intel: Add support for userptr objects

Allow userptr objects to be created and used via libdrm_intel.

At the moment tiling and mapping to GTT aperture is not supported
due hardware limitations across different generations and uncertainty
about its usefulness.

v2: Improved error handling in feature detection per review comments.

v3: Rebase on top of the drm_public addition, minor whitespace addition.

Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> (v3)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v1,v2)

diff --git a/intel/intel_bufmgr.c b/intel/intel_bufmgr.c
index 03dba50..234cd13 100644 (file)
--- a/intel/intel_bufmgr.c
+++ b/intel/intel_bufmgr.c
@@ -62,6 +62,20 @@ drm_intel_bo_alloc_for_render(drm_intel_bufmgr *bufmgr, const char *name,
 }
 
 drm_public drm_intel_bo *
+drm_intel_bo_alloc_userptr(drm_intel_bufmgr *bufmgr,
+                          const char *name, void *addr,
+                          uint32_t tiling_mode,
+                          uint32_t stride,
+                          unsigned long size,
+                          unsigned long flags)
+{
+       if (bufmgr->bo_alloc_userptr)
+               return bufmgr->bo_alloc_userptr(bufmgr, name, addr, tiling_mode,
+                                               stride, size, flags);
+       return NULL;
+}
+
+drm_public drm_intel_bo *
 drm_intel_bo_alloc_tiled(drm_intel_bufmgr *bufmgr, const char *name,
                         int x, int y, int cpp, uint32_t *tiling_mode,
                         unsigned long *pitch, unsigned long flags)

diff --git a/intel/intel_bufmgr.h b/intel/intel_bufmgr.h
index 9383c72..be83a56 100644 (file)
--- a/intel/intel_bufmgr.h
+++ b/intel/intel_bufmgr.h
@@ -113,6 +113,11 @@ drm_intel_bo *drm_intel_bo_alloc_for_render(drm_intel_bufmgr *bufmgr,
                                            const char *name,
                                            unsigned long size,
                                            unsigned int alignment);
+drm_intel_bo *drm_intel_bo_alloc_userptr(drm_intel_bufmgr *bufmgr,
+                                       const char *name,
+                                       void *addr, uint32_t tiling_mode,
+                                       uint32_t stride, unsigned long size,
+                                       unsigned long flags);
 drm_intel_bo *drm_intel_bo_alloc_tiled(drm_intel_bufmgr *bufmgr,
                                       const char *name,
                                       int x, int y, int cpp,

diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 4e34f75..f378e5c 100644 (file)
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -187,6 +187,11 @@ struct _drm_intel_bo_gem {
        void *mem_virtual;
        /** GTT virtual address for the buffer, saved across map/unmap cycles */
        void *gtt_virtual;
+       /**
+        * Virtual address of the buffer allocated by user, used for userptr
+        * objects only.
+        */
+       void *user_virtual;
        int map_count;
        drmMMListHead vma_list;
 
@@ -226,6 +231,11 @@ struct _drm_intel_bo_gem {
        bool idle;
 
        /**
+        * Boolean of whether this buffer was allocated with userptr
+        */
+       bool is_userptr;
+
+       /**
         * Size in bytes of this buffer and its relocation descendents.
         *
         * Used to avoid costly tree walking in
@@ -852,6 +862,80 @@ drm_intel_gem_bo_alloc_tiled(drm_intel_bufmgr *bufmgr, const char *name,
                                               tiling, stride);
 }
 
