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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
15static void tee_shm_release(struct tee_shm *shm)
16{
17 struct tee_device *teedev = shm->ctx->teedev;
18
19 if (shm->flags & TEE_SHM_DMA_BUF) {
20 mutex_lock(&teedev->mutex);
21 idr_remove(&teedev->idr, shm->id);
22 mutex_unlock(&teedev->mutex);
23 }
24
25 if (shm->flags & TEE_SHM_POOL) {
26 struct tee_shm_pool_mgr *poolm;
27
28 if (shm->flags & TEE_SHM_DMA_BUF)
29 poolm = teedev->pool->dma_buf_mgr;
30 else
31 poolm = teedev->pool->private_mgr;
32
33 poolm->ops->free(poolm, shm);
34 } else if (shm->flags & TEE_SHM_REGISTER) {
35 size_t n;
36 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
37
38 if (rc)
39 dev_err(teedev->dev.parent,
40 "unregister shm %p failed: %d", shm, rc);
41
42 for (n = 0; n < shm->num_pages; n++)
43 put_page(shm->pages[n]);
44
45 kfree(shm->pages);
46 }
47
48 teedev_ctx_put(shm->ctx);
49
50 kfree(shm);
51
52 tee_device_put(teedev);
53}
54
55static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
56 *attach, enum dma_data_direction dir)
57{
58 return NULL;
59}
60
61static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
62 struct sg_table *table,
63 enum dma_data_direction dir)
64{
65}
66
67static void tee_shm_op_release(struct dma_buf *dmabuf)
68{
69 struct tee_shm *shm = dmabuf->priv;
70
71 tee_shm_release(shm);
72}
73
74static 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 /* Refuse sharing shared memory provided by application */
80 if (shm->flags & TEE_SHM_USER_MAPPED)
81 return -EINVAL;
82
83 return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
84 size, vma->vm_page_prot);
85}
86
87static const struct dma_buf_ops tee_shm_dma_buf_ops = {
88 .map_dma_buf = tee_shm_op_map_dma_buf,
89 .unmap_dma_buf = tee_shm_op_unmap_dma_buf,
90 .release = tee_shm_op_release,
91 .mmap = tee_shm_op_mmap,
92};
93
94struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
95{
96 struct tee_device *teedev = ctx->teedev;
97 struct tee_shm_pool_mgr *poolm = NULL;
98 struct tee_shm *shm;
99 void *ret;
100 int rc;
101
102 if (!(flags & TEE_SHM_MAPPED)) {
103 dev_err(teedev->dev.parent,
104 "only mapped allocations supported\n");
105 return ERR_PTR(-EINVAL);
106 }
107
108 if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF))) {
109 dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
110 return ERR_PTR(-EINVAL);
111 }
112
113 if (!tee_device_get(teedev))
114 return ERR_PTR(-EINVAL);
115
116 if (!teedev->pool) {
117 /* teedev has been detached from driver */
118 ret = ERR_PTR(-EINVAL);
119 goto err_dev_put;
120 }
121
122 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
123 if (!shm) {
124 ret = ERR_PTR(-ENOMEM);
125 goto err_dev_put;
126 }
127
128 shm->flags = flags | TEE_SHM_POOL;
129 shm->ctx = ctx;
130 if (flags & TEE_SHM_DMA_BUF)
131 poolm = teedev->pool->dma_buf_mgr;
132 else
133 poolm = teedev->pool->private_mgr;
134
135 rc = poolm->ops->alloc(poolm, shm, size);
136 if (rc) {
137 ret = ERR_PTR(rc);
138 goto err_kfree;
139 }
140
141
142 if (flags & TEE_SHM_DMA_BUF) {
143 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
144
145 mutex_lock(&teedev->mutex);
146 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
147 mutex_unlock(&teedev->mutex);
148 if (shm->id < 0) {
149 ret = ERR_PTR(shm->id);
150 goto err_pool_free;
151 }
152
153 exp_info.ops = &tee_shm_dma_buf_ops;
154 exp_info.size = shm->size;
155 exp_info.flags = O_RDWR;
156 exp_info.priv = shm;
157
158 shm->dmabuf = dma_buf_export(&exp_info);
159 if (IS_ERR(shm->dmabuf)) {
160 ret = ERR_CAST(shm->dmabuf);
161 goto err_rem;
162 }
163 }
164
165 teedev_ctx_get(ctx);
166
167 return shm;
168err_rem:
169 if (flags & TEE_SHM_DMA_BUF) {
170 mutex_lock(&teedev->mutex);
171 idr_remove(&teedev->idr, shm->id);
172 mutex_unlock(&teedev->mutex);
173 }
174err_pool_free:
175 poolm->ops->free(poolm, shm);
176err_kfree:
177 kfree(shm);
178err_dev_put:
179 tee_device_put(teedev);
