1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __PARISC_UACCESS_H 3 #define __PARISC_UACCESS_H 4 5 /* 6 * User space memory access functions 7 */ 8 #include <asm/page.h> 9 #include <asm/cache.h> 10 11 #include <linux/bug.h> 12 #include <linux/string.h> 13 14 #define KERNEL_DS ((mm_segment_t){0}) 15 #define USER_DS ((mm_segment_t){1}) 16 17 #define segment_eq(a, b) ((a).seg == (b).seg) 18 19 #define get_ds() (KERNEL_DS) 20 #define get_fs() (current_thread_info()->addr_limit) 21 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 22 23 /* 24 * Note that since kernel addresses are in a separate address space on 25 * parisc, we don't need to do anything for access_ok(). 26 * We just let the page fault handler do the right thing. This also means 27 * that put_user is the same as __put_user, etc. 28 */ 29 30 #define access_ok(type, uaddr, size) \ 31 ( (uaddr) == (uaddr) ) 32 33 #define put_user __put_user 34 #define get_user __get_user 35 36 #if !defined(CONFIG_64BIT) 37 #define LDD_USER(val, ptr) __get_user_asm64(val, ptr) 38 #define STD_USER(x, ptr) __put_user_asm64(x, ptr) 39 #else 40 #define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr) 41 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr) 42 #endif 43 44 /* 45 * The exception table contains two values: the first is the relative offset to 46 * the address of the instruction that is allowed to fault, and the second is 47 * the relative offset to the address of the fixup routine. Since relative 48 * addresses are used, 32bit values are sufficient even on 64bit kernel. 49 */ 50 51 #define ARCH_HAS_RELATIVE_EXTABLE 52 struct exception_table_entry { 53 int insn; /* relative address of insn that is allowed to fault. */ 54 int fixup; /* relative address of fixup routine */ 55 }; 56 57 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\ 58 ".section __ex_table,\"aw\"\n" \ 59 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \ 60 ".previous\n" 61 62 /* 63 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry 64 * (with lowest bit set) for which the fault handler in fixup_exception() will 65 * load -EFAULT into %r8 for a read or write fault, and zeroes the target 66 * register in case of a read fault in get_user(). 67 */ 68 #define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\ 69 ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1) 70 71 /* 72 * load_sr2() preloads the space register %%sr2 - based on the value of 73 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which 74 * is 0), or with the current value of %%sr3 to access user space (USER_DS) 75 * memory. The following __get_user_asm() and __put_user_asm() functions have 76 * %%sr2 hard-coded to access the requested memory. 77 */ 78 #define load_sr2() \ 79 __asm__(" or,= %0,%%r0,%%r0\n\t" \ 80 " mfsp %%sr3,%0\n\t" \ 81 " mtsp %0,%%sr2\n\t" \ 82 : : "r"(get_fs()) : ) 83 84 #define __get_user_internal(val, ptr) \ 85 ({ \ 86 register long __gu_err __asm__ ("r8") = 0; \ 87 \ 88 switch (sizeof(*(ptr))) { \ 89 case 1: __get_user_asm(val, "ldb", ptr); break; \ 90 case 2: __get_user_asm(val, "ldh", ptr); break; \ 91 case 4: __get_user_asm(val, "ldw", ptr); break; \ 92 case 8: LDD_USER(val, ptr); break; \ 93 default: BUILD_BUG(); \ 94 } \ 95 \ 96 __gu_err; \ 97 }) 98 99 #define __get_user(val, ptr) \ 100 ({ \ 101 load_sr2(); \ 102 __get_user_internal(val, ptr); \ 103 }) 104 105 #define __get_user_asm(val, ldx, ptr) \ 106 { \ 107 register long __gu_val; \ 108 \ 109 __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \ 110 "9:\n" \ 111 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 112 : "=r"(__gu_val), "=r"(__gu_err) \ 113 : "r"(ptr), "1"(__gu_err)); \ 114 \ 115 (val) = (__force __typeof__(*(ptr))) __gu_val; \ 116 } 117 118 #if !defined(CONFIG_64BIT) 119 120 #define __get_user_asm64(val, ptr) \ 121 { \ 122 union { \ 123 unsigned long long l; \ 124 __typeof__(*(ptr)) t; \ 125 } __gu_tmp; \ 126 \ 127 __asm__(" copy %%r0,%R0\n" \ 128 "1: ldw 0(%%sr2,%2),%0\n" \ 129 "2: ldw 4(%%sr2,%2),%R0\n" \ 130 "9:\n" \ 131 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 132 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 133 : "=&r"(__gu_tmp.l), "=r"(__gu_err) \ 134 : "r"(ptr), "1"(__gu_err)); \ 135 \ 136 (val) = __gu_tmp.t; \ 137 } 138 139 #endif /* !defined(CONFIG_64BIT) */ 140 141 142 #define __put_user_internal(x, ptr) \ 143 ({ \ 144 register long __pu_err __asm__ ("r8") = 0; \ 145 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 146 \ 147 switch (sizeof(*(ptr))) { \ 148 case 1: __put_user_asm("stb", __x, ptr); break; \ 149 case 2: __put_user_asm("sth", __x, ptr); break; \ 150 case 4: __put_user_asm("stw", __x, ptr); break; \ 151 case 8: STD_USER(__x, ptr); break; \ 152 default: BUILD_BUG(); \ 153 } \ 154 \ 155 __pu_err; \ 156 }) 157 158 #define __put_user(x, ptr) \ 159 ({ \ 160 load_sr2(); \ 161 __put_user_internal(x, ptr); \ 162 }) 163 164 165 /* 166 * The "__put_user/kernel_asm()" macros tell gcc they read from memory 167 * instead of writing. This is because they do not write to any memory 168 * gcc knows about, so there are no aliasing issues. These macros must 169 * also be aware that fixups are executed in the context of the fault, 170 * and any registers used there must be listed as clobbers. 171 * r8 is already listed as err. 172 */ 173 174 #define __put_user_asm(stx, x, ptr) \ 175 __asm__ __volatile__ ( \ 176 "1: " stx " %2,0(%%sr2,%1)\n" \ 177 "9:\n" \ 178 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 179 : "=r"(__pu_err) \ 180 : "r"(ptr), "r"(x), "0"(__pu_err)) 181 182 183 #if !defined(CONFIG_64BIT) 184 185 #define __put_user_asm64(__val, ptr) do { \ 186 __asm__ __volatile__ ( \ 187 "1: stw %2,0(%%sr2,%1)\n" \ 188 "2: stw %R2,4(%%sr2,%1)\n" \ 189 "9:\n" \ 190 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 191 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 192 : "=r"(__pu_err) \ 193 : "r"(ptr), "r"(__val), "0"(__pu_err)); \ 194 } while (0) 195 196 #endif /* !defined(CONFIG_64BIT) */ 197 198 199 /* 200 * Complex access routines -- external declarations 201 */ 202 203 extern long strncpy_from_user(char *, const char __user *, long); 204 extern unsigned lclear_user(void __user *, unsigned long); 205 extern long lstrnlen_user(const char __user *, long); 206 /* 207 * Complex access routines -- macros 208 */ 209 #define user_addr_max() (~0UL) 210 211 #define strnlen_user lstrnlen_user 212 #define clear_user lclear_user 213 #define __clear_user lclear_user 214 215 unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src, 216 unsigned long len); 217 unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src, 218 unsigned long len); 219 unsigned long __must_check raw_copy_in_user(void __user *dst, const void __user *src, 220 unsigned long len); 221 #define INLINE_COPY_TO_USER 222 #define INLINE_COPY_FROM_USER 223 224 struct pt_regs; 225 int fixup_exception(struct pt_regs *regs); 226 227 #endif /* __PARISC_UACCESS_H */ 228