Commit 92de5fa2 authored by Dave Jiang's avatar Dave Jiang Committed by Vinod Koul
Browse files

dmaengine: idxd: add ATS disable knob for work queues 



With the DSA spec 1.1 update, a knob to disable ATS for individually is
introduced. Add enabling code to allow a system admin to make the
configuration through sysfs.

Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/160530810593.1288392.2561048329116529566.stgit@djiang5-desk3.ch.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 5d051f37

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

+7 −0
Original line number Diff line number Diff line
@@ -204,6 +204,13 @@ 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/wq<m>.<n>/ats_disable

Date:		Nov 13, 2020

KernelVersion:	5.11.0

Contact:	dmaengine@vger.kernel.org

Description:	Indicate whether ATS disable is turned on for the workqueue.

		0 indicates ATS is on, and 1 indicates ATS is off for the workqueue.



What:           /sys/bus/dsa/devices/engine<m>.<n>/group_id

Date:           Oct 25, 2019

KernelVersion:  5.6.0

drivers/dma/idxd/device.c

+4 −0
Original line number Diff line number Diff line
@@ -354,6 +354,7 @@ void idxd_wq_disable_cleanup(struct idxd_wq *wq) 
	wq->group = NULL;

	wq->threshold = 0;

	wq->priority = 0;

	wq->ats_dis = 0;

	clear_bit(WQ_FLAG_DEDICATED, &wq->flags);

	memset(wq->name, 0, WQ_NAME_SIZE);
@@ -631,6 +632,9 @@ static int idxd_wq_config_write(struct idxd_wq *wq) 
	    test_bit(WQ_FLAG_BLOCK_ON_FAULT, &wq->flags))

		wq->wqcfg->bof = 1;



	if (idxd->hw.wq_cap.wq_ats_support)

		wq->wqcfg->wq_ats_disable = wq->ats_dis;



	/* bytes 12-15 */

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

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

drivers/dma/idxd/idxd.h

+1 −0
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ struct idxd_wq { 
	char name[WQ_NAME_SIZE + 1];

	u64 max_xfer_bytes;

	u32 max_batch_size;

	bool ats_dis;

};



struct idxd_engine {

drivers/dma/idxd/registers.h

+3 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ union wq_cap_reg { 
		u64 rsvd:20;

		u64 shared_mode:1;

		u64 dedicated_mode:1;

		u64 rsvd2:1;

		u64 wq_ats_support:1;

		u64 priority:1;

		u64 occupancy:1;

		u64 occupancy_int:1;
@@ -303,7 +303,8 @@ union wqcfg { 
		/* bytes 8-11 */

		u32 mode:1;	/* shared or dedicated */

		u32 bof:1;	/* block on fault */

		u32 rsvd2:2;

		u32 wq_ats_disable:1;

		u32 rsvd2:1;

		u32 priority:4;

		u32 pasid:20;

		u32 pasid_en:1;

drivers/dma/idxd/sysfs.c

+34 −0
Original line number Diff line number Diff line
@@ -1261,6 +1261,39 @@ static ssize_t wq_max_batch_size_store(struct device *dev, struct device_attribu 
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 ssize_t wq_ats_disable_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->ats_dis);

}



static ssize_t wq_ats_disable_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;

	bool ats_dis;

	int rc;



	if (wq->state != IDXD_WQ_DISABLED)

		return -EPERM;



	if (!idxd->hw.wq_cap.wq_ats_support)

		return -EOPNOTSUPP;



	rc = kstrtobool(buf, &ats_dis);

	if (rc < 0)

		return rc;



	wq->ats_dis = ats_dis;



	return count;

}



static struct device_attribute dev_attr_wq_ats_disable =

		__ATTR(ats_disable, 0644, wq_ats_disable_show, wq_ats_disable_store);



static struct attribute *idxd_wq_attributes[] = {

	&dev_attr_wq_clients.attr,

	&dev_attr_wq_state.attr,
@@ -1275,6 +1308,7 @@ static struct attribute *idxd_wq_attributes[] = { 
	&dev_attr_wq_cdev_minor.attr,

	&dev_attr_wq_max_transfer_size.attr,

	&dev_attr_wq_max_batch_size.attr,

	&dev_attr_wq_ats_disable.attr,

	NULL,

};