winsys/radeon: Use a single buffer cache manager again
[mesa.git] / src / gallium / winsys / radeon / drm / radeon_drm_winsys.c
index a831816c06e55d769f870a20cb2874721f6933a7..caba37312a751dc49f69c9fda1fca6217ef30ad6 100644 (file)
 
 #include "pipebuffer/pb_bufmgr.h"
 #include "util/u_memory.h"
+#include "util/u_hash_table.h"
 
 #include <xf86drm.h>
 #include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
-/*
- * this are copy from radeon_drm, once an updated libdrm is released
- * we should bump configure.ac requirement for it and remove the following
- * field
- */
-#ifndef RADEON_INFO_TILING_CONFIG
-#define RADEON_INFO_TILING_CONFIG 6
-#endif
-
-#ifndef RADEON_INFO_WANT_HYPERZ
-#define RADEON_INFO_WANT_HYPERZ 7
-#endif
-
-#ifndef RADEON_INFO_WANT_CMASK
-#define RADEON_INFO_WANT_CMASK 8
-#endif
-
-#ifndef RADEON_INFO_CLOCK_CRYSTAL_FREQ
-#define RADEON_INFO_CLOCK_CRYSTAL_FREQ 9
-#endif
-
-#ifndef RADEON_INFO_NUM_BACKENDS
-#define RADEON_INFO_NUM_BACKENDS 0xa
-#endif
-
-#ifndef RADEON_INFO_NUM_TILE_PIPES
-#define RADEON_INFO_NUM_TILE_PIPES 0xb
-#endif
-
-#ifndef RADEON_INFO_BACKEND_MAP
-#define RADEON_INFO_BACKEND_MAP 0xd
-#endif
-
-#ifndef RADEON_INFO_VA_START
-/* virtual address start, va < start are reserved by the kernel */
-#define RADEON_INFO_VA_START        0x0e
-/* maximum size of ib using the virtual memory cs */
-#define RADEON_INFO_IB_VM_MAX_SIZE  0x0f
-#endif
-
-#ifndef RADEON_INFO_MAX_PIPES
-#define RADEON_INFO_MAX_PIPES 0x10
+#ifndef RADEON_INFO_ACTIVE_CU_COUNT
+#define RADEON_INFO_ACTIVE_CU_COUNT 0x20
 #endif
 
+static struct util_hash_table *fd_tab = NULL;
+pipe_static_mutex(fd_tab_mutex);
 
 /* Enable/disable feature access for one command stream.
  * If enable == TRUE, return TRUE on success.
@@ -95,7 +61,8 @@
 static boolean radeon_set_fd_access(struct radeon_drm_cs *applier,
                                     struct radeon_drm_cs **owner,
                                     pipe_mutex *mutex,
-                                    unsigned request, boolean enable)
+                                    unsigned request, const char *request_name,
+                                    boolean enable)
 {
     struct drm_radeon_info info;
     unsigned value = enable ? 1 : 0;
@@ -130,13 +97,13 @@ static boolean radeon_set_fd_access(struct radeon_drm_cs *applier,
     if (enable) {
         if (value) {
             *owner = applier;
-            fprintf(stderr, "radeon: Acquired Hyper-Z.\n");
+            printf("radeon: Acquired access to %s.\n", request_name);
             pipe_mutex_unlock(*mutex);
             return TRUE;
         }
     } else {
         *owner = NULL;
-        fprintf(stderr, "radeon: Released Hyper-Z.\n");
+        printf("radeon: Released access to %s.\n", request_name);
     }
 
     pipe_mutex_unlock(*mutex);
@@ -218,29 +185,132 @@ static boolean do_winsys_init(struct radeon_drm_winsys *ws)
 
     /* Check PCI ID. */
     switch (ws->info.pci_id) {
-#define CHIPSET(pci_id, name, family) case pci_id:
+#define CHIPSET(pci_id, name, cfamily) case pci_id: ws->info.family = CHIP_##cfamily; ws->gen = DRV_R300; break;
 #include "pci_ids/r300_pci_ids.h"
 #undef CHIPSET
-        ws->gen = R300;
-        break;
 
-#define CHIPSET(pci_id, name, family) case pci_id:
+#define CHIPSET(pci_id, name, cfamily) case pci_id: ws->info.family = CHIP_##cfamily; ws->gen = DRV_R600; break;
 #include "pci_ids/r600_pci_ids.h"
 #undef CHIPSET
-        ws->gen = R600;
-        break;
 
