From 86f41f4333e31b62d143c5e38c0c58c85193c4c8 Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Tue, 9 Jan 2024 17:24:36 -0800 Subject: [PATCH] drm/xe: Add build on bug to assert page fault queue works If PF_QUEUE_NUM_DW % PF_MSG_LEN_DW != 0 then the page fault queue logic does not work when wrapping occurs. Add a build bug on to assert PF_QUEUE_NUM_DW % PF_MSG_LEN_DW == 0 to enforce this restriction and document the code. v2: - s/NUM_PF_QUEUE/PF_QUEUE_NUM_DW (Brian) Cc: Lucas De Marchi Signed-off-by: Matthew Brost Reviewed-by: Lucas De Marchi --- drivers/gpu/drm/xe/xe_gt_pagefault.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c index 4489aadc7a525..0a61e4413679e 100644 --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c @@ -328,6 +328,11 @@ int xe_guc_pagefault_handler(struct xe_guc *guc, u32 *msg, u32 len) u32 asid; bool full; + /* + * The below logic doesn't work unless PF_QUEUE_NUM_DW % PF_MSG_LEN_DW == 0 + */ + BUILD_BUG_ON(PF_QUEUE_NUM_DW % PF_MSG_LEN_DW); + if (unlikely(len != PF_MSG_LEN_DW)) return -EPROTO; -- 2.30.2