This is a note to let you know that I've just added the patch titled
dmaengine: idxd: fix wq cleanup of WQCFG registers
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-idxd-fix-wq-cleanup-of-wqcfg-registers.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7614ad10d76dc4cf3ec6eae10e3279004d1c109b
Author: Dave Jiang <dave.jiang@xxxxxxxxx>
Date: Mon Apr 12 09:02:36 2021 -0700
dmaengine: idxd: fix wq cleanup of WQCFG registers
[ Upstream commit ea9aadc06a9f10ad20a90edc0a484f1147d88a7a ]
A pre-release silicon erratum workaround where wq reset does not clear
WQCFG registers was leaked into upstream code. Use wq reset command
instead of blasting the MMIO region. This also address an issue where
we clobber registers in future devices.
Fixes: da32b28c95a7 ("dmaengine: idxd: cleanup workqueue config after disabling")
Reported-by: Shreenivaas Devarajan <shreenivaas.devarajan@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/161824330020.881560.16375921906426627033.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index c09687013d29..31c819544a22 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -282,6 +282,22 @@ void idxd_wq_drain(struct idxd_wq *wq)
idxd_cmd_exec(idxd, IDXD_CMD_DRAIN_WQ, operand, NULL);
}
+void idxd_wq_reset(struct idxd_wq *wq)
+{
+ struct idxd_device *idxd = wq->idxd;
+ struct device *dev = &idxd->pdev->dev;
+ u32 operand;
+
+ if (wq->state != IDXD_WQ_ENABLED) {
+ dev_dbg(dev, "WQ %d in wrong state: %d\n", wq->id, wq->state);
+ return;
+ }
+
+ operand = BIT(wq->id % 16) | ((wq->id / 16) << 16);
+ idxd_cmd_exec(idxd, IDXD_CMD_RESET_WQ, operand, NULL);
+ wq->state = IDXD_WQ_DISABLED;
+}
+
int idxd_wq_map_portal(struct idxd_wq *wq)
{
struct idxd_device *idxd = wq->idxd;
@@ -363,8 +379,6 @@ int idxd_wq_disable_pasid(struct idxd_wq *wq)
void idxd_wq_disable_cleanup(struct idxd_wq *wq)
{
struct idxd_device *idxd = wq->idxd;
- struct device *dev = &idxd->pdev->dev;
- int i, wq_offset;
lockdep_assert_held(&idxd->dev_lock);
memset(wq->wqcfg, 0, idxd->wqcfg_size);
@@ -376,14 +390,6 @@ void idxd_wq_disable_cleanup(struct idxd_wq *wq)
wq->ats_dis = 0;
clear_bit(WQ_FLAG_DEDICATED, &wq->flags);
memset(wq->name, 0, WQ_NAME_SIZE);
-
- for (i = 0; i < WQCFG_STRIDES(idxd); i++) {
- wq_offset = WQCFG_OFFSET(idxd, wq->id, i);
- iowrite32(0, idxd->reg_base + wq_offset);
- dev_dbg(dev, "WQ[%d][%d][%#x]: %#x\n",
- wq->id, i, wq_offset,
- ioread32(idxd->reg_base + wq_offset));
- }
}
/* Device control bits */
@@ -672,7 +678,14 @@ static int idxd_wq_config_write(struct idxd_wq *wq)
if (!wq->group)
return 0;
- memset(wq->wqcfg, 0, idxd->wqcfg_size);
+ /*
+ * Instead of memset the entire shadow copy of WQCFG, copy from the hardware after
+ * wq reset. This will copy back the sticky values that are present on some devices.
+ */
+ for (i = 0; i < WQCFG_STRIDES(idxd); i++) {
+ wq_offset = WQCFG_OFFSET(idxd, wq->id, i);
+ wq->wqcfg->bits[i] = ioread32(idxd->reg_base + wq_offset);
+ }
/* byte 0-3 */
wq->wqcfg->wq_size = wq->size;
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index eda2ee10501f..76014c14f473 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -343,6 +343,7 @@ void idxd_wq_free_resources(struct idxd_wq *wq);
int idxd_wq_enable(struct idxd_wq *wq);
int idxd_wq_disable(struct idxd_wq *wq);
void idxd_wq_drain(struct idxd_wq *wq);
+void idxd_wq_reset(struct idxd_wq *wq);
int idxd_wq_map_portal(struct idxd_wq *wq);
void idxd_wq_unmap_portal(struct idxd_wq *wq);
void idxd_wq_disable_cleanup(struct idxd_wq *wq);
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 5f7bc4b1621a..18bf4d148989 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -275,7 +275,6 @@ static void disable_wq(struct idxd_wq *wq)
{
struct idxd_device *idxd = wq->idxd;
struct device *dev = &idxd->pdev->dev;
- int rc;
mutex_lock(&wq->wq_lock);
dev_dbg(dev, "%s removing WQ %s\n", __func__, dev_name(&wq->conf_dev));
@@ -296,17 +295,13 @@ static void disable_wq(struct idxd_wq *wq)
idxd_wq_unmap_portal(wq);
idxd_wq_drain(wq);
- rc = idxd_wq_disable(wq);
+ idxd_wq_reset(wq);
idxd_wq_free_resources(wq);
wq->client_count = 0;
mutex_unlock(&wq->wq_lock);
- if (rc < 0)
- dev_warn(dev, "Failed to disable %s: %d\n",
- dev_name(&wq->conf_dev), rc);
- else
- dev_info(dev, "wq %s disabled\n", dev_name(&wq->conf_dev));
+ dev_info(dev, "wq %s disabled\n", dev_name(&wq->conf_dev));
}
static int idxd_config_bus_remove(struct device *dev)
