On Wed, Oct 20, 2021 at 02:06:25AM -0700, Lucas De Marchi wrote:
PAGE_KERNEL_IO is only defined for x86 and is the same as PAGE_KERNEL. Use the latter since that is also available on other archs, which should help us getting i915 there.
This is the same that was done done in commit 80c33624e472 ("io-mapping: Fixup for different names of writecombine"). Later the commit 80c33624e472 ("io-mapping: Fixup for different names of writecombine") added a "Fixes" tag to the first one, but that is actually fixing a separate issue: the different names for pgprot_writecombine().
Fast-forward today, it seems the only 2 archs that define pgprot_noncached_wc() are microblaze and powerpc. Microblaze has the same definition for pgprot_writecombine() since commit 97ccedd793ac ("microblaze: Provide pgprot_device/writecombine macros for nommu"). Powerpc has 3 variants and all of them have the same behavior for pgprot_writecombine() and pgprot_noncached_wc(). From the commit message and linked issue, the fallback was needed for arm, but apparently today all the variants there also have pgprot_writecombine().
So, just use PAGE_KERNEL, and just use pgprot_writecombine().
Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com
I think a bit more history on PAGE_KERNEL_IO is useful to add. It was added in be43d72835ba ("x86: add _PAGE_IOMAP pte flag for IO mappings"). The one and only user was lost in f955371ca9d3 ("x86: remove the Xen-specific _PAGE_IOMAP PTE flag"), therefore it's safe to do this.
With that added Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
Also if you're motivated, maybe delete PAGE_KERNEL_IO across the tree and get x86 maintainers to merge the entire series? -Daniel
drivers/gpu/drm/i915/gem/i915_gem_pages.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c index 8eb1c3a6fc9c..68fe1837ef54 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c @@ -289,7 +289,7 @@ static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj, pgprot = PAGE_KERNEL; break; case I915_MAP_WC:
pgprot = pgprot_writecombine(PAGE_KERNEL_IO);
pgprot = pgprot_writecombine(PAGE_KERNEL);@@ -333,7 +333,7 @@ static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj, i = 0; for_each_sgt_daddr(addr, iter, obj->mm.pages) pfns[i++] = (iomap + addr) >> PAGE_SHIFT;
- vaddr = vmap_pfn(pfns, n_pfn, pgprot_writecombine(PAGE_KERNEL_IO));
- vaddr = vmap_pfn(pfns, n_pfn, pgprot_writecombine(PAGE_KERNEL)); if (pfns != stack) kvfree(pfns);
-- 2.33.1