180 return ret;
181}
182EXPORT_SYMBOL_GPL(tee_shm_alloc);
183
184struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
185 size_t length, u32 flags)
186{
187 struct tee_device *teedev = ctx->teedev;
188 const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
189 const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
190 struct tee_shm *shm;
191 void *ret;
192 int rc;
193 int num_pages;
194 unsigned long start;
195
196 if (flags != req_user_flags && flags != req_kernel_flags)
197 return ERR_PTR(-ENOTSUPP);
198
199 if (!tee_device_get(teedev))
200 return ERR_PTR(-EINVAL);
201
202 if (!teedev->desc->ops->shm_register ||
203 !teedev->desc->ops->shm_unregister) {
204 tee_device_put(teedev);
205 return ERR_PTR(-ENOTSUPP);
206 }
207
208 teedev_ctx_get(ctx);
209
210 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
211 if (!shm) {
212 ret = ERR_PTR(-ENOMEM);
213 goto err;
214 }
215
216 shm->flags = flags | TEE_SHM_REGISTER;
217 shm->ctx = ctx;
218 shm->id = -1;
219 addr = untagged_addr(addr);
220 start = rounddown(addr, PAGE_SIZE);
221 shm->offset = addr - start;
222 shm->size = length;
223 num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
224 shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
225 if (!shm->pages) {
226 ret = ERR_PTR(-ENOMEM);
227 goto err;
228 }
229
230 if (flags & TEE_SHM_USER_MAPPED) {
231 rc = get_user_pages_fast(start, num_pages, FOLL_WRITE,
232 shm->pages);
233 } else {
234 struct kvec *kiov;
235 int i;
236
237 kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
238 if (!kiov) {
239 ret = ERR_PTR(-ENOMEM);
240 goto err;
241 }
242
243 for (i = 0; i < num_pages; i++) {
244 kiov[i].iov_base = (void *)(start + i * PAGE_SIZE);
245 kiov[i].iov_len = PAGE_SIZE;
246 }
247
248 rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
249 kfree(kiov);
250 }
251 if (rc > 0)
252 shm->num_pages = rc;
253 if (rc != num_pages) {
254 if (rc >= 0)
255 rc = -ENOMEM;
256 ret = ERR_PTR(rc);
257 goto err;
258 }
259
260 mutex_lock(&teedev->mutex);
261 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
262 mutex_unlock(&teedev->mutex);
263
264 if (shm->id < 0) {
265 ret = ERR_PTR(shm->id);
266 goto err;
267 }
268
269 rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
270 shm->num_pages, start);
271 if (rc) {
272 ret = ERR_PTR(rc);
273 goto err;
274 }
275
276 if (flags & TEE_SHM_DMA_BUF) {
277 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
278
279 exp_info.ops = &tee_shm_dma_buf_ops;
280 exp_info.size = shm->size;
281 exp_info.flags = O_RDWR;
282 exp_info.priv = shm;
283
284 shm->dmabuf = dma_buf_export(&exp_info);
285 if (IS_ERR(shm->dmabuf)) {
286 ret = ERR_CAST(shm->dmabuf);
287 teedev->desc->ops->shm_unregister(ctx, shm);
288 goto err;
289 }
290 }
291
292 return shm;
293err:
294 if (shm) {
295 size_t n;
296
297 if (shm->id >= 0) {
298 mutex_lock(&teedev->mutex);
299 idr_remove(&teedev->idr, shm->id);
300 mutex_unlock(&teedev->mutex);
301 }
302 if (shm->pages) {
303 for (n = 0; n < shm->num_pages; n++)
304 put_page(shm->pages[n]);
305 kfree(shm->pages);
306 }
307 }
308 kfree(shm);
309 teedev_ctx_put(ctx);
310 tee_device_put(teedev);
311 return ret;
312}
313EXPORT_SYMBOL_GPL(tee_shm_register);
314
315/**
316 * tee_shm_get_fd() - Increase reference count and return file descriptor
317 * @shm: Shared memory handle
318 * @returns user space file descriptor to shared memory
319 */
320int tee_shm_get_fd(struct tee_shm *shm)
321{
322 int fd;
323
324 if (!(shm->flags & TEE_SHM_DMA_BUF))
325 return -EINVAL;
326
327 get_dma_buf(shm->dmabuf);
328 fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
329 if (fd < 0)
330 dma_buf_put(shm->dmabuf);
331 return fd;
332}
333
334/**
335 * tee_shm_free() - Free shared memory
336 * @shm: Handle to shared memory to free
337 */
338void tee_shm_free(struct tee_shm *shm)
339{
340 /*
341 * dma_buf_put() decreases the dmabuf reference counter and will
342 * call tee_shm_release() when the last reference is gone.
