Merge branches 'clk-baikal', 'clk-broadcom', 'clk-vc5' and 'clk-versaclock' into...
[platform/kernel/linux-starfive.git] / drivers / tee / tee_shm.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015-2017, 2019-2021 Linaro Limited
4  */
5 #include <linux/anon_inodes.h>
6 #include <linux/device.h>
7 #include <linux/idr.h>
8 #include <linux/mm.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 shm_put_kernel_pages(struct page **pages, size_t page_count)
16 {
17         size_t n;
18
19         for (n = 0; n < page_count; n++)
20                 put_page(pages[n]);
21 }
22
23 static int shm_get_kernel_pages(unsigned long start, size_t page_count,
24                                 struct page **pages)
25 {
26         size_t n;
27         int rc;
28
29         if (is_vmalloc_addr((void *)start)) {
30                 struct page *page;
31
32                 for (n = 0; n < page_count; n++) {
33                         page = vmalloc_to_page((void *)(start + PAGE_SIZE * n));
34                         if (!page)
35                                 return -ENOMEM;
36
37                         get_page(page);
38                         pages[n] = page;
39                 }
40                 rc = page_count;
41         } else {
42                 struct kvec *kiov;
43
44                 kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
45                 if (!kiov)
46                         return -ENOMEM;
47
48                 for (n = 0; n < page_count; n++) {
49                         kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
50                         kiov[n].iov_len = PAGE_SIZE;
51                 }
52
53                 rc = get_kernel_pages(kiov, page_count, 0, pages);
54                 kfree(kiov);
55         }
56
57         return rc;
58 }
59
60 static void release_registered_pages(struct tee_shm *shm)
61 {
62         if (shm->pages) {
63                 if (shm->flags & TEE_SHM_USER_MAPPED)
64                         unpin_user_pages(shm->pages, shm->num_pages);
65                 else
66                         shm_put_kernel_pages(shm->pages, shm->num_pages);
67
68                 kfree(shm->pages);
69         }
70 }
71
72 static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
73 {
74         if (shm->flags & TEE_SHM_POOL) {
75                 teedev->pool->ops->free(teedev->pool, shm);
76         } else if (shm->flags & TEE_SHM_DYNAMIC) {
77                 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
78
79                 if (rc)
80                         dev_err(teedev->dev.parent,
81                                 "unregister shm %p failed: %d", shm, rc);
82
83                 release_registered_pages(shm);
84         }
85
86         teedev_ctx_put(shm->ctx);
87
88         kfree(shm);
89
90         tee_device_put(teedev);
91 }
92
93 static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size,
94                                         size_t align, u32 flags, int id)
95 {
96         struct tee_device *teedev = ctx->teedev;
97         struct tee_shm *shm;
98         void *ret;
99         int rc;
100
101         if (!tee_device_get(teedev))
102                 return ERR_PTR(-EINVAL);
103
104         if (!teedev->pool) {
105                 /* teedev has been detached from driver */
106                 ret = ERR_PTR(-EINVAL);
107                 goto err_dev_put;
108         }
109
110         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
111         if (!shm) {
112                 ret = ERR_PTR(-ENOMEM);
113                 goto err_dev_put;
114         }
115
116         refcount_set(&shm->refcount, 1);
117         shm->flags = flags;
118         shm->id = id;
119
120         /*
121          * We're assigning this as it is needed if the shm is to be
122          * registered. If this function returns OK then the caller expected
123          * to call teedev_ctx_get() or clear shm->ctx in case it's not
124          * needed any longer.
125          */
126         shm->ctx = ctx;
127
128         rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align);
129         if (rc) {
130                 ret = ERR_PTR(rc);
131                 goto err_kfree;
132         }
133
134         teedev_ctx_get(ctx);
135         return shm;
136 err_kfree:
137         kfree(shm);
138 err_dev_put:
139         tee_device_put(teedev);
140         return ret;
141 }
142
143 /**
144  * tee_shm_alloc_user_buf() - Allocate shared memory for user space
145  * @ctx:        Context that allocates the shared memory
146  * @size:       Requested size of shared memory
147  *
148  * Memory allocated as user space shared memory is automatically freed when
149  * the TEE file pointer is closed. The primary usage of this function is
150  * when the TEE driver doesn't support registering ordinary user space
151  * memory.
152  *
153  * @returns a pointer to 'struct tee_shm'
154  */
155 struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
156 {
157         u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
158         struct tee_device *teedev = ctx->teedev;
159         struct tee_shm *shm;
160         void *ret;
161         int id;
162
163         mutex_lock(&teedev->mutex);
164         id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
165         mutex_unlock(&teedev->mutex);
166         if (id < 0)
167                 return ERR_PTR(id);
168
169         shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id);
170         if (IS_ERR(shm)) {
171                 mutex_lock(&teedev->mutex);
172                 idr_remove(&teedev->idr, id);
173                 mutex_unlock(&teedev->mutex);
174                 return shm;
175         }
176
177         mutex_lock(&teedev->mutex);
178         ret = idr_replace(&teedev->idr, shm, id);
179         mutex_unlock(&teedev->mutex);
180         if (IS_ERR(ret)) {
181                 tee_shm_free(shm);
182                 return ret;
183         }
184
185         return shm;
186 }
187
188 /**
189  * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
190  * @ctx:        Context that allocates the shared memory
191  * @size:       Requested size of shared memory
192  *
193  * The returned memory registered in secure world and is suitable to be
194  * passed as a memory buffer in parameter argument to
195  * tee_client_invoke_func(). The memory allocated is later freed with a
196  * call to tee_shm_free().
