static struct device_attribute dev_attr_wq_op_config =
__ATTR(op_config, 0644, wq_op_config_show, wq_op_config_store);

+static ssize_t wq_driver_name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct idxd_wq *wq = confdev_to_wq(dev);
+
+ return sysfs_emit(buf, "%s\n", wq->driver_name);
+}
+
+static ssize_t wq_driver_name_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct idxd_wq *wq = confdev_to_wq(dev);
+
+ if (wq->state != IDXD_WQ_DISABLED)
+ return -EPERM;
+
+ if (strlen(buf) > DRIVER_NAME_SIZE || strlen(buf) == 0)
+ return -EINVAL;
+
+ memset(wq->driver_name, 0, DRIVER_NAME_SIZE + 1);
+ strncpy(wq->driver_name, buf, DRIVER_NAME_SIZE);
+ strreplace(wq->name, '\n', '\0');
+ return count;
+}
+
+static struct device_attribute dev_attr_wq_driver_name =
+ __ATTR(driver_name, 0644, wq_driver_name_show, wq_driver_name_store);
+
static struct attribute *idxd_wq_attributes[] = {
&dev_attr_wq_clients.attr,
&dev_attr_wq_state.attr,
@@ -1285,6 +1312,7 @@ static struct attribute *idxd_wq_attributes[] = {
&dev_attr_wq_occupancy.attr,
&dev_attr_wq_enqcmds_retries.attr,
&dev_attr_wq_op_config.attr,
+ &dev_attr_wq_driver_name.attr,
NULL,
};

diff --git a/include/uapi/linux/idxd.h b/include/uapi/linux/idxd.h
index 606b52e88ce3..3d1987e1bb2d 100644
--- a/include/uapi/linux/idxd.h
+++ b/include/uapi/linux/idxd.h
@@ -31,6 +31,7 @@ enum idxd_scmd_stat {
IDXD_SCMD_WQ_IRQ_ERR = 0x80100000,
IDXD_SCMD_WQ_USER_NO_IOMMU = 0x80110000,
IDXD_SCMD_DEV_EVL_ERR = 0x80120000,
+ IDXD_SCMD_WQ_NO_DRV_NAME = 0x80200000,
};

#define IDXD_SCMD_SOFTERR_MASK 0x80000000
--
2.34.1