1 /* 2 * Standard user space access functions based on mvcp/mvcs and doing 3 * interesting things in the secondary space mode. 4 * 5 * Copyright IBM Corp. 2006,2014 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 7 * Gerald Schaefer (gerald.schaefer@de.ibm.com) 8 */ 9 10 #include <linux/jump_label.h> 11 #include <linux/uaccess.h> 12 #include <linux/export.h> 13 #include <linux/errno.h> 14 #include <linux/mm.h> 15 #include <asm/mmu_context.h> 16 #include <asm/facility.h> 17 18 #ifndef CONFIG_HAVE_MARCH_Z10_FEATURES 19 static DEFINE_STATIC_KEY_FALSE(have_mvcos); 20 21 static int __init uaccess_init(void) 22 { 23 if (test_facility(27)) 24 static_branch_enable(&have_mvcos); 25 return 0; 26 } 27 early_initcall(uaccess_init); 28 29 static inline int copy_with_mvcos(void) 30 { 31 if (static_branch_likely(&have_mvcos)) 32 return 1; 33 return 0; 34 } 35 #else 36 static inline int copy_with_mvcos(void) 37 { 38 return 1; 39 } 40 #endif 41 42 static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, 43 unsigned long size) 44 { 45 register unsigned long reg0 asm("0") = 0x81UL; 46 unsigned long tmp1, tmp2; 47 48 tmp1 = -4096UL; 49 asm volatile( 50 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n" 51 "6: jz 4f\n" 52 "1: algr %0,%3\n" 53 " slgr %1,%3\n" 54 " slgr %2,%3\n" 55 " j 0b\n" 56 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ 57 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ 58 " slgr %4,%1\n" 59 " clgr %0,%4\n" /* copy crosses next page boundary? */ 60 " jnh 5f\n" 61 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n" 62 "7: slgr %0,%4\n" 63 " j 5f\n" 64 "4: slgr %0,%0\n" 65 "5:\n" 66 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) 67 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 68 : "d" (reg0) : "cc", "memory"); 69 return size; 70 } 71 72 static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, 73 unsigned long size) 74 { 75 unsigned long tmp1, tmp2; 76 77 load_kernel_asce(); 78 tmp1 = -256UL; 79 asm volatile( 80 " sacf 0\n" 81 "0: mvcp 0(%0,%2),0(%1),%3\n" 82 "7: jz 5f\n" 83 "1: algr %0,%3\n" 84 " la %1,256(%1)\n" 85 " la %2,256(%2)\n" 86 "2: mvcp 0(%0,%2),0(%1),%3\n" 87 "8: jnz 1b\n" 88 " j 5f\n" 89 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 90 " lghi %3,-4096\n" 91 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 92 " slgr %4,%1\n" 93 " clgr %0,%4\n" /* copy crosses next page boundary? */ 94 " jnh 6f\n" 95 "4: mvcp 0(%4,%2),0(%1),%3\n" 96 "9: slgr %0,%4\n" 97 " j 6f\n" 98 "5: slgr %0,%0\n" 99 "6: sacf 768\n" 100 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) 101 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) 102 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 103 : : "cc", "memory"); 104 return size; 105 } 106 107 unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) 108 { 109 if (copy_with_mvcos()) 110 return copy_from_user_mvcos(to, from, n); 111 return copy_from_user_mvcp(to, from, n); 112 } 113 EXPORT_SYMBOL(raw_copy_from_user); 114 115 static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, 116 unsigned long size) 117 { 118 register unsigned long reg0 asm("0") = 0x810000UL; 119 unsigned long tmp1, tmp2; 120 121 tmp1 = -4096UL; 122 asm volatile( 123 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" 124 "6: jz 4f\n" 125 "1: algr %0,%3\n" 126 " slgr %1,%3\n" 127 " slgr %2,%3\n" 128 " j 0b\n" 129 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ 130 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ 131 " slgr %4,%1\n" 132 " clgr %0,%4\n" /* copy crosses next page boundary? */ 133 " jnh 5f\n" 134 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n" 135 "7: slgr %0,%4\n" 136 " j 5f\n" 137 "4: slgr %0,%0\n" 138 "5:\n" 139 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) 140 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 141 : "d" (reg0) : "cc", "memory"); 142 return size; 143 } 144 145 static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, 146 unsigned long size) 147 { 148 unsigned long tmp1, tmp2; 149 150 load_kernel_asce(); 151 tmp1 = -256UL; 152 asm volatile( 153 " sacf 0\n" 154 "0: mvcs 0(%0,%1),0(%2),%3\n" 155 "7: jz 5f\n" 156 "1: algr %0,%3\n" 157 " la %1,256(%1)\n" 158 " la %2,256(%2)\n" 159 "2: mvcs 0(%0,%1),0(%2),%3\n" 160 "8: jnz 1b\n" 161 " j 5f\n" 162 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 163 " lghi %3,-4096\n" 164 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 165 " slgr %4,%1\n" 166 " clgr %0,%4\n" /* copy crosses next page boundary? */ 167 " jnh 6f\n" 168 "4: mvcs 0(%4,%1),0(%2),%3\n" 169 "9: slgr %0,%4\n" 170 " j 6f\n" 171 "5: slgr %0,%0\n" 172 "6: sacf 768\n" 173 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) 174 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) 175 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 176 : : "cc", "memory"); 177 return size; 178 } 179 180 unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) 181 { 182 if (copy_with_mvcos()) 183 return copy_to_user_mvcos(to, from, n); 184 return copy_to_user_mvcs(to, from, n); 185 } 186 EXPORT_SYMBOL(raw_copy_to_user); 187 188 static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from, 189 unsigned long size) 190 { 191 register unsigned long reg0 asm("0") = 0x810081UL; 192 unsigned long tmp1, tmp2; 193 194 tmp1 = -4096UL; 195 /* FIXME: copy with reduced length. */ 196 asm volatile( 197 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" 198 " jz 2f\n" 199 "1: algr %0,%3\n" 200 " slgr %1,%3\n" 201 " slgr %2,%3\n" 202 " j 0b\n" 203 "2:slgr %0,%0\n" 204 "3: \n" 205 EX_TABLE(0b,3b) 206 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2) 207 : "d" (reg0) : "cc", "memory"); 208 return size; 209 } 210 211 static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from, 212 unsigned long size) 213 { 214 unsigned long tmp1; 215 216 load_kernel_asce(); 217 asm volatile( 218 " sacf 256\n" 219 " aghi %0,-1\n" 220 " jo 5f\n" 221 " bras %3,3f\n" 222 "0: aghi %0,257\n" 223 "1: mvc 0(1,%1),0(%2)\n" 224 " la %1,1(%1)\n" 225 " la %2,1(%2)\n" 226 " aghi %0,-1\n" 227 " jnz 1b\n" 228 " j 5f\n" 229 "2: mvc 0(256,%1),0(%2)\n" 230 " la %1,256(%1)\n" 231 " la %2,256(%2)\n" 232 "3: aghi %0,-256\n" 233 " jnm 2b\n" 234 "4: ex %0,1b-0b(%3)\n" 235 "5: slgr %0,%0\n" 236 "6: sacf 768\n" 237 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 238 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) 239 : : "cc", "memory"); 240 return size; 241 } 242 243 unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 244 { 245 if (copy_with_mvcos()) 246 return copy_in_user_mvcos(to, from, n); 247 return copy_in_user_mvc(to, from, n); 248 } 249 EXPORT_SYMBOL(raw_copy_in_user); 250 251 