| Michael Holzheu | d475f94 | 2013-06-06 09:52:08 +0200 | [diff] [blame] | 1 | /* |
| 2 | * IOCTL interface for SCLP |
| 3 | * |
| 4 | * Copyright IBM Corp. 2012 |
| 5 | * |
| 6 | * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com> |
| 7 | */ |
| 8 | |
| 9 | #include <linux/compat.h> |
| 10 | #include <linux/uaccess.h> |
| 11 | #include <linux/miscdevice.h> |
| 12 | #include <linux/gfp.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/ioctl.h> |
| 15 | #include <linux/fs.h> |
| Michael Holzheu | d475f94 | 2013-06-06 09:52:08 +0200 | [diff] [blame] | 16 | #include <asm/compat.h> |
| 17 | #include <asm/sclp_ctl.h> |
| 18 | #include <asm/sclp.h> |
| 19 | |
| 20 | #include "sclp.h" |
| 21 | |
| 22 | /* |
| 23 | * Supported command words |
| 24 | */ |
| 25 | static unsigned int sclp_ctl_sccb_wlist[] = { |
| 26 | 0x00400002, |
| 27 | 0x00410002, |
| 28 | }; |
| 29 | |
| 30 | /* |
| 31 | * Check if command word is supported |
| 32 | */ |
| 33 | static 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 | |
| 44 | static void __user *u64_to_uptr(u64 value) |
| 45 | { |
| 46 | if (is_compat_task()) |
| 47 | return compat_ptr(value); |
| 48 | else |
| 49 | return (void __user *)(unsigned long)value; |
| 50 | } |
| 51 | |
| 52 | /* |
| 53 | * Start SCLP request |
| 54 | */ |
| 55 | static int sclp_ctl_ioctl_sccb(void __user *user_area) |
| 56 | { |
| 57 | struct sclp_ctl_sccb ctl_sccb; |
| 58 | struct sccb_header *sccb; |
| 59 | int rc; |
| 60 | |
| 61 | if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb))) |
| 62 | return -EFAULT; |
| 63 | if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw)) |
| 64 | return -EOPNOTSUPP; |
| 65 | sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
| 66 | if (!sccb) |
| 67 | return -ENOMEM; |
| 68 | if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sizeof(*sccb))) { |
| 69 | rc = -EFAULT; |
| 70 | goto out_free; |
| 71 | } |
| 72 | if (sccb->length > PAGE_SIZE || sccb->length < 8) |
| 73 | return -EINVAL; |
| 74 | if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sccb->length)) { |
| 75 | rc = -EFAULT; |
| 76 | goto out_free; |
| 77 | } |
| 78 | rc = sclp_sync_request(ctl_sccb.cmdw, sccb); |
| 79 | if (rc) |
| 80 | goto out_free; |
| 81 | if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length)) |
| 82 | rc = -EFAULT; |
| 83 | out_free: |
| 84 | free_page((unsigned long) sccb); |
| 85 | return rc; |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * SCLP SCCB ioctl function |
| 90 | */ |
| 91 | static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd, |
| 92 | unsigned long arg) |
| 93 | { |
| 94 | void __user *argp; |
| 95 | |
| 96 | if (is_compat_task()) |
| 97 | argp = compat_ptr(arg); |
| 98 | else |
| 99 | argp = (void __user *) arg; |
| 100 | switch (cmd) { |
| 101 | case SCLP_CTL_SCCB: |
| 102 | return sclp_ctl_ioctl_sccb(argp); |
| 103 | default: /* unknown ioctl number */ |
| 104 | return -ENOTTY; |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * File operations |
| 110 | */ |
| 111 | static const struct file_operations sclp_ctl_fops = { |
| 112 | .owner = THIS_MODULE, |
| 113 | .open = nonseekable_open, |
| 114 | .unlocked_ioctl = sclp_ctl_ioctl, |
| 115 | .compat_ioctl = sclp_ctl_ioctl, |
| 116 | .llseek = no_llseek, |
| 117 | }; |
| 118 | |
| 119 | /* |
| 120 | * Misc device definition |
| 121 | */ |
| 122 | static struct miscdevice sclp_ctl_device = { |
| 123 | .minor = MISC_DYNAMIC_MINOR, |
| 124 | .name = "sclp", |
| 125 | .fops = &sclp_ctl_fops, |
| 126 | }; |
| 127 | |
| 128 | /* |
| 129 | * Register sclp_ctl misc device |
| 130 | */ |
| 131 | static int __init sclp_ctl_init(void) |
| 132 | { |
| 133 | return misc_register(&sclp_ctl_device); |
| 134 | } |
| 135 | module_init(sclp_ctl_init); |
| 136 | |
| 137 | /* |
| 138 | * Deregister sclp_ctl misc device |
| 139 | */ |
| 140 | static void __exit sclp_ctl_exit(void) |
| 141 | { |
| 142 | misc_deregister(&sclp_ctl_device); |
| 143 | } |
| 144 | module_exit(sclp_ctl_exit); |