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/qcom_scm.h> 18 19 #define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1) 20 21 static dev_t qcom_rmtfs_mem_major; 22 23 struct 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 36 static ssize_t qcom_rmtfs_mem_show(struct device *dev, 37 struct device_attribute *attr, 38 char *buf); 39 40 static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL); 41 static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL); 42 static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL); 43 44 static 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 62 static 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 }; 68 ATTRIBUTE_GROUPS(qcom_rmtfs_mem); 69 70 static 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 } 81 static 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 99 static 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 } 117 118 static 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 } 126 127 static struct class rmtfs_class = { 128 .owner = THIS_MODULE, 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[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; 256 257 remove_cdev: 258 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 259 put_device: 260 put_device(&rmtfs_mem->dev); 261 262 return ret; 263 } 264 265 static 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 } 283 284 static const struct of_device_id qcom_rmtfs_mem_of_match[] = { 285 { .compatible = "qcom,rmtfs-mem" }, 286 {} 287 }; 288 MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match); 289 290 static 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 }; 298 299 static 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; 321 322 unregister_chrdev: 323 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); 324 unregister_class: 325 class_unregister(&rmtfs_class); 326 return ret; 327 } 328 module_init(qcom_rmtfs_mem_init); 329 330 static 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 } 336 module_exit(qcom_rmtfs_mem_exit); 337 338 MODULE_AUTHOR("Linaro Ltd"); 339 MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver"); 340 MODULE_LICENSE("GPL v2"); 341