From 7f351077ee7414f0d88c20d7031da6dee4b7afcb Mon Sep 17 00:00:00 2001
From: Matthew Auld <matthew.auld@intel.com>
Date: Thu, 28 Oct 2021 10:26:37 +0100
Subject: drm/i915/gtt: flush the scratch page
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Git-commit: 2ca776068f1f9ece3ab093f1be39c87653fbff16
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
The scratch page is directly visible in the users address space, and
while this is forced as CACHE_LLC, by the kernel, we still have to
contend with things like "Bypass-LLC" MOCS. So just flush no matter
what.
v2(Thomas):
- Make sure we use drm_clflush_virt_range here, in case clflush support
is missing.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211028092638.3142258-1-matthew.auld@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/gt/intel_gtt.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index b67f620c3d93..9fee968d57db 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -8,6 +8,8 @@
#include <linux/fault-inject.h>
#include <linux/sched/mm.h>
+#include <drm/drm_cache.h>
+
#include "gem/i915_gem_lmem.h"
#include "i915_trace.h"
#include "intel_gt.h"
@@ -274,6 +276,7 @@ static void poison_scratch_page(struct drm_i915_gem_object *scratch)
val = POISON_FREE;
memset(vaddr, val, scratch->base.size);
+ drm_clflush_virt_range(vaddr, scratch->base.size);
}
int setup_scratch_page(struct i915_address_space *vm)
--
2.38.1