197  *
198  * @returns a pointer to 'struct tee_shm'
199  */
200 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
201 {
202         u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
203
204         return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1);
205 }
206 EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
207
208 /**
209  * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
210  *                            kernel buffer
211  * @ctx:        Context that allocates the shared memory
212  * @size:       Requested size of shared memory
213  *
214  * This function returns similar shared memory as
215  * tee_shm_alloc_kernel_buf(), but with the difference that the memory
216  * might not be registered in secure world in case the driver supports
217  * passing memory not registered in advance.
218  *
219  * This function should normally only be used internally in the TEE
220  * drivers.
221  *
222  * @returns a pointer to 'struct tee_shm'
223  */
224 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
225 {
226         u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL;
227
228         return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1);
229 }
230 EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
231
232 static struct tee_shm *
233 register_shm_helper(struct tee_context *ctx, unsigned long addr,
234                     size_t length, u32 flags, int id)
235 {
236         struct tee_device *teedev = ctx->teedev;
237         struct tee_shm *shm;
238         unsigned long start;
239         size_t num_pages;
240         void *ret;
241         int rc;
242
243         if (!tee_device_get(teedev))
244                 return ERR_PTR(-EINVAL);
245
246         if (!teedev->desc->ops->shm_register ||
247             !teedev->desc->ops->shm_unregister) {
248                 ret = ERR_PTR(-ENOTSUPP);
249                 goto err_dev_put;
250         }
251
252         teedev_ctx_get(ctx);
253
254         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
255         if (!shm) {
256                 ret = ERR_PTR(-ENOMEM);
257                 goto err_ctx_put;
258         }
259
260         refcount_set(&shm->refcount, 1);
261         shm->flags = flags;
262         shm->ctx = ctx;
263         shm->id = id;
264         addr = untagged_addr(addr);
265         start = rounddown(addr, PAGE_SIZE);
266         shm->offset = addr - start;
267         shm->size = length;
268         num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
269         shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
270         if (!shm->pages) {
271                 ret = ERR_PTR(-ENOMEM);
272                 goto err_free_shm;
273         }
274
275         if (flags & TEE_SHM_USER_MAPPED)
276                 rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
277                                          shm->pages);
278         else
279                 rc = shm_get_kernel_pages(start, num_pages, shm->pages);
280         if (rc > 0)
281                 shm->num_pages = rc;
282         if (rc != num_pages) {
283                 if (rc >= 0)
284                         rc = -ENOMEM;
285                 ret = ERR_PTR(rc);
286                 goto err_put_shm_pages;
287         }
288
289         rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
290                                              shm->num_pages, start);
291         if (rc) {
292                 ret = ERR_PTR(rc);
293                 goto err_put_shm_pages;
294         }
295
296         return shm;
297 err_put_shm_pages:
298         if (flags & TEE_SHM_USER_MAPPED)
299                 unpin_user_pages(shm->pages, shm->num_pages);
300         else
301                 shm_put_kernel_pages(shm->pages, shm->num_pages);
302         kfree(shm->pages);
303 err_free_shm:
304         kfree(shm);
305 err_ctx_put:
306         teedev_ctx_put(ctx);
307 err_dev_put:
308         tee_device_put(teedev);
309         return ret;
310 }
311
312 /**
313  * tee_shm_register_user_buf() - Register a userspace shared memory buffer
314  * @ctx:        Context that registers the shared memory
315  * @addr:       The userspace address of the shared buffer
316  * @length:     Length of the shared buffer
317  *
318  * @returns a pointer to 'struct tee_shm'
319  */
320 struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
321                                           unsigned long addr, size_t length)
322 {
323         u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
324         struct tee_device *teedev = ctx->teedev;
325         struct tee_shm *shm;
326         void *ret;
327         int id;
328
329         if (!access_ok((void __user *)addr, length))
330                 return ERR_PTR(-EFAULT);
331
332         mutex_lock(&teedev->mutex);
333         id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
334         mutex_unlock(&teedev->mutex);
335         if (id < 0)
336                 return ERR_PTR(id);
337
338         shm = register_shm_helper(ctx, addr, length, flags, id);
339         if (IS_ERR(shm)) {
340                 mutex_lock(&teedev->mutex);
341                 idr_remove(&teedev->idr, id);
342                 mutex_unlock(&teedev->mutex);
343                 return shm;
344         }
345
346         mutex_lock(&teedev->mutex);
347         ret = idr_replace(&teedev->idr, shm, id);
348         mutex_unlock(&teedev->mutex);
349         if (IS_ERR(ret)) {
350                 tee_shm_free(shm);
351                 return ret;
352         }
353
354         return shm;
355 }
356
357 /**
358  * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
359  *                                 secure world
360  * @ctx:        Context that registers the shared memory