+static drm_intel_bo *
+drm_intel_gem_bo_alloc_userptr(drm_intel_bufmgr *bufmgr,
+                               const char *name,
+                               void *addr,
+                               uint32_t tiling_mode,
+                               uint32_t stride,
+                               unsigned long size,
+                               unsigned long flags)
+{
+       drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bufmgr;
+       drm_intel_bo_gem *bo_gem;
+       int ret;
+       struct drm_i915_gem_userptr userptr;
+
+       /* Tiling with userptr surfaces is not supported
+        * on all hardware so refuse it for time being.
+        */
+       if (tiling_mode != I915_TILING_NONE)
+               return NULL;
+
+       bo_gem = calloc(1, sizeof(*bo_gem));
+       if (!bo_gem)
+               return NULL;
+
+       bo_gem->bo.size = size;
+
+       VG_CLEAR(userptr);
+       userptr.user_ptr = (__u64)((unsigned long)addr);
+       userptr.user_size = size;
+       userptr.flags = flags;
+
+       ret = drmIoctl(bufmgr_gem->fd,
+                       DRM_IOCTL_I915_GEM_USERPTR,
+                       &userptr);
+       if (ret != 0) {
+               DBG("bo_create_userptr: "
+                   "ioctl failed with user ptr %p size 0x%lx, "
+                   "user flags 0x%lx\n", addr, size, flags);
+               free(bo_gem);
+               return NULL;
+       }
+
+       bo_gem->gem_handle = userptr.handle;
+       bo_gem->bo.handle = bo_gem->gem_handle;
+       bo_gem->bo.bufmgr    = bufmgr;
+       bo_gem->is_userptr   = true;
+       bo_gem->bo.virtual   = addr;
+       /* Save the address provided by user */
+       bo_gem->user_virtual = addr;
+       bo_gem->tiling_mode  = I915_TILING_NONE;
+       bo_gem->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
+       bo_gem->stride       = 0;
+
+       DRMINITLISTHEAD(&bo_gem->name_list);
+       DRMINITLISTHEAD(&bo_gem->vma_list);
+
+       bo_gem->name = name;
+       atomic_set(&bo_gem->refcount, 1);
+       bo_gem->validate_index = -1;
+       bo_gem->reloc_tree_fences = 0;
+       bo_gem->used_as_reloc_target = false;
+       bo_gem->has_error = false;
+       bo_gem->reusable = false;
+
+       drm_intel_bo_gem_set_in_aperture_size(bufmgr_gem, bo_gem);
+
+       DBG("bo_create_userptr: "
+           "ptr %p buf %d (%s) size %ldb, stride 0x%x, tile mode %d\n",
+               addr, bo_gem->gem_handle, bo_gem->name,
+               size, stride, tiling_mode);
+
+       return &bo_gem->bo;
+}
+
 /**
  * Returns a drm_intel_bo wrapping the given buffer object handle.
  *
@@ -1183,6 +1267,12 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
        struct drm_i915_gem_set_domain set_domain;
        int ret;
 
+       if (bo_gem->is_userptr) {
+               /* Return the same user ptr */
+               bo->virtual = bo_gem->user_virtual;
+               return 0;
+       }
+
        pthread_mutex_lock(&bufmgr_gem->lock);
 
        if (bo_gem->map_count++ == 0)
@@ -1251,6 +1341,9 @@ map_gtt(drm_intel_bo *bo)
        drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
        int ret;
 
+       if (bo_gem->is_userptr)
+               return -EINVAL;
+
        if (bo_gem->map_count++ == 0)
                drm_intel_gem_bo_open_vma(bufmgr_gem, bo_gem);
 
@@ -1397,13 +1490,18 @@ drm_intel_gem_bo_map_unsynchronized(drm_intel_bo *bo)
 
 static int drm_intel_gem_bo_unmap(drm_intel_bo *bo)
 {
-       drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+       drm_intel_bufmgr_gem *bufmgr_gem;
        drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
        int ret = 0;
 
        if (bo == NULL)
                return 0;
 
+       if (bo_gem->is_userptr)
+               return 0;
+
+       bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+
        pthread_mutex_lock(&bufmgr_gem->lock);
 
        if (bo_gem->map_count <= 0) {
@@ -1462,6 +1560,9 @@ drm_intel_gem_bo_subdata(drm_intel_bo *bo, unsigned long offset,
        struct drm_i915_gem_pwrite pwrite;
        int ret;
 
+       if (bo_gem->is_userptr)
+               return -EINVAL;
+
        VG_CLEAR(pwrite);
        pwrite.handle = bo_gem->gem_handle;
        pwrite.offset = offset;
@@ -1514,6 +1615,9 @@ drm_intel_gem_bo_get_subdata(drm_intel_bo *bo, unsigned long offset,
        struct drm_i915_gem_pread pread;
        int ret;
 
