projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| d475f942 MH |
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> | |
| 16 | #include <linux/compat.h> | |
| 17 | #include <asm/compat.h> | |
| 18 | #include <asm/sclp_ctl.h> | |
| 19 | #include <asm/sclp.h> | |
| 20 | ||
| 21 | #include "sclp.h" | |
| 22 | ||
| 23 | /* | |
| 24 | * Supported command words | |
| 25 | */ | |
| 26 | static unsigned int sclp_ctl_sccb_wlist[] = { | |
| 27 | 0x00400002, | |
| 28 | 0x00410002, | |
| 29 | }; | |
| 30 | ||
| 31 | /* | |
| 32 | * Check if command word is supported | |
| 33 | */ | |
| 34 | static int sclp_ctl_cmdw_supported(unsigned int cmdw) | |
| 35 | { | |
| 36 | int i; | |
| 37 | ||
| 38 | for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) { | |
| 39 | if (cmdw == sclp_ctl_sccb_wlist[i]) | |
| 40 | return 1; | |
| 41 | } | |
| 42 | return 0; | |
| 43 | } | |
| 44 | ||
| 45 | static void __user *u64_to_uptr(u64 value) | |
| 46 | { | |
| 47 | if (is_compat_task()) | |
| 48 | return compat_ptr(value); | |
| 49 | else | |
| 50 | return (void __user *)(unsigned long)value; | |
| 51 | } | |
| 52 | ||
| 53 | /* | |
| 54 | * Start SCLP request | |
| 55 | */ | |
| 56 | static int sclp_ctl_ioctl_sccb(void __user *user_area) | |
| 57 | { | |
| 58 | struct sclp_ctl_sccb ctl_sccb; | |
| 59 | struct sccb_header *sccb; | |
| 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 | if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sizeof(*sccb))) { | |
| 70 | rc = -EFAULT; | |
| 71 | goto out_free; | |
| 72 | } | |
| 73 | if (sccb->length > PAGE_SIZE || sccb->length < 8) | |
| 74 | return -EINVAL; | |
| 75 | if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sccb->length)) { | |
| 76 | rc = -EFAULT; | |
| 77 | goto out_free; | |
| 78 | } | |
| 79 | rc = sclp_sync_request(ctl_sccb.cmdw, sccb); | |
| 80 | if (rc) | |
| 81 | goto out_free; | |
| 82 | if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length)) | |
| 83 | rc = -EFAULT; | |
| 84 | out_free: | |
| 85 | free_page((unsigned long) sccb); | |
| 86 | return rc; | |
| 87 | } | |
| 88 | ||
| 89 | /* | |
| 90 | * SCLP SCCB ioctl function | |
| 91 | */ | |
| 92 | static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd, | |
| 93 | unsigned long arg) | |
| 94 | { | |
| 95 | void __user *argp; | |
| 96 | ||
| 97 | if (is_compat_task()) | |
| 98 | argp = compat_ptr(arg); | |
| 99 | else | |
| 100 | argp = (void __user *) arg; | |
| 101 | switch (cmd) { | |
| 102 | case SCLP_CTL_SCCB: | |
| 103 | return sclp_ctl_ioctl_sccb(argp); | |
| 104 | default: /* unknown ioctl number */ | |
| 105 | return -ENOTTY; | |
| 106 | } | |
| 107 | } | |
| 108 | ||
| 109 | /* | |
| 110 | * File operations | |
| 111 | */ | |
| 112 | static const struct file_operations sclp_ctl_fops = { | |
| 113 | .owner = THIS_MODULE, | |
| 114 | .open = nonseekable_open, | |
| 115 | .unlocked_ioctl = sclp_ctl_ioctl, | |
| 116 | .compat_ioctl = sclp_ctl_ioctl, | |
| 117 | .llseek = no_llseek, | |
| 118 | }; | |
| 119 | ||
| 120 | /* | |
| 121 | * Misc device definition | |
| 122 | */ | |
| 123 | static struct miscdevice sclp_ctl_device = { | |
| 124 | .minor = MISC_DYNAMIC_MINOR, | |
| 125 | .name = "sclp", | |
| 126 | .fops = &sclp_ctl_fops, | |
| 127 | }; | |
| 128 | ||
| 129 | /* | |
| 130 | * Register sclp_ctl misc device | |
| 131 | */ | |
| 132 | static int __init sclp_ctl_init(void) | |
| 133 | { | |
| 134 | return misc_register(&sclp_ctl_device); | |
| 135 | } | |
| 136 | module_init(sclp_ctl_init); | |
| 137 | ||
| 138 | /* | |
| 139 | * Deregister sclp_ctl misc device | |
| 140 | */ | |
| 141 | static void __exit sclp_ctl_exit(void) | |
| 142 | { | |
| 143 | misc_deregister(&sclp_ctl_device); | |
| 144 | } | |
| 145 | module_exit(sclp_ctl_exit); |