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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-01-06 15:20:09 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-01-06 16:02:07 +0000 |
| commit | c4d3ae6852bd9f024611d2e8722736ca553e1e43 (patch) | |
| tree | 8401c340d8946f98d8e3c6a7b692a4476efa3eb3 /drivers/gpu/drm/i915/i915_drv.h | |
| parent | 7ec73b7e36d0bf165cea77770a490fcdf4418e93 (diff) | |
| download | lwn-c4d3ae6852bd9f024611d2e8722736ca553e1e43.tar.gz lwn-c4d3ae6852bd9f024611d2e8722736ca553e1e43.zip | |
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.h | 16 |
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 239a120a0ec1..ce051a5b97ca 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, |