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1// SPDX-License-Identifier: GPL-2.0-only2/*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 221 22static dev_t qcom_rmtfs_mem_major;23 24struct 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 37static ssize_t qcom_rmtfs_mem_show(struct device *dev,38 struct device_attribute *attr,39 char *buf);40 41static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL);42static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL);43static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL);44 45static 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 63static struct attribute *qcom_rmtfs_mem_attrs[] = {64 &dev_attr_phys_addr.attr,65 &dev_attr_size.attr,66 &dev_attr_client_id.attr,67 NULL68};69ATTRIBUTE_GROUPS(qcom_rmtfs_mem);70 71static 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}82static 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 100static 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 119static 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 128static struct class rmtfs_class = {129 .name = "rmtfs",130};131 132static 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 152static 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 162static 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 171static 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 ensure205 * 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 285remove_cdev:286 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);287put_device:288 put_device(&rmtfs_mem->dev);289 290 return ret;291}292 293static 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 310static const struct of_device_id qcom_rmtfs_mem_of_match[] = {311 { .compatible = "qcom,rmtfs-mem" },312 {}313};314MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match);315 316static 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 325static 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 348unregister_chrdev:349 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);350unregister_class:351 class_unregister(&rmtfs_class);352 return ret;353}354module_init(qcom_rmtfs_mem_init);355 356static 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}362module_exit(qcom_rmtfs_mem_exit);363 364MODULE_AUTHOR("Linaro Ltd");365MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");366MODULE_LICENSE("GPL v2");367