1 /*
2 * Copyright (c) 2015-2016, Linaro Limited
3 *
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14 #include <linux/device.h>
15 #include <linux/dma-buf.h>
16 #include <linux/fdtable.h>
17 #include <linux/idr.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/tee_drv.h>
21 #include "tee_private.h"
22
tee_shm_release(struct tee_shm * shm)23 static void tee_shm_release(struct tee_shm *shm)
24 {
25 struct tee_device *teedev = shm->teedev;
26 struct tee_shm_pool_mgr *poolm;
27
28 mutex_lock(&teedev->mutex);
29 idr_remove(&teedev->idr, shm->id);
30 if (shm->ctx)
31 list_del(&shm->link);
32 mutex_unlock(&teedev->mutex);
33
34 if (shm->flags & TEE_SHM_DMA_BUF)
35 poolm = &teedev->pool->dma_buf_mgr;
36 else
37 poolm = &teedev->pool->private_mgr;
38
39 poolm->ops->free(poolm, shm);
40 kfree(shm);
41
42 tee_device_put(teedev);
43 }
44
tee_shm_op_map_dma_buf(struct dma_buf_attachment * attach,enum dma_data_direction dir)45 static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
46 *attach, enum dma_data_direction dir)
47 {
48 return NULL;
49 }
50
tee_shm_op_unmap_dma_buf(struct dma_buf_attachment * attach,struct sg_table * table,enum dma_data_direction dir)51 static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
52 struct sg_table *table,
53 enum dma_data_direction dir)
54 {
55 }
56
tee_shm_op_release(struct dma_buf * dmabuf)57 static void tee_shm_op_release(struct dma_buf *dmabuf)
58 {
59 struct tee_shm *shm = dmabuf->priv;
60
61 tee_shm_release(shm);
62 }
63
tee_shm_op_map_atomic(struct dma_buf * dmabuf,unsigned long pgnum)64 static void *tee_shm_op_map_atomic(struct dma_buf *dmabuf, unsigned long pgnum)
65 {
66 return NULL;
67 }
68
tee_shm_op_map(struct dma_buf * dmabuf,unsigned long pgnum)69 static void *tee_shm_op_map(struct dma_buf *dmabuf, unsigned long pgnum)
70 {
71 return NULL;
72 }
73
tee_shm_op_mmap(struct dma_buf * dmabuf,struct vm_area_struct * vma)74 static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
75 {
76 struct tee_shm *shm = dmabuf->priv;
77 size_t size = vma->vm_end - vma->vm_start;
78
79 return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
80 size, vma->vm_page_prot);
81 }
82
83 static const struct dma_buf_ops tee_shm_dma_buf_ops = {
84 .map_dma_buf = tee_shm_op_map_dma_buf,
85 .unmap_dma_buf = tee_shm_op_unmap_dma_buf,
86 .release = tee_shm_op_release,
87 .map_atomic = tee_shm_op_map_atomic,
88 .map = tee_shm_op_map,
89 .mmap = tee_shm_op_mmap,
90 };
91
92 /**
93 * tee_shm_alloc() - Allocate shared memory
94 * @ctx: Context that allocates the shared memory
95 * @size: Requested size of shared memory
96 * @flags: Flags setting properties for the requested shared memory.
97 *
98 * Memory allocated as global shared memory is automatically freed when the
99 * TEE file pointer is closed. The @flags field uses the bits defined by
100 * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
101 * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
102 * associated with a dma-buf handle, else driver private memory.