-#define CHIPSET(pci_id, name, family) case pci_id:
+#define CHIPSET(pci_id, name, cfamily) case pci_id: ws->info.family = CHIP_##cfamily; ws->gen = DRV_SI; break;
 #include "pci_ids/radeonsi_pci_ids.h"
 #undef CHIPSET
-        ws->gen = SI;
-        break;
 
     default:
         fprintf(stderr, "radeon: Invalid PCI ID.\n");
         return FALSE;
     }
 
+    switch (ws->info.family) {
+    default:
+    case CHIP_UNKNOWN:
+        fprintf(stderr, "radeon: Unknown family.\n");
+        return FALSE;
+    case CHIP_R300:
+    case CHIP_R350:
+    case CHIP_RV350:
+    case CHIP_RV370:
+    case CHIP_RV380:
+    case CHIP_RS400:
+    case CHIP_RC410:
+    case CHIP_RS480:
+        ws->info.chip_class = R300;
+        break;
+    case CHIP_R420:     /* R4xx-based cores. */
+    case CHIP_R423:
+    case CHIP_R430:
+    case CHIP_R480:
+    case CHIP_R481:
+    case CHIP_RV410:
+    case CHIP_RS600:
+    case CHIP_RS690:
+    case CHIP_RS740:
+        ws->info.chip_class = R400;
+        break;
+    case CHIP_RV515:    /* R5xx-based cores. */
+    case CHIP_R520:
+    case CHIP_RV530:
+    case CHIP_R580:
+    case CHIP_RV560:
+    case CHIP_RV570:
+        ws->info.chip_class = R500;
+        break;
+    case CHIP_R600:
+    case CHIP_RV610:
+    case CHIP_RV630:
+    case CHIP_RV670:
+    case CHIP_RV620:
+    case CHIP_RV635:
+    case CHIP_RS780:
+    case CHIP_RS880:
+        ws->info.chip_class = R600;
+        break;
+    case CHIP_RV770:
+    case CHIP_RV730:
+    case CHIP_RV710:
+    case CHIP_RV740:
+        ws->info.chip_class = R700;
+        break;
+    case CHIP_CEDAR:
+    case CHIP_REDWOOD:
+    case CHIP_JUNIPER:
+    case CHIP_CYPRESS:
+    case CHIP_HEMLOCK:
+    case CHIP_PALM:
+    case CHIP_SUMO:
+    case CHIP_SUMO2:
+    case CHIP_BARTS:
+    case CHIP_TURKS:
+    case CHIP_CAICOS:
+        ws->info.chip_class = EVERGREEN;
+        break;
+    case CHIP_CAYMAN:
+    case CHIP_ARUBA:
+        ws->info.chip_class = CAYMAN;
+        break;
+    case CHIP_TAHITI:
+    case CHIP_PITCAIRN:
+    case CHIP_VERDE:
+    case CHIP_OLAND:
+    case CHIP_HAINAN:
+        ws->info.chip_class = SI;
+        break;
+    case CHIP_BONAIRE:
+    case CHIP_KAVERI:
+    case CHIP_KABINI:
+    case CHIP_HAWAII:
+    case CHIP_MULLINS:
+        ws->info.chip_class = CIK;
+        break;
+    }
+
+    /* Check for dma */
+    ws->info.r600_has_dma = FALSE;
+    /* DMA is disabled on R700. There is IB corruption and hangs. */
+    if (ws->info.chip_class >= EVERGREEN && ws->info.drm_minor >= 27) {
+        ws->info.r600_has_dma = TRUE;
+    }
+
+    /* Check for UVD and VCE */
+    ws->info.has_uvd = FALSE;
+    ws->info.vce_fw_version = 0x00000000;
+    if (ws->info.drm_minor >= 32) {
+       uint32_t value = RADEON_CS_RING_UVD;
+        if (radeon_get_drm_value(ws->fd, RADEON_INFO_RING_WORKING,
+                                 "UVD Ring working", &value))
+            ws->info.has_uvd = value;
+
+        value = RADEON_CS_RING_VCE;
+        if (radeon_get_drm_value(ws->fd, RADEON_INFO_RING_WORKING,
+                                 NULL, &value) && value) {
+
+            if (radeon_get_drm_value(ws->fd, RADEON_INFO_VCE_FW_VERSION,
+                                     "VCE FW version", &value))
+                ws->info.vce_fw_version = value;
+       }
+    }
+
     /* Get GEM info. */
     retval = drmCommandWriteRead(ws->fd, DRM_RADEON_GEM_INFO,
             &gem_info, sizeof(gem_info));
@@ -252,10 +322,15 @@ static boolean do_winsys_init(struct radeon_drm_winsys *ws)
     ws->info.gart_size = gem_info.gart_size;
     ws->info.vram_size = gem_info.vram_size;
 
