#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/firmware/qcom/qcom_scm.h>
#define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1)
#define NUM_MAX_VMIDS 2
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;
u64 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 const struct class rmtfs_class = {
.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[NUM_MAX_VMIDS + 1];
struct reserved_mem *rmem;
struct qcom_rmtfs_mem *rmtfs_mem;
u32 client_id;
u32 vmid[NUM_MAX_VMIDS];
int num_vmids;
int ret, i;
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_obj(*rmtfs_mem);
if (!rmtfs_mem)
return -ENOMEM;
rmtfs_mem->addr = rmem->base;
rmtfs_mem->client_id = client_id;
rmtfs_mem->size = rmem->size;
if (of_property_read_bool(node, "qcom,use-guard-pages")) {
rmtfs_mem->addr += SZ_4K;
rmtfs_mem->size -= 2 * SZ_4K;
}
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;
}
num_vmids = of_property_count_u32_elems(node, "qcom,vmid");
if (num_vmids == -EINVAL) {
num_vmids = 0;
} else if (num_vmids < 0) {
dev_err(&pdev->dev, "failed to count qcom,vmid elements: %d\n", num_vmids);
ret = num_vmids;
goto remove_cdev;
} else if (num_vmids > NUM_MAX_VMIDS) {
dev_warn(&pdev->dev,
"too many VMIDs (%d) specified! Only mapping first %d entries\n",
num_vmids, NUM_MAX_VMIDS);
num_vmids = NUM_MAX_VMIDS;
}
ret = of_property_read_u32_array(node, "qcom,vmid", vmid, num_vmids);
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;
for (i = 0; i < num_vmids; i++) {
perms[i + 1].vmid = vmid[i];
perms[i + 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, num_vmids + 1);
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 void 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);
}
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");
