1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2017 Linaro Ltd.
4 */
5
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/firmware/qcom/qcom_scm.h>
18
19 #define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1)
20 #define NUM_MAX_VMIDS 2
21
22 static dev_t qcom_rmtfs_mem_major;
23
24 struct qcom_rmtfs_mem {
25 struct device dev;
26 struct cdev cdev;
27
28 void *base;
29 phys_addr_t addr;
30 phys_addr_t size;
31
32 unsigned int client_id;
33
34 u64 perms;
35 };
36
37 static ssize_t qcom_rmtfs_mem_show(struct device *dev,
38 struct device_attribute *attr,
39 char *buf);
40
41 static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL);
42 static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL);
43 static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL);
44
qcom_rmtfs_mem_show(struct device * dev,struct device_attribute * attr,char * buf)45 static ssize_t qcom_rmtfs_mem_show(struct device *dev,
46 struct device_attribute *attr,
47 char *buf)
48 {
49 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
50 struct qcom_rmtfs_mem,
51 dev);
52
53 if (attr == &dev_attr_phys_addr)
54 return sprintf(buf, "%pa\n", &rmtfs_mem->addr);
55 if (attr == &dev_attr_size)
56 return sprintf(buf, "%pa\n", &rmtfs_mem->size);
57 if (attr == &dev_attr_client_id)
58 return sprintf(buf, "%d\n", rmtfs_mem->client_id);
59
60 return -EINVAL;
61 }
62
63 static struct attribute *qcom_rmtfs_mem_attrs[] = {
64 &dev_attr_phys_addr.attr,
65 &dev_attr_size.attr,
66 &dev_attr_client_id.attr,
67 NULL
68 };
69 ATTRIBUTE_GROUPS(qcom_rmtfs_mem);
70
qcom_rmtfs_mem_open(struct inode * inode,struct file * filp)71 static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp)
72 {
73 struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev,
74 struct qcom_rmtfs_mem,
75 cdev);
76
77 get_device(&rmtfs_mem->dev);
78 filp->private_data = rmtfs_mem;
79
80 return 0;
81 }
qcom_rmtfs_mem_read(struct file * filp,char __user * buf,size_t count,loff_t * f_pos)82 static ssize_t qcom_rmtfs_mem_read(struct file *filp,
83 char __user *buf, size_t count, loff_t *f_pos)
84 {
85 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
86
87 if (*f_pos >= rmtfs_mem->size)
88 return 0;
89
90 if (*f_pos + count >= rmtfs_mem->size)
91 count = rmtfs_mem->size - *f_pos;
92
93 if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count))
94 return -EFAULT;
95
96 *f_pos += count;
97 return count;
98 }
99
qcom_rmtfs_mem_write(struct file * filp,const char __user * buf,size_t count,loff_t * f_pos)100 static ssize_t qcom_rmtfs_mem_write(struct file *filp,
101 const char __user *buf, size_t count,
102 loff_t *f_pos)
103 {
104 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
105
106 if (*f_pos >= rmtfs_mem->size)
107 return 0;
108
109 if (*f_pos + count >= rmtfs_mem->size)
110 count = rmtfs_mem->size - *f_pos;
111
112 if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count))
113 return -EFAULT;
114
115 *f_pos += count;
116 return count;
117 }
118
qcom_rmtfs_mem_release(struct inode * inode,struct file * filp)119 static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
120 {
121 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
122
123 put_device(&rmtfs_mem->dev);
124
125 return 0;
126 }
127
128 static struct class rmtfs_class = {
129 .name = "rmtfs",
130 };
131
qcom_rmtfs_mem_mmap(struct file * filep,struct vm_area_struct * vma)132 static 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
152 static 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
qcom_rmtfs_mem_release_device(struct device * dev)162 static 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
qcom_rmtfs_mem_probe(struct platform_device * pdev)171 static 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[NUM_MAX_VMIDS + 1];
175 struct reserved_mem *rmem;
176 struct qcom_rmtfs_mem *rmtfs_mem;
177 u32 client_id;
178 u32 vmid[NUM_MAX_VMIDS];
179 int num_vmids;
180 int ret, i;
181
182 rmem = of_reserved_mem_lookup(node);
183 if (!rmem) {
184 dev_err(&pdev->dev, "failed to acquire memory region\n");
185 return -EINVAL;
186 }
187
188 ret = of_property_read_u32(node, "qcom,client-id", &client_id);
189 if (ret) {
190 dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n");
191 return ret;
192
193 }
194
195 rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL);
196 if (!rmtfs_mem)
197 return -ENOMEM;
198
199 rmtfs_mem->addr = rmem->base;
200 rmtfs_mem->client_id = client_id;
201 rmtfs_mem->size = rmem->size;
202
203 device_initialize(&rmtfs_mem->dev);
204 rmtfs_mem->dev.parent = &pdev->dev;
205 rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups;
