drm/vmwgfx: Implement a buffer object synccpu ioctl.
authorThomas Hellstrom <thellstrom@vmware.com>
Wed, 21 Nov 2012 11:32:19 +0000 (12:32 +0100)
committerThomas Hellstrom <thellstrom@vmware.com>
Fri, 17 Jan 2014 06:52:33 +0000 (07:52 +0100)
This ioctl enables inter-process synchronization of buffer objects,
which is needed for mesa Guest-Backed objects.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
include/uapi/drm/vmwgfx_drm.h

index cfeaa478dcd7154b92c0dc92e3e01429a60bbd21..fb56676ed3eeb3fbb58412a69a20cd19e841ed74 100644 (file)
 #define DRM_IOCTL_VMW_GB_SURFACE_REF                           \
        DRM_IOWR(DRM_COMMAND_BASE + DRM_VMW_GB_SURFACE_REF,     \
                 union drm_vmw_gb_surface_reference_arg)
+#define DRM_IOCTL_VMW_SYNCCPU                                  \
+       DRM_IOW(DRM_COMMAND_BASE + DRM_VMW_SYNCCPU,             \
+                struct drm_vmw_synccpu_arg)
 
 /**
  * The core DRM version of this macro doesn't account for
@@ -201,6 +204,9 @@ static const struct drm_ioctl_desc vmw_ioctls[] = {
        VMW_IOCTL_DEF(VMW_GB_SURFACE_REF,
                      vmw_gb_surface_reference_ioctl,
                      DRM_AUTH | DRM_UNLOCKED),
+       VMW_IOCTL_DEF(VMW_SYNCCPU,
+                     vmw_user_dmabuf_synccpu_ioctl,
+                     DRM_AUTH | DRM_UNLOCKED),
 };
 
 static struct pci_device_id vmw_pci_id_list[] = {
index e0859eebe7b6f1a6d92f66740c6d72ac196eb5d7..fe3c2e3e1cbe12e1e535686f7ea118b895e2e7aa 100644 (file)
@@ -533,6 +533,8 @@ extern int vmw_dmabuf_alloc_ioctl(struct drm_device *dev, void *data,
                                  struct drm_file *file_priv);
 extern int vmw_dmabuf_unref_ioctl(struct drm_device *dev, void *data,
                                  struct drm_file *file_priv);
+extern int vmw_user_dmabuf_synccpu_ioctl(struct drm_device *dev, void *data,
+                                        struct drm_file *file_priv);
 extern uint32_t vmw_dmabuf_validate_node(struct ttm_buffer_object *bo,
                                         uint32_t cur_validate_node);
 extern void vmw_dmabuf_validate_clear(struct ttm_buffer_object *bo);
index b40978f0ca967e13090087cb4b08ccb87d71f5ab..12e68e58d9e4b85474f78101a7f263172bc8f7f7 100644 (file)
@@ -441,6 +441,21 @@ static void vmw_user_dmabuf_release(struct ttm_base_object **p_base)
        ttm_bo_unref(&bo);
 }
 
+static void vmw_user_dmabuf_ref_obj_release(struct ttm_base_object *base,
+                                           enum ttm_ref_type ref_type)
+{
+       struct vmw_user_dma_buffer *user_bo;
+       user_bo = container_of(base, struct vmw_user_dma_buffer, prime.base);
+
+       switch (ref_type) {
+       case TTM_REF_SYNCCPU_WRITE:
+               ttm_bo_synccpu_write_release(&user_bo->dma.base);
+               break;
+       default:
+               BUG();
+       }
+}
+
 /**
  * vmw_user_dmabuf_alloc - Allocate a user dma buffer
  *
@@ -484,7 +499,8 @@ int vmw_user_dmabuf_alloc(struct vmw_private *dev_priv,
                                    &user_bo->prime,
                                    shareable,
                                    ttm_buffer_type,
-                                   &vmw_user_dmabuf_release, NULL);
+                                   &vmw_user_dmabuf_release,
+                                   &vmw_user_dmabuf_ref_obj_release);
        if (unlikely(ret != 0)) {
                ttm_bo_unref(&tmp);
                goto out_no_base_object;
@@ -517,6 +533,130 @@ int vmw_user_dmabuf_verify_access(struct ttm_buffer_object *bo,
                vmw_user_bo->prime.base.shareable) ? 0 : -EPERM;
 }
 