+    /* Get max clock frequency info and convert it to MHz */
+    radeon_get_drm_value(ws->fd, RADEON_INFO_MAX_SCLK, NULL,
+                         &ws->info.max_sclk);
+    ws->info.max_sclk /= 1000;
+
     ws->num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 
     /* Generation-specific queries. */
-    if (ws->gen == R300) {
+    if (ws->gen == DRV_R300) {
         if (!radeon_get_drm_value(ws->fd, RADEON_INFO_NUM_GB_PIPES,
                                   "GB pipe count",
                                   &ws->info.r300_num_gb_pipes))
@@ -266,7 +341,7 @@ static boolean do_winsys_init(struct radeon_drm_winsys *ws)
                                   &ws->info.r300_num_z_pipes))
             return FALSE;
     }
-    else if (ws->gen >= R600) {
+    else if (ws->gen >= DRV_R600) {
         if (ws->info.drm_minor >= 9 &&
             !radeon_get_drm_value(ws->fd, RADEON_INFO_NUM_BACKENDS,
                                   "num backends",
@@ -291,16 +366,18 @@ static boolean do_winsys_init(struct radeon_drm_winsys *ws)
 
         ws->info.r600_virtual_address = FALSE;
         if (ws->info.drm_minor >= 13) {
+            uint32_t ib_vm_max_size;
+
             ws->info.r600_virtual_address = TRUE;
             if (!radeon_get_drm_value(ws->fd, RADEON_INFO_VA_START, NULL,
-                                      &ws->info.r600_va_start))
+                                      &ws->va_start))
                 ws->info.r600_virtual_address = FALSE;
             if (!radeon_get_drm_value(ws->fd, RADEON_INFO_IB_VM_MAX_SIZE, NULL,
-                                      &ws->info.r600_ib_vm_max_size))
+                                      &ib_vm_max_size))
                 ws->info.r600_virtual_address = FALSE;
         }
-
-       ws->info.r600_has_streamout = ws->info.drm_minor >= 13;
+       if (ws->gen == DRV_R600 && !debug_get_bool_option("RADEON_VA", FALSE))
+               ws->info.r600_virtual_address = FALSE;
     }
 
     /* Get max pipes, this is only needed for compute shaders.  All evergreen+
@@ -309,6 +386,55 @@ static boolean do_winsys_init(struct radeon_drm_winsys *ws)
     radeon_get_drm_value(ws->fd, RADEON_INFO_MAX_PIPES, NULL,
                          &ws->info.r600_max_pipes);
 
+    radeon_get_drm_value(ws->fd, RADEON_INFO_ACTIVE_CU_COUNT, NULL,
+                         &ws->info.max_compute_units);
+
+    radeon_get_drm_value(ws->fd, RADEON_INFO_MAX_SE, NULL,
+                         &ws->info.max_se);
+
+    if (!ws->info.max_se) {
+        switch (ws->info.family) {
+        default:
+            ws->info.max_se = 1;
+            break;
+        case CHIP_CYPRESS:
+        case CHIP_HEMLOCK:
+        case CHIP_BARTS:
+        case CHIP_CAYMAN:
+        case CHIP_TAHITI:
+        case CHIP_PITCAIRN:
+        case CHIP_BONAIRE:
+            ws->info.max_se = 2;
+            break;
+        case CHIP_HAWAII:
+            ws->info.max_se = 4;
+            break;
+        }
+    }
+
+    radeon_get_drm_value(ws->fd, RADEON_INFO_MAX_SH_PER_SE, NULL,
+                         &ws->info.max_sh_per_se);
+
+    radeon_get_drm_value(ws->fd, RADEON_INFO_ACCEL_WORKING2, NULL,
+                         &ws->accel_working2);
+    if (ws->info.family == CHIP_HAWAII && ws->accel_working2 < 2) {
+        fprintf(stderr, "radeon: GPU acceleration for Hawaii disabled, "
+                "returned accel_working2 value %u is smaller than 2. "
+                "Please install a newer kernel.\n",
+                ws->accel_working2);
+        return FALSE;
+    }
+
+    if (radeon_get_drm_value(ws->fd, RADEON_INFO_SI_TILE_MODE_ARRAY, NULL,
+                             ws->info.si_tile_mode_array)) {
+        ws->info.si_tile_mode_array_valid = TRUE;
+    }
+
+    if (radeon_get_drm_value(ws->fd, RADEON_INFO_CIK_MACROTILE_MODE_ARRAY, NULL,
+                             ws->info.cik_macrotile_mode_array)) {
+        ws->info.cik_macrotile_mode_array_valid = TRUE;
+    }
+
     return TRUE;
 }
 