static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) 252 { 253 register unsigned long reg0 asm("0") = 0x810000UL; 254 unsigned long tmp1, tmp2; 255 256 tmp1 = -4096UL; 257 asm volatile( 258 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n" 259 " jz 4f\n" 260 "1: algr %0,%2\n" 261 " slgr %1,%2\n" 262 " j 0b\n" 263 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */ 264 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */ 265 " slgr %3,%1\n" 266 " clgr %0,%3\n" /* copy crosses next page boundary? */ 267 " jnh 5f\n" 268 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n" 269 " slgr %0,%3\n" 270 " j 5f\n" 271 "4: slgr %0,%0\n" 272 "5:\n" 273 EX_TABLE(0b,2b) EX_TABLE(3b,5b) 274 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) 275 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory"); 276 return size; 277 } 278 279 static inline unsigned long clear_user_xc(void __user *to, unsigned long size) 280 { 281 unsigned long tmp1, tmp2; 282 283 load_kernel_asce(); 284 asm volatile( 285 " sacf 256\n" 286 " aghi %0,-1\n" 287 " jo 5f\n" 288 " bras %3,3f\n" 289 " xc 0(1,%1),0(%1)\n" 290 "0: aghi %0,257\n" 291 " la %2,255(%1)\n" /* %2 = ptr + 255 */ 292 " srl %2,12\n" 293 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */ 294 " slgr %2,%1\n" 295 " clgr %0,%2\n" /* clear crosses next page boundary? */ 296 " jnh 5f\n" 297 " aghi %2,-1\n" 298 "1: ex %2,0(%3)\n" 299 " aghi %2,1\n" 300 " slgr %0,%2\n" 301 " j 5f\n" 302 "2: xc 0(256,%1),0(%1)\n" 303 " la %1,256(%1)\n" 304 "3: aghi %0,-256\n" 305 " jnm 2b\n" 306 "4: ex %0,0(%3)\n" 307 "5: slgr %0,%0\n" 308 "6: sacf 768\n" 309 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 310 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) 311 : : "cc", "memory"); 312 return size; 313 } 314 315 unsigned long __clear_user(void __user *to, unsigned long size) 316 { 317 if (copy_with_mvcos()) 318 return clear_user_mvcos(to, size); 319 return clear_user_xc(to, size); 320 } 321 EXPORT_SYMBOL(__clear_user); 322 323 static inline unsigned long strnlen_user_srst(const char __user *src, 324 unsigned long size) 325 { 326 register unsigned long reg0 asm("0") = 0; 327 unsigned long tmp1, tmp2; 328 329 asm volatile( 330 " la %2,0(%1)\n" 331 " la %3,0(%0,%1)\n" 332 " slgr %0,%0\n" 333 " sacf 256\n" 334 "0: srst %3,%2\n" 335 " jo 0b\n" 336 " la %0,1(%3)\n" /* strnlen_user results includes \0 */ 337 " slgr %0,%1\n" 338 "1: sacf 768\n" 339 EX_TABLE(0b,1b) 340 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) 341 : "d" (reg0) : "cc", "memory"); 342 return size; 343 } 344 345 unsigned long __strnlen_user(const char __user *src, unsigned long size) 346 { 347 if (unlikely(!size)) 348 return 0; 349 load_kernel_asce(); 350 return strnlen_user_srst(src, size); 351 } 352 EXPORT_SYMBOL(__strnlen_user); 353 354 long __strncpy_from_user(char *dst, const char __user *src, long size) 355 { 356 size_t done, len, offset, len_str; 357 358 if (unlikely(size <= 0)) 359 return 0; 360 done = 0; 361 do { 362 offset = (size_t)src & (L1_CACHE_BYTES - 1); 363 len = min(size - done, L1_CACHE_BYTES - offset); 364 if (copy_from_user(dst, src, len)) 365 return -EFAULT; 366 len_str = strnlen(dst, len); 367 done += len_str; 368 src += len_str; 369 dst += len_str; 370 } while ((len_str == len) && (done < size)); 371 return done; 372 } 373 EXPORT_SYMBOL(__strncpy_from_user); 374