[Mesa-dev] [PATCH] gallium/sw/kms: Fix multiple imports from PRIME FDs

[Tomasz Figa]

When a buffer with a GEM handle already existing in our context is
(re-)imported from a PRIME FD, the resulting GEM handle is exactly the
same as the original one. Since the GEM handles are not reference
counted, we need to detect duplicate imports and reference count our
internal buffer structs ourselves.

Signed-off-by: Tomasz Figa <tfiga at chromium.org>
---
 src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c | 30 +++++++++++++++++------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
index 21ac0d7..c4f56cb 100644
--- a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
+++ b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
@@ -211,7 +211,9 @@ kms_sw_displaytarget_map(struct sw_winsys *ws,
 }
 
 static struct kms_sw_displaytarget *
-kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd)
+kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd,
+                                    unsigned width, unsigned height,
+                                    unsigned stride)
 {
    uint32_t handle = -1;
    struct kms_sw_displaytarget * kms_sw_dt;
@@ -222,6 +224,17 @@ kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd)
    if (ret)
       return NULL;
 
+   LIST_FOR_EACH_ENTRY(kms_sw_dt, &kms_sw->bo_list, link) {
+      if (kms_sw_dt->handle == handle) {
+         kms_sw_dt->ref_count++;
+
+         DEBUG_PRINT("KMS-DEBUG: imported buffer %u (size %u)\n",
+                     kms_sw_dt->handle, kms_sw_dt->size);
+
+         return kms_sw_dt;
+      }
+   }
+
    kms_sw_dt = CALLOC_STRUCT(kms_sw_displaytarget);
    if (!kms_sw_dt)
       return NULL;
@@ -229,6 +242,9 @@ kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd)
    kms_sw_dt->ref_count = 1;
    kms_sw_dt->handle = handle;
    kms_sw_dt->size = lseek(fd, 0, SEEK_END);
+   kms_sw_dt->width = width;
+   kms_sw_dt->height = height;
+   kms_sw_dt->stride = stride;
 
    if (kms_sw_dt->size == (off_t)-1) {
       FREE(kms_sw_dt);
@@ -274,14 +290,12 @@ kms_sw_displaytarget_from_handle(struct sw_winsys *ws,
 
    switch(whandle->type) {
    case DRM_API_HANDLE_TYPE_FD:
-      kms_sw_dt = kms_sw_displaytarget_add_from_prime(kms_sw, whandle->handle);
-      if (kms_sw_dt) {
-         kms_sw_dt->ref_count++;
-         kms_sw_dt->width = templ->width0;
-         kms_sw_dt->height = templ->height0;
-         kms_sw_dt->stride = whandle->stride;
+      kms_sw_dt = kms_sw_displaytarget_add_from_prime(kms_sw, whandle->handle,
+                                                      templ->width0,
+                                                      templ->height0,
+                                                      whandle->stride);
+      if (kms_sw_dt)
          *stride = kms_sw_dt->stride;
-      }
       return (struct sw_displaytarget *)kms_sw_dt;
    case DRM_API_HANDLE_TYPE_KMS:
       LIST_FOR_EACH_ENTRY(kms_sw_dt, &kms_sw->bo_list, link) {
-- 
2.8.0.rc3.226.g39d4020