[PATCH 1/4] habanalabs: improve MMU cache invalidation code

From: Oded Gabbay
Date: Thu May 21 2020 - 03:02:20 EST


From: Omer Shpigelman <oshpigelman@xxxxxxxxx>

A new sequence is introduced to invalidate the MMU cache in order to avoid
timeouts.

Signed-off-by: Omer Shpigelman <oshpigelman@xxxxxxxxx>
Reviewed-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
---
drivers/misc/habanalabs/gaudi/gaudi.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c
index 4cb1f71dd4f1..093384731f0d 100644
--- a/drivers/misc/habanalabs/gaudi/gaudi.c
+++ b/drivers/misc/habanalabs/gaudi/gaudi.c
@@ -5982,16 +5982,18 @@ static void gaudi_mmu_invalidate_cache(struct hl_device *hdev, bool is_hard,
timeout_usec = MMU_CONFIG_TIMEOUT_USEC;

/* L0 & L1 invalidation */
- WREG32(mmSTLB_INV_ALL_START, 1);
+ WREG32(mmSTLB_INV_PS, 2);

rc = hl_poll_timeout(
hdev,
- mmSTLB_INV_ALL_START,
+ mmSTLB_INV_PS,
status,
!status,
1000,
timeout_usec);

+ WREG32(mmSTLB_INV_SET, 0);
+
if (rc)
dev_notice_ratelimited(hdev->dev,
"Timeout when waiting for MMU cache invalidation\n");
--
2.17.1