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6#include <linux/kernel.h>
7#include <linux/cdev.h>
8#include <linux/err.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/of.h>
12#include <linux/of_reserved_mem.h>
13#include <linux/dma-mapping.h>
14#include <linux/slab.h>
15#include <linux/uaccess.h>
16#include <linux/io.h>
17#include <linux/qcom_scm.h>
18
19#define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1)
20
21static dev_t qcom_rmtfs_mem_major;
22
23struct qcom_rmtfs_mem {
24 struct device dev;
25 struct cdev cdev;
26
27 void *base;
28 phys_addr_t addr;
29 phys_addr_t size;
30
31 unsigned int client_id;
32
33 unsigned int perms;
34};
35
36static ssize_t qcom_rmtfs_mem_show(struct device *dev,
37 struct device_attribute *attr,
38 char *buf);
39
40static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL);
41static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL);
42static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL);
43
44static ssize_t qcom_rmtfs_mem_show(struct device *dev,
45 struct device_attribute *attr,
46 char *buf)
47{
48 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
49 struct qcom_rmtfs_mem,
50 dev);
51
52 if (attr == &dev_attr_phys_addr)
53 return sprintf(buf, "%pa\n", &rmtfs_mem->addr);
54 if (attr == &dev_attr_size)
55 return sprintf(buf, "%pa\n", &rmtfs_mem->size);
56 if (attr == &dev_attr_client_id)
57 return sprintf(buf, "%d\n", rmtfs_mem->client_id);
58
59 return -EINVAL;
60}
61
62static struct attribute *qcom_rmtfs_mem_attrs[] = {
63 &dev_attr_phys_addr.attr,
64 &dev_attr_size.attr,
65 &dev_attr_client_id.attr,
66 NULL
67};
68ATTRIBUTE_GROUPS(qcom_rmtfs_mem);
69
70static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp)
71{
72 struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev,
73 struct qcom_rmtfs_mem,
74 cdev);
75
76 get_device(&rmtfs_mem->dev);
77 filp->private_data = rmtfs_mem;
78
79 return 0;
80}
81static ssize_t qcom_rmtfs_mem_read(struct file *filp,
82 char __user *buf, size_t count, loff_t *f_pos)
83{
84 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
85
86 if (*f_pos >= rmtfs_mem->size)
87 return 0;
88
89 if (*f_pos + count >= rmtfs_mem->size)
90 count = rmtfs_mem->size - *f_pos;
91
92 if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count))
93 return -EFAULT;
94
95 *f_pos += count;
96 return count;
97}
98
99static ssize_t qcom_rmtfs_mem_write(struct file *filp,
100 const char __user *buf, size_t count,
101 loff_t *f_pos)
102{
103 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
104
105 if (*f_pos >= rmtfs_mem->size)
106 return 0;
107
108 if (*f_pos + count >= rmtfs_mem->size)
109 count = rmtfs_mem->size - *f_pos;
110
111 if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count))
112 return -EFAULT;
113
114 *f_pos += count;
115 return count;
116}
117
118static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
119{
120 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
121
122 put_device(&rmtfs_mem->dev);
123
124 return 0;
125}
126
127static struct class rmtfs_class = {
128 .owner = THIS_MODULE,
129 .name = "rmtfs",
130};
131
132static int qcom_rmtfs_mem_mmap(struct file *filep, struct vm_area_struct *vma)
133{
134 struct qcom_rmtfs_mem *rmtfs_mem = filep->private_data;
135
136 if (vma->vm_end - vma->vm_start > rmtfs_mem->size) {
137 dev_dbg(&rmtfs_mem->dev,
138 "vm_end[%lu] - vm_start[%lu] [%lu] > mem->size[%pa]\n",
139 vma->vm_end, vma->vm_start,
140 (vma->vm_end - vma->vm_start), &rmtfs_mem->size);
141 return -EINVAL;
142 }
143
144 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
145 return remap_pfn_range(vma,
146 vma->vm_start,
147 rmtfs_mem->addr >> PAGE_SHIFT,
148 vma->vm_end - vma->vm_start,
149 vma->vm_page_prot);
150}
151
152static const struct file_operations qcom_rmtfs_mem_fops = {
153 .owner = THIS_MODULE,
154 .open = qcom_rmtfs_mem_open,
155 .read = qcom_rmtfs_mem_read,
156 .write = qcom_rmtfs_mem_write,
157 .release = qcom_rmtfs_mem_release,
158 .llseek = default_llseek,
159 .mmap = qcom_rmtfs_mem_mmap,
160};
161
162static void qcom_rmtfs_mem_release_device(struct device *dev)
163{
164 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
165 struct qcom_rmtfs_mem,
166 dev);
167
168 kfree(rmtfs_mem);
169}
170
171static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
172{
173 struct device_node *node = pdev->dev.of_node;
174 struct qcom_scm_vmperm perms[2];
175 struct reserved_mem *rmem;
176 struct qcom_rmtfs_mem *rmtfs_mem;
177 u32 client_id;
178 u32 vmid;
179 int ret;
