515.43.04

kernel-open/nvidia/nv-rsync.c

@@ -0,0 +1,201 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2018 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "nv-linux.h"
+#include "nv-rsync.h"
+
+nv_rsync_info_t g_rsync_info;
+
+void nv_init_rsync_info(
+    void
+)
+{
+    g_rsync_info.relaxed_ordering_mode = NV_FALSE;
+    g_rsync_info.usage_count = 0;
+    g_rsync_info.data = NULL;
+    NV_INIT_MUTEX(&g_rsync_info.lock);
+}
+
+void nv_destroy_rsync_info(
+    void
+)
+{
+    WARN_ON(g_rsync_info.data);
+    WARN_ON(g_rsync_info.usage_count);
+    WARN_ON(g_rsync_info.relaxed_ordering_mode);
+}
+
+int nv_get_rsync_info(
+    void
+)
+{
+    int mode;
+    int rc = 0;
+
+    down(&g_rsync_info.lock);
+
+    if (g_rsync_info.usage_count == 0)
+    {
+        if (g_rsync_info.get_relaxed_ordering_mode)
+        {
+            rc = g_rsync_info.get_relaxed_ordering_mode(&mode,
+                                                        g_rsync_info.data);
+            if (rc != 0)
+            {
+                goto done;
+            }
+
+            g_rsync_info.relaxed_ordering_mode = !!mode;
+        }
+    }
+
+    g_rsync_info.usage_count++;
+
+done:
+    up(&g_rsync_info.lock);
+
+    return rc;
+}
+
+void nv_put_rsync_info(
+    void
+)
+{
+    int mode;
+
+    down(&g_rsync_info.lock);
+
+    g_rsync_info.usage_count--;
+
+    if (g_rsync_info.usage_count == 0)
+    {
+        if (g_rsync_info.put_relaxed_ordering_mode)
+        {
+            mode = g_rsync_info.relaxed_ordering_mode;
+            g_rsync_info.put_relaxed_ordering_mode(mode, g_rsync_info.data);
+            g_rsync_info.relaxed_ordering_mode = NV_FALSE;
+        }
+    }
+
+    up(&g_rsync_info.lock);
+}
+
+int nv_register_rsync_driver(
+    int (*get_relaxed_ordering_mode)(int *mode, void *data),
+    void (*put_relaxed_ordering_mode)(int mode, void *data),
+    void (*wait_for_rsync)(struct pci_dev *gpu, void *data),
+    void *data
+)
+{
+    int rc = 0;
+
+    down(&g_rsync_info.lock);
+
+    if (g_rsync_info.get_relaxed_ordering_mode != NULL)
+    {
+        rc = -EBUSY;
+        goto done;
+    }
+
+    if (g_rsync_info.usage_count != 0)
+    {
+        rc = -EBUSY;
+        goto done;
+    }
+
+    g_rsync_info.get_relaxed_ordering_mode = get_relaxed_ordering_mode;
+    g_rsync_info.put_relaxed_ordering_mode = put_relaxed_ordering_mode;
+    g_rsync_info.wait_for_rsync = wait_for_rsync;
+    g_rsync_info.data = data;
+
+done:
+    up(&g_rsync_info.lock);
+
+    return rc;
+}
+
+void nv_unregister_rsync_driver(
+    int (*get_relaxed_ordering_mode)(int *mode, void *data),
+    void (*put_relaxed_ordering_mode)(int mode, void *data),
+    void (*wait_for_rsync)(struct pci_dev *gpu, void *data),
+    void *data
+)
+{
+    down(&g_rsync_info.lock);
+
+    WARN_ON(g_rsync_info.usage_count != 0);
+
+    WARN_ON(g_rsync_info.get_relaxed_ordering_mode !=
+            get_relaxed_ordering_mode);
+    WARN_ON(g_rsync_info.put_relaxed_ordering_mode !=
+            put_relaxed_ordering_mode);
+    WARN_ON(g_rsync_info.wait_for_rsync != wait_for_rsync);
+    WARN_ON(g_rsync_info.data != data);
+
+    g_rsync_info.get_relaxed_ordering_mode = NULL;
+    g_rsync_info.put_relaxed_ordering_mode = NULL;
+    g_rsync_info.wait_for_rsync = NULL;
+    g_rsync_info.data = NULL;
+
+    up(&g_rsync_info.lock);
+}
+
+NvBool nv_get_rsync_relaxed_ordering_mode(
+    nv_state_t *nv
+)
+{
+    nv_linux_state_t *nvl = NV_GET_NVL_FROM_NV_STATE(nv);
+
+    /* shouldn't be called without opening a device */
+    WARN_ON(NV_ATOMIC_READ(nvl->usage_count) == 0);
+
+    /*
+     * g_rsync_info.relaxed_ordering_mode can be safely accessed outside of
+     * g_rsync_info.lock once a device is opened. During nvidia_open(), we
+     * lock the relaxed ordering state by ref-counting the rsync module
+     * through get_relaxed_ordering_mode.
+     */
+    return g_rsync_info.relaxed_ordering_mode;
+}
+
+void nv_wait_for_rsync(
+    nv_state_t *nv
+)
+{
+    nv_linux_state_t *nvl = NV_GET_NVL_FROM_NV_STATE(nv);
+
+    /* shouldn't be called without opening a device */
+    WARN_ON(NV_ATOMIC_READ(nvl->usage_count) == 0);
+
+    /*
+     * g_rsync_info.relaxed_ordering_mode can be safely accessed outside of
+     * g_rsync_info.lock once a device is opened. During nvidia_open(), we
+     * block unregistration of the rsync driver by ref-counting the module
+     * through get_relaxed_ordering_mode.
+     */
+    if (g_rsync_info.relaxed_ordering_mode)
+    {
+        WARN_ON(g_rsync_info.wait_for_rsync == NULL);
+        g_rsync_info.wait_for_rsync(nvl->pci_dev, g_rsync_info.data);
+    }
+}