1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Hypervisor filesystem for Linux on s390. 4 * Set Partition-Resource Parameter interface. 5 * 6 * Copyright IBM Corp. 2013 7 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> 8 */ 9 10 #include <linux/compat.h> 11 #include <linux/errno.h> 12 #include <linux/gfp.h> 13 #include <linux/string.h> 14 #include <linux/types.h> 15 #include <linux/uaccess.h> 16 #include <asm/diag.h> 17 #include <asm/sclp.h> 18 #include "hypfs.h" 19 20 #define DIAG304_SET_WEIGHTS 0 21 #define DIAG304_QUERY_PRP 1 22 #define DIAG304_SET_CAPPING 2 23 24 #define DIAG304_CMD_MAX 2 25 26 static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd) 27 { 28 register unsigned long _data asm("2") = (unsigned long) data; 29 register unsigned long _rc asm("3"); 30 register unsigned long _cmd asm("4") = cmd; 31 32 asm volatile("diag %1,%2,0x304\n" 33 : "=d" (_rc) : "d" (_data), "d" (_cmd) : "memory"); 34 35 return _rc; 36 } 37 38 static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd) 39 { 40 diag_stat_inc(DIAG_STAT_X304); 41 return __hypfs_sprp_diag304(data, cmd); 42 } 43 44 static void hypfs_sprp_free(const void *data) 45 { 46 free_page((unsigned long) data); 47 } 48 49 static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size) 50 { 51 unsigned long rc; 52 void *data; 53 54 data = (void *) get_zeroed_page(GFP_KERNEL); 55 if (!data) 56 return -ENOMEM; 57 rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP); 58 if (rc != 1) { 59 *data_ptr = *free_ptr = NULL; 60 *size = 0; 61 free_page((unsigned long) data); 62 return -EIO; 63 } 64 *data_ptr = *free_ptr = data; 65 *size = PAGE_SIZE; 66 return 0; 67 } 68 69 static int __hypfs_sprp_ioctl(void __user *user_area) 70 { 71 struct hypfs_diag304 diag304; 72 unsigned long cmd; 73 void __user *udata; 74 void *data; 75 int rc; 76 77 if (copy_from_user(&diag304, user_area, sizeof(diag304))) 78 return -EFAULT; 79 if ((diag304.args[0] >> 8) != 0 || diag304.args[1] > DIAG304_CMD_MAX) 80 return -EINVAL; 81 82 data = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 83 if (!data) 84 return -ENOMEM; 85 86 udata = (void __user *)(unsigned long) diag304.data; 87 if (diag304.args[1] == DIAG304_SET_WEIGHTS || 88 diag304.args[1] == DIAG304_SET_CAPPING) 89 if (copy_from_user(data, udata, PAGE_SIZE)) { 90 rc = -EFAULT; 91 goto out; 92 } 93 94 cmd = *(unsigned long *) &diag304.args[0]; 95 diag304.rc = hypfs_sprp_diag304(data, cmd); 96 97 if (diag304.args[1] == DIAG304_QUERY_PRP) 98 if (copy_to_user(udata, data, PAGE_SIZE)) { 99 rc = -EFAULT; 100 goto out; 101 } 102 103 rc = copy_to_user(user_area, &diag304, sizeof(diag304)) ? -EFAULT : 0; 104 out: 105 free_page((unsigned long) data); 106 return rc; 107 } 108 109 static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd, 110 unsigned long arg) 111 { 112 void __user *argp; 113 114 if (!capable(CAP_SYS_ADMIN)) 115 return -EACCES; 116 if (is_compat_task()) 117 argp = compat_ptr(arg); 118 else 119 argp = (void __user *) arg; 120 switch (cmd) { 121 case HYPFS_DIAG304: 122 return __hypfs_sprp_ioctl(argp); 123 default: /* unknown ioctl number */ 124 return -ENOTTY; 125 } 126 return 0; 127 } 128 129 static struct hypfs_dbfs_file hypfs_sprp_file = { 130 .name = "diag_304", 131 .data_create = hypfs_sprp_create, 132 .data_free = hypfs_sprp_free, 133 .unlocked_ioctl = hypfs_sprp_ioctl, 134 }; 135 136 int hypfs_sprp_init(void) 137 { 138 if (!sclp.has_sprp) 139 return 0; 140 return hypfs_dbfs_create_file(&hypfs_sprp_file); 141 } 142 143 void hypfs_sprp_exit(void) 144 { 145 if (!sclp.has_sprp) 146 return; 147 hypfs_dbfs_remove_file(&hypfs_sprp_file); 148 } 149