343 *
344 * In the case of driver private memory we call tee_shm_release
345 * directly instead as it doesn't have a reference counter.
346 */
347 if (shm->flags & TEE_SHM_DMA_BUF)
348 dma_buf_put(shm->dmabuf);
349 else
350 tee_shm_release(shm);
351}
352EXPORT_SYMBOL_GPL(tee_shm_free);
353
354/**
355 * tee_shm_va2pa() - Get physical address of a virtual address
356 * @shm: Shared memory handle
357 * @va: Virtual address to tranlsate
358 * @pa: Returned physical address
359 * @returns 0 on success and < 0 on failure
360 */
361int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
362{
363 if (!(shm->flags & TEE_SHM_MAPPED))
364 return -EINVAL;
365 /* Check that we're in the range of the shm */
366 if ((char *)va < (char *)shm->kaddr)
367 return -EINVAL;
368 if ((char *)va >= ((char *)shm->kaddr + shm->size))
369 return -EINVAL;
370
371 return tee_shm_get_pa(
372 shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
373}
374EXPORT_SYMBOL_GPL(tee_shm_va2pa);
375
376/**
377 * tee_shm_pa2va() - Get virtual address of a physical address
378 * @shm: Shared memory handle
379 * @pa: Physical address to tranlsate
380 * @va: Returned virtual address
381 * @returns 0 on success and < 0 on failure
382 */
383int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
384{
385 if (!(shm->flags & TEE_SHM_MAPPED))
386 return -EINVAL;
387 /* Check that we're in the range of the shm */
388 if (pa < shm->paddr)
389 return -EINVAL;
390 if (pa >= (shm->paddr + shm->size))
391 return -EINVAL;
392
393 if (va) {
394 void *v = tee_shm_get_va(shm, pa - shm->paddr);
395
396 if (IS_ERR(v))
397 return PTR_ERR(v);
398 *va = v;
399 }
400 return 0;
401}
402EXPORT_SYMBOL_GPL(tee_shm_pa2va);
403
404/**
405 * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
406 * @shm: Shared memory handle
407 * @offs: Offset from start of this shared memory
408 * @returns virtual address of the shared memory + offs if offs is within
409 * the bounds of this shared memory, else an ERR_PTR
410 */
411void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
412{
413 if (!(shm->flags & TEE_SHM_MAPPED))
414 return ERR_PTR(-EINVAL);
415 if (offs >= shm->size)
416 return ERR_PTR(-EINVAL);
417 return (char *)shm->kaddr + offs;
418}
419EXPORT_SYMBOL_GPL(tee_shm_get_va);
420
421/**
422 * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
423 * @shm: Shared memory handle
424 * @offs: Offset from start of this shared memory
425 * @pa: Physical address to return
426 * @returns 0 if offs is within the bounds of this shared memory, else an
427 * error code.
