diff options
Diffstat (limited to 'drivers/soc/qcom/rmtfs_mem.c')
| -rw-r--r-- | drivers/soc/qcom/rmtfs_mem.c | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/drivers/soc/qcom/rmtfs_mem.c b/drivers/soc/qcom/rmtfs_mem.c new file mode 100644 index 000000000..0feaae357 --- /dev/null +++ b/drivers/soc/qcom/rmtfs_mem.c @@ -0,0 +1,340 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2017 Linaro Ltd. + */ + +#include <linux/kernel.h> +#include <linux/cdev.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/of_reserved_mem.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/qcom_scm.h> + +#define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1) + +static dev_t qcom_rmtfs_mem_major; + +struct qcom_rmtfs_mem { + struct device dev; + struct cdev cdev; + + void *base; + phys_addr_t addr; + phys_addr_t size; + + unsigned int client_id; + + unsigned int perms; +}; + +static ssize_t qcom_rmtfs_mem_show(struct device *dev, + struct device_attribute *attr, + char *buf); + +static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL); +static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL); +static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL); + +static ssize_t qcom_rmtfs_mem_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev, + struct qcom_rmtfs_mem, + dev); + + if (attr == &dev_attr_phys_addr) + return sprintf(buf, "%pa\n", &rmtfs_mem->addr); + if (attr == &dev_attr_size) + return sprintf(buf, "%pa\n", &rmtfs_mem->size); + if (attr == &dev_attr_client_id) + return sprintf(buf, "%d\n", rmtfs_mem->client_id); + + return -EINVAL; +} + +static struct attribute *qcom_rmtfs_mem_attrs[] = { + &dev_attr_phys_addr.attr, + &dev_attr_size.attr, + &dev_attr_client_id.attr, + NULL +}; +ATTRIBUTE_GROUPS(qcom_rmtfs_mem); + +static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp) +{ + struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev, + struct qcom_rmtfs_mem, + cdev); + + get_device(&rmtfs_mem->dev); + filp->private_data = rmtfs_mem; + + return 0; +} +static ssize_t qcom_rmtfs_mem_read(struct file *filp, + char __user *buf, size_t count, loff_t *f_pos) +{ + struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; + + if (*f_pos >= rmtfs_mem->size) + return 0; + + if (*f_pos + count >= rmtfs_mem->size) + count = rmtfs_mem->size - *f_pos; + + if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count)) + return -EFAULT; + + *f_pos += count; + return count; +} + +static ssize_t qcom_rmtfs_mem_write(struct file *filp, + const char __user *buf, size_t count, + loff_t *f_pos) +{ + struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; + + if (*f_pos >= rmtfs_mem->size) + return 0; + + if (*f_pos + count >= rmtfs_mem->size) + count = rmtfs_mem->size - *f_pos; + + if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count)) + return -EFAULT; + + *f_pos += count; + return count; +} + +static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp) +{ + struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; + + put_device(&rmtfs_mem->dev); + + return 0; +} + +static struct class rmtfs_class = { + .owner = THIS_MODULE, + .name = "rmtfs", +}; + +static int qcom_rmtfs_mem_mmap(struct file *filep, struct vm_area_struct *vma) +{ + struct qcom_rmtfs_mem *rmtfs_mem = filep->private_data; + + if (vma->vm_end - vma->vm_start > rmtfs_mem->size) { + dev_dbg(&rmtfs_mem->dev, + "vm_end[%lu] - vm_start[%lu] [%lu] > mem->size[%pa]\n", + vma->vm_end, vma->vm_start, + (vma->vm_end - vma->vm_start), &rmtfs_mem->size); + return -EINVAL; + } + + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); + return remap_pfn_range(vma, + vma->vm_start, + rmtfs_mem->addr >> PAGE_SHIFT, + vma->vm_end - vma->vm_start, + vma->vm_page_prot); +} + +static const struct file_operations qcom_rmtfs_mem_fops = { + .owner = THIS_MODULE, + .open = qcom_rmtfs_mem_open, + .read = qcom_rmtfs_mem_read, + .write = qcom_rmtfs_mem_write, + .release = qcom_rmtfs_mem_release, + .llseek = default_llseek, + .mmap = qcom_rmtfs_mem_mmap, +}; + +static void qcom_rmtfs_mem_release_device(struct device *dev) +{ + struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev, + struct qcom_rmtfs_mem, + dev); + + kfree(rmtfs_mem); +} + +static int qcom_rmtfs_mem_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct qcom_scm_vmperm perms[2]; + struct reserved_mem *rmem; + struct qcom_rmtfs_mem *rmtfs_mem; + u32 client_id; + u32 vmid; + int ret; + + rmem = of_reserved_mem_lookup(node); + if (!rmem) { + dev_err(&pdev->dev, "failed to acquire memory region\n"); + return -EINVAL; + } + + ret = of_property_read_u32(node, "qcom,client-id", &client_id); + if (ret) { + dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n"); + return ret; + + } + + rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL); + if (!rmtfs_mem) + return -ENOMEM; + + rmtfs_mem->addr = rmem->base; + rmtfs_mem->client_id = client_id; + rmtfs_mem->size = rmem->size; + + device_initialize(&rmtfs_mem->dev); + rmtfs_mem->dev.parent = &pdev->dev; + rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups; + rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device; + + rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr, + rmtfs_mem->size, MEMREMAP_WC); + if (IS_ERR(rmtfs_mem->base)) { + dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n"); + ret = PTR_ERR(rmtfs_mem->base); + goto put_device; + } + + cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops); + rmtfs_mem->cdev.owner = THIS_MODULE; + + dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id); + rmtfs_mem->dev.id = client_id; + rmtfs_mem->dev.class = &rmtfs_class; + rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id); + + ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev); + if (ret) { + dev_err(&pdev->dev, "failed to add cdev: %d\n", ret); + goto put_device; + } + + ret = of_property_read_u32(node, "qcom,vmid", &vmid); + if (ret < 0 && ret != -EINVAL) { + dev_err(&pdev->dev, "failed to parse qcom,vmid\n"); + goto remove_cdev; + } else if (!ret) { + if (!qcom_scm_is_available()) { + ret = -EPROBE_DEFER; + goto remove_cdev; + } + + perms[0].vmid = QCOM_SCM_VMID_HLOS; + perms[0].perm = QCOM_SCM_PERM_RW; + perms[1].vmid = vmid; + perms[1].perm = QCOM_SCM_PERM_RW; + + rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS); + ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size, + &rmtfs_mem->perms, perms, 2); + if (ret < 0) { + dev_err(&pdev->dev, "assign memory failed\n"); + goto remove_cdev; + } + } + + dev_set_drvdata(&pdev->dev, rmtfs_mem); + + return 0; + +remove_cdev: + cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); +put_device: + put_device(&rmtfs_mem->dev); + + return ret; +} + +static int qcom_rmtfs_mem_remove(struct platform_device *pdev) +{ + struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev); + struct qcom_scm_vmperm perm; + + if (rmtfs_mem->perms) { + perm.vmid = QCOM_SCM_VMID_HLOS; + perm.perm = QCOM_SCM_PERM_RW; + + qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size, + &rmtfs_mem->perms, &perm, 1); + } + + cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); + put_device(&rmtfs_mem->dev); + + return 0; +} + +static const struct of_device_id qcom_rmtfs_mem_of_match[] = { + { .compatible = "qcom,rmtfs-mem" }, + {} +}; +MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match); + +static struct platform_driver qcom_rmtfs_mem_driver = { + .probe = qcom_rmtfs_mem_probe, + .remove = qcom_rmtfs_mem_remove, + .driver = { + .name = "qcom_rmtfs_mem", + .of_match_table = qcom_rmtfs_mem_of_match, + }, +}; + +static int __init qcom_rmtfs_mem_init(void) +{ + int ret; + + ret = class_register(&rmtfs_class); + if (ret) + return ret; + + ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0, + QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem"); + if (ret < 0) { + pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n"); + goto unregister_class; + } + + ret = platform_driver_register(&qcom_rmtfs_mem_driver); + if (ret < 0) { + pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n"); + goto unregister_chrdev; + } + + return 0; + +unregister_chrdev: + unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); +unregister_class: + class_unregister(&rmtfs_class); + return ret; +} +module_init(qcom_rmtfs_mem_init); + +static void __exit qcom_rmtfs_mem_exit(void) +{ + platform_driver_unregister(&qcom_rmtfs_mem_driver); + unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); + class_unregister(&rmtfs_class); +} +module_exit(qcom_rmtfs_mem_exit); + +MODULE_AUTHOR("Linaro Ltd"); +MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver"); +MODULE_LICENSE("GPL v2"); |