linux-kernel - [PATCH] drm/i915: Call page_address() on page acquired with GFP

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Date:   Wed, 14 Jun 2023 05:35:56 -0700
From:   Sumitra Sharma <sumitraartsy@...il.com>
To:     Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Cc:     Ira Weiny <ira.weiny@...el.com>, Fabio <fmdefrancesco@...il.com>,
        Deepak R Varma <drv@...lo.com>,
        Sumitra Sharma <sumitraartsy@...il.com>
Subject: [PATCH] drm/i915: Call page_address() on page acquired with
 GFP_KERNEL flag

Pages allocated with GFP_KERNEL cannot come from Highmem.
That is why there is no need to call kmap() on them.

Therefore, don't call kmap() on the page coming from
vma_res->bi.pages using for_each_sgt_page() in
i915_vma_coredump_create().

Use a plain page_address() to get the kernel address instead.

Signed-off-by: Sumitra Sharma <sumitraartsy@...il.com>
---
 drivers/gpu/drm/i915/i915_gpu_error.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index f020c0086fbc..6f51cb4fc55c 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1164,9 +1164,8 @@ i915_vma_coredump_create(const struct intel_gt *gt,
 
 			drm_clflush_pages(&page, 1);
 
-			s = kmap(page);
+			s = page_address(page);
 			ret = compress_page(compress, s, dst, false);
-			kunmap(page);
 
 			drm_clflush_pages(&page, 1);
 
-- 
2.25.1