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

diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index 5ea81ff..55285c1 100644 (file)
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -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

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index d6f551d..b75f9a0 100644 (file)
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -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);

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 7e54209..149934f 100644 (file)
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -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 {

diff --git a/drivers/dma/idxd/registers.h b/drivers/dma/idxd/registers.h
index d29a58e..0cdc540 100644 (file)
--- a/drivers/dma/idxd/registers.h
+++ b/drivers/dma/idxd/registers.h
@@ -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;

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 6d292eb..3af83f1 100644 (file)
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -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,
 };