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 union register_pair r1 = { .even = virt_to_phys(data), }; 29 30 asm volatile("diag %[r1],%[r3],0x304\n" 31 : [r1] "+&d" (r1.pair) 32 : [r3] "d" (cmd) 33 : "memory"); 34 return r1.odd; 35 } 36 37 static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd) 38 { 39 diag_stat_inc(DIAG_STAT_X304); 40 return __hypfs_sprp_diag304(data, cmd); 41 } 42 43 static void hypfs_sprp_free(const void *data) 44 { 45 free_page((unsigned long) data); 46 } 47 48 static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size) 49 { 50 unsigned long rc; 51 void *data; 52 53 data = (void *) get_zeroed_page(GFP_KERNEL); 54 if (!data) 55 return -ENOMEM; 56 rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP); 57 if (rc != 1) { 58 *data_ptr = *free_ptr = NULL; 59 *size = 0; 60 free_page((unsigned long) data); 61 return -EIO; 62 } 63 *data_ptr = *free_ptr = data; 64 *size = PAGE_SIZE; 65 return 0; 66 } 67 68 static int __hypfs_sprp_ioctl(void __user *user_area) 69 { 70 struct hypfs_diag304 *diag304; 71 unsigned long cmd; 72 void __user *udata; 73 void *data; 74 int rc; 75 76 rc = -ENOMEM; 77 data = (void *)get_zeroed_page(GFP_KERNEL); 78 diag304 = kzalloc(sizeof(*diag304), GFP_KERNEL); 79 if (!data || !diag304) 80 goto out; 81 82 rc = -EFAULT; 83 if (copy_from_user(diag304, user_area, sizeof(*diag304))) 84 goto out; 85 rc = -EINVAL; 86 if ((diag304->args[0] >> 8) != 0 || diag304->args[1] > DIAG304_CMD_MAX) 87 goto out; 88 89 rc = -EFAULT; 90 udata = (void __user *)(unsigned long) diag304->data; 91 if (diag304->args[1] == DIAG304_SET_WEIGHTS || 92 diag304->args[1] == DIAG304_SET_CAPPING) 93 if (copy_from_user(data, udata, PAGE_SIZE)) 94 goto out; 95 96 cmd = *(unsigned long *) &diag304->args[0]; 97 diag304->rc = hypfs_sprp_diag304(data, cmd); 98 99 if (diag304->args[1] == DIAG304_QUERY_PRP) 100 if (copy_to_user(udata, data, PAGE_SIZE)) { 101 rc = -EFAULT; 102 goto out; 103 } 104 105 rc = copy_to_user(user_area, diag304, sizeof(*diag304)) ? -EFAULT : 0; 106 out: 107 kfree(diag304); 108 free_page((unsigned long) data); 109 return rc; 110 } 111 112 static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd, 113 unsigned long arg) 114 { 115 void __user *argp; 116 117 if (!capable(CAP_SYS_ADMIN)) 118 return -EACCES; 119 if (is_compat_task()) 120 argp = compat_ptr(arg); 121 else 122 argp = (void __user *) arg; 123 switch (cmd) { 124 case HYPFS_DIAG304: 125 return __hypfs_sprp_ioctl(argp); 126 default: /* unknown ioctl number */ 127 return -ENOTTY; 128 } 129 return 0; 130 } 131 132 static struct hypfs_dbfs_file hypfs_sprp_file = { 133 .name = "diag_304", 134 .data_create = hypfs_sprp_create, 135 .data_free = hypfs_sprp_free, 136 .unlocked_ioctl = hypfs_sprp_ioctl, 137 }; 138 139 void hypfs_sprp_init(void) 140 { 141 if (!sclp.has_sprp) 142 return; 143 hypfs_dbfs_create_file(&hypfs_sprp_file); 144 } 145 146 void hypfs_sprp_exit(void) 147 { 148 if (!sclp.has_sprp) 149 return; 150 hypfs_dbfs_remove_file(&hypfs_sprp_file); 151 } 152