1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * NVM helpers
4 *
5 * Copyright (C) 2020, Intel Corporation
6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
7 */
8
9 #include <linux/idr.h>
10 #include <linux/slab.h>
11 #include <linux/vmalloc.h>
12
13 #include "tb.h"
14
15 static DEFINE_IDA(nvm_ida);
16
17 /**
18 * tb_nvm_alloc() - Allocate new NVM structure
19 * @dev: Device owning the NVM
20 *
21 * Allocates new NVM structure with unique @id and returns it. In case
22 * of error returns ERR_PTR().
23 */
tb_nvm_alloc(struct device * dev)24 struct tb_nvm *tb_nvm_alloc(struct device *dev)
25 {
26 struct tb_nvm *nvm;
27 int ret;
28
29 nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
30 if (!nvm)
31 return ERR_PTR(-ENOMEM);
32
33 ret = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
34 if (ret < 0) {
35 kfree(nvm);
36 return ERR_PTR(ret);
37 }
38
39 nvm->id = ret;
40 nvm->dev = dev;
41
42 return nvm;
43 }
44
45 /**
46 * tb_nvm_add_active() - Adds active NVMem device to NVM
47 * @nvm: NVM structure
48 * @size: Size of the active NVM in bytes
49 * @reg_read: Pointer to the function to read the NVM (passed directly to the
50 * NVMem device)
51 *
52 * Registers new active NVmem device for @nvm. The @reg_read is called
53 * directly from NVMem so it must handle possible concurrent access if
54 * needed. The first parameter passed to @reg_read is @nvm structure.
55 * Returns %0 in success and negative errno otherwise.
56 */
tb_nvm_add_active(struct tb_nvm * nvm,size_t size,nvmem_reg_read_t reg_read)57 int tb_nvm_add_active(struct tb_nvm *nvm, size_t size, nvmem_reg_read_t reg_read)
58 {
59 struct nvmem_config config;
60 struct nvmem_device *nvmem;
61
62 memset(&config, 0, sizeof(config));
63
64 config.name = "nvm_active";
65 config.reg_read = reg_read;
66 config.read_only = true;
67 config.id = nvm->id;
68 config.stride = 4;
69 config.word_size = 4;
70 config.size = size;
71 config.dev = nvm->dev;
72 config.owner = THIS_MODULE;
73 config.priv = nvm;
74
75 nvmem = nvmem_register(&config);
76 if (IS_ERR(nvmem))
77 return PTR_ERR(nvmem);
78
79 nvm->active = nvmem;
80 return 0;
81 }
82
83 /**
84 * tb_nvm_write_buf() - Write data to @nvm buffer
85 * @nvm: NVM structure
86 * @offset: Offset where to write the data
87 * @val: Data buffer to write
88 * @bytes: Number of bytes to write
89 *
90 * Helper function to cache the new NVM image before it is actually
91 * written to the flash. Copies @bytes from @val to @nvm->buf starting
92 * from @offset.
93 */
tb_nvm_write_buf(struct tb_nvm * nvm,unsigned int offset,void * val,size_t bytes)94 int tb_nvm_write_buf(struct tb_nvm *nvm, unsigned int offset, void *val,
95 size_t bytes)
96 {
97 if (!nvm->buf) {
98 nvm->buf = vmalloc(NVM_MAX_SIZE);
99 if (!nvm->buf)
100 return -ENOMEM;
101 }
102
103 nvm->flushed = false;
104 nvm->buf_data_size = offset + bytes;
105 memcpy(nvm->buf + offset, val, bytes);
106 return 0;
107 }
108
109 /**
110 * tb_nvm_add_non_active() - Adds non-active NVMem device to NVM
111 * @nvm: NVM structure
112 * @size: Size of the non-active NVM in bytes
113 * @reg_write: Pointer to the function to write the NVM (passed directly
114 * to the NVMem device)
115 *
116 * Registers new non-active NVmem device for @nvm. The @reg_write is called
117 * directly from NVMem so it must handle possible concurrent access if
118 * needed. The first parameter passed to @reg_write is @nvm structure.
119 * Returns %0 in success and negative errno otherwise.
120 */
tb_nvm_add_non_active(struct tb_nvm * nvm,size_t size,nvmem_reg_write_t reg_write)121 int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size,
122 nvmem_reg_write_t reg_write)
123 {
124 struct nvmem_config config;
125 struct nvmem_device *nvmem;
126
127 memset(&config, 0, sizeof(config));
128
129 config.name = "nvm_non_active";
130 config.reg_write = reg_write;
131 config.root_only = true;
132 config.id = nvm->id;
133 config.stride = 4;
134 config.word_size = 4;
135 config.size = size;
136 config.dev = nvm->dev;
137 config.owner = THIS_MODULE;
138 config.priv = nvm;
139
140 nvmem = nvmem_register(&config);
141 if (IS_ERR(nvmem))
142 return PTR_ERR(nvmem);
143
144 nvm->non_active = nvmem;
145 return 0;
146 }
147
148 /**
149 * tb_nvm_free() - Release NVM and its resources
150 * @nvm: NVM structure to release
151 *
152 * Releases NVM and the NVMem devices if they were registered.
153 */
tb_nvm_free(struct tb_nvm * nvm)154 void tb_nvm_free(struct tb_nvm *nvm)
155 {
156 if (nvm) {
157 if (nvm->non_active)
158 nvmem_unregister(nvm->non_active);
159 if (nvm->active)
160 nvmem_unregister(nvm->active);
161 vfree(nvm->buf);
162 ida_simple_remove(&nvm_ida, nvm->id);
163 }
164 kfree(nvm);
165 }
166
tb_nvm_exit(void)167 void tb_nvm_exit(void)
168 {
169 ida_destroy(&nvm_ida);
170 }
171