drm/amdgpu: Implement a new 64bit sequence memory driver

Developed a new driver which allocates a 64bit memory on
each request in sequence order. At the moment, user queue
fence memory is the main consumer of this seq64 driver.

v2: Worked on review comments from Christian for the following
    modifications

    - Move driver name from "semaphore" to "seq64"
    - Remove unnecessary PT/PD mapping
    - Move enable_mes check into init/fini functions.

v3: Worked on review comments from Christian

    - drop enable_mes check
    - use DECLARE_BITMAP for bit array
    - added kerneldoc for seq64

v4: Worked on review comments from Christian
    - Rename amdgpu_seq64_get name with amdgpu_seq64_alloc

v5: Worked on review comments from Christian
    - Fix seq64 lockdep warning
    - move fpriv->seq64_va check into amdgpu_seq64_unmap()
    - make the function amdgpu_seq64_unmap() return as void.
    - reserve the buffers as not interruptible.

v6: port to drm_exec (Alex)
v7: disable for now (Arun)

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 247 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
new file mode 100644
index 000000000000..f3de02193138
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2023 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 "amdgpu.h"
+#include "amdgpu_seq64.h"
+
+#include <drm/drm_exec.h>
+
+/**
+ * DOC: amdgpu_seq64
+ *
+ * amdgpu_seq64 allocates a 64bit memory on each request in sequence order.
+ * seq64 driver is required for user queue fence memory allocation, TLB
+ * counters and VM updates. It has maximum count of 32768 64 bit slots.
+ */
+
+/**
+ * amdgpu_seq64_map - Map the seq64 memory to VM
+ *
+ * @adev: amdgpu_device pointer
+ * @vm: vm pointer
+ * @bo_va: bo_va pointer
+ * @seq64_addr: seq64 vaddr start address
+ * @size: seq64 pool size
+ *
+ * Map the seq64 memory to the given VM.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure
+ */
+int amdgpu_seq64_map(struct amdgpu_device *adev, struct amdgpu_vm *vm,
+		     struct amdgpu_bo_va **bo_va, u64 seq64_addr,
+		     uint32_t size)
+{
+	struct amdgpu_bo *bo;
+	struct drm_exec exec;
+	int r;
+
+	bo = adev->seq64.sbo;
+	if (!bo)
+		return -EINVAL;
+
+	drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT);
+	drm_exec_until_all_locked(&exec) {
+		r = amdgpu_vm_lock_pd(vm, &exec, 0);
+		if (likely(!r))
+			r = drm_exec_lock_obj(&exec, &bo->tbo.base);
+		drm_exec_retry_on_contention(&exec);
+		if (unlikely(r))
+			goto error;
+	}
+
+	*bo_va = amdgpu_vm_bo_add(adev, vm, bo);
+	if (!*bo_va) {
+		r = -ENOMEM;
+		goto error;
+	}
+
+	r = amdgpu_vm_bo_map(adev, *bo_va, seq64_addr, 0, size,
+			     AMDGPU_PTE_READABLE | AMDGPU_PTE_WRITEABLE |
+			     AMDGPU_PTE_EXECUTABLE);
+	if (r) {
+		DRM_ERROR("failed to do bo_map on userq sem, err=%d\n", r);
+		amdgpu_vm_bo_del(adev, *bo_va);
+		goto error;
+	}
+
+	r = amdgpu_vm_bo_update(adev, *bo_va, false);
+	if (r) {
+		DRM_ERROR("failed to do vm_bo_update on userq sem\n");
+		amdgpu_vm_bo_del(adev, *bo_va);
+		goto error;
+	}
+
+error:
+	drm_exec_fini(&exec);
+	return r;
+}
+
+/**
+ * amdgpu_seq64_unmap - Unmap the seq64 memory
+ *
+ * @adev: amdgpu_device pointer