@@ -316,12 +442,20 @@ static void radeon_winsys_destroy(struct radeon_winsys *rws)
 {
     struct radeon_drm_winsys *ws = (struct radeon_drm_winsys*)rws;
 
+    if (ws->thread) {
+        ws->kill_thread = 1;
+        pipe_semaphore_signal(&ws->cs_queued);
+        pipe_thread_wait(ws->thread);
+    }
+    pipe_semaphore_destroy(&ws->cs_queued);
+
     pipe_mutex_destroy(ws->hyperz_owner_mutex);
     pipe_mutex_destroy(ws->cmask_owner_mutex);
+    pipe_mutex_destroy(ws->cs_stack_lock);
 
     ws->cman->destroy(ws->cman);
     ws->kman->destroy(ws->kman);
-    if (ws->gen >= R600) {
+    if (ws->gen >= DRV_R600) {
         radeon_surface_manager_free(ws->surf_man);
     }
     FREE(rws);
@@ -341,22 +475,16 @@ static boolean radeon_cs_request_feature(struct radeon_winsys_cs *rcs,
 
     switch (fid) {
     case RADEON_FID_R300_HYPERZ_ACCESS:
-        if (debug_get_bool_option("RADEON_HYPERZ", FALSE)) {
-            return radeon_set_fd_access(cs, &cs->ws->hyperz_owner,
-                                        &cs->ws->hyperz_owner_mutex,
-                                        RADEON_INFO_WANT_HYPERZ, enable);
-        } else {
-            return FALSE;
-        }
+        return radeon_set_fd_access(cs, &cs->ws->hyperz_owner,
+                                    &cs->ws->hyperz_owner_mutex,
+                                    RADEON_INFO_WANT_HYPERZ, "Hyper-Z",
+                                    enable);
 
     case RADEON_FID_R300_CMASK_ACCESS:
-        if (debug_get_bool_option("RADEON_CMASK", FALSE)) {
-            return radeon_set_fd_access(cs, &cs->ws->cmask_owner,
-                                        &cs->ws->cmask_owner_mutex,
-                                        RADEON_INFO_WANT_CMASK, enable);
-        } else {
-            return FALSE;
-        }
+        return radeon_set_fd_access(cs, &cs->ws->cmask_owner,
+                                    &cs->ws->cmask_owner_mutex,
+                                    RADEON_INFO_WANT_CMASK, "AA optimizations",
+                                    enable);
     }
     return FALSE;
 }
@@ -377,10 +505,157 @@ static int radeon_drm_winsys_surface_best(struct radeon_winsys *rws,
     return radeon_surface_best(ws->surf_man, surf);
 }
 