+/**
+ * vmw_user_dmabuf_synccpu_grab - Grab a struct vmw_user_dma_buffer for cpu
+ * access, idling previous GPU operations on the buffer and optionally
+ * blocking it for further command submissions.
+ *
+ * @user_bo: Pointer to the buffer object being grabbed for CPU access
+ * @tfile: Identifying the caller.
+ * @flags: Flags indicating how the grab should be performed.
+ *
+ * A blocking grab will be automatically released when @tfile is closed.
+ */
+static int vmw_user_dmabuf_synccpu_grab(struct vmw_user_dma_buffer *user_bo,
+                                       struct ttm_object_file *tfile,
+                                       uint32_t flags)
+{
+       struct ttm_buffer_object *bo = &user_bo->dma.base;
+       bool existed;
+       int ret;
+
+       if (flags & drm_vmw_synccpu_allow_cs) {
+               struct ttm_bo_device *bdev = bo->bdev;
+
+               spin_lock(&bdev->fence_lock);
+               ret = ttm_bo_wait(bo, false, true,
+                                 !!(flags & drm_vmw_synccpu_dontblock));
+               spin_unlock(&bdev->fence_lock);
+               return ret;
+       }
+
+       ret = ttm_bo_synccpu_write_grab
+               (bo, !!(flags & drm_vmw_synccpu_dontblock));
+       if (unlikely(ret != 0))
+               return ret;
+
+       ret = ttm_ref_object_add(tfile, &user_bo->prime.base,
+                                TTM_REF_SYNCCPU_WRITE, &existed);
+       if (ret != 0 || existed)
+               ttm_bo_synccpu_write_release(&user_bo->dma.base);
+
+       return ret;
+}
+
+/**
+ * vmw_user_dmabuf_synccpu_release - Release a previous grab for CPU access,
+ * and unblock command submission on the buffer if blocked.
+ *
+ * @handle: Handle identifying the buffer object.
+ * @tfile: Identifying the caller.
+ * @flags: Flags indicating the type of release.
+ */
+static int vmw_user_dmabuf_synccpu_release(uint32_t handle,
+                                          struct ttm_object_file *tfile,
+                                          uint32_t flags)
+{
+       if (!(flags & drm_vmw_synccpu_allow_cs))
+               return ttm_ref_object_base_unref(tfile, handle,
+                                                TTM_REF_SYNCCPU_WRITE);
+
+       return 0;
+}
+
+/**
+ * vmw_user_dmabuf_synccpu_release - ioctl function implementing the synccpu
+ * functionality.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller.
+ *
+ * This function checks the ioctl arguments for validity and calls the
+ * relevant synccpu functions.
+ */
+int vmw_user_dmabuf_synccpu_ioctl(struct drm_device *dev, void *data,
+                                 struct drm_file *file_priv)
+{
+       struct drm_vmw_synccpu_arg *arg =
+               (struct drm_vmw_synccpu_arg *) data;
+       struct vmw_dma_buffer *dma_buf;
+       struct vmw_user_dma_buffer *user_bo;
+       struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
+       int ret;
+
+       if ((arg->flags & (drm_vmw_synccpu_read | drm_vmw_synccpu_write)) == 0
+           || (arg->flags & ~(drm_vmw_synccpu_read | drm_vmw_synccpu_write |
+                              drm_vmw_synccpu_dontblock |
+                              drm_vmw_synccpu_allow_cs)) != 0) {
+               DRM_ERROR("Illegal synccpu flags.\n");
+               return -EINVAL;
+       }
+
+       switch (arg->op) {
+       case drm_vmw_synccpu_grab:
+               ret = vmw_user_dmabuf_lookup(tfile, arg->handle, &dma_buf);
+               if (unlikely(ret != 0))
+                       return ret;
+
+               user_bo = container_of(dma_buf, struct vmw_user_dma_buffer,
+                                      dma);
+               ret = vmw_user_dmabuf_synccpu_grab(user_bo, tfile, arg->flags);
+               vmw_dmabuf_unreference(&dma_buf);
+               if (unlikely(ret != 0 && ret != -ERESTARTSYS &&
+                            ret != -EBUSY)) {
+                       DRM_ERROR("Failed synccpu grab on handle 0x%08x.\n",
+                                 (unsigned int) arg->handle);
+                       return ret;
+               }
+               break;
+       case drm_vmw_synccpu_release:
+               ret = vmw_user_dmabuf_synccpu_release(arg->handle, tfile,
+                                                     arg->flags);
+               if (unlikely(ret != 0)) {
+                       DRM_ERROR("Failed synccpu release on handle 0x%08x.\n",
+                                 (unsigned int) arg->handle);
+                       return ret;
+               }
+               break;
+       default:
+               DRM_ERROR("Invalid synccpu operation.\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 int vmw_dmabuf_alloc_ioctl(struct drm_device *dev, void *data,
                           struct drm_file *file_priv)
 {
index bb3b91d84914837315fc3785a79c0a9cdbf55739..adb7e0d0d3b674bbcfd25402c599ccec75e79ad4 100644 (file)
 #ifndef __VMWGFX_DRM_H__
 #define __VMWGFX_DRM_H__
 
