From: Adrián Larumbe Date: Sun, 19 Oct 2025 14:52:10 +0000 (+0100) Subject: drm/panfrost: Check sgt to know whether pages are already mapped X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3d7c626716aae6e96d7d463f184a09df4cd4bdb2;p=thirdparty%2Fkernel%2Flinux.git drm/panfrost: Check sgt to know whether pages are already mapped In the MMU's page fault ISR for a heap object, determine whether the faulting address belongs to a 2MiB block that was already mapped by checking its corresponding sgt in the Panfrost BO. This is done in preparation for a future commit in which the MMU mapping helper might fail, but the page array is left populated, so this cannot be used as a check for an early bail-out. Reviewed-by: Steven Price Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Adrián Larumbe Link: https://lore.kernel.org/r/20251019145225.3621989-6-adrian.larumbe@collabora.com Signed-off-by: Steven Price --- diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index fd148d5746c04..17897edaa2b4a 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -602,10 +602,12 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as, refcount_set(&bo->base.pages_use_count, 1); } else { pages = bo->base.pages; - if (pages[page_offset]) { - /* Pages are already mapped, bail out. */ - goto out; - } + } + + sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)]; + if (sgt->sgl) { + /* Pages are already mapped, bail out. */ + goto out; } mapping = bo->base.base.filp->f_mapping; @@ -627,7 +629,6 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as, } } - sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)]; ret = sg_alloc_table_from_pages(sgt, pages + page_offset, NUM_FAULT_PAGES, 0, SZ_2M, GFP_KERNEL); if (ret)