diff options
Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_mmu.c')
| -rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_mmu.c | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index f7f83cf63f42..f51d3f791a17 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -58,17 +58,33 @@ static int write_cmd(struct panfrost_device *pfdev, u32 as_nr, u32 cmd) } static void lock_region(struct panfrost_device *pfdev, u32 as_nr, - u64 iova, u64 size) + u64 region_start, u64 size) { u8 region_width; - u64 region = iova & PAGE_MASK; + u64 region; + u64 region_end = region_start + size; - /* The size is encoded as ceil(log2) minus(1), which may be calculated - * with fls. The size must be clamped to hardware bounds. + if (!size) + return; + + /* + * The locked region is a naturally aligned power of 2 block encoded as + * log2 minus(1). + * Calculate the desired start/end and look for the highest bit which + * differs. The smallest naturally aligned block must include this bit + * change, the desired region starts with this bit (and subsequent bits) + * zeroed and ends with the bit (and subsequent bits) set to one. */ - size = max_t(u64, size, AS_LOCK_REGION_MIN_SIZE); - region_width = fls64(size - 1) - 1; - region |= region_width; + region_width = max(fls64(region_start ^ (region_end - 1)), + const_ilog2(AS_LOCK_REGION_MIN_SIZE)) - 1; + + /* + * Mask off the low bits of region_start (which would be ignored by + * the hardware anyway) + */ + region_start &= GENMASK_ULL(63, region_width); + + region = region_width | region_start; /* Lock the region that needs to be updated */ mmu_write(pfdev, AS_LOCKADDR_LO(as_nr), lower_32_bits(region)); |