Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[platform/kernel/linux-rpi.git] / drivers / tee / tee_shm.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015-2016, Linaro Limited
4  */
5 #include <linux/device.h>
6 #include <linux/dma-buf.h>
7 #include <linux/fdtable.h>
8 #include <linux/idr.h>
9 #include <linux/sched.h>
10 #include <linux/slab.h>
11 #include <linux/tee_drv.h>
12 #include <linux/uio.h>
13 #include "tee_private.h"
14
15 static void release_registered_pages(struct tee_shm *shm)
16 {
17         if (shm->pages) {
18                 if (shm->flags & TEE_SHM_USER_MAPPED) {
19                         unpin_user_pages(shm->pages, shm->num_pages);
20                 } else {
21                         size_t n;
22
23                         for (n = 0; n < shm->num_pages; n++)
24                                 put_page(shm->pages[n]);
25                 }
26
27                 kfree(shm->pages);
28         }
29 }
30
31 static void tee_shm_release(struct tee_shm *shm)
32 {
33         struct tee_device *teedev = shm->ctx->teedev;
34
35         if (shm->flags & TEE_SHM_DMA_BUF) {
36                 mutex_lock(&teedev->mutex);
37                 idr_remove(&teedev->idr, shm->id);
38                 mutex_unlock(&teedev->mutex);
39         }
40
41         if (shm->flags & TEE_SHM_POOL) {
42                 struct tee_shm_pool_mgr *poolm;
43
44                 if (shm->flags & TEE_SHM_DMA_BUF)
45                         poolm = teedev->pool->dma_buf_mgr;
46                 else
47                         poolm = teedev->pool->private_mgr;
48
49                 poolm->ops->free(poolm, shm);
50         } else if (shm->flags & TEE_SHM_REGISTER) {
51                 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
52
53                 if (rc)
54                         dev_err(teedev->dev.parent,
55                                 "unregister shm %p failed: %d", shm, rc);
56
57                 release_registered_pages(shm);
58         }
59
60         teedev_ctx_put(shm->ctx);
61
62         kfree(shm);
63
64         tee_device_put(teedev);
65 }
66
67 static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
68                         *attach, enum dma_data_direction dir)
69 {
70         return NULL;
71 }
72
73 static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
74                                      struct sg_table *table,
75                                      enum dma_data_direction dir)
76 {
77 }
78
79 static void tee_shm_op_release(struct dma_buf *dmabuf)
80 {
81         struct tee_shm *shm = dmabuf->priv;
82
83         tee_shm_release(shm);
84 }
85
86 static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
87 {
88         struct tee_shm *shm = dmabuf->priv;
89         size_t size = vma->vm_end - vma->vm_start;
90
91         /* Refuse sharing shared memory provided by application */
92         if (shm->flags & TEE_SHM_USER_MAPPED)
93                 return -EINVAL;
94
95         return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
96                                size, vma->vm_page_prot);
97 }
98
99 static const struct dma_buf_ops tee_shm_dma_buf_ops = {
100         .map_dma_buf = tee_shm_op_map_dma_buf,
101         .unmap_dma_buf = tee_shm_op_unmap_dma_buf,
102         .release = tee_shm_op_release,
103         .mmap = tee_shm_op_mmap,
104 };
105
106 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
107 {
108         struct tee_device *teedev = ctx->teedev;
109         struct tee_shm_pool_mgr *poolm = NULL;
110         struct tee_shm *shm;
111         void *ret;
112         int rc;
113
114         if (!(flags & TEE_SHM_MAPPED)) {
115                 dev_err(teedev->dev.parent,
116                         "only mapped allocations supported\n");
117                 return ERR_PTR(-EINVAL);
118         }
119
120         if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF | TEE_SHM_PRIV))) {
121                 dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
122                 return ERR_PTR(-EINVAL);
123         }
124
125         if (!tee_device_get(teedev))
126                 return ERR_PTR(-EINVAL);
127
128         if (!teedev->pool) {
