diff options
Diffstat (limited to 'arch/um/drivers/mmapper_kern.c')
-rw-r--r-- | arch/um/drivers/mmapper_kern.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c new file mode 100644 index 00000000000..a63231dffe0 --- /dev/null +++ b/arch/um/drivers/mmapper_kern.c @@ -0,0 +1,150 @@ +/* + * arch/um/drivers/mmapper_kern.c + * + * BRIEF MODULE DESCRIPTION + * + * Copyright (C) 2000 RidgeRun, Inc. + * Author: RidgeRun, Inc. + * Greg Lonnon glonnon@ridgerun.com or info@ridgerun.com + * + */ + +#include <linux/types.h> +#include <linux/kdev_t.h> +#include <linux/time.h> +#include <linux/devfs_fs_kernel.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/smp_lock.h> +#include <asm/uaccess.h> +#include <asm/irq.h> +#include <asm/pgtable.h> +#include "mem_user.h" +#include "user_util.h" + +/* These are set in mmapper_init, which is called at boot time */ +static unsigned long mmapper_size; +static unsigned long p_buf = 0; +static char *v_buf = NULL; + +static ssize_t +mmapper_read(struct file *file, char *buf, size_t count, loff_t *ppos) +{ + if(*ppos > mmapper_size) + return -EINVAL; + + if(count + *ppos > mmapper_size) + count = count + *ppos - mmapper_size; + + if(count < 0) + return -EINVAL; + + copy_to_user(buf,&v_buf[*ppos],count); + + return count; +} + +static ssize_t +mmapper_write(struct file *file, const char *buf, size_t count, loff_t *ppos) +{ + if(*ppos > mmapper_size) + return -EINVAL; + + if(count + *ppos > mmapper_size) + count = count + *ppos - mmapper_size; + + if(count < 0) + return -EINVAL; + + copy_from_user(&v_buf[*ppos],buf,count); + + return count; +} + +static int +mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + return(-ENOIOCTLCMD); +} + +static int +mmapper_mmap(struct file *file, struct vm_area_struct * vma) +{ + int ret = -EINVAL; + int size; + + lock_kernel(); + if (vma->vm_pgoff != 0) + goto out; + + size = vma->vm_end - vma->vm_start; + if(size > mmapper_size) return(-EFAULT); + + /* XXX A comment above remap_pfn_range says it should only be + * called when the mm semaphore is held + */ + if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size, + vma->vm_page_prot)) + goto out; + ret = 0; +out: + unlock_kernel(); + return ret; +} + +static int +mmapper_open(struct inode *inode, struct file *file) +{ + return 0; +} + +static int +mmapper_release(struct inode *inode, struct file *file) +{ + return 0; +} + +static struct file_operations mmapper_fops = { + .owner = THIS_MODULE, + .read = mmapper_read, + .write = mmapper_write, + .ioctl = mmapper_ioctl, + .mmap = mmapper_mmap, + .open = mmapper_open, + .release = mmapper_release, +}; + +static int __init mmapper_init(void) +{ + printk(KERN_INFO "Mapper v0.1\n"); + + v_buf = (char *) find_iomem("mmapper", &mmapper_size); + if(mmapper_size == 0){ + printk(KERN_ERR "mmapper_init - find_iomem failed\n"); + return(0); + } + + p_buf = __pa(v_buf); + + devfs_mk_cdev(MKDEV(30, 0), S_IFCHR|S_IRUGO|S_IWUGO, "mmapper"); + return(0); +} + +static void mmapper_exit(void) +{ +} + +module_init(mmapper_init); +module_exit(mmapper_exit); + +MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>"); +MODULE_DESCRIPTION("DSPLinux simulator mmapper driver"); +/* + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |