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 | |
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, fmt: "%pa\n" , &rmtfs_mem->addr); |
55 | if (attr == &dev_attr_size) |
56 | return sprintf(buf, fmt: "%pa\n" , &rmtfs_mem->size); |
57 | if (attr == &dev_attr_client_id) |
58 | return sprintf(buf, fmt: "%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 | |
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(dev: &rmtfs_mem->dev); |
78 | filp->private_data = rmtfs_mem; |
79 | |
80 | return 0; |
81 | } |
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(to: buf, from: rmtfs_mem->base + *f_pos, n: count)) |
94 | return -EFAULT; |
95 | |
96 | *f_pos += count; |
97 | return count; |
98 | } |
99 | |
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(to: rmtfs_mem->base + *f_pos, from: buf, n: count)) |
113 | return -EFAULT; |
114 | |
115 | *f_pos += count; |
116 | return count; |
117 | } |
118 | |
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(dev: &rmtfs_mem->dev); |
124 | |
125 | return 0; |
126 | } |
127 | |
128 | static struct class rmtfs_class = { |
129 | .name = "rmtfs" , |
130 | }; |
131 | |
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(prot: vma->vm_page_prot); |
145 | return remap_pfn_range(vma, |
146 | addr: vma->vm_start, |
147 | pfn: rmtfs_mem->addr >> PAGE_SHIFT, |
148 | size: 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 | |
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(objp: rmtfs_mem); |
169 | } |
170 | |
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(np: 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(np: node, propname: "qcom,client-id" , out_value: &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(size: 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 | /* |
204 | * If requested, discard the first and last 4k block in order to ensure |
205 | * that the rmtfs region isn't adjacent to other protected regions. |
206 | */ |
207 | if (of_property_read_bool(np: node, propname: "qcom,use-guard-pages" )) { |
208 | rmtfs_mem->addr += SZ_4K; |
209 | rmtfs_mem->size -= 2 * SZ_4K; |
210 | } |
211 | |
212 | device_initialize(dev: &rmtfs_mem->dev); |
213 | rmtfs_mem->dev.parent = &pdev->dev; |
214 | rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups; |
215 | rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device; |
216 | |
217 | rmtfs_mem->base = devm_memremap(dev: &rmtfs_mem->dev, offset: rmtfs_mem->addr, |
218 | size: rmtfs_mem->size, flags: MEMREMAP_WC); |
219 | if (IS_ERR(ptr: rmtfs_mem->base)) { |
220 | dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n" ); |
221 | ret = PTR_ERR(ptr: rmtfs_mem->base); |
222 | goto put_device; |
223 | } |
224 | |
225 | cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops); |
226 | rmtfs_mem->cdev.owner = THIS_MODULE; |
227 | |
228 | dev_set_name(dev: &rmtfs_mem->dev, name: "qcom_rmtfs_mem%d" , client_id); |
229 | rmtfs_mem->dev.id = client_id; |
230 | rmtfs_mem->dev.class = &rmtfs_class; |
231 | rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id); |
232 | |
233 | ret = cdev_device_add(cdev: &rmtfs_mem->cdev, dev: &rmtfs_mem->dev); |
234 | if (ret) { |
235 | dev_err(&pdev->dev, "failed to add cdev: %d\n" , ret); |
236 | goto put_device; |
237 | } |
238 | |
239 | num_vmids = of_property_count_u32_elems(np: node, propname: "qcom,vmid" ); |
240 | if (num_vmids == -EINVAL) { |
241 | /* qcom,vmid is optional */ |
242 | num_vmids = 0; |
243 | } else if (num_vmids < 0) { |
244 | dev_err(&pdev->dev, "failed to count qcom,vmid elements: %d\n" , num_vmids); |
245 | ret = num_vmids; |
246 | goto remove_cdev; |
247 | } else if (num_vmids > NUM_MAX_VMIDS) { |
248 | dev_warn(&pdev->dev, |
249 | "too many VMIDs (%d) specified! Only mapping first %d entries\n" , |
250 | num_vmids, NUM_MAX_VMIDS); |