206 rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device;
207
208 rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr,
209 rmtfs_mem->size, MEMREMAP_WC);
210 if (IS_ERR(rmtfs_mem->base)) {
211 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n");
212 ret = PTR_ERR(rmtfs_mem->base);
213 goto put_device;
214 }
215
216 cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops);
217 rmtfs_mem->cdev.owner = THIS_MODULE;
218
219 dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id);
220 rmtfs_mem->dev.id = client_id;
221 rmtfs_mem->dev.class = &rmtfs_class;
222 rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id);
223
224 ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev);
225 if (ret) {
226 dev_err(&pdev->dev, "failed to add cdev: %d\n", ret);
227 goto put_device;
228 }
229
230 num_vmids = of_property_count_u32_elems(node, "qcom,vmid");
231 if (num_vmids == -EINVAL) {
232 /* qcom,vmid is optional */
233 num_vmids = 0;
234 } else if (num_vmids < 0) {
235 dev_err(&pdev->dev, "failed to count qcom,vmid elements: %d\n", num_vmids);
236 ret = num_vmids;
237 goto remove_cdev;
238 } else if (num_vmids > NUM_MAX_VMIDS) {
239 dev_warn(&pdev->dev,
240 "too many VMIDs (%d) specified! Only mapping first %d entries\n",
241 num_vmids, NUM_MAX_VMIDS);
242 num_vmids = NUM_MAX_VMIDS;
243 }
244
245 ret = of_property_read_u32_array(node, "qcom,vmid", vmid, num_vmids);
246 if (ret < 0 && ret != -EINVAL) {
247 dev_err(&pdev->dev, "failed to parse qcom,vmid\n");
248 goto remove_cdev;
249 } else if (!ret) {
250 if (!qcom_scm_is_available()) {
251 ret = -EPROBE_DEFER;
252 goto remove_cdev;
253 }
254
255 perms[0].vmid = QCOM_SCM_VMID_HLOS;
256 perms[0].perm = QCOM_SCM_PERM_RW;
257
258 for (i = 0; i < num_vmids; i++) {
259 perms[i + 1].vmid = vmid[i];
260 perms[i + 1].perm = QCOM_SCM_PERM_RW;
261 }
262
263 rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
264 ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
265 &rmtfs_mem->perms, perms, num_vmids + 1);
266 if (ret < 0) {
267 dev_err(&pdev->dev, "assign memory failed\n");
268 goto remove_cdev;
269 }
270 }
271
272 dev_set_drvdata(&pdev->dev, rmtfs_mem);
273
274 return 0;
275
276 remove_cdev:
277 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
278 put_device:
279 put_device(&rmtfs_mem->dev);
280
281 return ret;
282 }
283
qcom_rmtfs_mem_remove(struct platform_device * pdev)284 static int qcom_rmtfs_mem_remove(struct platform_device *pdev)
285 {
286 struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev);
287 struct qcom_scm_vmperm perm;
288
289 if (rmtfs_mem->perms) {
290 perm.vmid = QCOM_SCM_VMID_HLOS;
291 perm.perm = QCOM_SCM_PERM_RW;
292
293 qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
294 &rmtfs_mem->perms, &perm, 1);
295 }
296
297 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
298 put_device(&rmtfs_mem->dev);
299
300 return 0;
301 }
302
303 static const struct of_device_id qcom_rmtfs_mem_of_match[] = {
304 { .compatible = "qcom,rmtfs-mem" },
305 {}
306 };
307 MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match);
308
309 static struct platform_driver qcom_rmtfs_mem_driver = {
310 .probe = qcom_rmtfs_mem_probe,
311 .remove = qcom_rmtfs_mem_remove,
312 .driver = {
313 .name = "qcom_rmtfs_mem",
314 .of_match_table = qcom_rmtfs_mem_of_match,
315 },
316 };
317
qcom_rmtfs_mem_init(void)318 static int __init qcom_rmtfs_mem_init(void)
319 {
320 int ret;
321
322 ret = class_register(&rmtfs_class);
323 if (ret)
324 return ret;
325
326 ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0,
327 QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem");
328 if (ret < 0) {
329 pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n");
330 goto unregister_class;
331 }
332
333 ret = platform_driver_register(&qcom_rmtfs_mem_driver);
334 if (ret < 0) {
335 pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n");
336 goto unregister_chrdev;
337 }
338
339 return 0;
340
341 unregister_chrdev:
342 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
343 unregister_class:
344 class_unregister(&rmtfs_class);
345 return ret;
346 }
347 module_init(qcom_rmtfs_mem_init);
348
qcom_rmtfs_mem_exit(void)349 static void __exit qcom_rmtfs_mem_exit(void)
350 {
351 platform_driver_unregister(&qcom_rmtfs_mem_driver);
352 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
353 class_unregister(&rmtfs_class);
354 }
355 module_exit(qcom_rmtfs_mem_exit);
356
357 MODULE_AUTHOR("Linaro Ltd");
358 MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");
359 MODULE_LICENSE("GPL v2");
360