Commit f45da820 authored Feb 05, 2021 by Boris Brezillon

drm/panfrost: Don't try to map pages that are already mapped



We allocate 2MB chunks at a time, so it might appear that a page fault
has already been handled by a previous page fault when we reach
panfrost_mmu_map_fault_addr(). Bail out in that case to avoid mapping the
same area twice.

Cc: <stable@vger.kernel.org>
Fixes: 187d2929 ("drm/panfrost: Add support for GPU heap allocations")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210205111757.585248-3-boris.brezillon@collabora.com

parent 3aa0a80f

drivers/gpu/drm/panfrost/panfrost_mmu.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -488,8 +488,14 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
		}
		bo->base.pages = pages;
		bo->base.pages_use_count = 1;
		} else
		} else {
		pages = bo->base.pages;
		if (pages[page_offset]) {
		/* Pages are already mapped, bail out. */
		mutex_unlock(&bo->base.pages_lock);
		goto out;
		}
		}

		mapping = bo->base.base.filp->f_mapping;
		mapping_set_unevictable(mapping);
		@@ -522,6 +528,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,

		dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);

		out:
		panfrost_gem_mapping_put(bomapping);

		return 0;