The patch below does not apply to the 6.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.15.y git checkout FETCH_HEAD git cherry-pick -x afcad92411772a1f361339f22c49f855c6cc7d0f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025071259-unrelated-extrovert-b5a9@gregkh' --subject-prefix 'PATCH 6.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From afcad92411772a1f361339f22c49f855c6cc7d0f Mon Sep 17 00:00:00 2001 From: Matthew Brost matthew.brost@intel.com Date: Wed, 11 Jun 2025 20:19:25 -0700 Subject: [PATCH] drm/xe: Make WA BB part of LRC BO

No idea why, but without this GuC context switches randomly fail when running IGTs in a loop. Need to follow up why this fixes the aforementioned issue but can live with a stable driver for now.

Fixes: 617d824c5323 ("drm/xe: Add WA BB to capture active context utilization") Cc: stable@vger.kernel.org Signed-off-by: Matthew Brost matthew.brost@intel.com Reviewed-by: Lucas De Marchi lucas.demarchi@intel.com Tested-by: Shuicheng Lin shuicheng.lin@intel.com Link: https://lore.kernel.org/r/20250612031925.4009701-1-matthew.brost@intel.com (cherry picked from commit 3a1edef8f4b58b0ba826bc68bf4bce4bdf59ecf3) Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com

diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c index bf7c3981897d..6e7b70532d11 100644 --- a/drivers/gpu/drm/xe/xe_lrc.c +++ b/drivers/gpu/drm/xe/xe_lrc.c @@ -40,6 +40,7 @@

#define LRC_PPHWSP_SIZE SZ_4K #define LRC_INDIRECT_RING_STATE_SIZE SZ_4K +#define LRC_WA_BB_SIZE SZ_4K

static struct xe_device * lrc_to_xe(struct xe_lrc *lrc) @@ -910,7 +911,11 @@ static void xe_lrc_finish(struct xe_lrc *lrc) { xe_hw_fence_ctx_finish(&lrc->fence_ctx); xe_bo_unpin_map_no_vm(lrc->bo); - xe_bo_unpin_map_no_vm(lrc->bb_per_ctx_bo); +} + +static size_t wa_bb_offset(struct xe_lrc *lrc) +{ + return lrc->bo->size - LRC_WA_BB_SIZE; }

/* @@ -943,15 +948,16 @@ static void xe_lrc_finish(struct xe_lrc *lrc) #define CONTEXT_ACTIVE 1ULL static int xe_lrc_setup_utilization(struct xe_lrc *lrc) { + const size_t max_size = LRC_WA_BB_SIZE; u32 *cmd, *buf = NULL;

- if (lrc->bb_per_ctx_bo->vmap.is_iomem) { - buf = kmalloc(lrc->bb_per_ctx_bo->size, GFP_KERNEL); + if (lrc->bo->vmap.is_iomem) { + buf = kmalloc(max_size, GFP_KERNEL); if (!buf) return -ENOMEM; cmd = buf; } else { - cmd = lrc->bb_per_ctx_bo->vmap.vaddr; + cmd = lrc->bo->vmap.vaddr + wa_bb_offset(lrc); }

*cmd++ = MI_STORE_REGISTER_MEM | MI_SRM_USE_GGTT | MI_SRM_ADD_CS_OFFSET; @@ -974,13 +980,14 @@ static int xe_lrc_setup_utilization(struct xe_lrc *lrc) *cmd++ = MI_BATCH_BUFFER_END;

if (buf) { - xe_map_memcpy_to(gt_to_xe(lrc->gt), &lrc->bb_per_ctx_bo->vmap, 0, - buf, (cmd - buf) * sizeof(*cmd)); + xe_map_memcpy_to(gt_to_xe(lrc->gt), &lrc->bo->vmap, + wa_bb_offset(lrc), buf, + (cmd - buf) * sizeof(*cmd)); kfree(buf); }

- xe_lrc_write_ctx_reg(lrc, CTX_BB_PER_CTX_PTR, - xe_bo_ggtt_addr(lrc->bb_per_ctx_bo) | 1); + xe_lrc_write_ctx_reg(lrc, CTX_BB_PER_CTX_PTR, xe_bo_ggtt_addr(lrc->bo) + + wa_bb_offset(lrc) + 1);

return 0; } @@ -1018,20 +1025,13 @@ static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe, * FIXME: Perma-pinning LRC as we don't yet support moving GGTT address * via VM bind calls. */ - lrc->bo = xe_bo_create_pin_map(xe, tile, NULL, lrc_size, + lrc->bo = xe_bo_create_pin_map(xe, tile, NULL, + lrc_size + LRC_WA_BB_SIZE, ttm_bo_type_kernel, bo_flags); if (IS_ERR(lrc->bo)) return PTR_ERR(lrc->bo);

- lrc->bb_per_ctx_bo = xe_bo_create_pin_map(xe, tile, NULL, SZ_4K, - ttm_bo_type_kernel, - bo_flags); - if (IS_ERR(lrc->bb_per_ctx_bo)) { - err = PTR_ERR(lrc->bb_per_ctx_bo); - goto err_lrc_finish; - } - lrc->size = lrc_size; lrc->ring.size = ring_size; lrc->ring.tail = 0; @@ -1819,7 +1819,8 @@ struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc) snapshot->seqno = xe_lrc_seqno(lrc); snapshot->lrc_bo = xe_bo_get(lrc->bo); snapshot->lrc_offset = xe_lrc_pphwsp_offset(lrc); - snapshot->lrc_size = lrc->bo->size - snapshot->lrc_offset; + snapshot->lrc_size = lrc->bo->size - snapshot->lrc_offset - + LRC_WA_BB_SIZE; snapshot->lrc_snapshot = NULL; snapshot->ctx_timestamp = lower_32_bits(xe_lrc_ctx_timestamp(lrc)); snapshot->ctx_job_timestamp = xe_lrc_ctx_job_timestamp(lrc); diff --git a/drivers/gpu/drm/xe/xe_lrc_types.h b/drivers/gpu/drm/xe/xe_lrc_types.h index ae24cf6f8dd9..883e550a9423 100644 --- a/drivers/gpu/drm/xe/xe_lrc_types.h +++ b/drivers/gpu/drm/xe/xe_lrc_types.h @@ -53,9 +53,6 @@ struct xe_lrc {

/** @ctx_timestamp: readout value of CTX_TIMESTAMP on last update */ u64 ctx_timestamp; - - /** @bb_per_ctx_bo: buffer object for per context batch wa buffer */ - struct xe_bo *bb_per_ctx_bo; };

struct xe_lrc_snapshot;