103 */
tee_shm_alloc(struct tee_context * ctx,size_t size,u32 flags)104 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
105 {
106 struct tee_device *teedev = ctx->teedev;
107 struct tee_shm_pool_mgr *poolm = NULL;
108 struct tee_shm *shm;
109 void *ret;
110 int rc;
111
112 if (!(flags & TEE_SHM_MAPPED)) {
113 dev_err(teedev->dev.parent,
114 "only mapped allocations supported\n");
115 return ERR_PTR(-EINVAL);
116 }
117
118 if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF))) {
119 dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
120 return ERR_PTR(-EINVAL);
121 }
122
123 if (!tee_device_get(teedev))
124 return ERR_PTR(-EINVAL);
125
126 if (!teedev->pool) {
127 /* teedev has been detached from driver */
128 ret = ERR_PTR(-EINVAL);
129 goto err_dev_put;
130 }
131
132 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
133 if (!shm) {
134 ret = ERR_PTR(-ENOMEM);
135 goto err_dev_put;
136 }
137
138 shm->flags = flags;
139 shm->teedev = teedev;
140 shm->ctx = ctx;
141 if (flags & TEE_SHM_DMA_BUF)
142 poolm = &teedev->pool->dma_buf_mgr;
143 else
144 poolm = &teedev->pool->private_mgr;
145
146 rc = poolm->ops->alloc(poolm, shm, size);
147 if (rc) {
148 ret = ERR_PTR(rc);
149 goto err_kfree;
150 }
151
152 mutex_lock(&teedev->mutex);
153 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
154 mutex_unlock(&teedev->mutex);
155 if (shm->id < 0) {
156 ret = ERR_PTR(shm->id);
157 goto err_pool_free;
158 }
159
160 if (flags & TEE_SHM_DMA_BUF) {
161 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
162
163 exp_info.ops = &tee_shm_dma_buf_ops;
164 exp_info.size = shm->size;
165 exp_info.flags = O_RDWR;
166 exp_info.priv = shm;
167
168 shm->dmabuf = dma_buf_export(&exp_info);
169 if (IS_ERR(shm->dmabuf)) {
170 ret = ERR_CAST(shm->dmabuf);
171 goto err_rem;
172 }
173 }
174 mutex_lock(&teedev->mutex);
175 list_add_tail(&shm->link, &ctx->list_shm);
176 mutex_unlock(&teedev->mutex);
177
178 return shm;
179 err_rem:
180 mutex_lock(&teedev->mutex);
181 idr_remove(&teedev->idr, shm->id);
182 mutex_unlock(&teedev->mutex);
183 err_pool_free:
184 poolm->ops->free(poolm, shm);
185 err_kfree:
186 kfree(shm);
187 err_dev_put:
188 tee_device_put(teedev);
189 return ret;
190 }
191 EXPORT_SYMBOL_GPL(tee_shm_alloc);
192
193 /**
194 * tee_shm_get_fd() - Increase reference count and return file descriptor
195 * @shm: Shared memory handle
196 * @returns user space file descriptor to shared memory
197 */
tee_shm_get_fd(struct tee_shm * shm)198 int tee_shm_get_fd(struct tee_shm *shm)
199 {
200 u32 req_flags = TEE_SHM_MAPPED | TEE_SHM_DMA_BUF;
201 int fd;
202
203 if ((shm->flags & req_flags) != req_flags)
204 return -EINVAL;
205
206 get_dma_buf(shm->dmabuf);
207 fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
208 if (fd < 0)
209 dma_buf_put(shm->dmabuf);
210 return fd;
211 }
212
213 /**
214 * tee_shm_free() - Free shared memory
215 * @shm: Handle to shared memory to free
216 */
tee_shm_free(struct tee_shm * shm)217 void tee_shm_free(struct tee_shm *shm)
218 {
219 /*
220 * dma_buf_put() decreases the dmabuf reference counter and will
221 * call tee_shm_release() when the last reference is gone.
222 *
223 * In the case of driver private memory we call tee_shm_release
224 * directly instead as it doesn't have a reference counter.
