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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-18 19:17:13 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-19 00:36:59 +0300 |
| commit | ed13033f0287051577bc1678cde63a42fa419f3c (patch) | |
| tree | eb373a58eaa673846e9fc24f324b62cc7587a6ca /drivers/gpu/drm/i915/i915_cmd_parser.c | |
| parent | 0b5372727be37944239100ff05a63df9771c8484 (diff) | |
| download | linux-ed13033f0287051577bc1678cde63a42fa419f3c.tar.xz | |
drm/i915/cmdparser: Only cache the dst vmap
For simplicity, we want to continue using a contiguous mapping of the
command buffer, but we can reduce the number of vmappings we hold by
switching over to a page-by-page copy from the user batch buffer to the
shadow. The cost for saving one linear mapping is about 5% in trivial
workloads - which is more or less the overhead in calling kmap_atomic().
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-34-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_cmd_parser.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_cmd_parser.c | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 5d9ea163d1c8..d1858f80d64c 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -946,7 +946,8 @@ static u32 *copy_batch(struct drm_i915_gem_object *dst_obj, { unsigned int src_needs_clflush; unsigned int dst_needs_clflush; - void *src, *dst; + void *dst, *ptr; + int offset, n; int ret; ret = i915_gem_obj_prepare_shmem_read(src_obj, &src_needs_clflush); @@ -959,19 +960,12 @@ static u32 *copy_batch(struct drm_i915_gem_object *dst_obj, goto unpin_src; } - src = i915_gem_object_pin_map(src_obj, I915_MAP_WB); - if (IS_ERR(src)) { - dst = src; - goto unpin_dst; - } - dst = i915_gem_object_pin_map(dst_obj, I915_MAP_WB); if (IS_ERR(dst)) - goto unmap_src; + goto unpin_dst; - src += batch_start_offset; - if (src_needs_clflush) - drm_clflush_virt_range(src, batch_len); + ptr = dst; + offset = offset_in_page(batch_start_offset); /* We can avoid clflushing partial cachelines before the write if we * only every write full cache-lines. Since we know that both the @@ -982,13 +976,24 @@ static u32 *copy_batch(struct drm_i915_gem_object *dst_obj, if (dst_needs_clflush & CLFLUSH_BEFORE) batch_len = roundup(batch_len, boot_cpu_data.x86_clflush_size); - memcpy(dst, src, batch_len); + for (n = batch_start_offset >> PAGE_SHIFT; batch_len; n++) { + int len = min_t(int, batch_len, PAGE_SIZE - offset); + void *vaddr; + + vaddr = kmap_atomic(i915_gem_object_get_page(src_obj, n)); + if (src_needs_clflush) + drm_clflush_virt_range(vaddr + offset, len); + memcpy(ptr, vaddr + offset, len); + kunmap_atomic(vaddr); + + ptr += len; + batch_len -= len; + offset = 0; + } /* dst_obj is returned with vmap pinned */ *needs_clflush_after = dst_needs_clflush & CLFLUSH_AFTER; -unmap_src: - i915_gem_object_unpin_map(src_obj); unpin_dst: i915_gem_obj_finish_shmem_access(dst_obj); unpin_src: |