[Intel-gfx] [RFC 3/3] drm/i915: Create new ioctl to request gem object resize
arun.siluvery at linux.intel.com
arun.siluvery at linux.intel.com
Thu Mar 27 16:28:29 CET 2014
From: "Siluvery, Arun" <arun.siluvery at intel.com>
This patch adds a new ioctl to resize gem object. If the object is created
as resizeable scatter/gather table contains dummy entries that point to a
scratch page. A marker denotes end of real pages.
This ioctl creates new pages and updates the dummy entries in the sg table.
The object size can only be increased, resize request fails otherwise.
Change-Id: I56a7f798e578753623044bb7f6216c70dbaf7543
Signed-off-by: Siluvery, Arun <arun.siluvery at intel.com>
---
drivers/gpu/drm/i915/i915_dma.c | 2 +
drivers/gpu/drm/i915/i915_drv.h | 2 +
drivers/gpu/drm/i915/i915_gem.c | 111 ++++++++++++++++++++++++++++++++++++++++
include/uapi/drm/i915_drm.h | 26 ++++++++++
4 files changed, 141 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 31c499f..2ff1c46 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -2000,6 +2000,8 @@ const struct drm_ioctl_desc i915_ioctls[] = {
DRM_IOCTL_DEF_DRV(I915_GET_RESET_STATS, i915_get_reset_stats_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_USERPTR, i915_gem_userptr_ioctl, \
DRM_UNLOCKED|DRM_RENDER_ALLOW),
+ DRM_IOCTL_DEF_DRV(I915_GEM_RESIZE, i915_gem_resize_ioctl, \
+ DRM_UNLOCKED|DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_SET_PLANE_180_ROTATION, \
i915_set_plane_180_rotation, DRM_AUTH | DRM_UNLOCKED),
DRM_IOCTL_DEF_DRV(I915_ENABLE_PLANE_RESERVED_REG_BIT_2,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index cf65aad..a426f0f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2217,6 +2217,8 @@ int i915_gem_get_tiling(struct drm_device *dev, void *data,
int i915_gem_init_userptr(struct drm_device *dev);
int i915_gem_userptr_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
+int i915_gem_resize_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file);
int i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
int i915_gem_wait_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d045eee..8c45d3b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -372,6 +372,117 @@ unlock:
return ret;
}
+/**
+ * Resizes an existing gem object.
+ */
+int i915_gem_resize_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
+{
+ int i, ret;
+ int page_range;
+ int total_page_count, resize_page_count;
+ struct drm_i915_private *dev_priv;
+ struct drm_i915_gem_object *obj;
+ struct drm_i915_gem_resize *args = data;
+ struct address_space *mapping;
+ struct sg_page_iter sg_iter;
+ struct page *page;
+ gfp_t gfp;
+
+ obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
+ if (&obj->base == NULL)
+ return -ENOENT;
+
+ /* Not valid to be called on unbound objects. */
+ if (!i915_gem_obj_bound_any(obj))
+ return -EINVAL;
+
+ if (obj->base.size != args->size ||
+ obj->gem_resize.base_size != args->curr_size) {
+ DRM_DEBUG_DRIVER("invalid object size(s)\n");
+ return -EINVAL;
+ }
+
+ total_page_count = obj->base.size / PAGE_SIZE;
+ resize_page_count = args->resize / PAGE_SIZE;
+ if (resize_page_count < obj->gem_resize.stop) {
+ DRM_DEBUG_DRIVER("cannot resize to smaller size\n");
+ return -EINVAL;
+ }
+
+ DRM_DEBUG_DRIVER("resize object from %d to %d pages, total pages %d\n",
+ obj->gem_resize.stop, resize_page_count, total_page_count);
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return ret;
+
+ if (!obj->pages) {
+ DRM_DEBUG_DRIVER("backing store not yet allocated for this obj\n");
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ dev_priv = obj->base.dev->dev_private;
+ page_range = resize_page_count - obj->gem_resize.stop;
+ mapping = file_inode(obj->base.filp)->i_mapping;
+ gfp = mapping_gfp_mask(mapping);
+ gfp |= __GFP_NORETRY | __GFP_NOWARN | __GFP_NO_KSWAPD;
+ gfp &= ~(__GFP_IO | __GFP_WAIT);
+
+ i = 0;
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
+ page = sg_page_iter_page(&sg_iter);
+
+ if (i < obj->gem_resize.stop) {
+ ++i;
+ continue;
+ }
+ WARN_ON(page != obj->gem_resize.scratch_page);
+
+ page = shmem_read_mapping_page_gfp(mapping, i, gfp);
+ if (IS_ERR(page)) {
+ i915_gem_purge(dev_priv, page_count);
+ page = shmem_read_mapping_page_gfp(mapping, i, gfp);
+ }
+ if (IS_ERR(page)) {
+ /* We've tried hard to allocate the memory by reaping
+ * our own buffer, now let the real VM do its job and
+ * go down in flames if truly OOM.
