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/compat.h> 17 #include <asm/diag.h> 18 #include <asm/sclp.h> 19 #include "hypfs.h" 20 21 #define DIAG304_SET_WEIGHTS 0 22 #define DIAG304_QUERY_PRP 1 23 #define DIAG304_SET_CAPPING 2 24 25 #define DIAG304_CMD_MAX 2 26 27 static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd) 28 { 29 register unsigned long _data asm("2") = (unsigned long) data; 30 register unsigned long _rc asm("3"); 31 register unsigned long _cmd asm("4") = cmd; 32 33 asm volatile("diag %1,%2,0x304\n" 34 : "=d" (_rc) : "d" (_data), "d" (_cmd) : "memory"); 35 36 return _rc; 37 } 38 39 static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd) 40 { 41 diag_stat_inc(DIAG_STAT_X304); 42 return __hypfs_sprp_diag304(data, cmd); 43 } 44 45 static void hypfs_sprp_free(const void *data) 46 { 47 free_page((unsigned long) data); 48 } 49 50 static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size) 51 { 52 unsigned long rc; 53 void *data; 54 55 data = (void *) get_zeroed_page(GFP_KERNEL); 56 if (!data) 57 return -ENOMEM; 58 rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP); 59 if (rc != 1) { 60 *data_ptr = *free_ptr = NULL; 61 *size = 0; 62 free_page((unsigned long) data); 63 return -EIO; 64 } 65 *data_ptr = *free_ptr = data; 66 *size = PAGE_SIZE; 67 return 0; 68 } 69 70 static int __hypfs_sprp_ioctl(void __user *user_area) 71 { 72 struct hypfs_diag304 diag304; 73 unsigned long cmd; 74 void __user *udata; 75 void *data; 76 int rc; 77 78 if (copy_from_user(&diag304, user_area, sizeof(diag304))) 79 return -EFAULT; 80 if ((diag304.args[0] >> 8) != 0 || diag304.args[1] > DIAG304_CMD_MAX) 81 return -EINVAL; 82 83 data = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 84 if (!data) 85 return -ENOMEM; 86 87 udata = (void __user *)(unsigned long) diag304.data; 88 if (diag304.args[1] == DIAG304_SET_WEIGHTS || 89 diag304.args[1] == DIAG304_SET_CAPPING) 90 if (copy_from_user(data, udata, PAGE_SIZE)) { 91 rc = -EFAULT; 92 goto out; 93 } 94 95 cmd = *(unsigned long *) &diag304.args[0]; 96 diag304.rc = hypfs_sprp_diag304(data, cmd); 97 98 if (diag304.args[1] == DIAG304_QUERY_PRP) 99 if (copy_to_user(udata, data, PAGE_SIZE)) { 100 rc = -EFAULT; 101 goto out; 102 } 103 104 rc = copy_to_user(user_area, &diag304, sizeof(diag304)) ? -EFAULT : 0; 105 out: 106 free_page((unsigned long) data); 107 return rc; 108 } 109 110 static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd, 111 unsigned long arg) 112 { 113 void __user *argp; 114 115 if (!capable(CAP_SYS_ADMIN)) 116 return -EACCES; 117 if (is_compat_task()) 118 argp = compat_ptr(arg); 119 else 120 argp = (void __user *) arg; 121 switch (cmd) { 122 case HYPFS_DIAG304: 123 return __hypfs_sprp_ioctl(argp); 124 default: /* unknown ioctl number */ 125 return -ENOTTY; 126 } 127 return 0; 128 } 129 130 static struct hypfs_dbfs_file hypfs_sprp_file = { 131 .name = "diag_304", 132 .data_create = hypfs_sprp_create, 133 .data_free = hypfs_sprp_free, 134 .unlocked_ioctl = hypfs_sprp_ioctl, 135 }; 136 137 int hypfs_sprp_init(void) 138 { 139 if (!sclp.has_sprp) 140 return 0; 141 return hypfs_dbfs_create_file(&hypfs_sprp_file); 142 } 143 144 void hypfs_sprp_exit(void) 145 { 146 if (!sclp.has_sprp) 147 return; 148 hypfs_dbfs_remove_file(&hypfs_sprp_file); 149 } 150