1// SPDX-License-Identifier: GPL-2.0 or MIT
2/* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
3/* Copyright 2023 Collabora ltd. */
4
5#include <linux/dma-buf.h>
6#include <linux/dma-mapping.h>
7#include <linux/err.h>
8#include <linux/slab.h>
9
10#include <drm/panthor_drm.h>
11
12#include "panthor_device.h"
13#include "panthor_gem.h"
14#include "panthor_mmu.h"
15
16static void panthor_gem_free_object(struct drm_gem_object *obj)
17{
18	struct panthor_gem_object *bo = to_panthor_bo(obj);
19	struct drm_gem_object *vm_root_gem = bo->exclusive_vm_root_gem;
20
21	drm_gem_free_mmap_offset(&bo->base.base);
22	mutex_destroy(&bo->gpuva_list_lock);
23	drm_gem_shmem_free(&bo->base);
24	drm_gem_object_put(vm_root_gem);
25}
26
27/**
28 * panthor_kernel_bo_destroy() - Destroy a kernel buffer object
29 * @bo: Kernel buffer object to destroy. If NULL or an ERR_PTR(), the destruction
30 * is skipped.
31 */
32void panthor_kernel_bo_destroy(struct panthor_kernel_bo *bo)
33{
34	struct panthor_vm *vm;
35	int ret;
36
37	if (IS_ERR_OR_NULL(bo))
38		return;
39
40	vm = bo->vm;
41	panthor_kernel_bo_vunmap(bo);
42
43	if (drm_WARN_ON(bo->obj->dev,
44			to_panthor_bo(bo->obj)->exclusive_vm_root_gem != panthor_vm_root_gem(vm)))
45		goto out_free_bo;
46
47	ret = panthor_vm_unmap_range(vm, bo->va_node.start,
48				     panthor_kernel_bo_size(bo));
49	if (ret)
50		goto out_free_bo;
51
52	panthor_vm_free_va(vm, &bo->va_node);
53	drm_gem_object_put(bo->obj);
54
55out_free_bo:
56	panthor_vm_put(vm);
57	kfree(bo);
58}
59
60/**
61 * panthor_kernel_bo_create() - Create and map a GEM object to a VM
62 * @ptdev: Device.
63 * @vm: VM to map the GEM to. If NULL, the kernel object is not GPU mapped.
64 * @size: Size of the buffer object.
65 * @bo_flags: Combination of drm_panthor_bo_flags flags.
66 * @vm_map_flags: Combination of drm_panthor_vm_bind_op_flags (only those
67 * that are related to map operations).
68 * @gpu_va: GPU address assigned when mapping to the VM.
69 * If gpu_va == PANTHOR_VM_KERNEL_AUTO_VA, the virtual address will be
70 * automatically allocated.
71 *
72 * Return: A valid pointer in case of success, an ERR_PTR() otherwise.
73 */
74struct panthor_kernel_bo *
75panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm,
76			 size_t size, u32 bo_flags, u32 vm_map_flags,
77			 u64 gpu_va)
78{
79	struct drm_gem_shmem_object *obj;
80	struct panthor_kernel_bo *kbo;
81	struct panthor_gem_object *bo;
82	int ret;
83
84	if (drm_WARN_ON(&ptdev->base, !vm))
85		return ERR_PTR(-EINVAL);
86
87	kbo = kzalloc(sizeof(*kbo), GFP_KERNEL);
88	if (!kbo)
89		return ERR_PTR(-ENOMEM);
90
91	obj = drm_gem_shmem_create(&ptdev->base, size);
92	if (IS_ERR(obj)) {
93		ret = PTR_ERR(obj);
94		goto err_free_bo;
95	}
96
97	bo = to_panthor_bo(&obj->base);
98	size = obj->base.size;
99	kbo->obj = &obj->base;
100	bo->flags = bo_flags;
101
102	ret = panthor_vm_alloc_va(vm, gpu_va, size, &kbo->va_node);
103	if (ret)
104		goto err_put_obj;
105
106	ret = panthor_vm_map_bo_range(vm, bo, 0, size, kbo->va_node.start, vm_map_flags);
107	if (ret)
108		goto err_free_va;
109
110	kbo->vm = panthor_vm_get(vm);
111	bo->exclusive_vm_root_gem = panthor_vm_root_gem(vm);
112	drm_gem_object_get(bo->exclusive_vm_root_gem);
113	bo->base.base.resv = bo->exclusive_vm_root_gem->resv;
114	return kbo;
115
116err_free_va:
117	panthor_vm_free_va(vm, &kbo->va_node);
118
119err_put_obj:
120	drm_gem_object_put(&obj->base);
121
122err_free_bo:
123	kfree(kbo);
124	return ERR_PTR(ret);
