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1// SPDX-License-Identifier: GPL-2.02/*3 * IOCTL interface for SCLP4 *5 * Copyright IBM Corp. 20126 *7 * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com>8 */9 10#include <linux/compat.h>11#include <linux/uaccess.h>12#include <linux/miscdevice.h>13#include <linux/gfp.h>14#include <linux/init.h>15#include <linux/ioctl.h>16#include <linux/fs.h>17#include <asm/sclp_ctl.h>18#include <asm/sclp.h>19 20#include "sclp.h"21 22/*23 * Supported command words24 */25static unsigned int sclp_ctl_sccb_wlist[] = {26 0x00400002,27 0x00410002,28};29 30/*31 * Check if command word is supported32 */33static int sclp_ctl_cmdw_supported(unsigned int cmdw)34{35 int i;36 37 for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) {38 if (cmdw == sclp_ctl_sccb_wlist[i])39 return 1;40 }41 return 0;42}43 44static void __user *u64_to_uptr(u64 value)45{46 if (is_compat_task())47 return compat_ptr(value);48 else49 return (void __user *)(unsigned long)value;50}51 52/*53 * Start SCLP request54 */55static int sclp_ctl_ioctl_sccb(void __user *user_area)56{57 struct sclp_ctl_sccb ctl_sccb;58 struct sccb_header *sccb;59 unsigned long copied;60 int rc;61 62 if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb)))63 return -EFAULT;64 if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw))65 return -EOPNOTSUPP;66 sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);67 if (!sccb)68 return -ENOMEM;69 copied = PAGE_SIZE -70 copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), PAGE_SIZE);71 if (offsetof(struct sccb_header, length) +72 sizeof(sccb->length) > copied || sccb->length > copied) {73 rc = -EFAULT;74 goto out_free;75 }76 if (sccb->length < 8) {77 rc = -EINVAL;78 goto out_free;79 }80 rc = sclp_sync_request(ctl_sccb.cmdw, sccb);81 if (rc)82 goto out_free;83 if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length))84 rc = -EFAULT;85out_free:86 free_page((unsigned long) sccb);87 return rc;88}89 90/*91 * SCLP SCCB ioctl function92 */93static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd,94 unsigned long arg)95{96 void __user *argp;97 98 if (is_compat_task())99 argp = compat_ptr(arg);100 else101 argp = (void __user *) arg;102 switch (cmd) {103 case SCLP_CTL_SCCB:104 return sclp_ctl_ioctl_sccb(argp);105 default: /* unknown ioctl number */106 return -ENOTTY;107 }108}109 110/*111 * File operations112 */113static const struct file_operations sclp_ctl_fops = {114 .owner = THIS_MODULE,115 .open = nonseekable_open,116 .unlocked_ioctl = sclp_ctl_ioctl,117 .compat_ioctl = sclp_ctl_ioctl,118};119 120/*121 * Misc device definition122 */123static struct miscdevice sclp_ctl_device = {124 .minor = MISC_DYNAMIC_MINOR,125 .name = "sclp",126 .fops = &sclp_ctl_fops,127};128builtin_misc_device(sclp_ctl_device);129