[RFC 1/3] drm/i915: Added a new 'I915_CPU_MAP_NOT_NEEDED' flag to gem_create ioctl.

sourab.gupta
2014-03-05T11:35:28Z

From: Sourab Gupta <sourab.gupta@intel.com>

Adding the flag 'I915_CPU_MAP_NOT_NEEDED' to gem_create ioctl.
This is to indicate the driver that direct cpu access to this
buffer object is not needed and hence Driver can opt to use Stolen
area as a backing store for it.

Testcase: igt/gem_stolen_mem

Signed-off-by: Sourab Gupta <sourab.gupta@intel.com>

Signed-off-by: Akash Goel <akash.goel@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 6 ++++++
drivers/gpu/drm/i915/i915_gem.c | 12 +++++++++---
include/uapi/drm/i915_drm.h | 3 ++-
3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 05cfcc1..8a066a7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1714,6 +1714,12 @@ struct drm_i915_gem_object {
unsigned int has_global_gtt_mapping:1;
unsigned int has_dma_mapping:1;

+ /*
+ * Is the object not required to be accessed from CPU
+ */
+ unsigned int cpu_map_not_needed:1;
+
+
struct sg_table *pages;
int pages_pin_count;

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3618bb0..8421b80 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -224,7 +224,9 @@ static int
i915_gem_create(struct drm_file *file,
struct drm_device *dev,
uint64_t size,
- uint32_t *handle_p)
+ uint32_t *handle_p,
+ uint32_t flags)
+
{
struct drm_i915_gem_object *obj;
int ret;
@@ -245,6 +247,10 @@ i915_gem_create(struct drm_file *file,
if (ret)
return ret;

+ if (flags & I915_CPU_MAP_NOT_NEEDED)
+ obj->cpu_map_not_needed = 1;
+
+
*handle_p = handle;
return 0;
}
@@ -258,7 +264,7 @@ i915_gem_dumb_create(struct drm_file *file,
args->pitch = ALIGN(args->width * DIV_ROUND_UP(args->bpp, 8), 64);
args->size = args->pitch * args->height;
return i915_gem_create(file, dev,
- args->size, &args->handle);
+ args->size, &args->handle, args->flags);
}

/**
@@ -271,7 +277,7 @@ i915_gem_create_ioctl(struct drm_device *dev, void *data,
struct drm_i915_gem_create *args = data;

return i915_gem_create(file, dev,
- args->size, &args->handle);
+ args->size, &args->handle, args->flags);
}

static inline int
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 126bfaa..8625f54 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -431,7 +431,8 @@ struct drm_i915_gem_create {
* Object handles are nonzero.
*/
__u32 handle;
- __u32 pad;
+ __u32 flags;
+#define I915_CPU_MAP_NOT_NEEDED 0x1
};

struct drm_i915_gem_pread {
--
1.7.9.5