[PATCH 4/5] drm/i915: cpu-map based dumb buffers

Abdiel Janulgue
2019-10-23T08:25:11Z

Prefer CPU WC mmaps via our new mmap offset plumbing otherwise fall-
back to GTT mmaps when hw doesn't support PAT

Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 13 +++++++++++++
drivers/gpu/drm/i915/i915_drv.c | 1 +
drivers/gpu/drm/i915/i915_drv.h | 2 ++
3 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index a3eb194fd3b4..db810af1cc13 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -566,6 +566,19 @@ static int gem_mmap_offset(struct drm_device *dev, void *data,
&args->offset);
}

+int
+i915_gem_mmap_dumb(struct drm_file *file,
+ struct drm_device *dev,
+ u32 handle,
+ u64 *offset)
+{
+ enum i915_mmap_type mmap_type = boot_cpu_has(X86_FEATURE_PAT) ?
+ I915_MMAP_TYPE_WC : I915_MMAP_TYPE_GTT;
+
+ return __assign_gem_object_mmap_data(file, handle, mmap_type,
+ offset);
+}
+
/**
* i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
* @dev: DRM device
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 7dba9b2ea00b..031f59c9e5c9 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2750,6 +2750,7 @@ static struct drm_driver driver = {
.get_scanout_position = i915_get_crtc_scanoutpos,

.dumb_create = i915_gem_dumb_create,
+ .dumb_map_offset = i915_gem_mmap_dumb,
.ioctls = i915_ioctls,
.num_ioctls = ARRAY_SIZE(i915_ioctls),
.fops = &i915_driver_fops,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ed0fc1d6dfab..fa26f0575efe 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1932,6 +1932,8 @@ i915_mutex_lock_interruptible(struct drm_device *dev)
int i915_gem_dumb_create(struct drm_file *file_priv,
struct drm_device *dev,
struct drm_mode_create_dumb *args);
+int i915_gem_mmap_dumb(struct drm_file *file_priv, struct drm_device *dev,
+ u32 handle, u64 *offset);
int i915_gem_mmap_gtt_version(void);

int __must_check i915_gem_set_global_seqno(struct drm_device *dev, u32 seqno);