We need to add support for pread'ing an LMEM object.

Signed-off-by: Matthew Auld <matthew.a...@intel.com>
Cc: Joonas Lahtinen <joonas.lahti...@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janul...@linux.intel.com>
---
 .../gpu/drm/i915/gem/i915_gem_object_types.h  |  2 +
 drivers/gpu/drm/i915/i915_gem.c               |  6 ++
 drivers/gpu/drm/i915/intel_region_lmem.c      | 76 +++++++++++++++++++
 3 files changed, 84 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h 
b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 80ff5ad9bc07..8cdee185251a 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -52,6 +52,8 @@ struct drm_i915_gem_object_ops {
        void (*truncate)(struct drm_i915_gem_object *obj);
        void (*writeback)(struct drm_i915_gem_object *obj);
 
+       int (*pread)(struct drm_i915_gem_object *,
+                    const struct drm_i915_gem_pread *arg);
        int (*pwrite)(struct drm_i915_gem_object *obj,
                      const struct drm_i915_gem_pwrite *arg);
 
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 85677ae89849..4ba386ab35e7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -463,6 +463,12 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
 
        trace_i915_gem_object_pread(obj, args->offset, args->size);
 
+       ret = -ENODEV;
+       if (obj->ops->pread)
+               ret = obj->ops->pread(obj, args);
+       if (ret != -ENODEV)
+               goto out;
+
        ret = i915_gem_object_wait(obj,
                                   I915_WAIT_INTERRUPTIBLE,
                                   MAX_SCHEDULE_TIMEOUT);
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.c 
b/drivers/gpu/drm/i915/intel_region_lmem.c
index 701bcac3479e..54b2c7bf177d 100644
--- a/drivers/gpu/drm/i915/intel_region_lmem.c
+++ b/drivers/gpu/drm/i915/intel_region_lmem.c
@@ -7,10 +7,86 @@
 #include "intel_memory_region.h"
 #include "intel_region_lmem.h"
 
+static int lmem_pread(struct drm_i915_gem_object *obj,
+                     const struct drm_i915_gem_pread *arg)
+{
+       struct drm_i915_private *i915 = to_i915(obj->base.dev);
+       struct intel_runtime_pm *rpm = &i915->runtime_pm;
+       intel_wakeref_t wakeref;
+       struct dma_fence *fence;
+       char __user *user_data;
+       unsigned int offset;
+       unsigned long idx;
+       u64 remain;
+       int ret;
+
+       ret = i915_gem_object_pin_pages(obj);
+       if (ret)
+               return ret;
+
+       i915_gem_object_lock(obj);
+       ret = i915_gem_object_set_to_wc_domain(obj, false);
+       if (ret) {
+               i915_gem_object_unlock(obj);
+               goto out_unpin;
+       }
+
+       fence = i915_gem_object_lock_fence(obj);
+       i915_gem_object_unlock(obj);
+       if (!fence) {
+               ret = -ENOMEM;
+               goto out_unpin;
+       }
+
+       wakeref = intel_runtime_pm_get(rpm);
+
+       remain = arg->size;
+       user_data = u64_to_user_ptr(arg->data_ptr);
+       offset = offset_in_page(arg->offset);
+       for (idx = arg->offset >> PAGE_SHIFT; remain; idx++) {
+               unsigned long unwritten;
+               void __iomem *vaddr;
+               int length;
+
+               length = remain;
+               if (offset + length > PAGE_SIZE)
+                       length = PAGE_SIZE - offset;
+
+               vaddr = i915_gem_object_lmem_io_map_page(obj, idx);
+               if (!vaddr) {
+                       ret = -ENOMEM;
+                       goto out_put;
+               }
+
+               unwritten = copy_to_user(user_data,
+                                        (void __force *)vaddr + offset,
+                                        length);
+               io_mapping_unmap_atomic(vaddr);
+               if (unwritten) {
+                       ret = -EFAULT;
+                       goto out_put;
+               }
+
+               remain -= length;
+               user_data += length;
+               offset = 0;
+       }
+
+out_put:
+       intel_runtime_pm_put(rpm, wakeref);
+       i915_gem_object_unlock_fence(obj, fence);
+out_unpin:
+       i915_gem_object_unpin_pages(obj);
+
+       return ret;
+}
+
 static const struct drm_i915_gem_object_ops region_lmem_obj_ops = {
        .get_pages = i915_memory_region_get_pages_buddy,
        .put_pages = i915_memory_region_put_pages_buddy,
        .release = i915_gem_object_release_memory_region,
+
+       .pread = lmem_pread,
 };
 
 static struct drm_i915_gem_object *
-- 
2.20.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to