drivers/soc/qcom/rmtfs_mem.c

   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         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
 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
 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
 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");