129                 /* teedev has been detached from driver */
130                 ret = ERR_PTR(-EINVAL);
131                 goto err_dev_put;
132         }
133
134         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
135         if (!shm) {
136                 ret = ERR_PTR(-ENOMEM);
137                 goto err_dev_put;
138         }
139
140         shm->flags = flags | TEE_SHM_POOL;
141         shm->ctx = ctx;
142         if (flags & TEE_SHM_DMA_BUF)
143                 poolm = teedev->pool->dma_buf_mgr;
144         else
145                 poolm = teedev->pool->private_mgr;
146
147         rc = poolm->ops->alloc(poolm, shm, size);
148         if (rc) {
149                 ret = ERR_PTR(rc);
150                 goto err_kfree;
151         }
152
153
154         if (flags & TEE_SHM_DMA_BUF) {
155                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
156
157                 mutex_lock(&teedev->mutex);
158                 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
159                 mutex_unlock(&teedev->mutex);
160                 if (shm->id < 0) {
161                         ret = ERR_PTR(shm->id);
162                         goto err_pool_free;
163                 }
164
165                 exp_info.ops = &tee_shm_dma_buf_ops;
166                 exp_info.size = shm->size;
167                 exp_info.flags = O_RDWR;
168                 exp_info.priv = shm;
169
170                 shm->dmabuf = dma_buf_export(&exp_info);
171                 if (IS_ERR(shm->dmabuf)) {
172                         ret = ERR_CAST(shm->dmabuf);
173                         goto err_rem;
174                 }
175         }
176
177         teedev_ctx_get(ctx);
178
179         return shm;
180 err_rem:
181         if (flags & TEE_SHM_DMA_BUF) {
182                 mutex_lock(&teedev->mutex);
183                 idr_remove(&teedev->idr, shm->id);
184                 mutex_unlock(&teedev->mutex);
185         }
186 err_pool_free:
187         poolm->ops->free(poolm, shm);
188 err_kfree:
189         kfree(shm);
190 err_dev_put:
191         tee_device_put(teedev);
192         return ret;
193 }
194 EXPORT_SYMBOL_GPL(tee_shm_alloc);
195
196 /**
197  * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
198  * @ctx:        Context that allocates the shared memory
199  * @size:       Requested size of shared memory
200  *
201  * The returned memory registered in secure world and is suitable to be
202  * passed as a memory buffer in parameter argument to
203  * tee_client_invoke_func(). The memory allocated is later freed with a
204  * call to tee_shm_free().
205  *
206  * @returns a pointer to 'struct tee_shm'
207  */
208 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
209 {
210         return tee_shm_alloc(ctx, size, TEE_SHM_MAPPED);
211 }
212 EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
213
214 struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
215                                  size_t length, u32 flags)
216 {
217         struct tee_device *teedev = ctx->teedev;
218         const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
219         const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
220         struct tee_shm *shm;
221         void *ret;
222         int rc;
223         int num_pages;
224         unsigned long start;
225
226         if (flags != req_user_flags && flags != req_kernel_flags)
227                 return ERR_PTR(-ENOTSUPP);
228
229         if (!tee_device_get(teedev))
230                 return ERR_PTR(-EINVAL);
231
232         if (!teedev->desc->ops->shm_register ||
233             !teedev->desc->ops->shm_unregister) {
234                 tee_device_put(teedev);
235                 return ERR_PTR(-ENOTSUPP);
236         }
237
238         teedev_ctx_get(ctx);
239
240         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
241         if (!shm) {
242                 ret = ERR_PTR(-ENOMEM);
243                 goto err;
244         }
245
246         shm->flags = flags | TEE_SHM_REGISTER;
247         shm->ctx = ctx;
248         shm->id = -1;
249         addr = untagged_addr(addr);
250         start = rounddown(addr, PAGE_SIZE);
