Add sysfs attribute max_xfer_size to wq in order to allow the max xfer
size configured on a per wq basis. Add support code to configure
the valid user input on wq enable. This is a performance tuning
parameter.
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
v2:
- Added ABI documentation (Vinod)
Documentation/ABI/stable/sysfs-driver-dma-idxd | 7 ++++
drivers/dma/idxd/device.c | 2 +
drivers/dma/idxd/idxd.h | 1 +
drivers/dma/idxd/init.c | 1 +
drivers/dma/idxd/sysfs.c | 40 ++++++++++++++++++++++++
5 files changed, 50 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index 1af9c4175213..452f353b4748 100644
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -170,6 +170,13 @@ Contact: dmaengine@xxxxxxxxxxxxxxx
Description: The number of entries in this work queue that may be filled
via a limited portal.
+What: /sys/bus/dsa/devices/wq<m>.<n>/max_transfer_size
+Date: Aug 28, 2020
+KernelVersion: 5.10.0
+Contact: dmaengine@xxxxxxxxxxxxxxx
+Description: The max transfer sized for this workqueue. Cannot exceed device
+ max transfer size. Configurable parameter.
+
What: /sys/bus/dsa/devices/engine<m>.<n>/group_id
Date: Oct 25, 2019
KernelVersion: 5.6.0
diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 14b45853aa5f..b8dbb7001933 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -529,7 +529,7 @@ static int idxd_wq_config_write(struct idxd_wq *wq)
wq->wqcfg.priority = wq->priority;
/* bytes 12-15 */
- wq->wqcfg.max_xfer_shift = idxd->hw.gen_cap.max_xfer_shift;
+ wq->wqcfg.max_xfer_shift = ilog2(wq->max_xfer_bytes);
wq->wqcfg.max_batch_shift = idxd->hw.gen_cap.max_batch_shift;
dev_dbg(dev, "WQ %d CFGs\n", wq->id);
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index e62b4799d189..81db2a472822 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -114,6 +114,7 @@ struct idxd_wq {
struct sbitmap_queue sbq;
struct dma_chan dma_chan;
char name[WQ_NAME_SIZE + 1];
+ u64 max_xfer_bytes;
};
struct idxd_engine {
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index c7c61974f20f..e5ed5750a6d0 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -176,6 +176,7 @@ static int idxd_setup_internals(struct idxd_device *idxd)
wq->idxd = idxd;
mutex_init(&wq->wq_lock);
wq->idxd_cdev.minor = -1;
+ wq->max_xfer_bytes = idxd->max_xfer_bytes;
}
for (i = 0; i < idxd->max_engines; i++) {
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index dcba60953217..a3bac7285975 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1064,6 +1064,45 @@ static ssize_t wq_cdev_minor_show(struct device *dev,
static struct device_attribute dev_attr_wq_cdev_minor =
__ATTR(cdev_minor, 0444, wq_cdev_minor_show, NULL);
+static ssize_t wq_max_transfer_size_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct idxd_wq *wq = container_of(dev, struct idxd_wq, conf_dev);
+
+ return sprintf(buf, "%llu\n", wq->max_xfer_bytes);
+}
+
+static ssize_t wq_max_transfer_size_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct idxd_wq *wq = container_of(dev, struct idxd_wq, conf_dev);
+ struct idxd_device *idxd = wq->idxd;
+ u64 xfer_size;
+ int rc;
+
+ if (wq->state != IDXD_WQ_DISABLED)
+ return -EPERM;
+
+ rc = kstrtou64(buf, 0, &xfer_size);
+ if (rc < 0)
+ return -EINVAL;
+
+ if (xfer_size == 0)
+ return -EINVAL;
+
+ xfer_size = roundup_pow_of_two(xfer_size);
+ if (xfer_size > idxd->max_xfer_bytes)
+ return -EINVAL;
+
+ wq->max_xfer_bytes = xfer_size;
+
+ return count;
+}
+
+static struct device_attribute dev_attr_wq_max_transfer_size =
+ __ATTR(max_transfer_size, 0644,
+ wq_max_transfer_size_show, wq_max_transfer_size_store);
+
static struct attribute *idxd_wq_attributes[] = {
&dev_attr_wq_clients.attr,
&dev_attr_wq_state.attr,
@@ -1074,6 +1113,7 @@ static struct attribute *idxd_wq_attributes[] = {
&dev_attr_wq_type.attr,
&dev_attr_wq_name.attr,
&dev_attr_wq_cdev_minor.attr,
+ &dev_attr_wq_max_transfer_size.attr,
NULL,
};
