From e0096fdcf88ce5e64a4c2e62d3198f05a70052d8 Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Mon, 5 May 2025 14:19:22 +0200 Subject: [PATCH] drm/xe: Implement a helper for reading out a GGTT PTE at a specified offset Split the GGTT PTE readout to a separate function, this is useful for adding testcases in the next commit, and also cleaner than manually reading out GGTT. Reviewed-by: Juha-Pekka Heikkila Link: https://lore.kernel.org/r/20250505121924.921544-10-dev@lankhorst.se Signed-off-by: Maarten Lankhorst --- drivers/gpu/drm/xe/display/xe_plane_initial.c | 6 +----- drivers/gpu/drm/xe/xe_ggtt.c | 12 ++++++++++++ drivers/gpu/drm/xe/xe_ggtt.h | 1 + 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/xe/display/xe_plane_initial.c b/drivers/gpu/drm/xe/display/xe_plane_initial.c index 6502b82741732..59b2ff2026d47 100644 --- a/drivers/gpu/drm/xe/display/xe_plane_initial.c +++ b/drivers/gpu/drm/xe/display/xe_plane_initial.c @@ -87,12 +87,8 @@ initial_plane_bo(struct xe_device *xe, base = round_down(plane_config->base, page_size); if (IS_DGFX(xe)) { - u64 __iomem *gte = tile0->mem.ggtt->gsm; - u64 pte; + u64 pte = xe_ggtt_read_pte(tile0->mem.ggtt, base); - gte += base / XE_PAGE_SIZE; - - pte = ioread64(gte); if (!(pte & XE_GGTT_PTE_DM)) { drm_err(&xe->drm, "Initial plane programming missing DM bit\n"); diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c index b4b3ecd1c1b9e..ad0479c96b217 100644 --- a/drivers/gpu/drm/xe/xe_ggtt.c +++ b/drivers/gpu/drm/xe/xe_ggtt.c @@ -957,3 +957,15 @@ u64 xe_ggtt_encode_pte_flags(struct xe_ggtt *ggtt, { return ggtt->pt_ops->pte_encode_flags(bo, pat_index); } + +/** + * xe_ggtt_read_pte - Read a PTE from the GGTT + * @ggtt: &xe_ggtt + * @offset: the offset for which the mapping should be read. + * + * Used by testcases, and by display reading out an inherited bios FB. + */ +u64 xe_ggtt_read_pte(struct xe_ggtt *ggtt, u64 offset) +{ + return ioread64(ggtt->gsm + (offset / XE_PAGE_SIZE)); +} diff --git a/drivers/gpu/drm/xe/xe_ggtt.h b/drivers/gpu/drm/xe/xe_ggtt.h index fc4ffb090a5a0..dd43c82f4cade 100644 --- a/drivers/gpu/drm/xe/xe_ggtt.h +++ b/drivers/gpu/drm/xe/xe_ggtt.h @@ -51,5 +51,6 @@ void xe_ggtt_might_lock(struct xe_ggtt *ggtt); #endif u64 xe_ggtt_encode_pte_flags(struct xe_ggtt *ggtt, struct xe_bo *bo, u16 pat_index); +u64 xe_ggtt_read_pte(struct xe_ggtt *ggtt, u64 offset); #endif -- 2.47.2