251         shm->offset = addr - start;
252         shm->size = length;
253         num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
254         shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
255         if (!shm->pages) {
256                 ret = ERR_PTR(-ENOMEM);
257                 goto err;
258         }
259
260         if (flags & TEE_SHM_USER_MAPPED) {
261                 rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
262                                          shm->pages);
263         } else {
264                 struct kvec *kiov;
265                 int i;
266
267                 kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
268                 if (!kiov) {
269                         ret = ERR_PTR(-ENOMEM);
270                         goto err;
271                 }
272
273                 for (i = 0; i < num_pages; i++) {
274                         kiov[i].iov_base = (void *)(start + i * PAGE_SIZE);
275                         kiov[i].iov_len = PAGE_SIZE;
276                 }
277
278                 rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
279                 kfree(kiov);
280         }
281         if (rc > 0)
282                 shm->num_pages = rc;
283         if (rc != num_pages) {
284                 if (rc >= 0)
285                         rc = -ENOMEM;
286                 ret = ERR_PTR(rc);
287                 goto err;
288         }
289
290         mutex_lock(&teedev->mutex);
291         shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
292         mutex_unlock(&teedev->mutex);
293
294         if (shm->id < 0) {
295                 ret = ERR_PTR(shm->id);
296                 goto err;
297         }
298
299         rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
300                                              shm->num_pages, start);
301         if (rc) {
302                 ret = ERR_PTR(rc);
303                 goto err;
304         }
305
306         if (flags & TEE_SHM_DMA_BUF) {
307                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
308
309                 exp_info.ops = &tee_shm_dma_buf_ops;
310                 exp_info.size = shm->size;
311                 exp_info.flags = O_RDWR;
312                 exp_info.priv = shm;
313
314                 shm->dmabuf = dma_buf_export(&exp_info);
315                 if (IS_ERR(shm->dmabuf)) {
316                         ret = ERR_CAST(shm->dmabuf);
317                         teedev->desc->ops->shm_unregister(ctx, shm);
318                         goto err;
319                 }
320         }
321
322         return shm;
323 err:
324         if (shm) {
325                 if (shm->id >= 0) {
326                         mutex_lock(&teedev->mutex);
327                         idr_remove(&teedev->idr, shm->id);
328                         mutex_unlock(&teedev->mutex);
329                 }
330                 release_registered_pages(shm);
331         }
332         kfree(shm);
333         teedev_ctx_put(ctx);
334         tee_device_put(teedev);
335         return ret;
336 }
337 EXPORT_SYMBOL_GPL(tee_shm_register);
338
339 /**
340  * tee_shm_get_fd() - Increase reference count and return file descriptor
341  * @shm:        Shared memory handle
342  * @returns user space file descriptor to shared memory
343  */
344 int tee_shm_get_fd(struct tee_shm *shm)
345 {
346         int fd;
347
348         if (!(shm->flags & TEE_SHM_DMA_BUF))
349                 return -EINVAL;
350
351         get_dma_buf(shm->dmabuf);
352         fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
353         if (fd < 0)
354                 dma_buf_put(shm->dmabuf);
355         return fd;
356 }
357
358 /**
359  * tee_shm_free() - Free shared memory
360  * @shm:        Handle to shared memory to free
361  */
362 void tee_shm_free(struct tee_shm *shm)
363 {
364         /*
365          * dma_buf_put() decreases the dmabuf reference counter and will
366          * call tee_shm_release() when the last reference is gone.
367          *
368          * In the case of driver private memory we call tee_shm_release
369          * directly instead as it doesn't have a reference counter.
