Am 03.03.21 um 14:20 schrieb Thomas Gleixner:
From: Thomas Gleixner tglx@linutronix.de
There is no reason to disable pagefaults and preemption as a side effect of kmap_atomic_prot().
Use kmap_local_page_prot() instead and document the reasoning for the mapping usage with the given pgprot.
Remove the NULL pointer check for the map. These functions return a valid address for valid pages and the return was bogus anyway as it would have left preemption and pagefaults disabled.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Christian Koenig christian.koenig@amd.com Cc: Huang Rui ray.huang@amd.com Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: dri-devel@lists.freedesktop.org
drivers/gpu/drm/ttm/ttm_bo_util.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -181,13 +181,15 @@ static int ttm_copy_io_ttm_page(struct t return -ENOMEM;
src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
- dst = kmap_atomic_prot(d, prot);
- if (!dst)
return -ENOMEM;
- /*
* Ensure that a highmem page is mapped with the correct* pgprot. For non highmem the mapping is already there.*/
I find the comment a bit misleading. Maybe write:
/* * Locally map highmem pages with the correct pgprot. * Normal memory should already have the correct pgprot in the linear mapping. */
Apart from that looks good to me.
Regards, Christian.
dst = kmap_local_page_prot(d, prot);
memcpy_fromio(dst, src, PAGE_SIZE);
- kunmap_atomic(dst);
kunmap_local(dst);
return 0; }
@@ -203,13 +205,15 @@ static int ttm_copy_ttm_io_page(struct t return -ENOMEM;
dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
- src = kmap_atomic_prot(s, prot);
- if (!src)
return -ENOMEM;
/*
* Ensure that a highmem page is mapped with the correct* pgprot. For non highmem the mapping is already there.*/src = kmap_local_page_prot(s, prot);
memcpy_toio(dst, src, PAGE_SIZE);
- kunmap_atomic(src);
kunmap_local(src);
return 0; }