drm/panfrost: Clamp lock region to Bifrost minimum

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@collabora.com>
Tested-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210824173028.7528-4-alyssa.rosenzweig@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 614033f22682ad9fb9b58a52c3e651da38cb98b4..eea6ade902cb479d0fe65cd12e38e927e1e023b2 100644 (file)
--- 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_device *pfdev, u32 as_nr,
        /* 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;
 

diff --git a/drivers/gpu/drm/panfrost/panfrost_regs.h b/drivers/gpu/drm/panfrost/panfrost_regs.h
index eddaa62ad8b0eb81d54e7062e73ceb4be2bdb835..2ae3a4d301d39df96af0916ae74bbd2b79218d4f 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_regs.h
+++ b/drivers/gpu/drm/panfrost/panfrost_regs.h
@@ -318,6 +318,8 @@
 #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)