370          */
371         if (shm->flags & TEE_SHM_DMA_BUF)
372                 dma_buf_put(shm->dmabuf);
373         else
374                 tee_shm_release(shm);
375 }
376 EXPORT_SYMBOL_GPL(tee_shm_free);
377
378 /**
379  * tee_shm_va2pa() - Get physical address of a virtual address
380  * @shm:        Shared memory handle
381  * @va:         Virtual address to tranlsate
382  * @pa:         Returned physical address
383  * @returns 0 on success and < 0 on failure
384  */
385 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
386 {
387         if (!(shm->flags & TEE_SHM_MAPPED))
388                 return -EINVAL;
389         /* Check that we're in the range of the shm */
390         if ((char *)va < (char *)shm->kaddr)
391                 return -EINVAL;
392         if ((char *)va >= ((char *)shm->kaddr + shm->size))
393                 return -EINVAL;
394
395         return tee_shm_get_pa(
396                         shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
397 }
398 EXPORT_SYMBOL_GPL(tee_shm_va2pa);
399
400 /**
401  * tee_shm_pa2va() - Get virtual address of a physical address
402  * @shm:        Shared memory handle
403  * @pa:         Physical address to tranlsate
404  * @va:         Returned virtual address
405  * @returns 0 on success and < 0 on failure
406  */
407 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
408 {
409         if (!(shm->flags & TEE_SHM_MAPPED))
410                 return -EINVAL;
411         /* Check that we're in the range of the shm */
412         if (pa < shm->paddr)
413                 return -EINVAL;
414         if (pa >= (shm->paddr + shm->size))
415                 return -EINVAL;
416
417         if (va) {
418                 void *v = tee_shm_get_va(shm, pa - shm->paddr);
419
420                 if (IS_ERR(v))
421                         return PTR_ERR(v);
422                 *va = v;
423         }
424         return 0;
425 }
426 EXPORT_SYMBOL_GPL(tee_shm_pa2va);
427
428 /**
429  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
430  * @shm:        Shared memory handle
431  * @offs:       Offset from start of this shared memory
432  * @returns virtual address of the shared memory + offs if offs is within
433  *      the bounds of this shared memory, else an ERR_PTR
434  */
435 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
436 {
437         if (!(shm->flags & TEE_SHM_MAPPED))
438                 return ERR_PTR(-EINVAL);
439         if (offs >= shm->size)
440                 return ERR_PTR(-EINVAL);
441         return (char *)shm->kaddr + offs;
442 }
443 EXPORT_SYMBOL_GPL(tee_shm_get_va);
444
445 /**
446  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
447  * @shm:        Shared memory handle
448  * @offs:       Offset from start of this shared memory
449  * @pa:         Physical address to return
450  * @returns 0 if offs is within the bounds of this shared memory, else an
451  *      error code.
452  */
453 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
454 {
455         if (offs >= shm->size)
456                 return -EINVAL;
457         if (pa)
458                 *pa = shm->paddr + offs;
459         return 0;
460 }
461 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
462
463 /**
464  * tee_shm_get_from_id() - Find shared memory object and increase reference
465  * count
466  * @ctx:        Context owning the shared memory
467  * @id:         Id of shared memory object
468  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
469  */
470 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
471 {
472         struct tee_device *teedev;
473         struct tee_shm *shm;
474
475         if (!ctx)
476                 return ERR_PTR(-EINVAL);
477
478         teedev = ctx->teedev;
479         mutex_lock(&teedev->mutex);
480         shm = idr_find(&teedev->idr, id);
481         if (!shm || shm->ctx != ctx)
482                 shm = ERR_PTR(-EINVAL);
483         else if (shm->flags & TEE_SHM_DMA_BUF)
484                 get_dma_buf(shm->dmabuf);
485         mutex_unlock(&teedev->mutex);
486         return shm;
487 }
488 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
489
490 /**
491  * tee_shm_put() - Decrease reference count on a shared memory handle
492  * @shm:        Shared memory handle
493  */
494 void tee_shm_put(struct tee_shm *shm)
495 {
496         if (shm->flags & TEE_SHM_DMA_BUF)
497                 dma_buf_put(shm->dmabuf);
498 }
499 EXPORT_SYMBOL_GPL(tee_shm_put);