428 */
429int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
430{
431 if (offs >= shm->size)
432 return -EINVAL;
433 if (pa)
434 *pa = shm->paddr + offs;
435 return 0;
436}
437EXPORT_SYMBOL_GPL(tee_shm_get_pa);
438
439/**
440 * tee_shm_get_from_id() - Find shared memory object and increase reference
441 * count
442 * @ctx: Context owning the shared memory
443 * @id: Id of shared memory object
444 * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
445 */
446struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
447{
448 struct tee_device *teedev;
449 struct tee_shm *shm;
450
451 if (!ctx)
452 return ERR_PTR(-EINVAL);
453
454 teedev = ctx->teedev;
455 mutex_lock(&teedev->mutex);
456 shm = idr_find(&teedev->idr, id);
457 if (!shm || shm->ctx != ctx)
458 shm = ERR_PTR(-EINVAL);
459 else if (shm->flags & TEE_SHM_DMA_BUF)
460 get_dma_buf(shm->dmabuf);
461 mutex_unlock(&teedev->mutex);
462 return shm;
463}
464EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
465
466/**
467 * tee_shm_put() - Decrease reference count on a shared memory handle
468 * @shm: Shared memory handle
469 */
470void tee_shm_put(struct tee_shm *shm)
471{
472 if (shm->flags & TEE_SHM_DMA_BUF)
473 dma_buf_put(shm->dmabuf);
474}
475EXPORT_SYMBOL_GPL(tee_shm_put);
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/io.h>
9#include <linux/mm.h>
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/tee_core.h>
13#include <linux/uaccess.h>
14#include <linux/uio.h>
15#include <linux/highmem.h>
16#include "tee_private.h"
17
18static void shm_put_kernel_pages(struct page **pages, size_t page_count)
19{
20 size_t n;
21
22 for (n = 0; n < page_count; n++)
23 put_page(pages[n]);
24}
25
26static void shm_get_kernel_pages(struct page **pages, size_t page_count)
27{
28 size_t n;
29
30 for (n = 0; n < page_count; n++)
31 get_page(pages[n]);
32}
33
34static void release_registered_pages(struct tee_shm *shm)
35{
36 if (shm->pages) {
37 if (shm->flags & TEE_SHM_USER_MAPPED)
38 unpin_user_pages(shm->pages, shm->num_pages);
39 else
40 shm_put_kernel_pages(shm->pages, shm->num_pages);
41
42 kfree(shm->pages);
43 }
44}
45
46static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
47{
48 if (shm->flags & TEE_SHM_POOL) {
49 teedev->pool->ops->free(teedev->pool, shm);
50 } else if (shm->flags & TEE_SHM_DYNAMIC) {
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
67static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size,
68 size_t align, u32 flags, int id)
69{
70 struct tee_device *teedev = ctx->teedev;
71 struct tee_shm *shm;
72 void *ret;
73 int rc;
74
75 if (!tee_device_get(teedev))
76 return ERR_PTR(-EINVAL);
77
78 if (!teedev->pool) {
79 /* teedev has been detached from driver */
80 ret = ERR_PTR(-EINVAL);
81 goto err_dev_put;
82 }
83
84 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
85 if (!shm) {
86 ret = ERR_PTR(-ENOMEM);
87 goto err_dev_put;
88 }
89
90 refcount_set(&shm->refcount, 1);
91 shm->flags = flags;
92 shm->id = id;
93
94 /*
95 * We're assigning this as it is needed if the shm is to be
96 * registered. If this function returns OK then the caller expected
97 * to call teedev_ctx_get() or clear shm->ctx in case it's not
98 * needed any longer.
99 */
100 shm->ctx = ctx;
101
102 rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align);
103 if (rc) {
104 ret = ERR_PTR(rc);
105 goto err_kfree;
106 }
107
108 teedev_ctx_get(ctx);
109 return shm;
110err_kfree:
111 kfree(shm);
112err_dev_put:
113 tee_device_put(teedev);
114 return ret;
115}
116
117/**
118 * tee_shm_alloc_user_buf() - Allocate shared memory for user space
119 * @ctx: Context that allocates the shared memory
120 * @size: Requested size of shared memory
121 *
122 * Memory allocated as user space shared memory is automatically freed when
123 * the TEE file pointer is closed. The primary usage of this function is
124 * when the TEE driver doesn't support registering ordinary user space
125 * memory.