-struct radeon_winsys *radeon_drm_winsys_create(int fd)
+static uint64_t radeon_query_value(struct radeon_winsys *rws,
+                                   enum radeon_value_id value)
+{
+    struct radeon_drm_winsys *ws = (struct radeon_drm_winsys*)rws;
+    uint64_t retval = 0;
+
+    switch (value) {
+    case RADEON_REQUESTED_VRAM_MEMORY:
+        return ws->allocated_vram;
+    case RADEON_REQUESTED_GTT_MEMORY:
+        return ws->allocated_gtt;
+    case RADEON_BUFFER_WAIT_TIME_NS:
+        return ws->buffer_wait_time;
+    case RADEON_TIMESTAMP:
+        if (ws->info.drm_minor < 20 || ws->gen < DRV_R600) {
+            assert(0);
+            return 0;
+        }
+
+        radeon_get_drm_value(ws->fd, RADEON_INFO_TIMESTAMP, "timestamp",
+                             (uint32_t*)&retval);
+        return retval;
+    case RADEON_NUM_CS_FLUSHES:
+        return ws->num_cs_flushes;
+    case RADEON_NUM_BYTES_MOVED:
+        radeon_get_drm_value(ws->fd, RADEON_INFO_NUM_BYTES_MOVED,
+                             "num-bytes-moved", (uint32_t*)&retval);
+        return retval;
+    case RADEON_VRAM_USAGE:
+        radeon_get_drm_value(ws->fd, RADEON_INFO_VRAM_USAGE,
+                             "vram-usage", (uint32_t*)&retval);
+        return retval;
+    case RADEON_GTT_USAGE:
+        radeon_get_drm_value(ws->fd, RADEON_INFO_GTT_USAGE,
+                             "gtt-usage", (uint32_t*)&retval);
+        return retval;
+    }
+    return 0;
+}
+
+static unsigned hash_fd(void *key)
 {
-    struct radeon_drm_winsys *ws = CALLOC_STRUCT(radeon_drm_winsys);
+    int fd = pointer_to_intptr(key);
+    struct stat stat;
+    fstat(fd, &stat);
+
+    return stat.st_dev ^ stat.st_ino ^ stat.st_rdev;
+}
+
+static int compare_fd(void *key1, void *key2)
+{
+    int fd1 = pointer_to_intptr(key1);
+    int fd2 = pointer_to_intptr(key2);
+    struct stat stat1, stat2;
+    fstat(fd1, &stat1);
+    fstat(fd2, &stat2);
+
+    return stat1.st_dev != stat2.st_dev ||
+           stat1.st_ino != stat2.st_ino ||
+           stat1.st_rdev != stat2.st_rdev;
+}
+
+void radeon_drm_ws_queue_cs(struct radeon_drm_winsys *ws, struct radeon_drm_cs *cs)
+{
+retry:
+    pipe_mutex_lock(ws->cs_stack_lock);
+    if (ws->ncs >= RING_LAST) {
+        /* no room left for a flush */
+        pipe_mutex_unlock(ws->cs_stack_lock);
+        goto retry;
+    }
+    ws->cs_stack[ws->ncs++] = cs;
+    pipe_mutex_unlock(ws->cs_stack_lock);
+    pipe_semaphore_signal(&ws->cs_queued);
+}
+
+static PIPE_THREAD_ROUTINE(radeon_drm_cs_emit_ioctl, param)
+{
+    struct radeon_drm_winsys *ws = (struct radeon_drm_winsys *)param;
+    struct radeon_drm_cs *cs;
+    unsigned i;
+
+    while (1) {
+        pipe_semaphore_wait(&ws->cs_queued);
+        if (ws->kill_thread)
+            break;
+
+        pipe_mutex_lock(ws->cs_stack_lock);
+        cs = ws->cs_stack[0];
+        for (i = 1; i < ws->ncs; i++)
+            ws->cs_stack[i - 1] = ws->cs_stack[i];
+        ws->cs_stack[--ws->ncs] = NULL;
+        pipe_mutex_unlock(ws->cs_stack_lock);
+
+        if (cs) {
+            radeon_drm_cs_emit_ioctl_oneshot(cs, cs->cst);
+            pipe_semaphore_signal(&cs->flush_completed);
+        }
+    }
+    pipe_mutex_lock(ws->cs_stack_lock);
+    for (i = 0; i < ws->ncs; i++) {
+        pipe_semaphore_signal(&ws->cs_stack[i]->flush_completed);
+        ws->cs_stack[i] = NULL;
+    }
+    ws->ncs = 0;
+    pipe_mutex_unlock(ws->cs_stack_lock);
+    return 0;
+}
+
+DEBUG_GET_ONCE_BOOL_OPTION(thread, "RADEON_THREAD", TRUE)
+static PIPE_THREAD_ROUTINE(radeon_drm_cs_emit_ioctl, param);
+
+static bool radeon_winsys_unref(struct radeon_winsys *ws)
+{
+    struct radeon_drm_winsys *rws = (struct radeon_drm_winsys*)ws;
+    bool destroy;
+
+    /* When the reference counter drops to zero, remove the fd from the table.
+     * This must happen while the mutex is locked, so that
+     * radeon_drm_winsys_create in another thread doesn't get the winsys
+     * from the table when the counter drops to 0. */
+    pipe_mutex_lock(fd_tab_mutex);
+
+    destroy = pipe_reference(&rws->reference, NULL);
+    if (destroy && fd_tab)
+        util_hash_table_remove(fd_tab, intptr_to_pointer(rws->fd));
+
+    pipe_mutex_unlock(fd_tab_mutex);
+    return destroy;
+}
+
+PUBLIC struct radeon_winsys *
+radeon_drm_winsys_create(int fd, radeon_screen_create_t screen_create)
+{
+    struct radeon_drm_winsys *ws;
+
+    pipe_mutex_lock(fd_tab_mutex);
+    if (!fd_tab) {
+        fd_tab = util_hash_table_create(hash_fd, compare_fd);
+    }
+
+    ws = util_hash_table_get(fd_tab, intptr_to_pointer(fd));
+    if (ws) {
+        pipe_reference(NULL, &ws->reference);
+        pipe_mutex_unlock(fd_tab_mutex);
+        return &ws->base;
+    }
+
+    ws = CALLOC_STRUCT(radeon_drm_winsys);
     if (!ws) {
+        pipe_mutex_unlock(fd_tab_mutex);
         return NULL;
     }
 
