drivers/soc/qcom/rmtfs_mem.c - linux - Git at Google

 // 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");
	// 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");