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/errno.h> 11 #include <linux/gfp.h> 12 #include <linux/string.h> 13 #include <linux/types.h> 14 #include <linux/uaccess.h> 15 #include <asm/diag.h> 16 #include <asm/sclp.h> 17 #include "hypfs.h" 18 19 #define DIAG304_SET_WEIGHTS 0 20 #define DIAG304_QUERY_PRP 1 21 #define DIAG304_SET_CAPPING 2 22 23 #define DIAG304_CMD_MAX 2 24 25 static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd) 26 { 27 union register_pair r1 = { .even = virt_to_phys(data), }; 28 29 asm volatile("diag %[r1],%[r3],0x304" 30 : [r1] "+&d" (r1.pair) 31 : [r3] "d" (cmd) 32 : "memory"); 33 return r1.odd; 34 } 35 36 static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd) 37 { 38 diag_stat_inc(DIAG_STAT_X304); 39 return __hypfs_sprp_diag304(data, cmd); 40 } 41 42 static void hypfs_sprp_free(const void *data) 43 { 44 free_page((unsigned long) data); 45 } 46 47 static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size) 48 { 49 unsigned long rc; 50 void *data; 51 52 data = (void *) get_zeroed_page(GFP_KERNEL); 53 if (!data) 54 return -ENOMEM; 55 rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP); 56 if (rc != 1) { 57 *data_ptr = *free_ptr = NULL; 58 *size = 0; 59 free_page((unsigned long) data); 60 return -EIO; 61 } 62 *data_ptr = *free_ptr = data; 63 *size = PAGE_SIZE; 64 return 0; 65 } 66 67 static int __hypfs_sprp_ioctl(void __user *user_area) 68 { 69 struct hypfs_diag304 *diag304; 70 unsigned long cmd; 71 void __user *udata; 72 void *data; 73 int rc; 74 75 rc = -ENOMEM; 76 data = (void *)get_zeroed_page(GFP_KERNEL); 77 diag304 = kzalloc(sizeof(*diag304), GFP_KERNEL); 78 if (!data || !diag304) 79 goto out; 80 81 rc = -EFAULT; 82 if (copy_from_user(diag304, user_area, sizeof(*diag304))) 83 goto out; 84 rc = -EINVAL; 85 if ((diag304->args[0] >> 8) != 0 || diag304->args[1] > DIAG304_CMD_MAX) 86 goto out; 87 88 rc = -EFAULT; 89 udata = (void __user *)(unsigned long) diag304->data; 90 if (diag304->args[1] == DIAG304_SET_WEIGHTS || 91 diag304->args[1] == DIAG304_SET_CAPPING) 92 if (copy_from_user(data, udata, PAGE_SIZE)) 93 goto out; 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 kfree(diag304); 107 free_page((unsigned long) data); 108 return rc; 109 } 110 111 static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd, 112 unsigned long arg) 113 { 114 void __user *argp; 115 116 if (!capable(CAP_SYS_ADMIN)) 117 return -EACCES; 118 argp = (void __user *)arg; 119 switch (cmd) { 120 case HYPFS_DIAG304: 121 return __hypfs_sprp_ioctl(argp); 122 default: /* unknown ioctl number */ 123 return -ENOTTY; 124 } 125 return 0; 126 } 127 128 static struct hypfs_dbfs_file hypfs_sprp_file = { 129 .name = "diag_304", 130 .data_create = hypfs_sprp_create, 131 .data_free = hypfs_sprp_free, 132 .unlocked_ioctl = hypfs_sprp_ioctl, 133 }; 134 135 void hypfs_sprp_init(void) 136 { 137 if (!sclp.has_sprp) 138 return; 139 hypfs_dbfs_create_file(&hypfs_sprp_file); 140 } 141 142 void hypfs_sprp_exit(void) 143 { 144 if (!sclp.has_sprp) 145 return; 146 hypfs_dbfs_remove_file(&hypfs_sprp_file); 147 } 148