Commit d7aad555 authored by Dave Jiang's avatar Dave Jiang Committed by Vinod Koul
Browse files

dmaengine: idxd: add support for configurable max wq xfer size 



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: default avatarDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159865265404.29141.3049399618578194052.stgit@djiang5-desk3.ch.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent b0ef489e

Documentation/ABI/stable/sysfs-driver-dma-idxd

+7 −0
Original line number Diff line number Diff line
@@ -170,6 +170,13 @@ Contact: dmaengine@vger.kernel.org 
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@vger.kernel.org

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

drivers/dma/idxd/device.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/dma/idxd/idxd.h

+1 −0
Original line number Diff line number Diff line
@@ -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 {

drivers/dma/idxd/init.c

+1 −0
Original line number Diff line number Diff line
@@ -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++) {

drivers/dma/idxd/sysfs.c

+40 −0
Original line number Diff line number Diff line
@@ -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,

};