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authorChris Wilson <chris@chris-wilson.co.uk>2017-01-06 15:20:09 +0000
committerChris Wilson <chris@chris-wilson.co.uk>2017-01-06 16:02:07 +0000
commitc4d3ae6852bd9f024611d2e8722736ca553e1e43 (patch)
tree8401c340d8946f98d8e3c6a7b692a4476efa3eb3 /drivers/gpu/drm/i915/i915_drv.h
parent7ec73b7e36d0bf165cea77770a490fcdf4418e93 (diff)
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drm/i915: Consolidate checks for memcpy-from-wc support
In order to silence sparse: ../drivers/gpu/drm/i915/i915_gpu_error.c:200:39: warning: Using plain integer as NULL pointer add a helper to check whether we have sse4.1 and that the desired alignment is valid for acceleration. v2: Explain the macros and split the two use cases between i915_has_memcpy_from_wc() and i915_can_memcpy_from_wc(). Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170106152013.24684-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_drv.h')
-rw-r--r--drivers/gpu/drm/i915/i915_drv.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 239a120..ce051a5 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -4021,6 +4021,22 @@ __i915_request_irq_complete(struct drm_i915_gem_request *req)
void i915_memcpy_init_early(struct drm_i915_private *dev_priv);
bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len);
+/* The movntdqa instructions used for memcpy-from-wc require 16-byte alignment,
+ * as well as SSE4.1 support. i915_memcpy_from_wc() will report if it cannot
+ * perform the operation. To check beforehand, pass in the parameters to
+ * to i915_can_memcpy_from_wc() - since we only care about the low 4 bits,
+ * you only need to pass in the minor offsets, page-aligned pointers are
+ * always valid.
+ *
+ * For just checking for SSE4.1, in the foreknowledge that the future use
+ * will be correctly aligned, just use i915_has_memcpy_from_wc().
+ */
+#define i915_can_memcpy_from_wc(dst, src, len) \
+ i915_memcpy_from_wc((void *)((unsigned long)(dst) | (unsigned long)(src) | (len)), NULL, 0)
+
+#define i915_has_memcpy_from_wc() \
+ i915_memcpy_from_wc(NULL, NULL, 0)
+
/* i915_mm.c */
int remap_io_mapping(struct vm_area_struct *vma,
unsigned long addr, unsigned long pfn, unsigned long size,
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