+#ifndef __KERNEL__
+#include <drm.h>
+#endif
+
 #define DRM_VMW_MAX_SURFACE_FACES 6
 #define DRM_VMW_MAX_MIP_LEVELS 24
 
@@ -59,7 +63,7 @@
 #define DRM_VMW_UNREF_SHADER         22
 #define DRM_VMW_GB_SURFACE_CREATE    23
 #define DRM_VMW_GB_SURFACE_REF       24
-
+#define DRM_VMW_SYNCCPU              25
 
 /*************************************************************************/
 /**
@@ -985,5 +989,62 @@ union drm_vmw_gb_surface_reference_arg {
 };
 
 
+/*************************************************************************/
+/**
+ * DRM_VMW_SYNCCPU - Sync a DMA buffer / MOB for CPU access.
+ *
+ * Idles any previously submitted GPU operations on the buffer and
+ * by default blocks command submissions that reference the buffer.
+ * If the file descriptor used to grab a blocking CPU sync is closed, the
+ * cpu sync is released.
+ * The flags argument indicates how the grab / release operation should be
+ * performed:
+ */
+
+/**
+ * enum drm_vmw_synccpu_flags - Synccpu flags:
+ *
+ * @drm_vmw_synccpu_read: Sync for read. If sync is done for read only, it's a
+ * hint to the kernel to allow command submissions that references the buffer
+ * for read-only.
+ * @drm_vmw_synccpu_write: Sync for write. Block all command submissions
+ * referencing this buffer.
+ * @drm_vmw_synccpu_dontblock: Dont wait for GPU idle, but rather return
+ * -EBUSY should the buffer be busy.
+ * @drm_vmw_synccpu_allow_cs: Allow command submission that touches the buffer
+ * while the buffer is synced for CPU. This is similar to the GEM bo idle
+ * behavior.
+ */
+enum drm_vmw_synccpu_flags {
+       drm_vmw_synccpu_read = (1 << 0),
+       drm_vmw_synccpu_write = (1 << 1),
+       drm_vmw_synccpu_dontblock = (1 << 2),
+       drm_vmw_synccpu_allow_cs = (1 << 3)
+};
+
+/**
+ * enum drm_vmw_synccpu_op - Synccpu operations:
+ *
+ * @drm_vmw_synccpu_grab:    Grab the buffer for CPU operations
+ * @drm_vmw_synccpu_release: Release a previous grab.
+ */
+enum drm_vmw_synccpu_op {
+       drm_vmw_synccpu_grab,
+       drm_vmw_synccpu_release
+};
+
+/**
+ * struct drm_vmw_synccpu_arg
+ *
+ * @op:                             The synccpu operation as described above.
+ * @handle:                 Handle identifying the buffer object.
+ * @flags:                  Flags as described above.
+ */
+struct drm_vmw_synccpu_arg {
+       enum drm_vmw_synccpu_op op;
+       enum drm_vmw_synccpu_flags flags;
+       uint32_t handle;
+       uint32_t pad64;
+};
 
 #endif