Commit e7184b15 authored by Dave Jiang's avatar Dave Jiang Committed by Vinod Koul
Browse files

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



Add sysfs attribute max_batch_size to wq in order to allow the max batch
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/159865273617.29141.4383066301730821749.stgit@djiang5-desk3.ch.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent d7aad555

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

+7 −0
Original line number Diff line number Diff line
@@ -177,6 +177,13 @@ 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/wq<m>.<n>/max_batch_size

Date:		Aug 28, 2020

KernelVersion:	5.10.0

Contact:	dmaengine@vger.kernel.org

Description:	The max batch size for this workqueue. Cannot exceed device

		max batch 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
@@ -530,7 +530,7 @@ static int idxd_wq_config_write(struct idxd_wq *wq) 


	/* bytes 12-15 */

	wq->wqcfg.max_xfer_shift = ilog2(wq->max_xfer_bytes);

	wq->wqcfg.max_batch_shift = idxd->hw.gen_cap.max_batch_shift;

	wq->wqcfg.max_batch_shift = ilog2(wq->max_batch_size);



	dev_dbg(dev, "WQ %d CFGs\n", wq->id);

	for (i = 0; i < 8; i++) {

drivers/dma/idxd/idxd.h

+1 −0
Original line number Diff line number Diff line
@@ -115,6 +115,7 @@ struct idxd_wq { 
	struct dma_chan dma_chan;

	char name[WQ_NAME_SIZE + 1];

	u64 max_xfer_bytes;

	u32 max_batch_size;

};



struct idxd_engine {

drivers/dma/idxd/init.c

+1 −0
Original line number Diff line number Diff line
@@ -177,6 +177,7 @@ static int idxd_setup_internals(struct idxd_device *idxd) 
		mutex_init(&wq->wq_lock);

		wq->idxd_cdev.minor = -1;

		wq->max_xfer_bytes = idxd->max_xfer_bytes;

		wq->max_batch_size = idxd->max_batch_size;

	}



	for (i = 0; i < idxd->max_engines; i++) {

drivers/dma/idxd/sysfs.c

+51 −6
Original line number Diff line number Diff line
@@ -1064,6 +1064,21 @@ 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 int __get_sysfs_u64(const char *buf, u64 *val)

{

	int rc;



	rc = kstrtou64(buf, 0, val);

	if (rc < 0)

		return -EINVAL;



	if (*val == 0)

		return -EINVAL;



	*val = roundup_pow_of_two(*val);

	return 0;

}



static ssize_t wq_max_transfer_size_show(struct device *dev, struct device_attribute *attr,

					 char *buf)

{
@@ -1083,14 +1098,10 @@ static ssize_t wq_max_transfer_size_store(struct device *dev, struct device_attr 
	if (wq->state != IDXD_WQ_DISABLED)

		return -EPERM;



	rc = kstrtou64(buf, 0, &xfer_size);

	rc = __get_sysfs_u64(buf, &xfer_size);

	if (rc < 0)

		return -EINVAL;



	if (xfer_size == 0)

		return -EINVAL;

		return rc;



	xfer_size = roundup_pow_of_two(xfer_size);

	if (xfer_size > idxd->max_xfer_bytes)

		return -EINVAL;
@@ -1103,6 +1114,39 @@ 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 ssize_t wq_max_batch_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, "%u\n", wq->max_batch_size);

}



static ssize_t wq_max_batch_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 batch_size;

	int rc;



	if (wq->state != IDXD_WQ_DISABLED)

		return -EPERM;



	rc = __get_sysfs_u64(buf, &batch_size);

	if (rc < 0)

		return rc;



	if (batch_size > idxd->max_batch_size)

		return -EINVAL;



	wq->max_batch_size = (u32)batch_size;



	return count;

}



static struct device_attribute dev_attr_wq_max_batch_size =

		__ATTR(max_batch_size, 0644, wq_max_batch_size_show, wq_max_batch_size_store);



static struct attribute *idxd_wq_attributes[] = {

	&dev_attr_wq_clients.attr,

	&dev_attr_wq_state.attr,
@@ -1114,6 +1158,7 @@ static struct attribute *idxd_wq_attributes[] = { 
	&dev_attr_wq_name.attr,

	&dev_attr_wq_cdev_minor.attr,

	&dev_attr_wq_max_transfer_size.attr,

	&dev_attr_wq_max_batch_size.attr,

	NULL,

};

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