@@ -393,33 +668,65 @@ struct radeon_winsys *radeon_drm_winsys_create(int fd)
     ws->kman = radeon_bomgr_create(ws);
     if (!ws->kman)
         goto fail;
-    ws->cman = pb_cache_manager_create(ws->kman, 1000000);
+
+    ws->cman = pb_cache_manager_create(ws->kman, 1000000, 2.0f, 0,
+                                       (ws->info.vram_size + ws->info.gart_size) / 8);
     if (!ws->cman)
         goto fail;
 
-    /* FIXME check for libdrm version ?? */
-    if (ws->gen >= R600) {
+    if (ws->gen >= DRV_R600) {
         ws->surf_man = radeon_surface_manager_new(fd);
         if (!ws->surf_man)
             goto fail;
     }
 
+    /* init reference */
+    pipe_reference_init(&ws->reference, 1);
+
     /* Set functions. */
+    ws->base.unref = radeon_winsys_unref;
     ws->base.destroy = radeon_winsys_destroy;
     ws->base.query_info = radeon_query_info;
     ws->base.cs_request_feature = radeon_cs_request_feature;
     ws->base.surface_init = radeon_drm_winsys_surface_init;
     ws->base.surface_best = radeon_drm_winsys_surface_best;
+    ws->base.query_value = radeon_query_value;
 
     radeon_bomgr_init_functions(ws);
     radeon_drm_cs_init_functions(ws);
 
     pipe_mutex_init(ws->hyperz_owner_mutex);
     pipe_mutex_init(ws->cmask_owner_mutex);
+    pipe_mutex_init(ws->cs_stack_lock);
+
+    ws->ncs = 0;
+    pipe_semaphore_init(&ws->cs_queued, 0);
+    if (ws->num_cpus > 1 && debug_get_option_thread())
+        ws->thread = pipe_thread_create(radeon_drm_cs_emit_ioctl, ws);
+
+    /* Create the screen at the end. The winsys must be initialized
+     * completely.
+     *
+     * Alternatively, we could create the screen based on "ws->gen"
+     * and link all drivers into one binary blob. */
+    ws->base.screen = screen_create(&ws->base);
+    if (!ws->base.screen) {
+        radeon_winsys_destroy(&ws->base);
+        pipe_mutex_unlock(fd_tab_mutex);
+        return NULL;
+    }
+
+    util_hash_table_set(fd_tab, intptr_to_pointer(fd), ws);
+
+    /* 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. */
+    pipe_mutex_unlock(fd_tab_mutex);
 
     return &ws->base;
 
 fail:
+    pipe_mutex_unlock(fd_tab_mutex);
     if (ws->cman)
         ws->cman->destroy(ws->cman);
     if (ws->kman)