+       if (bo_gem->is_userptr)
+               return -EINVAL;
+
        VG_CLEAR(pread);
        pread.handle = bo_gem->gem_handle;
        pread.offset = offset;
@@ -2481,6 +2585,12 @@ drm_intel_gem_bo_set_tiling(drm_intel_bo *bo, uint32_t * tiling_mode,
        drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
        int ret;
 
+       /* Tiling with userptr surfaces is not supported
+        * on all hardware so refuse it for time being.
+        */
+       if (bo_gem->is_userptr)
+               return -EINVAL;
+
        /* Linear buffers have no stride. By ensuring that we only ever use
         * stride 0 with linear buffers, we simplify our code.
         */
@@ -3237,6 +3347,53 @@ drm_intel_bufmgr_gem_unref(drm_intel_bufmgr *bufmgr)
        }
 }
 
+static bool
+has_userptr(drm_intel_bufmgr_gem *bufmgr_gem)
+{
+       int ret;
+       void *ptr;
+       long pgsz;
+       struct drm_i915_gem_userptr userptr;
+       struct drm_gem_close close_bo;
+
+       pgsz = sysconf(_SC_PAGESIZE);
+       assert(pgsz > 0);
+
+       ret = posix_memalign(&ptr, pgsz, pgsz);
+       if (ret) {
+               DBG("Failed to get a page (%ld) for userptr detection!\n",
+                       pgsz);
+               return false;
+       }
+
+       memset(&userptr, 0, sizeof(userptr));
+       userptr.user_ptr = (__u64)(unsigned long)ptr;
+       userptr.user_size = pgsz;
+
+retry:
+       ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_USERPTR, &userptr);
+       if (ret) {
+               if (errno == ENODEV && userptr.flags == 0) {
+                       userptr.flags = I915_USERPTR_UNSYNCHRONIZED;
+                       goto retry;
+               }
+               free(ptr);
+               return false;
+       }
+
+       close_bo.handle = userptr.handle;
+       ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_GEM_CLOSE, &close_bo);
+       if (ret == 0) {
+               free(ptr);
+       } else {
+               fprintf(stderr, "Failed to release test userptr object! (%d) "
+                               "i915 kernel driver may not be sane!\n", errno);
+               return false;
+       }
+
+       return true;
+}
+
 /**
  * Initializes the GEM buffer manager, which uses the kernel to allocate, map,
  * and manage map buffer objections.
@@ -3338,6 +3495,10 @@ drm_intel_bufmgr_gem_init(int fd, int batch_size)
        ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GETPARAM, &gp);
        bufmgr_gem->has_relaxed_fencing = ret == 0;
 
+       if (has_userptr(bufmgr_gem))
+               bufmgr_gem->bufmgr.bo_alloc_userptr =
+                       drm_intel_gem_bo_alloc_userptr;
+
        gp.param = I915_PARAM_HAS_WAIT_TIMEOUT;
        ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GETPARAM, &gp);
        bufmgr_gem->has_wait_timeout = ret == 0;

diff --git a/intel/intel_bufmgr_priv.h b/intel/intel_bufmgr_priv.h
index 2592d42..59ebd18 100644 (file)
--- a/intel/intel_bufmgr_priv.h
+++ b/intel/intel_bufmgr_priv.h
@@ -62,6 +62,18 @@ struct _drm_intel_bufmgr {
                                              unsigned int alignment);
 
        /**
+        * Allocate a buffer object from an existing user accessible
+        * address malloc'd with the provided size.
+        * Alignment is used when mapping to the gtt.
+        * Flags may be I915_VMAP_READ_ONLY or I915_USERPTR_UNSYNCHRONIZED
+        */
+       drm_intel_bo *(*bo_alloc_userptr)(drm_intel_bufmgr *bufmgr,
+                                         const char *name, void *addr,
+                                         uint32_t tiling_mode, uint32_t stride,
+                                         unsigned long size,
+                                         unsigned long flags);
+
+       /**
         * Allocate a tiled buffer object.
         *
         * Alignment for tiled objects is set automatically; the 'flags'