126 *
127 * @returns a pointer to 'struct tee_shm'
128 */
129struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
130{
131 u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
132 struct tee_device *teedev = ctx->teedev;
133 struct tee_shm *shm;
134 void *ret;
135 int id;
136
137 mutex_lock(&teedev->mutex);
138 id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
139 mutex_unlock(&teedev->mutex);
140 if (id < 0)
141 return ERR_PTR(id);
142
143 shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id);
144 if (IS_ERR(shm)) {
145 mutex_lock(&teedev->mutex);
146 idr_remove(&teedev->idr, id);
147 mutex_unlock(&teedev->mutex);
148 return shm;
149 }
150
151 mutex_lock(&teedev->mutex);
152 ret = idr_replace(&teedev->idr, shm, id);
153 mutex_unlock(&teedev->mutex);
154 if (IS_ERR(ret)) {
155 tee_shm_free(shm);
156 return ret;
157 }
158
159 return shm;
160}
161
162/**
163 * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
164 * @ctx: Context that allocates the shared memory
165 * @size: Requested size of shared memory
166 *
167 * The returned memory registered in secure world and is suitable to be
168 * passed as a memory buffer in parameter argument to
169 * tee_client_invoke_func(). The memory allocated is later freed with a
170 * call to tee_shm_free().
171 *
172 * @returns a pointer to 'struct tee_shm'
173 */
174struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
175{
176 u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
177
178 return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1);
179}
180EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
181
182/**
183 * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
184 * kernel buffer
185 * @ctx: Context that allocates the shared memory
186 * @size: Requested size of shared memory
187 *
188 * This function returns similar shared memory as
189 * tee_shm_alloc_kernel_buf(), but with the difference that the memory
190 * might not be registered in secure world in case the driver supports
191 * passing memory not registered in advance.
192 *
193 * This function should normally only be used internally in the TEE
194 * drivers.
195 *
196 * @returns a pointer to 'struct tee_shm'
197 */
198struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
199{
200 u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL;
201
202 return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1);
203}
204EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
205
206int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
207 int (*shm_register)(struct tee_context *ctx,
208 struct tee_shm *shm,
209 struct page **pages,
210 size_t num_pages,
211 unsigned long start))
212{
213 size_t nr_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE;
214 struct page **pages;
215 unsigned int i;
216 int rc = 0;
217
218 /*
219 * Ignore alignment since this is already going to be page aligned
220 * and there's no need for any larger alignment.
221 */
222 shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE,
223 GFP_KERNEL | __GFP_ZERO);
224 if (!shm->kaddr)
225 return -ENOMEM;
226
227 shm->paddr = virt_to_phys(shm->kaddr);
228 shm->size = nr_pages * PAGE_SIZE;
229
230 pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
231 if (!pages) {
232 rc = -ENOMEM;
233 goto err;
234 }
235
236 for (i = 0; i < nr_pages; i++)
237 pages[i] = virt_to_page((u8 *)shm->kaddr + i * PAGE_SIZE);
238
239 shm->pages = pages;
240 shm->num_pages = nr_pages;
241
242 if (shm_register) {
243 rc = shm_register(shm->ctx, shm, pages, nr_pages,
244 (unsigned long)shm->kaddr);
245 if (rc)
246 goto err;
247 }
248
249 return 0;
250err:
251 free_pages_exact(shm->kaddr, shm->size);
252 shm->kaddr = NULL;
253 return rc;
254}
255EXPORT_SYMBOL_GPL(tee_dyn_shm_alloc_helper);
256
257void tee_dyn_shm_free_helper(struct tee_shm *shm,
258 int (*shm_unregister)(struct tee_context *ctx,
259 struct tee_shm *shm))
260{
261 if (shm_unregister)
262 shm_unregister(shm->ctx, shm);
263 free_pages_exact(shm->kaddr, shm->size);
264 shm->kaddr = NULL;
265 kfree(shm->pages);
266 shm->pages = NULL;
267}
268EXPORT_SYMBOL_GPL(tee_dyn_shm_free_helper);
269
270static struct tee_shm *
271register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
272 int id)
273{
274 struct tee_device *teedev = ctx->teedev;
275 struct tee_shm *shm;
276 unsigned long start, addr;
277 size_t num_pages, off;
278 ssize_t len;
279 void *ret;
280 int rc;
281
282 if (!tee_device_get(teedev))
283 return ERR_PTR(-EINVAL);
284
285 if (!teedev->desc->ops->shm_register ||
286 !teedev->desc->ops->shm_unregister) {
287 ret = ERR_PTR(-ENOTSUPP);
288 goto err_dev_put;
289 }
290
291 teedev_ctx_get(ctx);
292
293 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
294 if (!shm) {
295 ret = ERR_PTR(-ENOMEM);
296 goto err_ctx_put;
297 }
298
299 refcount_set(&shm->refcount, 1);
300 shm->flags = flags;
301 shm->ctx = ctx;
302 shm->id = id;
303 addr = untagged_addr((unsigned long)iter_iov_addr(iter));
304 start = rounddown(addr, PAGE_SIZE);
305 num_pages = iov_iter_npages(iter, INT_MAX);
306 if (!num_pages) {
307 ret = ERR_PTR(-ENOMEM);
308 goto err_ctx_put;
309 }
310
311 shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
312 if (!shm->pages) {
313 ret = ERR_PTR(-ENOMEM);
314 goto err_free_shm;
315 }
316
317 len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
318 &off);
319 if (unlikely(len <= 0)) {
320 ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
321 goto err_free_shm_pages;
322 }
323
324 /*
325 * iov_iter_extract_kvec_pages does not get reference on the pages,
326 * get a reference on them.
