From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
This enables mapping via CPU using the proper DRM mmap API for
better debug (Valgrind) and implementation symmetry in the
driver.
v2:
* Use normal mutex, skip domain management and pin pages. (Chris Wilson)
* No need to drop struct mutex over vma_insert_pfn.
* Turn off write-combine set up by the DRM core.
* Commit message.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem.c | 98 ++++++++++++++++++++++++++++++++++++++---
include/uapi/drm/i915_drm.h | 3 ++
2 files changed, 95 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a1e2832047e2..a690cee31f20 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1954,6 +1954,62 @@ out:
return i915_gem_ret_to_vm_ret(dev_priv, ret);
}
+static int
+i915_gem_cpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct drm_i915_gem_object *obj = to_intel_bo(vma->vm_private_data);
+ struct drm_device *dev = obj->base.dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ bool write = !!(vmf->flags & FAULT_FLAG_WRITE);
+ pgoff_t page_offset;
+ struct page *page;
+ unsigned long pgprot;
+ int ret;
+
+ /* We don't use vmf->pgoff since that has the fake offset */
+ page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
+ PAGE_SHIFT;
+
+ trace_i915_gem_object_fault(obj, page_offset, true, write);
+
+ intel_runtime_pm_get(dev_priv);
+
+ ret = mutex_lock_interruptible(&dev->struct_mutex);
+ if (ret)
+ goto out;
+
+ ret = i915_gem_object_get_pages(obj);
+ if (ret)
+ goto out_unlock;
+
+ i915_gem_object_pin_pages(obj);
+
+ page = i915_gem_object_get_page(obj, page_offset);
+ if (!page) {
+ ret = -EFAULT;
+ goto out_unpin;
+ }
+
+ ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address,
+ page_to_pfn(page));
+ if (ret == 0) {
+ /* DRM core sets up WC by default and we want WB. */
+ pgprot = pgprot_val(vm_get_page_prot(vma->vm_flags));
+ pgprot &= ~_PAGE_CACHE_MASK;
+ pgprot |= cachemode2protval(_PAGE_CACHE_MODE_WB);
+ vma->vm_page_prot = __pgprot(pgprot);
+ }
+
+out_unpin:
+ i915_gem_object_unpin_pages(obj);
+out_unlock:
+ mutex_unlock(&dev->struct_mutex);
+out:
+ intel_runtime_pm_put(dev_priv);
+
+ return i915_gem_ret_to_vm_ret(dev_priv, ret);
+}
+
/**
* i915_gem_release_mmap - remove physical page mappings
* @obj: obj in question
@@ -2078,11 +2134,18 @@ static void i915_gem_object_free_mmap_offset(struct drm_i915_gem_object *obj)
drm_gem_free_mmap_offset(&obj->base);
}
-int
-i915_gem_mmap_gtt(struct drm_file *file,
- struct drm_device *dev,
- uint32_t handle,
- uint64_t *offset)
+static const struct vm_operations_struct i915_gem_cpu_vm_ops = {
+ .fault = i915_gem_cpu_fault,
+ .open = drm_gem_vm_open,
+ .close = drm_gem_vm_close,
+};
+
+static int
+i915_gem_mmap(struct drm_file *file,
+ struct drm_device *dev,
+ uint32_t handle,
+ uint32_t flags,
+ uint64_t *offset)
{
struct drm_i915_gem_object *obj;
int ret;
@@ -2103,10 +2166,23 @@ i915_gem_mmap_gtt(struct drm_file *file,
goto out;
}
+ if (!obj->base.filp && (flags & I915_MMAP2_CPU)) {
+ DRM_DEBUG("Attempting to mmap non-shm based object via CPU!\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
ret = i915_gem_object_create_mmap_offset(obj);
if (ret)
goto out;
+ if (flags & I915_MMAP2_CPU) {
+ ret = drm_vma_node_set_vm_ops(&obj->base.vma_node,
+ &i915_gem_cpu_vm_ops);
+ if (ret)
+ goto out;
+ }
+
*offset = drm_vma_node_offset_addr(&obj->base.vma_node);
out:
@@ -2116,6 +2192,15 @@ unlock:
return ret;
}
+int
+i915_gem_mmap_gtt(struct drm_file *file,
+ struct drm_device *dev,
+ uint32_t handle,
+ uint64_t *offset)
+{
+ return i915_gem_mmap(file, dev, handle, 0, offset);
+}
+
/**
* i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
* @dev: DRM device
@@ -2137,7 +2222,8 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
{
struct drm_i915_gem_mmap_gtt *args = data;
- return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
+ return i915_gem_mmap(file, dev, args->handle, args->flags,
+ &args->offset);
}
/* Immediately discard the backing storage */
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 6a19371391fa..359a36d604bb 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -528,6 +528,9 @@ struct drm_i915_gem_mmap_gtt {
* This is a fixed-size type for 32/64 compatibility.
*/
__u64 offset;
+
+#define I915_MMAP2_CPU 0x1
+ __u64 flags;
};
struct drm_i915_gem_set_domain {
--
1.9.1
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