251 | num_vmids = NUM_MAX_VMIDS; |
252 | } |
253 | |
254 | ret = of_property_read_u32_array(np: node, propname: "qcom,vmid" , out_values: vmid, sz: num_vmids); |
255 | if (ret < 0 && ret != -EINVAL) { |
256 | dev_err(&pdev->dev, "failed to parse qcom,vmid\n" ); |
257 | goto remove_cdev; |
258 | } else if (!ret) { |
259 | if (!qcom_scm_is_available()) { |
260 | ret = -EPROBE_DEFER; |
261 | goto remove_cdev; |
262 | } |
263 | |
264 | perms[0].vmid = QCOM_SCM_VMID_HLOS; |
265 | perms[0].perm = QCOM_SCM_PERM_RW; |
266 | |
267 | for (i = 0; i < num_vmids; i++) { |
268 | perms[i + 1].vmid = vmid[i]; |
269 | perms[i + 1].perm = QCOM_SCM_PERM_RW; |
270 | } |
271 | |
272 | rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS); |
273 | ret = qcom_scm_assign_mem(mem_addr: rmtfs_mem->addr, mem_sz: rmtfs_mem->size, |
274 | src: &rmtfs_mem->perms, newvm: perms, dest_cnt: num_vmids + 1); |
275 | if (ret < 0) { |
276 | dev_err(&pdev->dev, "assign memory failed\n" ); |
277 | goto remove_cdev; |
278 | } |
279 | } |
280 | |
281 | dev_set_drvdata(dev: &pdev->dev, data: rmtfs_mem); |
282 | |
283 | return 0; |
284 | |
285 | remove_cdev: |
286 | cdev_device_del(cdev: &rmtfs_mem->cdev, dev: &rmtfs_mem->dev); |
287 | put_device: |
288 | put_device(dev: &rmtfs_mem->dev); |
289 | |
290 | return ret; |
291 | } |
292 | |
293 | static void qcom_rmtfs_mem_remove(struct platform_device *pdev) |
294 | { |
295 | struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(dev: &pdev->dev); |
296 | struct qcom_scm_vmperm perm; |
297 | |
298 | if (rmtfs_mem->perms) { |
299 | perm.vmid = QCOM_SCM_VMID_HLOS; |
300 | perm.perm = QCOM_SCM_PERM_RW; |
301 | |
302 | qcom_scm_assign_mem(mem_addr: rmtfs_mem->addr, mem_sz: rmtfs_mem->size, |
303 | src: &rmtfs_mem->perms, newvm: &perm, dest_cnt: 1); |
304 | } |
305 | |
306 | cdev_device_del(cdev: &rmtfs_mem->cdev, dev: &rmtfs_mem->dev); |
307 | put_device(dev: &rmtfs_mem->dev); |
308 | } |
309 | |
310 | static const struct of_device_id qcom_rmtfs_mem_of_match[] = { |
311 | { .compatible = "qcom,rmtfs-mem" }, |
312 | {} |
313 | }; |
314 | MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match); |
315 | |
316 | static struct platform_driver qcom_rmtfs_mem_driver = { |
317 | .probe = qcom_rmtfs_mem_probe, |
318 | .remove_new = qcom_rmtfs_mem_remove, |
319 | .driver = { |
320 | .name = "qcom_rmtfs_mem" , |
321 | .of_match_table = qcom_rmtfs_mem_of_match, |
322 | }, |
323 | }; |
324 | |
325 | static int __init qcom_rmtfs_mem_init(void) |
326 | { |
327 | int ret; |
328 | |
329 | ret = class_register(class: &rmtfs_class); |
330 | if (ret) |
331 | return ret; |
332 | |
333 | ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0, |
334 | QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem" ); |
335 | if (ret < 0) { |
336 | pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n" ); |
337 | goto unregister_class; |
338 | } |
339 | |
340 | ret = platform_driver_register(&qcom_rmtfs_mem_driver); |
341 | if (ret < 0) { |
342 | pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n" ); |
343 | goto unregister_chrdev; |
344 | } |
345 | |
346 | return 0; |
347 | |
348 | unregister_chrdev: |
349 | unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); |
350 | unregister_class: |
351 | class_unregister(class: &rmtfs_class); |
352 | return ret; |
353 | } |
354 | module_init(qcom_rmtfs_mem_init); |
355 | |
356 | static void __exit qcom_rmtfs_mem_exit(void) |
357 | { |
358 | platform_driver_unregister(&qcom_rmtfs_mem_driver); |
359 | unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); |
360 | class_unregister(class: &rmtfs_class); |
361 | } |
362 | module_exit(qcom_rmtfs_mem_exit); |
363 | |
364 | MODULE_AUTHOR("Linaro Ltd" ); |
365 | MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver" ); |
366 | MODULE_LICENSE("GPL v2" ); |
367 | |