1 /* 2 * Copyright (c) 2017 Linaro Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 and 6 * only version 2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/cdev.h> 16 #include <linux/err.h> 17 #include <linux/module.h> 18 #include <linux/platform_device.h> 19 #include <linux/of.h> 20 #include <linux/of_reserved_mem.h> 21 #include <linux/dma-mapping.h> 22 #include <linux/slab.h> 23 #include <linux/uaccess.h> 24 #include <linux/io.h> 25 #include <linux/qcom_scm.h> 26 27 #define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1) 28 29 static dev_t qcom_rmtfs_mem_major; 30 31 struct qcom_rmtfs_mem { 32 struct device dev; 33 struct cdev cdev; 34 35 void *base; 36 phys_addr_t addr; 37 phys_addr_t size; 38 39 unsigned int client_id; 40 41 unsigned int perms; 42 }; 43 44 static ssize_t qcom_rmtfs_mem_show(struct device *dev, 45 struct device_attribute *attr, 46 char *buf); 47 48 static DEVICE_ATTR(phys_addr, 0400, qcom_rmtfs_mem_show, NULL); 49 static DEVICE_ATTR(size, 0400, qcom_rmtfs_mem_show, NULL); 50 static DEVICE_ATTR(client_id, 0400, qcom_rmtfs_mem_show, NULL); 51 52 static ssize_t qcom_rmtfs_mem_show(struct device *dev, 53 struct device_attribute *attr, 54 char *buf) 55 { 56 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev, 57 struct qcom_rmtfs_mem, 58 dev); 59 60 if (attr == &dev_attr_phys_addr) 61 return sprintf(buf, "%pa\n", &rmtfs_mem->addr); 62 if (attr == &dev_attr_size) 63 return sprintf(buf, "%pa\n", &rmtfs_mem->size); 64 if (attr == &dev_attr_client_id) 65 return sprintf(buf, "%d\n", rmtfs_mem->client_id); 66 67 return -EINVAL; 68 } 69 70 static struct attribute *qcom_rmtfs_mem_attrs[] = { 71 &dev_attr_phys_addr.attr, 72 &dev_attr_size.attr, 73 &dev_attr_client_id.attr, 74 NULL 75 }; 76 ATTRIBUTE_GROUPS(qcom_rmtfs_mem); 77 78 static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp) 79 { 80 struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev, 81 struct qcom_rmtfs_mem, 82 cdev); 83 84 get_device(&rmtfs_mem->dev); 85 filp->private_data = rmtfs_mem; 86 87 return 0; 88 } 89 static ssize_t qcom_rmtfs_mem_read(struct file *filp, 90 char __user *buf, size_t count, loff_t *f_pos) 91 { 92 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; 93 94 if (*f_pos >= rmtfs_mem->size) 95 return 0; 96 97 if (*f_pos + count >= rmtfs_mem->size) 98 count = rmtfs_mem->size - *f_pos; 99 100 if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count)) 101 return -EFAULT; 102 103 *f_pos += count; 104 return count; 105 } 106 107 static ssize_t qcom_rmtfs_mem_write(struct file *filp, 108 const char __user *buf, size_t count, 109 loff_t *f_pos) 110 { 111 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; 112 113 if (*f_pos >= rmtfs_mem->size) 114 return 0; 115 116 if (*f_pos + count >= rmtfs_mem->size) 117 count = rmtfs_mem->size - *f_pos; 118 119 if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count)) 120 return -EFAULT; 121 122 *f_pos += count; 123 return count; 124 } 125 126 static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp) 127 { 128 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; 129 130 put_device(&rmtfs_mem->dev); 131 132 return 0; 133 } 134 135 static const struct file_operations qcom_rmtfs_mem_fops = { 136 .owner = THIS_MODULE, 137 .open = qcom_rmtfs_mem_open, 138 .read = qcom_rmtfs_mem_read, 139 .write = qcom_rmtfs_mem_write, 140 .release = qcom_rmtfs_mem_release, 141 .llseek = default_llseek, 142 }; 143 144 static void qcom_rmtfs_mem_release_device(struct device *dev) 145 { 146 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev, 147 struct qcom_rmtfs_mem, 148 dev); 149 150 kfree(rmtfs_mem); 151 } 152 153 static int qcom_rmtfs_mem_probe(struct platform_device *pdev) 154 { 155 struct device_node *node = pdev->dev.of_node; 156 struct qcom_scm_vmperm perms[2]; 157 struct reserved_mem *rmem; 158 struct qcom_rmtfs_mem *rmtfs_mem; 159 u32 client_id; 160 u32 vmid; 161 int ret; 162 163 rmem = of_reserved_mem_lookup(node); 164 if (!rmem) { 165 dev_err(&pdev->dev, "failed to acquire memory region\n"); 166 return -EINVAL; 167 } 168 169 ret = of_property_read_u32(node, "qcom,client-id", &client_id); 170 if (ret) { 171 dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n"); 172 return ret; 173 174 } 175 176 rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL); 177 if (!rmtfs_mem) 178 return -ENOMEM; 179 180 rmtfs_mem->addr = rmem->base; 181 rmtfs_mem->client_id = client_id; 182 rmtfs_mem->size = rmem->size; 183 184 device_initialize(&rmtfs_mem->dev); 185 rmtfs_mem->dev.parent = &pdev->dev; 186 rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups; 187 rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device; 188 189 rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr, 190 rmtfs_mem->size, MEMREMAP_WC); 191 if (IS_ERR(rmtfs_mem->base)) { 192 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n"); 193 ret = PTR_ERR(rmtfs_mem->base); 194 goto put_device; 195 } 196 197 cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops); 198 rmtfs_mem->cdev.owner = THIS_MODULE; 199 200 dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id); 201 rmtfs_mem->dev.id = client_id; 202 rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id); 203 204 ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev); 205 if (ret) { 206 dev_err(&pdev->dev, "failed to add cdev: %d\n", ret); 207 goto put_device; 208 } 209 210 ret = of_property_read_u32(node, "qcom,vmid", &vmid); 211 if (ret < 0 && ret != -EINVAL) { 212 dev_err(&pdev->dev, "failed to parse qcom,vmid\n"); 213 goto remove_cdev; 214 } else if (!ret) { 215 if (!qcom_scm_is_available()) { 216 ret = -EPROBE_DEFER; 217 goto remove_cdev; 218 } 219 220 perms[0].vmid = QCOM_SCM_VMID_HLOS; 221 perms[0].perm = QCOM_SCM_PERM_RW; 222 perms[1].vmid = vmid; 223 perms[1].perm = QCOM_SCM_PERM_RW; 224 225 rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS); 226 ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size, 227 &rmtfs_mem->perms, perms, 2); 228 if (ret < 0) { 229 dev_err(&pdev->dev, "assign memory failed\n"); 230 goto remove_cdev; 231 } 232 } 233 234 dev_set_drvdata(&pdev->dev, rmtfs_mem); 235 236 return 0; 237 238 remove_cdev: 239 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 240 put_device: 241 put_device(&rmtfs_mem->dev); 242 243 return ret; 244 } 245 246 static int qcom_rmtfs_mem_remove(struct platform_device *pdev) 247 { 248 struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev); 249 struct qcom_scm_vmperm perm; 250 251 if (rmtfs_mem->perms) { 252 perm.vmid = QCOM_SCM_VMID_HLOS; 253 perm.perm = QCOM_SCM_PERM_RW; 254 255 qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size, 256 &rmtfs_mem->perms, &perm, 1); 257 } 258 259 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 260 put_device(&rmtfs_mem->dev); 261 262 return 0; 263 } 264 265 static const struct of_device_id qcom_rmtfs_mem_of_match[] = { 266 { .compatible = "qcom,rmtfs-mem" }, 267 {} 268 }; 269 MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match); 270 271 static struct platform_driver qcom_rmtfs_mem_driver = { 272 .probe = qcom_rmtfs_mem_probe, 273 .remove = qcom_rmtfs_mem_remove, 274 .driver = { 275 .name = "qcom_rmtfs_mem", 276 .of_match_table = qcom_rmtfs_mem_of_match, 277 }, 278 }; 279 280 static int qcom_rmtfs_mem_init(void) 281 { 282 int ret; 283 284 ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0, 285 QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem"); 286 if (ret < 0) { 287 pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n"); 288 return ret; 289 } 290 291 ret = platform_driver_register(&qcom_rmtfs_mem_driver); 292 if (ret < 0) { 293 pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n"); 294 unregister_chrdev_region(qcom_rmtfs_mem_major, 295 QCOM_RMTFS_MEM_DEV_MAX); 296 } 297 298 return ret; 299 } 300 module_init(qcom_rmtfs_mem_init); 301 302 static void qcom_rmtfs_mem_exit(void) 303 { 304 platform_driver_unregister(&qcom_rmtfs_mem_driver); 305 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); 306 } 307 module_exit(qcom_rmtfs_mem_exit); 308 309 MODULE_AUTHOR("Linaro Ltd"); 310 MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver"); 311 MODULE_LICENSE("GPL v2"); 312