+ */
+ gfp &= ~(__GFP_NORETRY | __GFP_NOWARN | __GFP_NO_KSWAPD);
+ gfp |= __GFP_IO | __GFP_WAIT;
+
+ i915_gem_shrink_all(dev_priv);
+ page = shmem_read_mapping_page_gfp(mapping, i, gfp);
+ if (IS_ERR(page)) {
+ DRM_ERROR("out of memory\n");
+ goto err_pages;
+ }
+
+ gfp |= __GFP_NORETRY | __GFP_NOWARN | __GFP_NO_KSWAPD;
+ gfp &= ~(__GFP_IO | __GFP_WAIT);
+ }
+ sg_set_page((&sg_iter)->sg, page, PAGE_SIZE, 0);
+
+ ++i;
+ }
+ obj->gem_resize.stop = resize_page_count;
+
+ mutex_unlock(&dev->struct_mutex);
+ return 0;
+
+err_pages:
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
+ page_cache_release(sg_page_iter_page(&sg_iter));
+ sg_free_table(obj->pages);
+ kfree(obj->pages);
+ ret = PTR_ERR(page);
+
+unlock:
+ mutex_unlock(&dev->struct_mutex);
+ return ret;
+}
+
static inline int
__copy_to_user_swizzled(char __user *cpu_vaddr,
const char *gpu_vaddr, int gpu_offset,
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index e455c9d..a807ff4 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -275,6 +275,7 @@ struct csc_coeff {
#define DRM_I915_GET_RESET_STATS 0x32
#define DRM_I915_SET_PLANE_ZORDER 0x33
#define DRM_I915_GEM_USERPTR 0x34
+#define DRM_I915_GEM_RESIZE 0x35
#define DRM_I915_SET_PLANE_180_ROTATION 0x36
#define DRM_I915_ENABLE_PLANE_RESERVED_REG_BIT_2 0x37
#define DRM_I915_SET_CSC 0x39
@@ -339,6 +340,9 @@ struct csc_coeff {
#define DRM_IOCTL_I915_GEM_USERPTR \
DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_USERPTR, \
struct drm_i915_gem_userptr)
+#define DRM_IOCTL_I915_GEM_RESIZE \
+ DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_RESIZE, \
+ struct drm_i915_gem_resize)
#define DRM_IOCTL_I915_SET_PLANE_ALPHA \
DRM_IOW(DRM_COMMAND_BASE + DRM_I915_SET_PLANE_ALPHA, \
struct drm_i915_set_plane_alpha)
@@ -530,6 +534,28 @@ struct drm_i915_gem_create {
__u64 base_size;
};
+struct drm_i915_gem_resize {
+ /**
+ * The size for which the backing store is created initially
+ */
+ __u64 curr_size;
+ /**
+ * The new size of the object
+ */
+ __u64 resize;
+ /**
+ * Requested size for the object, remains constant.
+ */
+ __u64 size;
+ __u32 flags;
+ /**
+ * Returned handle for the object.
+ *
+ * Object handles are nonzero.
+ */
+ __u32 handle;
+};
+
struct drm_i915_gem_pread {
/** Handle for the object being read. */
__u32 handle;
--
1.9.1
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