225 */
226 if (shm->flags & TEE_SHM_DMA_BUF)
227 dma_buf_put(shm->dmabuf);
228 else
229 tee_shm_release(shm);
230 }
231 EXPORT_SYMBOL_GPL(tee_shm_free);
232
233 /**
234 * tee_shm_va2pa() - Get physical address of a virtual address
235 * @shm: Shared memory handle
236 * @va: Virtual address to tranlsate
237 * @pa: Returned physical address
238 * @returns 0 on success and < 0 on failure
239 */
tee_shm_va2pa(struct tee_shm * shm,void * va,phys_addr_t * pa)240 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
241 {
242 /* Check that we're in the range of the shm */
243 if ((char *)va < (char *)shm->kaddr)
244 return -EINVAL;
245 if ((char *)va >= ((char *)shm->kaddr + shm->size))
246 return -EINVAL;
247
248 return tee_shm_get_pa(
249 shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
250 }
251 EXPORT_SYMBOL_GPL(tee_shm_va2pa);
252
253 /**
254 * tee_shm_pa2va() - Get virtual address of a physical address
255 * @shm: Shared memory handle
256 * @pa: Physical address to tranlsate
257 * @va: Returned virtual address
258 * @returns 0 on success and < 0 on failure
259 */
tee_shm_pa2va(struct tee_shm * shm,phys_addr_t pa,void ** va)260 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
261 {
262 /* Check that we're in the range of the shm */
263 if (pa < shm->paddr)
264 return -EINVAL;
265 if (pa >= (shm->paddr + shm->size))
266 return -EINVAL;
267
268 if (va) {
269 void *v = tee_shm_get_va(shm, pa - shm->paddr);
270
271 if (IS_ERR(v))
272 return PTR_ERR(v);
273 *va = v;
274 }
275 return 0;
276 }
277 EXPORT_SYMBOL_GPL(tee_shm_pa2va);
278
279 /**
280 * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
281 * @shm: Shared memory handle
282 * @offs: Offset from start of this shared memory
283 * @returns virtual address of the shared memory + offs if offs is within
284 * the bounds of this shared memory, else an ERR_PTR
285 */
tee_shm_get_va(struct tee_shm * shm,size_t offs)286 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
287 {
288 if (offs >= shm->size)
289 return ERR_PTR(-EINVAL);
290 return (char *)shm->kaddr + offs;
291 }
292 EXPORT_SYMBOL_GPL(tee_shm_get_va);
293
294 /**
295 * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
296 * @shm: Shared memory handle
297 * @offs: Offset from start of this shared memory
298 * @pa: Physical address to return
299 * @returns 0 if offs is within the bounds of this shared memory, else an
300 * error code.
301 */
tee_shm_get_pa(struct tee_shm * shm,size_t offs,phys_addr_t * pa)302 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
303 {
304 if (offs >= shm->size)
305 return -EINVAL;
306 if (pa)
307 *pa = shm->paddr + offs;
308 return 0;
309 }
310 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
311
312 /**
313 * tee_shm_get_from_id() - Find shared memory object and increase reference
314 * count
315 * @ctx: Context owning the shared memory
316 * @id: Id of shared memory object
317 * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
318 */
tee_shm_get_from_id(struct tee_context * ctx,int id)319 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
320 {
321 struct tee_device *teedev;
322 struct tee_shm *shm;
323
324 if (!ctx)
325 return ERR_PTR(-EINVAL);
326
327 teedev = ctx->teedev;
328 mutex_lock(&teedev->mutex);
329 shm = idr_find(&teedev->idr, id);
330 if (!shm || shm->ctx != ctx)
331 shm = ERR_PTR(-EINVAL);
332 else if (shm->flags & TEE_SHM_DMA_BUF)
333 get_dma_buf(shm->dmabuf);
334 mutex_unlock(&teedev->mutex);
335 return shm;
336 }
337 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
338
339 /**
340 * tee_shm_get_id() - Get id of a shared memory object
341 * @shm: Shared memory handle
342 * @returns id
343 */
tee_shm_get_id(struct tee_shm * shm)344 int tee_shm_get_id(struct tee_shm *shm)
345 {
346 return shm->id;
347 }
348 EXPORT_SYMBOL_GPL(tee_shm_get_id);
349
350 /**
351 * tee_shm_put() - Decrease reference count on a shared memory handle
352 * @shm: Shared memory handle
353 */
tee_shm_put(struct tee_shm * shm)354 void tee_shm_put(struct tee_shm *shm)
355 {
356 if (shm->flags & TEE_SHM_DMA_BUF)
357 dma_buf_put(shm->dmabuf);
358 }
359 EXPORT_SYMBOL_GPL(tee_shm_put);
360