This is a note to let you know that I've just added the patch titled
drm/panfrost: Clamp lock region to Bifrost minimum
to the 5.14-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:
drm-panfrost-clamp-lock-region-to-bifrost-minimum.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bd7ffbc3ca12629aeb66fb9e28cf42b7f37e3e3b Mon Sep 17 00:00:00 2001
From: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
Date: Tue, 24 Aug 2021 13:30:27 -0400
Subject: drm/panfrost: Clamp lock region to Bifrost minimum
From: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
commit bd7ffbc3ca12629aeb66fb9e28cf42b7f37e3e3b upstream.
When locking a region, we currently clamp to a PAGE_SIZE as the minimum
lock region. While this is valid for Midgard, it is invalid for Bifrost,
where the minimum locking size is 8x larger than the 4k page size. Add a
hardware definition for the minimum lock region size (corresponding to
KBASE_LOCK_REGION_MIN_SIZE_LOG2 in kbase) and respect it.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
Tested-by: Chris Morgan <macromorgan@xxxxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210824173028.7528-4-alyssa.rosenzweig@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_mmu.c | 2 +-
drivers/gpu/drm/panfrost/panfrost_regs.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -63,7 +63,7 @@ static void lock_region(struct panfrost_
/* The size is encoded as ceil(log2) minus(1), which may be calculated
* with fls. The size must be clamped to hardware bounds.
*/
- size = max_t(u64, size, PAGE_SIZE);
+ size = max_t(u64, size, AS_LOCK_REGION_MIN_SIZE);
region_width = fls64(size - 1) - 1;
region |= region_width;
--- a/drivers/gpu/drm/panfrost/panfrost_regs.h
+++ b/drivers/gpu/drm/panfrost/panfrost_regs.h
@@ -319,6 +319,8 @@
#define AS_FAULTSTATUS_ACCESS_TYPE_READ (0x2 << 8)
#define AS_FAULTSTATUS_ACCESS_TYPE_WRITE (0x3 << 8)
+#define AS_LOCK_REGION_MIN_SIZE (1ULL << 15)
+
#define gpu_write(dev, reg, data) writel(data, dev->iomem + reg)
#define gpu_read(dev, reg) readl(dev->iomem + reg)
Patches currently in stable-queue which might be from alyssa.rosenzweig@xxxxxxxxxxxxx are
queue-5.14/drm-panfrost-clamp-lock-region-to-bifrost-minimum.patch
queue-5.14/drm-panfrost-simplify-lock_region-calculation.patch
queue-5.14/drm-panfrost-use-u64-for-size-in-lock_region.patch
