Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem.c | 184 ++++++++++++++++++++++++++++++++++++--
1 files changed, 174 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 37a8a29..8f60bc5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -542,6 +542,146 @@ out:
return ret;
}
+static int
+i915_gem_gtt_pread_fast(struct drm_device *dev,
+ struct drm_i915_gem_object *obj,
+ struct drm_i915_gem_pread *args,
+ struct drm_file *file_priv)
+{
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ ssize_t remain;
+ loff_t offset, page_base;
+ char __user *user_data;
+ int page_offset, page_length;
+
+ user_data = (char __user *) (uintptr_t) args->data_ptr;
+ remain = args->size;
+
+ offset = obj->gtt_offset + args->offset;
+
+ while (remain > 0) {
+ u8 __iomem *vaddr;
+ unsigned long unwritten;
+
+ /* Operation in this page
+ *
+ * page_base = page offset within aperture
+ * page_offset = offset within page
+ * page_length = bytes to copy for this page
+ */
+ page_base = offset & PAGE_MASK;
+ page_offset = offset_in_page(offset);
+ page_length = remain;
+ if ((page_offset + remain) > PAGE_SIZE)
+ page_length = PAGE_SIZE - page_offset;
+
+ /* If we get a fault while copying data, then (presumably) our
+ * source page isn't available. Return the error and we'll
+ * retry in the slow path.
+ */
+
+ vaddr = io_mapping_map_atomic_wc(dev_priv->mm.gtt_mapping,
+ page_base);
+ unwritten = __copy_to_user_inatomic(user_data,
+ vaddr + page_offset,
+ page_length);
+ io_mapping_unmap_atomic(vaddr);
+
+ if (unwritten)
+ return -EFAULT;
+
+ remain -= page_length;
+ user_data += page_length;
+ offset += page_length;
+ }
+
+ return 0;
+}
+
+static int
+i915_gem_gtt_pread_slow(struct drm_device *dev,
+ struct drm_i915_gem_object *obj,
+ struct drm_i915_gem_pread *args,
+ struct drm_file *file_priv)
+{
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ ssize_t remain;
+ loff_t gtt_page_base, offset;
+ loff_t first_data_page, last_data_page;
+ int num_pages, i;
+ struct page **user_pages;
+ int gtt_page_offset, user_page_offset, user_page_index, page_length;
+ int ret;
+ uint64_t data_ptr = args->data_ptr;
+
+ remain = args->size;
+
+ /* Pin the user pages containing the data. We can't fault while
+ * holding the struct mutex, and all of the pwrite implementations
+ * want to hold it while dereferencing the user data.
+ */
+ first_data_page = data_ptr / PAGE_SIZE;
+ last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE;
+ num_pages = last_data_page - first_data_page + 1;
+
+ ret = i915_gem_get_user_pages(dev, data_ptr, false,
+ &num_pages, &user_pages);
+ if (ret)
+ goto out;
+
+ ret = i915_gem_object_set_to_gtt_domain(obj, false);
+ if (ret)
+ goto out;
+
+ offset = obj->gtt_offset + args->offset;
+
+ while (remain > 0) {
+ u8 __iomem *src_vaddr;
+ u8 *dst_vaddr;
+
+ /* Operation in this page
+ *
+ * gtt_page_base = page offset within aperture
+ * gtt_page_offset = offset within page in aperture
+ * user_page_index = page number in get_user_pages return
+ * user_page_offset = offset with user_page_index page.
+ * page_length = bytes to copy for this page
+ */
+ gtt_page_base = offset & PAGE_MASK;
+ gtt_page_offset = offset_in_page(offset);
+ user_page_index = data_ptr / PAGE_SIZE - first_data_page;
+ user_page_offset = offset_in_page(data_ptr);
+
+ page_length = remain;
+ if ((gtt_page_offset + page_length) > PAGE_SIZE)
+ page_length = PAGE_SIZE - gtt_page_offset;
+ if ((user_page_offset + page_length) > PAGE_SIZE)
+ page_length = PAGE_SIZE - user_page_offset;
+
+ src_vaddr = io_mapping_map_atomic_wc(dev_priv->mm.gtt_mapping,
+ gtt_page_base);
+ dst_vaddr = kmap_atomic(user_pages[user_page_index]);
+
+ memcpy_fromio(dst_vaddr + user_page_offset,
+ src_vaddr + gtt_page_offset,
+ page_length);
+
+ kunmap_atomic(dst_vaddr);
+ io_mapping_unmap_atomic(src_vaddr);
+
+ remain -= page_length;
+ offset += page_length;
+ data_ptr += page_length;
+ }
+
+out:
+ for (i = 0; i < num_pages; i++)
+ page_cache_release(user_pages[i]);
+ drm_free_large(user_pages);
+
+ return ret;
+}
+
/**
* Reads data from the object referenced by handle.
*
@@ -587,17 +727,41 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
trace_i915_gem_object_pread(obj, args->offset, args->size);
- ret = i915_gem_object_set_cpu_read_domain_range(obj,
- args->offset,
- args->size);
- if (ret)
- goto out;
+ if (obj->gtt_space &&
+ obj->map_and_fenceable &&
+ obj->cache_level == I915_CACHE_NONE &&
+ (obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0) {
+ ret = i915_gem_object_pin(obj, 0, true);
+ if (ret)
+ goto out;
+
+ ret = i915_gem_object_set_to_gtt_domain(obj, false);
+ if (ret)
+ goto out_unpin;
- ret = -EFAULT;
- if (!i915_gem_object_needs_bit17_swizzle(obj))
- ret = i915_gem_shmem_pread_fast(dev, obj, args, file);
- if (ret == -EFAULT)
- ret = i915_gem_shmem_pread_slow(dev, obj, args, file);
+ ret = i915_gem_object_put_fence(obj);
+ if (ret)
+ goto out_unpin;
+
+ ret = i915_gem_gtt_pread_fast(dev, obj, args, file);
+ if (ret == -EFAULT)
+ ret = i915_gem_gtt_pread_slow(dev, obj, args, file);
+
+out_unpin:
+ i915_gem_object_unpin(obj);
+ } else {
+ ret = i915_gem_object_set_cpu_read_domain_range(obj,
+ args->offset,
+ args->size);
+ if (ret)
+ goto out;
+
+ ret = -EFAULT;
+ if (!i915_gem_object_needs_bit17_swizzle(obj))
+ ret = i915_gem_shmem_pread_fast(dev, obj, args, file);
+ if (ret == -EFAULT)
+ ret = i915_gem_shmem_pread_slow(dev, obj, args, file);
+ }
out:
drm_gem_object_unreference(&obj->base);
--
1.7.4.1
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