361  * @addr:       The buffer
362  * @length:     Length of the buffer
363  *
364  * @returns a pointer to 'struct tee_shm'
365  */
366
367 struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
368                                             void *addr, size_t length)
369 {
370         u32 flags = TEE_SHM_DYNAMIC;
371
372         return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
373 }
374 EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
375
376 static int tee_shm_fop_release(struct inode *inode, struct file *filp)
377 {
378         tee_shm_put(filp->private_data);
379         return 0;
380 }
381
382 static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma)
383 {
384         struct tee_shm *shm = filp->private_data;
385         size_t size = vma->vm_end - vma->vm_start;
386
387         /* Refuse sharing shared memory provided by application */
388         if (shm->flags & TEE_SHM_USER_MAPPED)
389                 return -EINVAL;
390
391         /* check for overflowing the buffer's size */
392         if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT)
393                 return -EINVAL;
394
395         return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
396                                size, vma->vm_page_prot);
397 }
398
399 static const struct file_operations tee_shm_fops = {
400         .owner = THIS_MODULE,
401         .release = tee_shm_fop_release,
402         .mmap = tee_shm_fop_mmap,
403 };
404
405 /**
406  * tee_shm_get_fd() - Increase reference count and return file descriptor
407  * @shm:        Shared memory handle
408  * @returns user space file descriptor to shared memory
409  */
410 int tee_shm_get_fd(struct tee_shm *shm)
411 {
412         int fd;
413
414         if (shm->id < 0)
415                 return -EINVAL;
416
417         /* matched by tee_shm_put() in tee_shm_op_release() */
418         refcount_inc(&shm->refcount);
419         fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR);
420         if (fd < 0)
421                 tee_shm_put(shm);
422         return fd;
423 }
424
425 /**
426  * tee_shm_free() - Free shared memory
427  * @shm:        Handle to shared memory to free
428  */
429 void tee_shm_free(struct tee_shm *shm)
430 {
431         tee_shm_put(shm);
432 }
433 EXPORT_SYMBOL_GPL(tee_shm_free);
434
435 /**
436  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
437  * @shm:        Shared memory handle
438  * @offs:       Offset from start of this shared memory
439  * @returns virtual address of the shared memory + offs if offs is within
440  *      the bounds of this shared memory, else an ERR_PTR
441  */
442 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
443 {
444         if (!shm->kaddr)
445                 return ERR_PTR(-EINVAL);
446         if (offs >= shm->size)
447                 return ERR_PTR(-EINVAL);
448         return (char *)shm->kaddr + offs;
449 }
450 EXPORT_SYMBOL_GPL(tee_shm_get_va);
451
452 /**
453  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
454  * @shm:        Shared memory handle
455  * @offs:       Offset from start of this shared memory
456  * @pa:         Physical address to return
457  * @returns 0 if offs is within the bounds of this shared memory, else an
458  *      error code.
459  */
460 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
461 {
462         if (offs >= shm->size)
463                 return -EINVAL;
464         if (pa)
465                 *pa = shm->paddr + offs;
466         return 0;
467 }
468 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
469
470 /**
471  * tee_shm_get_from_id() - Find shared memory object and increase reference
472  * count
473  * @ctx:        Context owning the shared memory
474  * @id:         Id of shared memory object
475  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
476  */
477 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
478 {
479         struct tee_device *teedev;
480         struct tee_shm *shm;
481
482         if (!ctx)
483                 return ERR_PTR(-EINVAL);
484
485         teedev = ctx->teedev;
486         mutex_lock(&teedev->mutex);
487         shm = idr_find(&teedev->idr, id);
488         /*
489          * If the tee_shm was found in the IDR it must have a refcount
490          * larger than 0 due to the guarantee in tee_shm_put() below. So
491          * it's safe to use refcount_inc().
492          */
493         if (!shm || shm->ctx != ctx)
494                 shm = ERR_PTR(-EINVAL);
495         else
496                 refcount_inc(&shm->refcount);
497         mutex_unlock(&teedev->mutex);
498         return shm;
499 }
500 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
501
502 /**
503  * tee_shm_put() - Decrease reference count on a shared memory handle
504  * @shm:        Shared memory handle
505  */
506 void tee_shm_put(struct tee_shm *shm)
507 {
508         struct tee_device *teedev = shm->ctx->teedev;
509         bool do_release = false;
510
511         mutex_lock(&teedev->mutex);
512         if (refcount_dec_and_test(&shm->refcount)) {
513                 /*
514                  * refcount has reached 0, we must now remove it from the
515                  * IDR before releasing the mutex. This will guarantee that
516                  * the refcount_inc() in tee_shm_get_from_id() never starts
517                  * from 0.
518                  */
519                 if (shm->id >= 0)
520                         idr_remove(&teedev->idr, shm->id);
521                 do_release = true;
522         }
523         mutex_unlock(&teedev->mutex);
524
525         if (do_release)
526                 tee_shm_release(teedev, shm);
527 }
528 EXPORT_SYMBOL_GPL(tee_shm_put);