125}
126
127static int panthor_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
128{
129	struct panthor_gem_object *bo = to_panthor_bo(obj);
130
131	/* Don't allow mmap on objects that have the NO_MMAP flag set. */
132	if (bo->flags & DRM_PANTHOR_BO_NO_MMAP)
133		return -EINVAL;
134
135	return drm_gem_shmem_object_mmap(obj, vma);
136}
137
138static struct dma_buf *
139panthor_gem_prime_export(struct drm_gem_object *obj, int flags)
140{
141	/* We can't export GEMs that have an exclusive VM. */
142	if (to_panthor_bo(obj)->exclusive_vm_root_gem)
143		return ERR_PTR(-EINVAL);
144
145	return drm_gem_prime_export(obj, flags);
146}
147
148static const struct drm_gem_object_funcs panthor_gem_funcs = {
149	.free = panthor_gem_free_object,
150	.print_info = drm_gem_shmem_object_print_info,
151	.pin = drm_gem_shmem_object_pin,
152	.unpin = drm_gem_shmem_object_unpin,
153	.get_sg_table = drm_gem_shmem_object_get_sg_table,
154	.vmap = drm_gem_shmem_object_vmap,
155	.vunmap = drm_gem_shmem_object_vunmap,
156	.mmap = panthor_gem_mmap,
157	.export = panthor_gem_prime_export,
158	.vm_ops = &drm_gem_shmem_vm_ops,
159};
160
161/**
162 * panthor_gem_create_object - Implementation of driver->gem_create_object.
163 * @ddev: DRM device
164 * @size: Size in bytes of the memory the object will reference
165 *
166 * This lets the GEM helpers allocate object structs for us, and keep
167 * our BO stats correct.
168 */
169struct drm_gem_object *panthor_gem_create_object(struct drm_device *ddev, size_t size)
170{
171	struct panthor_device *ptdev = container_of(ddev, struct panthor_device, base);
172	struct panthor_gem_object *obj;
173
174	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
175	if (!obj)
176		return ERR_PTR(-ENOMEM);
177
178	obj->base.base.funcs = &panthor_gem_funcs;
179	obj->base.map_wc = !ptdev->coherent;
180	mutex_init(&obj->gpuva_list_lock);
181	drm_gem_gpuva_set_lock(&obj->base.base, &obj->gpuva_list_lock);
182
183	return &obj->base.base;
184}
185
186/**
187 * panthor_gem_create_with_handle() - Create a GEM object and attach it to a handle.
188 * @file: DRM file.
189 * @ddev: DRM device.
190 * @exclusive_vm: Exclusive VM. Not NULL if the GEM object can't be shared.
191 * @size: Size of the GEM object to allocate.
192 * @flags: Combination of drm_panthor_bo_flags flags.
193 * @handle: Pointer holding the handle pointing to the new GEM object.
194 *
195 * Return: Zero on success
196 */
197int
198panthor_gem_create_with_handle(struct drm_file *file,
199			       struct drm_device *ddev,
200			       struct panthor_vm *exclusive_vm,
201			       u64 *size, u32 flags, u32 *handle)
202{
203	int ret;
204	struct drm_gem_shmem_object *shmem;
205	struct panthor_gem_object *bo;
206
207	shmem = drm_gem_shmem_create(ddev, *size);
208	if (IS_ERR(shmem))
209		return PTR_ERR(shmem);
210
211	bo = to_panthor_bo(&shmem->base);
212	bo->flags = flags;
213
214	if (exclusive_vm) {
215		bo->exclusive_vm_root_gem = panthor_vm_root_gem(exclusive_vm);
216		drm_gem_object_get(bo->exclusive_vm_root_gem);
217		bo->base.base.resv = bo->exclusive_vm_root_gem->resv;
218	}
219
220	/*
221	 * Allocate an id of idr table where the obj is registered
222	 * and handle has the id what user can see.
223	 */
224	ret = drm_gem_handle_create(file, &shmem->base, handle);
225	if (!ret)
226		*size = bo->base.base.size;
227
228	/* drop reference from allocate - handle holds it now. */
229	drm_gem_object_put(&shmem->base);
230
231	return ret;
232}
233