Revert "winsys/amdgpu: Re-use amdgpu_screen_winsys when possible"

This reverts commit b60f5cbc15a99ddd9251bce40eae7d84c3a1c373.

This fixes dmesg errors and X freezes:
[   29.543096] amdgpu 0000:0c:00.0: No GEM object associated to handle 0x00000009, can't create framebuffer
[   29.543103] amdgpu 0000:0c:00.0: No GEM object associated to handle 0x00000009, can't create framebuffer

2 files changed, 24 insertions, 45 deletions

diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c
index 8fadf584e3f..000abd00a14 100644
--- a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c
+++ b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c
@@ -30,7 +30,6 @@
 #include "amdgpu_cs.h"
 #include "amdgpu_public.h"
 
-#include "util/os_file.h"
 #include "util/u_cpu_detect.h"
 #include "util/u_hash_table.h"
 #include "util/hash_table.h"
@@ -173,8 +172,26 @@ static void amdgpu_winsys_destroy(struct radeon_winsys *rws)
 
    simple_mtx_unlock(&dev_tab_mutex);
 
-   if (destroy)
+   if (destroy) {
       do_winsys_deinit(ws);
+   } else {
+      struct amdgpu_screen_winsys **sws_iter;
+
+      /* Remove this amdgpu_screen_winsys from amdgpu_winsys' list */
+      simple_mtx_lock(&ws->sws_list_lock);
+      for (sws_iter = &ws->sws_list; *sws_iter; sws_iter = &(*sws_iter)->next) {
+         if (*sws_iter == sws) {
+            *sws_iter = sws->next;
+            break;
+         }
+      }
+      simple_mtx_unlock(&ws->sws_list_lock);
+   }
+
+   if (sws->kms_handles) {
+      assert(!destroy);
+      _mesa_hash_table_destroy(sws->kms_handles, NULL);
+   }
 
    close(sws->fd);
    FREE(rws);
@@ -280,34 +297,11 @@ static int compare_pointers(void *key1, void *key2)
 
 static bool amdgpu_winsys_unref(struct radeon_winsys *rws)
 {
-   struct amdgpu_screen_winsys *sws = amdgpu_screen_winsys(rws);
-   struct amdgpu_winsys *aws = sws->aws;
-   bool ret;
-
-   simple_mtx_lock(&aws->sws_list_lock);
-
-   ret = pipe_reference(&sws->reference, NULL);
-   if (ret) {
-      struct amdgpu_screen_winsys **sws_iter;
-      struct amdgpu_winsys *aws = sws->aws;
-
-      /* Remove this amdgpu_screen_winsys from amdgpu_winsys' list, so that
-       * amdgpu_winsys_create can't re-use it anymore
-       */
-      for (sws_iter = &aws->sws_list; *sws_iter; sws_iter = &(*sws_iter)->next) {
-         if (*sws_iter == sws) {
-            *sws_iter = sws->next;
-            break;
-         }
-      }
-   }
-
-   simple_mtx_unlock(&aws->sws_list_lock);
-
-   if (ret && sws->kms_handles)
-      _mesa_hash_table_destroy(sws->kms_handles, NULL);
-
-   return ret;
+   /* radeon_winsys corresponds to amdgpu_screen_winsys, which is never
+    * referenced multiple times, so amdgpu_winsys_destroy always needs to be
+    * called. It handles reference counting for amdgpu_winsys.
+    */
+   return true;
 }
 
 static void amdgpu_pin_threads_to_L3_cache(struct radeon_winsys *rws,
@@ -344,7 +338,6 @@ amdgpu_winsys_create(int fd, const struct pipe_screen_config *config,
    if (!ws)
       return NULL;
 
-   pipe_reference_init(&ws->reference, 1);
    ws->fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
 
    /* Look up the winsys from the dev table. */
@@ -363,24 +356,12 @@ amdgpu_winsys_create(int fd, const struct pipe_screen_config *config,
    /* Lookup a winsys if we have already created one for this device. */
    aws = util_hash_table_get(dev_tab, dev);
    if (aws) {
-      struct amdgpu_screen_winsys *sws_iter;
-
       /* Release the device handle, because we don't need it anymore.
        * This function is returning an existing winsys instance, which
        * has its own device handle.
        */
       amdgpu_device_deinitialize(dev);
 
-      for (sws_iter = aws->sws_list; sws_iter; sws_iter = sws_iter->next) {
-         if (os_same_file_description(sws_iter->fd, aws->fd)) {
-            close(ws->fd);
-            FREE(ws);
-            ws = sws_iter;
-            pipe_reference(NULL, &ws->reference);
-            goto unlock;
-         }
-      }
-
       ws->kms_handles = _mesa_hash_table_create(NULL, kms_handle_hash,
                                                 kms_handle_equals);
       if (!ws->kms_handles)
@@ -497,7 +478,6 @@ amdgpu_winsys_create(int fd, const struct pipe_screen_config *config,
    aws->sws_list = ws;
    simple_mtx_unlock(&aws->sws_list_lock);
 
-unlock:
    /* We must unlock the mutex once the winsys is fully initialized, so that
     * other threads attempting to create the winsys from the same fd will
     * get a fully initialized winsys and not just half-way initialized. */
diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
index a22be6086dc..c2edf4f46dc 100644
--- a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
+++ b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
@@ -107,7 +107,6 @@ struct amdgpu_screen_winsys {
    struct radeon_winsys base;
    struct amdgpu_winsys *aws;
    int fd;
-   struct pipe_reference reference;
    struct amdgpu_screen_winsys *next;
 
    /* Maps a BO to its KMS handle valid for this DRM file descriptor