+ * @fpriv: DRM file private
+ *
+ * Unmap the seq64 memory from the given VM.
+ */
+void amdgpu_seq64_unmap(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv)
+{
+	struct amdgpu_vm *vm;
+	struct amdgpu_bo *bo;
+	struct drm_exec exec;
+	int r;
+
+	if (!fpriv->seq64_va)
+		return;
+
+	bo = adev->seq64.sbo;
+	if (!bo)
+		return;
+
+	vm = &fpriv->vm;
+
+	drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT);
+	drm_exec_until_all_locked(&exec) {
+		r = amdgpu_vm_lock_pd(vm, &exec, 0);
+		if (likely(!r))
+			r = drm_exec_lock_obj(&exec, &bo->tbo.base);
+		drm_exec_retry_on_contention(&exec);
+		if (unlikely(r))
+			goto error;
+	}
+
+	amdgpu_vm_bo_del(adev, fpriv->seq64_va);
+
+	fpriv->seq64_va = NULL;
+
+error:
+	drm_exec_fini(&exec);
+}
+
+/**
+ * amdgpu_seq64_alloc - Allocate a 64 bit memory
+ *
+ * @adev: amdgpu_device pointer
+ * @gpu_addr: allocated gpu VA start address
+ * @cpu_addr: allocated cpu VA start address
+ *
+ * Alloc a 64 bit memory from seq64 pool.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure
+ */
+int amdgpu_seq64_alloc(struct amdgpu_device *adev, u64 *gpu_addr,
+		       u64 **cpu_addr)
+{
+	unsigned long bit_pos;
+	u32 offset;
+
+	bit_pos = find_first_zero_bit(adev->seq64.used, adev->seq64.num_sem);
+
+	if (bit_pos < adev->seq64.num_sem) {
+		__set_bit(bit_pos, adev->seq64.used);
+		offset = bit_pos << 6; /* convert to qw offset */
+	} else {
+		return -EINVAL;
+	}
+
+	*gpu_addr = offset + AMDGPU_SEQ64_VADDR_START;
+	*cpu_addr = offset + adev->seq64.cpu_base_addr;
+
+	return 0;
+}
+
+/**
+ * amdgpu_seq64_free - Free the given 64 bit memory
+ *
+ * @adev: amdgpu_device pointer
+ * @gpu_addr: gpu start address to be freed
+ *
+ * Free the given 64 bit memory from seq64 pool.
+ *
+ */
+void amdgpu_seq64_free(struct amdgpu_device *adev, u64 gpu_addr)
+{
+	u32 offset;
+
+	offset = gpu_addr - AMDGPU_SEQ64_VADDR_START;
+
+	offset >>= 6;
+	if (offset < adev->seq64.num_sem)
+		__clear_bit(offset, adev->seq64.used);
+}
+
+/**
+ * amdgpu_seq64_fini - Cleanup seq64 driver
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Free the memory space allocated for seq64.
+ *
+ */
+void amdgpu_seq64_fini(struct amdgpu_device *adev)
+{
+	amdgpu_bo_free_kernel(&adev->seq64.sbo,
+			      NULL,
+			      (void **)&adev->seq64.cpu_base_addr);
+}
+
+/**
+ * amdgpu_seq64_init - Initialize seq64 driver
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Allocate the required memory space for seq64.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure
+ */
+int amdgpu_seq64_init(struct amdgpu_device *adev)
+{
+	int r;
+
+	if (adev->seq64.sbo)
+		return 0;
+
+	/*
+	 * AMDGPU_MAX_SEQ64_SLOTS * sizeof(u64) * 8 = AMDGPU_MAX_SEQ64_SLOTS
+	 * 64bit slots
+	 */
+	r = amdgpu_bo_create_kernel(adev, AMDGPU_SEQ64_SIZE,
+				    PAGE_SIZE, AMDGPU_GEM_DOMAIN_GTT,
+				    &adev->seq64.sbo, NULL,
+				    (void **)&adev->seq64.cpu_base_addr);
+	if (r) {
+		dev_warn(adev->dev, "(%d) create seq64 failed\n", r);
+		return r;
+	}
+
+	memset(adev->seq64.cpu_base_addr, 0, AMDGPU_SEQ64_SIZE);
+
+	adev->seq64.num_sem = AMDGPU_MAX_SEQ64_SLOTS;
+	memset(&adev->seq64.used, 0, sizeof(adev->seq64.used));
+
+	return 0;
+}