diff options
Diffstat (limited to 'drivers/s390/char/sclp_ctl.c')
-rw-r--r-- | drivers/s390/char/sclp_ctl.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/s390/char/sclp_ctl.c b/drivers/s390/char/sclp_ctl.c new file mode 100644 index 000000000000..abe8ef13d148 --- /dev/null +++ b/drivers/s390/char/sclp_ctl.c @@ -0,0 +1,145 @@ +/* + * IOCTL interface for SCLP + * + * Copyright IBM Corp. 2012 + * + * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com> + */ + +#include <linux/compat.h> +#include <linux/uaccess.h> +#include <linux/miscdevice.h> +#include <linux/gfp.h> +#include <linux/module.h> +#include <linux/ioctl.h> +#include <linux/fs.h> +#include <linux/compat.h> +#include <asm/compat.h> +#include <asm/sclp_ctl.h> +#include <asm/sclp.h> + +#include "sclp.h" + +/* + * Supported command words + */ +static unsigned int sclp_ctl_sccb_wlist[] = { + 0x00400002, + 0x00410002, +}; + +/* + * Check if command word is supported + */ +static int sclp_ctl_cmdw_supported(unsigned int cmdw) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) { + if (cmdw == sclp_ctl_sccb_wlist[i]) + return 1; + } + return 0; +} + +static void __user *u64_to_uptr(u64 value) +{ + if (is_compat_task()) + return compat_ptr(value); + else + return (void __user *)(unsigned long)value; +} + +/* + * Start SCLP request + */ +static int sclp_ctl_ioctl_sccb(void __user *user_area) +{ + struct sclp_ctl_sccb ctl_sccb; + struct sccb_header *sccb; + int rc; + + if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb))) + return -EFAULT; + if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw)) + return -EOPNOTSUPP; + sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); + if (!sccb) + return -ENOMEM; + if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sizeof(*sccb))) { + rc = -EFAULT; + goto out_free; + } + if (sccb->length > PAGE_SIZE || sccb->length < 8) + return -EINVAL; + if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sccb->length)) { + rc = -EFAULT; + goto out_free; + } + rc = sclp_sync_request(ctl_sccb.cmdw, sccb); + if (rc) + goto out_free; + if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length)) + rc = -EFAULT; +out_free: + free_page((unsigned long) sccb); + return rc; +} + +/* + * SCLP SCCB ioctl function + */ +static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + void __user *argp; + + if (is_compat_task()) + argp = compat_ptr(arg); + else + argp = (void __user *) arg; + switch (cmd) { + case SCLP_CTL_SCCB: + return sclp_ctl_ioctl_sccb(argp); + default: /* unknown ioctl number */ + return -ENOTTY; + } +} + +/* + * File operations + */ +static const struct file_operations sclp_ctl_fops = { + .owner = THIS_MODULE, + .open = nonseekable_open, + .unlocked_ioctl = sclp_ctl_ioctl, + .compat_ioctl = sclp_ctl_ioctl, + .llseek = no_llseek, +}; + +/* + * Misc device definition + */ +static struct miscdevice sclp_ctl_device = { + .minor = MISC_DYNAMIC_MINOR, + .name = "sclp", + .fops = &sclp_ctl_fops, +}; + +/* + * Register sclp_ctl misc device + */ +static int __init sclp_ctl_init(void) +{ + return misc_register(&sclp_ctl_device); +} +module_init(sclp_ctl_init); + +/* + * Deregister sclp_ctl misc device + */ +static void __exit sclp_ctl_exit(void) +{ + misc_deregister(&sclp_ctl_device); +} +module_exit(sclp_ctl_exit); |