xref: /openbmc/linux/drivers/tee/amdtee/shm_pool.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright 2019 Advanced Micro Devices, Inc.
4  */
5 
6 #include <linux/slab.h>
7 #include <linux/tee_drv.h>
8 #include <linux/psp-sev.h>
9 #include "amdtee_private.h"
10 
11 static int pool_op_alloc(struct tee_shm_pool_mgr *poolm, struct tee_shm *shm,
12 			 size_t size)
13 {
14 	unsigned int order = get_order(size);
15 	unsigned long va;
16 	int rc;
17 
18 	va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
19 	if (!va)
20 		return -ENOMEM;
21 
22 	shm->kaddr = (void *)va;
23 	shm->paddr = __psp_pa((void *)va);
24 	shm->size = PAGE_SIZE << order;
25 
26 	/* Map the allocated memory in to TEE */
27 	rc = amdtee_map_shmem(shm);
28 	if (rc) {
29 		free_pages(va, order);
30 		shm->kaddr = NULL;
31 		return rc;
32 	}
33 
34 	return 0;
35 }
36 
37 static void pool_op_free(struct tee_shm_pool_mgr *poolm, struct tee_shm *shm)
38 {
39 	/* Unmap the shared memory from TEE */
40 	amdtee_unmap_shmem(shm);
41 	free_pages((unsigned long)shm->kaddr, get_order(shm->size));
42 	shm->kaddr = NULL;
43 }
44 
45 static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
46 {
47 	kfree(poolm);
48 }
49 
50 static const struct tee_shm_pool_mgr_ops pool_ops = {
51 	.alloc = pool_op_alloc,
52 	.free = pool_op_free,
53 	.destroy_poolmgr = pool_op_destroy_poolmgr,
54 };
55 
56 static struct tee_shm_pool_mgr *pool_mem_mgr_alloc(void)
57 {
58 	struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
59 
60 	if (!mgr)
61 		return ERR_PTR(-ENOMEM);
62 
63 	mgr->ops = &pool_ops;
64 
65 	return mgr;
66 }
67 
68 struct tee_shm_pool *amdtee_config_shm(void)
69 {
70 	struct tee_shm_pool_mgr *priv_mgr;
71 	struct tee_shm_pool_mgr *dmabuf_mgr;
72 	void *rc;
73 
74 	rc = pool_mem_mgr_alloc();
75 	if (IS_ERR(rc))
76 		return rc;
77 	priv_mgr = rc;
78 
79 	rc = pool_mem_mgr_alloc();
80 	if (IS_ERR(rc)) {
81 		tee_shm_pool_mgr_destroy(priv_mgr);
82 		return rc;
83 	}
84 	dmabuf_mgr = rc;
85 
86 	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
87 	if (IS_ERR(rc)) {
88 		tee_shm_pool_mgr_destroy(priv_mgr);
89 		tee_shm_pool_mgr_destroy(dmabuf_mgr);
90 	}
91 
92 	return rc;
93 }
94