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/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");