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authorChris Wilson <chris@chris-wilson.co.uk>2015-06-29 16:01:19 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-07-09 10:36:44 +0300
commit19ee835cdb0b5a8eb11a68f25a51b8039d564488 (patch)
tree7fac6c795d3c0fb87ccf235dd7eea63d2a801780 /drivers/gpu
parentdec4f799d0a4c9edae20512fa60b0a36f3299ca2 (diff)
downloadlinux-19ee835cdb0b5a8eb11a68f25a51b8039d564488.tar.xz
drm/i915: Declare the swizzling unknown for L-shaped configurations
The old style of memory interleaving swizzled upto the end of the first even bank of memory, and then used the remainder as unswizzled on the unpaired bank - i.e. swizzling is not constant for all memory. This causes problems when we try to migrate memory and so the kernel prevents migration at all when we detect L-shaped inconsistent swizzling. However, this issue also extends to userspace who try to manually detile into memory as the swizzling for an individual page is unknown (it depends on its physical address only known to the kernel), userspace cannot correctly swizzle objects. v2: Mark the global swizzling as unknown rather than adjust the value reported to userspace. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91105 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/i915_gem_tiling.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index 633bd1fcab69..d61e74a08f82 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -183,8 +183,18 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
if (IS_GEN4(dev)) {
uint32_t ddc2 = I915_READ(DCC2);
- if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE))
+ if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE)) {
+ /* Since the swizzling may vary within an
+ * object, we have no idea what the swizzling
+ * is for any page in particular. Thus we
+ * cannot migrate tiled pages using the GPU,
+ * nor can we tell userspace what the exact
+ * swizzling is for any object.
+ */
dev_priv->quirks |= QUIRK_PIN_SWIZZLED_PAGES;
+ swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
+ swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
+ }
}
if (dcc == 0xffffffff) {