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, "%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 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 } 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 } 99 100 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 } 118 119 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 }; 131 132 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 }; 161 162 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 } 170 171 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 /* 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(node, "qcom,use-guard-pages")) { 208 rmtfs_mem->addr += SZ_4K; 209 rmtfs_mem->size -= 2 * SZ_4K; 210 } 211 212 device_initialize(&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(&rmtfs_mem->dev, rmtfs_mem->addr, 218 rmtfs_mem->size, MEMREMAP_WC); 219 if (IS_ERR(rmtfs_mem->base)) { 220 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n"); 221 ret = PTR_ERR(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(&rmtfs_mem->dev, "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(&rmtfs_mem->cdev, &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(node, "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(node, "qcom,vmid", vmid, 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(rmtfs_mem->addr, rmtfs_mem->size, 274 &rmtfs_mem->perms, perms, 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(&pdev->dev, rmtfs_mem); 282 283 return 0; 284 285 remove_cdev: 286 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 287 put_device: 288 put_device(&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(&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(rmtfs_mem->addr, rmtfs_mem->size, 303 &rmtfs_mem->perms, &perm, 1); 304 } 305 306 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 307 put_device(&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(&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(&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(&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