180
181 rmem = of_reserved_mem_lookup(node);
182 if (!rmem) {
183 dev_err(&pdev->dev, "failed to acquire memory region\n");
184 return -EINVAL;
185 }
186
187 ret = of_property_read_u32(node, "qcom,client-id", &client_id);
188 if (ret) {
189 dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n");
190 return ret;
191
192 }
193
194 rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL);
195 if (!rmtfs_mem)
196 return -ENOMEM;
197
198 rmtfs_mem->addr = rmem->base;
199 rmtfs_mem->client_id = client_id;
200 rmtfs_mem->size = rmem->size;
201
202 device_initialize(&rmtfs_mem->dev);
203 rmtfs_mem->dev.parent = &pdev->dev;
204 rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups;
205 rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device;
206
207 rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr,
208 rmtfs_mem->size, MEMREMAP_WC);
209 if (IS_ERR(rmtfs_mem->base)) {
210 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n");
211 ret = PTR_ERR(rmtfs_mem->base);
212 goto put_device;
213 }
214
215 cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops);
216 rmtfs_mem->cdev.owner = THIS_MODULE;
217
218 dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id);
219 rmtfs_mem->dev.id = client_id;
220 rmtfs_mem->dev.class = &rmtfs_class;
221 rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id);
222
223 ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev);
224 if (ret) {
225 dev_err(&pdev->dev, "failed to add cdev: %d\n", ret);
226 goto put_device;
227 }
228
229 ret = of_property_read_u32(node, "qcom,vmid", &vmid);
230 if (ret < 0 && ret != -EINVAL) {
231 dev_err(&pdev->dev, "failed to parse qcom,vmid\n");
232 goto remove_cdev;
233 } else if (!ret) {
234 if (!qcom_scm_is_available()) {
235 ret = -EPROBE_DEFER;
236 goto remove_cdev;
237 }
238
239 perms[0].vmid = QCOM_SCM_VMID_HLOS;
240 perms[0].perm = QCOM_SCM_PERM_RW;
241 perms[1].vmid = vmid;
242 perms[1].perm = QCOM_SCM_PERM_RW;
243
244 rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
245 ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
246 &rmtfs_mem->perms, perms, 2);
247 if (ret < 0) {
248 dev_err(&pdev->dev, "assign memory failed\n");
249 goto remove_cdev;
250 }
251 }
252
253 dev_set_drvdata(&pdev->dev, rmtfs_mem);
254
255 return 0;
256
257remove_cdev:
258 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
259put_device:
260 put_device(&rmtfs_mem->dev);
261
262 return ret;
263}
264
265static int qcom_rmtfs_mem_remove(struct platform_device *pdev)
266{
267 struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev);
268 struct qcom_scm_vmperm perm;
269
270 if (rmtfs_mem->perms) {
271 perm.vmid = QCOM_SCM_VMID_HLOS;
272 perm.perm = QCOM_SCM_PERM_RW;
273
274 qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
275 &rmtfs_mem->perms, &perm, 1);
276 }
277
278 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
279 put_device(&rmtfs_mem->dev);
280
281 return 0;
282}
283
284static const struct of_device_id qcom_rmtfs_mem_of_match[] = {
285 { .compatible = "qcom,rmtfs-mem" },
286 {}
287};
288MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match);
289
290static struct platform_driver qcom_rmtfs_mem_driver = {
291 .probe = qcom_rmtfs_mem_probe,
292 .remove = qcom_rmtfs_mem_remove,
293 .driver = {
294 .name = "qcom_rmtfs_mem",
295 .of_match_table = qcom_rmtfs_mem_of_match,
296 },
297};
298
299static int __init qcom_rmtfs_mem_init(void)
300{
301 int ret;
302
303 ret = class_register(&rmtfs_class);
304 if (ret)
305 return ret;
306
307 ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0,
308 QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem");
309 if (ret < 0) {
310 pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n");
311 goto unregister_class;
312 }
313
314 ret = platform_driver_register(&qcom_rmtfs_mem_driver);
315 if (ret < 0) {
316 pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n");
317 goto unregister_chrdev;
318 }
319
320 return 0;
321
322unregister_chrdev:
323 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
324unregister_class:
325 class_unregister(&rmtfs_class);
326 return ret;
327}
328module_init(qcom_rmtfs_mem_init);
329
330static void __exit qcom_rmtfs_mem_exit(void)
331{
332 platform_driver_unregister(&qcom_rmtfs_mem_driver);
333 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
334 class_unregister(&rmtfs_class);
335}
336module_exit(qcom_rmtfs_mem_exit);
337
338MODULE_AUTHOR("Linaro Ltd");
339MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");
340MODULE_LICENSE("GPL v2");
341