327 */
328 if (iov_iter_is_kvec(iter))
329 shm_get_kernel_pages(shm->pages, num_pages);
330
331 shm->offset = off;
332 shm->size = len;
333 shm->num_pages = num_pages;
334
335 rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
336 shm->num_pages, start);
337 if (rc) {
338 ret = ERR_PTR(rc);
339 goto err_put_shm_pages;
340 }
341
342 return shm;
343err_put_shm_pages:
344 if (!iov_iter_is_kvec(iter))
345 unpin_user_pages(shm->pages, shm->num_pages);
346 else
347 shm_put_kernel_pages(shm->pages, shm->num_pages);
348err_free_shm_pages:
349 kfree(shm->pages);
350err_free_shm:
351 kfree(shm);
352err_ctx_put:
353 teedev_ctx_put(ctx);
354err_dev_put:
355 tee_device_put(teedev);
356 return ret;
357}
358
359/**
360 * tee_shm_register_user_buf() - Register a userspace shared memory buffer
361 * @ctx: Context that registers the shared memory
362 * @addr: The userspace address of the shared buffer
363 * @length: Length of the shared buffer
364 *
365 * @returns a pointer to 'struct tee_shm'
366 */
367struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
368 unsigned long addr, size_t length)
369{
370 u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
371 struct tee_device *teedev = ctx->teedev;
372 struct tee_shm *shm;
373 struct iov_iter iter;
374 void *ret;
375 int id;
376
377 if (!access_ok((void __user *)addr, length))
378 return ERR_PTR(-EFAULT);
379
380 mutex_lock(&teedev->mutex);
381 id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
382 mutex_unlock(&teedev->mutex);
383 if (id < 0)
384 return ERR_PTR(id);
385
386 iov_iter_ubuf(&iter, ITER_DEST, (void __user *)addr, length);
387 shm = register_shm_helper(ctx, &iter, flags, id);
388 if (IS_ERR(shm)) {
389 mutex_lock(&teedev->mutex);
390 idr_remove(&teedev->idr, id);
391 mutex_unlock(&teedev->mutex);
392 return shm;
393 }
394
395 mutex_lock(&teedev->mutex);
396 ret = idr_replace(&teedev->idr, shm, id);
397 mutex_unlock(&teedev->mutex);
398 if (IS_ERR(ret)) {
399 tee_shm_free(shm);
400 return ret;
401 }
402
403 return shm;
404}
405
406/**
407 * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
408 * secure world
409 * @ctx: Context that registers the shared memory
410 * @addr: The buffer
411 * @length: Length of the buffer
412 *
413 * @returns a pointer to 'struct tee_shm'
414 */
415
416struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
417 void *addr, size_t length)
418{
419 u32 flags = TEE_SHM_DYNAMIC;
420 struct kvec kvec;
421 struct iov_iter iter;
422
423 kvec.iov_base = addr;
424 kvec.iov_len = length;
425 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
426
427 return register_shm_helper(ctx, &iter, flags, -1);
428}
429EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
430
431static int tee_shm_fop_release(struct inode *inode, struct file *filp)
432{
433 tee_shm_put(filp->private_data);
434 return 0;
435}
436
437static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma)
438{
439 struct tee_shm *shm = filp->private_data;
440 size_t size = vma->vm_end - vma->vm_start;
441
442 /* Refuse sharing shared memory provided by application */
443 if (shm->flags & TEE_SHM_USER_MAPPED)
444 return -EINVAL;
445
446 /* check for overflowing the buffer's size */
447 if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT)
448 return -EINVAL;
449
450 return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
451 size, vma->vm_page_prot);
452}
453
454static const struct file_operations tee_shm_fops = {
455 .owner = THIS_MODULE,
456 .release = tee_shm_fop_release,
