SecBSD 1.3 -current: The Digital Resistance. A belief in the importance of privacy and the right to secure communication.

sys/dev/pci/drm/amd/amdgpu/amdgpu_preempt_mgr.c

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+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright 2016-2021 Advanced Micro Devices, Inc.
+ *
+ * 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ *
+ * Authors: Christian König, Felix Kuehling
+ */
+
+#include "amdgpu.h"
+
+/**
+ * DOC: mem_info_preempt_used
+ *
+ * The amdgpu driver provides a sysfs API for reporting current total amount of
+ * used preemptible memory.
+ * The file mem_info_preempt_used is used for this, and returns the current
+ * used size of the preemptible block, in bytes
+ */
+static ssize_t mem_info_preempt_used_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct amdgpu_device *adev = drm_to_adev(ddev);
+	struct ttm_resource_manager *man = &adev->mman.preempt_mgr;
+
+	return sysfs_emit(buf, "%llu\n", ttm_resource_manager_usage(man));
+}
+
+static DEVICE_ATTR_RO(mem_info_preempt_used);
+
+/**
+ * amdgpu_preempt_mgr_new - allocate a new node
+ *
+ * @man: TTM memory type manager
+ * @tbo: TTM BO we need this range for
+ * @place: placement flags and restrictions
+ * @res: TTM memory object
+ *
+ * Dummy, just count the space used without allocating resources or any limit.
+ */
+static int amdgpu_preempt_mgr_new(struct ttm_resource_manager *man,
+				  struct ttm_buffer_object *tbo,
+				  const struct ttm_place *place,
+				  struct ttm_resource **res)
+{
+	*res = kzalloc(sizeof(**res), GFP_KERNEL);
+	if (!*res)
+		return -ENOMEM;
+
+	ttm_resource_init(tbo, place, *res);
+	(*res)->start = AMDGPU_BO_INVALID_OFFSET;
+	return 0;
+}
+
+/**
+ * amdgpu_preempt_mgr_del - free ranges
+ *
+ * @man: TTM memory type manager
+ * @res: TTM memory object
+ *
+ * Free the allocated GTT again.
+ */
+static void amdgpu_preempt_mgr_del(struct ttm_resource_manager *man,
+				   struct ttm_resource *res)
+{
+	ttm_resource_fini(man, res);
+	kfree(res);
+}
+
+static const struct ttm_resource_manager_func amdgpu_preempt_mgr_func = {
+	.alloc = amdgpu_preempt_mgr_new,
+	.free = amdgpu_preempt_mgr_del,
+};
+
+/**
+ * amdgpu_preempt_mgr_init - init PREEMPT manager and DRM MM
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Allocate and initialize the GTT manager.
+ */
+int amdgpu_preempt_mgr_init(struct amdgpu_device *adev)
+{
+	struct ttm_resource_manager *man = &adev->mman.preempt_mgr;
+	int ret;
+
+	man->use_tt = true;
+	man->func = &amdgpu_preempt_mgr_func;
+
+	ttm_resource_manager_init(man, &adev->mman.bdev, (1 << 30));
+
+	ret = device_create_file(adev->dev, &dev_attr_mem_info_preempt_used);
+	if (ret) {
+		DRM_ERROR("Failed to create device file mem_info_preempt_used\n");
+		return ret;
+	}
+
+	ttm_set_driver_manager(&adev->mman.bdev, AMDGPU_PL_PREEMPT, man);
+	ttm_resource_manager_set_used(man, true);
+	return 0;
+}
+
+/**
+ * amdgpu_preempt_mgr_fini - free and destroy GTT manager
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Destroy and free the GTT manager, returns -EBUSY if ranges are still
+ * allocated inside it.
+ */
+void amdgpu_preempt_mgr_fini(struct amdgpu_device *adev)
+{
+	struct ttm_resource_manager *man = &adev->mman.preempt_mgr;
+	int ret;
+
+	ttm_resource_manager_set_used(man, false);
+
+	ret = ttm_resource_manager_evict_all(&adev->mman.bdev, man);
+	if (ret)
+		return;
+
+	device_remove_file(adev->dev, &dev_attr_mem_info_preempt_used);
+
+	ttm_resource_manager_cleanup(man);
+	ttm_set_driver_manager(&adev->mman.bdev, AMDGPU_PL_PREEMPT, NULL);
+}