Merge tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[muen/linux.git] / drivers / tee / tee_shm.c
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
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
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
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
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
64 static void *tee_shm_op_map_atomic(struct dma_buf *dmabuf, unsigned long pgnum)
65 {
66         return NULL;
67 }
68
69 static void *tee_shm_op_map(struct dma_buf *dmabuf, unsigned long pgnum)
70 {
71         return NULL;
72 }
73
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 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  */
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  */
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         fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
207         if (fd >= 0)
208                 get_dma_buf(shm->dmabuf);
209         return fd;
210 }
211
212 /**
213  * tee_shm_free() - Free shared memory
214  * @shm:        Handle to shared memory to free
215  */
216 void tee_shm_free(struct tee_shm *shm)
217 {
218         /*
219          * dma_buf_put() decreases the dmabuf reference counter and will
220          * call tee_shm_release() when the last reference is gone.
221          *
222          * In the case of driver private memory we call tee_shm_release
223          * directly instead as it doesn't have a reference counter.
224          */
225         if (shm->flags & TEE_SHM_DMA_BUF)
226                 dma_buf_put(shm->dmabuf);
227         else
228                 tee_shm_release(shm);
229 }
230 EXPORT_SYMBOL_GPL(tee_shm_free);
231
232 /**
233  * tee_shm_va2pa() - Get physical address of a virtual address
234  * @shm:        Shared memory handle
235  * @va:         Virtual address to tranlsate
236  * @pa:         Returned physical address
237  * @returns 0 on success and < 0 on failure
238  */
239 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
240 {
241         /* Check that we're in the range of the shm */
242         if ((char *)va < (char *)shm->kaddr)
243                 return -EINVAL;
244         if ((char *)va >= ((char *)shm->kaddr + shm->size))
245                 return -EINVAL;
246
247         return tee_shm_get_pa(
248                         shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
249 }
250 EXPORT_SYMBOL_GPL(tee_shm_va2pa);
251
252 /**
253  * tee_shm_pa2va() - Get virtual address of a physical address
254  * @shm:        Shared memory handle
255  * @pa:         Physical address to tranlsate
256  * @va:         Returned virtual address
257  * @returns 0 on success and < 0 on failure
258  */
259 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
260 {
261         /* Check that we're in the range of the shm */
262         if (pa < shm->paddr)
263                 return -EINVAL;
264         if (pa >= (shm->paddr + shm->size))
265                 return -EINVAL;
266
267         if (va) {
268                 void *v = tee_shm_get_va(shm, pa - shm->paddr);
269
270                 if (IS_ERR(v))
271                         return PTR_ERR(v);
272                 *va = v;
273         }
274         return 0;
275 }
276 EXPORT_SYMBOL_GPL(tee_shm_pa2va);
277
278 /**
279  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
280  * @shm:        Shared memory handle
281  * @offs:       Offset from start of this shared memory
282  * @returns virtual address of the shared memory + offs if offs is within
283  *      the bounds of this shared memory, else an ERR_PTR
284  */
285 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
286 {
287         if (offs >= shm->size)
288                 return ERR_PTR(-EINVAL);
289         return (char *)shm->kaddr + offs;
290 }
291 EXPORT_SYMBOL_GPL(tee_shm_get_va);
292
293 /**
294  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
295  * @shm:        Shared memory handle
296  * @offs:       Offset from start of this shared memory
297  * @pa:         Physical address to return
298  * @returns 0 if offs is within the bounds of this shared memory, else an
299  *      error code.
300  */
301 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
302 {
303         if (offs >= shm->size)
304                 return -EINVAL;
305         if (pa)
306                 *pa = shm->paddr + offs;
307         return 0;
308 }
309 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
310
311 /**
312  * tee_shm_get_from_id() - Find shared memory object and increase reference
313  * count
314  * @ctx:        Context owning the shared memory
315  * @id:         Id of shared memory object
316  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
317  */
318 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
319 {
320         struct tee_device *teedev;
321         struct tee_shm *shm;
322
323         if (!ctx)
324                 return ERR_PTR(-EINVAL);
325
326         teedev = ctx->teedev;
327         mutex_lock(&teedev->mutex);
328         shm = idr_find(&teedev->idr, id);
329         if (!shm || shm->ctx != ctx)
330                 shm = ERR_PTR(-EINVAL);
331         else if (shm->flags & TEE_SHM_DMA_BUF)
332                 get_dma_buf(shm->dmabuf);
333         mutex_unlock(&teedev->mutex);
334         return shm;
335 }
336 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
337
338 /**
339  * tee_shm_get_id() - Get id of a shared memory object
340  * @shm:        Shared memory handle
341  * @returns id
342  */
343 int tee_shm_get_id(struct tee_shm *shm)
344 {
345         return shm->id;
346 }
347 EXPORT_SYMBOL_GPL(tee_shm_get_id);
348
349 /**
350  * tee_shm_put() - Decrease reference count on a shared memory handle
351  * @shm:        Shared memory handle
352  */
353 void tee_shm_put(struct tee_shm *shm)
354 {
355         if (shm->flags & TEE_SHM_DMA_BUF)
356                 dma_buf_put(shm->dmabuf);
357 }
358 EXPORT_SYMBOL_GPL(tee_shm_put);