linux-kernel - [PATCH 07/11] drm/i915: stop using kmap in i915_gem_object

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Date:   Fri,  2 Oct 2020 14:22:00 +0200
From:   Christoph Hellwig <hch@....de>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        Matthew Auld <matthew.auld@...el.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Minchan Kim <minchan@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Nitin Gupta <ngupta@...are.org>, x86@...nel.org,
        xen-devel@...ts.xenproject.org, linux-kernel@...r.kernel.org,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-mm@...ck.org, Tvrtko Ursulin <tvrtko.ursulin@...el.com>
Subject: [PATCH 07/11] drm/i915: stop using kmap in i915_gem_object_map

kmap for !PageHighmem is just a convoluted way to say page_address,
and kunmap is a no-op in that case.

Signed-off-by: Christoph Hellwig <hch@....de>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@...el.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_pages.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index d6eeefab3d018b..6550c0bc824ea2 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -162,8 +162,6 @@ static void unmap_object(struct drm_i915_gem_object *obj, void *ptr)
 {
 	if (is_vmalloc_addr(ptr))
 		vunmap(ptr);
-	else
-		kunmap(kmap_to_page(ptr));
 }
 
 struct sg_table *
@@ -277,11 +275,10 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
 		 * forever.
 		 *
 		 * So if the page is beyond the 32b boundary, make an explicit
-		 * vmap. On 64b, this check will be optimised away as we can
-		 * directly kmap any page on the system.
+		 * vmap.
 		 */
 		if (!PageHighMem(page))
-			return kmap(page);
+			return page_address(page);
 	}
 
 	mem = stack;
-- 
2.28.0