457 .mmap = tee_shm_fop_mmap,
458};
459
460/**
461 * tee_shm_get_fd() - Increase reference count and return file descriptor
462 * @shm: Shared memory handle
463 * @returns user space file descriptor to shared memory
464 */
465int tee_shm_get_fd(struct tee_shm *shm)
466{
467 int fd;
468
469 if (shm->id < 0)
470 return -EINVAL;
471
472 /* matched by tee_shm_put() in tee_shm_op_release() */
473 refcount_inc(&shm->refcount);
474 fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR);
475 if (fd < 0)
476 tee_shm_put(shm);
477 return fd;
478}
479
480/**
481 * tee_shm_free() - Free shared memory
482 * @shm: Handle to shared memory to free
483 */
484void tee_shm_free(struct tee_shm *shm)
485{
486 tee_shm_put(shm);
487}
488EXPORT_SYMBOL_GPL(tee_shm_free);
489
490/**
491 * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
492 * @shm: Shared memory handle
493 * @offs: Offset from start of this shared memory
494 * @returns virtual address of the shared memory + offs if offs is within
495 * the bounds of this shared memory, else an ERR_PTR
496 */
497void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
498{
499 if (!shm->kaddr)
500 return ERR_PTR(-EINVAL);
501 if (offs >= shm->size)
502 return ERR_PTR(-EINVAL);
503 return (char *)shm->kaddr + offs;
504}
505EXPORT_SYMBOL_GPL(tee_shm_get_va);
506
507/**
508 * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
509 * @shm: Shared memory handle
510 * @offs: Offset from start of this shared memory
511 * @pa: Physical address to return
512 * @returns 0 if offs is within the bounds of this shared memory, else an
513 * error code.
514 */
515int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
516{
517 if (offs >= shm->size)
518 return -EINVAL;
519 if (pa)
520 *pa = shm->paddr + offs;
521 return 0;
522}
523EXPORT_SYMBOL_GPL(tee_shm_get_pa);
524
525/**
526 * tee_shm_get_from_id() - Find shared memory object and increase reference
527 * count
528 * @ctx: Context owning the shared memory
529 * @id: Id of shared memory object
530 * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
531 */
532struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
533{
534 struct tee_device *teedev;
535 struct tee_shm *shm;
536
537 if (!ctx)
538 return ERR_PTR(-EINVAL);
539
540 teedev = ctx->teedev;
541 mutex_lock(&teedev->mutex);
542 shm = idr_find(&teedev->idr, id);
543 /*
544 * If the tee_shm was found in the IDR it must have a refcount
545 * larger than 0 due to the guarantee in tee_shm_put() below. So
546 * it's safe to use refcount_inc().
547 */
548 if (!shm || shm->ctx != ctx)
549 shm = ERR_PTR(-EINVAL);
550 else
551 refcount_inc(&shm->refcount);
552 mutex_unlock(&teedev->mutex);
553 return shm;
554}
555EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
556
557/**
558 * tee_shm_put() - Decrease reference count on a shared memory handle
559 * @shm: Shared memory handle
560 */
561void tee_shm_put(struct tee_shm *shm)
562{
563 struct tee_device *teedev = shm->ctx->teedev;
564 bool do_release = false;
565
566 mutex_lock(&teedev->mutex);
567 if (refcount_dec_and_test(&shm->refcount)) {
568 /*
569 * refcount has reached 0, we must now remove it from the
570 * IDR before releasing the mutex. This will guarantee that
571 * the refcount_inc() in tee_shm_get_from_id() never starts
572 * from 0.
573 */
574 if (shm->id >= 0)
575 idr_remove(&teedev->idr, shm->id);
576 do_release = true;
577 }
578 mutex_unlock(&teedev->mutex);
579
580 if (do_release)
581 tee_shm_release(teedev, shm);
582}
583EXPORT_SYMBOL_GPL(tee_shm_put);