diff options
| -rw-r--r-- | drivers/gpu/drm/xe/xe_ggtt.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c index 14b6d68a6324..0722c49585a0 100644 --- a/drivers/gpu/drm/xe/xe_ggtt.c +++ b/drivers/gpu/drm/xe/xe_ggtt.c @@ -24,6 +24,9 @@ #define MTL_GGTT_PTE_PAT0 BIT_ULL(52) #define MTL_GGTT_PTE_PAT1 BIT_ULL(53) +/* GuC addresses above GUC_GGTT_TOP also don't map through the GTT */ +#define GUC_GGTT_TOP 0xFEE00000 + u64 xe_ggtt_pte_encode(struct xe_bo *bo, u64 bo_offset) { struct xe_device *xe = xe_bo_device(bo); @@ -111,12 +114,18 @@ int xe_ggtt_init_noalloc(struct xe_ggtt *ggtt) /* * 8B per entry, each points to a 4KB page. * - * The GuC owns the WOPCM space, thus we can't allocate GGTT address in - * this area. Even though we likely configure the WOPCM to less than the - * maximum value, to simplify the driver load (no need to fetch HuC + - * GuC firmwares and determine there sizes before initializing the GGTT) - * just start the GGTT allocation above the max WOPCM size. This might - * waste space in the GGTT (WOPCM is 2MB on modern platforms) but we can + * The GuC address space is limited on both ends of the GGTT, because + * the GuC shim HW redirects accesses to those addresses to other HW + * areas instead of going through the GGTT. On the bottom end, the GuC + * can't access offsets below the WOPCM size, while on the top side the + * limit is fixed at GUC_GGTT_TOP. To keep things simple, instead of + * checking each object to see if they are accessed by GuC or not, we + * just exclude those areas from the allocator. Additionally, to + * simplify the driver load, we use the maximum WOPCM size in this logic + * instead of the programmed one, so we don't need to wait until the + * actual size to be programmed is determined (which requires FW fetch) + * before initializing the GGTT. These simplifications might waste space + * in the GGTT (about 20-25 MBs depending on the platform) but we can * live with this. * * Another benifit of this is the GuC bootrom can't access anything @@ -125,6 +134,9 @@ int xe_ggtt_init_noalloc(struct xe_ggtt *ggtt) * Starting the GGTT allocations above the WOPCM max give us the correct * placement for free. */ + if (ggtt->size > GUC_GGTT_TOP) + ggtt->size = GUC_GGTT_TOP; + drm_mm_init(&ggtt->mm, xe_wopcm_size(xe), ggtt->size - xe_wopcm_size(xe)); mutex_init(&ggtt->lock); |