drm/amdgpu: add gfx eviction fence helpers

This patch adds basic eviction fence framework for the gfx buffers.
The idea is to:
- One eviction fence is created per gfx process, at kms_open.
- This fence is attached to all the gem buffers created
  by this process.
- This fence is detached to all the gem buffers at postclose_kms.

This framework will be further used for usermode queues.

V2: Addressed review comments from Christian
    - keep fence_ctx and fence_seq directly in fpriv
    - evcition_fence should be dynamically allocated
    - do not save eviction fence instance in BO, there could be many
      such fences attached to one BO
    - use dma_resv_replace_fence() in detach

V3: Addressed review comments from Christian
    - eviction fence create and destroy functions should be called
      only once from fpriv create/destroy
    - use dma_fence_put() in eviction_fence_destroy

V4: Addressed review comments from Christian:
    - create a separate ev_fence_mgr structure
    - cleanup fence init part
    - do not add a domain for fence owner KGD

V5: Addressed review comments from Christian:
    - drop the dma_fence_is_signaled check
    - use a local variable to access evf_mgr->ev_fence under the
      spin_lock() multiple places
    - remove the vm->is_compute_ctx check to attach gfx eviction fence,
      in gem_object_open

V6: Addressed review comments from Christian:
    - drop the return value from eviction_fence_signal
    - reserve_fence should be the first thing inside the
      attach_eviction_fence function, also keep the resv_add_fence inside
      the lock
    - remove the unwanted ev_fence check inside detach function
    - fix wrong variable check in eviction_fence_init function
    - return the error value of eviction_fence_init to the caller, dont
      keep it void.
    - fail gem_object_open if attaching of eviction_fence fails
    - detach the eviction fence only when amdgpu_vm_is_bo_always_valid
      is not true.

V7: Addressed review comments from Christian:
    - Do not add a uq_mgr ptr in ev_fence, rather add evf_mgr

V8: Move eviction fence enabling into separate patch for CI

Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian Koenig <christian.koenig@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 144 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
new file mode 100644
index 000000000000..056798e2b050
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2024 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.
+ *
+ */
+#include <linux/sched.h>
+#include "amdgpu.h"
+
+static const char *
+amdgpu_eviction_fence_get_driver_name(struct dma_fence *fence)
+{
+	return "amdgpu";
+}
+
+static const char *
+amdgpu_eviction_fence_get_timeline_name(struct dma_fence *f)
+{
+	struct amdgpu_eviction_fence *ef;
+
+	ef = container_of(f, struct amdgpu_eviction_fence, base);
+	return ef->timeline_name;
+}
+
+static const struct dma_fence_ops amdgpu_eviction_fence_ops = {
+	.use_64bit_seqno = true,
+	.get_driver_name = amdgpu_eviction_fence_get_driver_name,
+	.get_timeline_name = amdgpu_eviction_fence_get_timeline_name,
+};
+
+void amdgpu_eviction_fence_signal(struct amdgpu_eviction_fence_mgr *evf_mgr)
+{
+	spin_lock(&evf_mgr->ev_fence_lock);
+	dma_fence_signal(&evf_mgr->ev_fence->base);
+	spin_unlock(&evf_mgr->ev_fence_lock);
+}
+
+struct amdgpu_eviction_fence *
+amdgpu_eviction_fence_create(struct amdgpu_eviction_fence_mgr *evf_mgr)
+{
+	struct amdgpu_eviction_fence *ev_fence;
+
+	ev_fence = kzalloc(sizeof(*ev_fence), GFP_KERNEL);
+	if (!ev_fence)
+		return NULL;
+
+	ev_fence->evf_mgr = evf_mgr;
+	get_task_comm(ev_fence->timeline_name, current);
+	spin_lock_init(&ev_fence->lock);
+	dma_fence_init(&ev_fence->base, &amdgpu_eviction_fence_ops,
+		       &ev_fence->lock, evf_mgr->ev_fence_ctx,
+		       atomic_inc_return(&evf_mgr->ev_fence_seq));
+	return ev_fence;
+}
+
+void amdgpu_eviction_fence_destroy(struct amdgpu_eviction_fence_mgr *evf_mgr)
+{
+	struct amdgpu_eviction_fence *ev_fence;
+
+	spin_lock(&evf_mgr->ev_fence_lock);
+	ev_fence = evf_mgr->ev_fence;
+	spin_unlock(&evf_mgr->ev_fence_lock);
+
+	if (!ev_fence)
+		return;
+
+	/* Last unref of ev_fence */
+	dma_fence_put(&evf_mgr->ev_fence->base);
+}
+
+int amdgpu_eviction_fence_attach(struct amdgpu_eviction_fence_mgr *evf_mgr,
+				 struct amdgpu_bo *bo)
+{
+	struct dma_fence *ef;
+	struct amdgpu_eviction_fence *ev_fence;
+	struct dma_resv *resv = bo->tbo.base.resv;
+	int ret;
+
+	if (!resv)
+		return 0;
+
+	ret = dma_resv_reserve_fences(resv, 1);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Failed to resv fence space\n");
+		return ret;
+	}
+
+	spin_lock(&evf_mgr->ev_fence_lock);
+	ev_fence = evf_mgr->ev_fence;
+	if (ev_fence) {
+		ef = dma_fence_get(&ev_fence->base);
+		dma_resv_add_fence(resv, ef, DMA_RESV_USAGE_BOOKKEEP);
+	}
+	spin_unlock(&evf_mgr->ev_fence_lock);
+	return 0;
+}
+
+void amdgpu_eviction_fence_detach(struct amdgpu_eviction_fence_mgr *evf_mgr,
+				  struct amdgpu_bo *bo)
+{
+	struct dma_fence *stub = dma_fence_get_stub();
+
+	dma_resv_replace_fences(bo->tbo.base.resv, evf_mgr->ev_fence_ctx,
+				stub, DMA_RESV_USAGE_BOOKKEEP);
+	dma_fence_put(stub);
+}
+
+int amdgpu_eviction_fence_init(struct amdgpu_eviction_fence_mgr *evf_mgr)
+{
+	struct amdgpu_eviction_fence *ev_fence;
+
+	/* This needs to be done one time per open */
+	atomic_set(&evf_mgr->ev_fence_seq, 0);
+	evf_mgr->ev_fence_ctx = dma_fence_context_alloc(1);
+	spin_lock_init(&evf_mgr->ev_fence_lock);
+
+	ev_fence = amdgpu_eviction_fence_create(evf_mgr);
+	if (!ev_fence) {
+		DRM_ERROR("Failed to craete eviction fence\n");
+		return -ENOMEM;
+	}
+
+	spin_lock(&evf_mgr->ev_fence_lock);
+	evf_mgr->ev_fence = ev_fence;
+	spin_unlock(&evf_mgr->ev_fence_lock);
+	return 0;
+}