1 /* 2 * Bit operations for the Hexagon architecture 3 * 4 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. 5 * 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 and 9 * only version 2 as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 * 02110-1301, USA. 20 */ 21 22 #ifndef _ASM_BITOPS_H 23 #define _ASM_BITOPS_H 24 25 #include <linux/compiler.h> 26 #include <asm/byteorder.h> 27 #include <asm/atomic.h> 28 29 #ifdef __KERNEL__ 30 31 #define smp_mb__before_clear_bit() barrier() 32 #define smp_mb__after_clear_bit() barrier() 33 34 /* 35 * The offset calculations for these are based on BITS_PER_LONG == 32 36 * (i.e. I get to shift by #5-2 (32 bits per long, 4 bytes per access), 37 * mask by 0x0000001F) 38 * 39 * Typically, R10 is clobbered for address, R11 bit nr, and R12 is temp 40 */ 41 42 /** 43 * test_and_clear_bit - clear a bit and return its old value 44 * @nr: bit number to clear 45 * @addr: pointer to memory 46 */ 47 static inline int test_and_clear_bit(int nr, volatile void *addr) 48 { 49 int oldval; 50 51 __asm__ __volatile__ ( 52 " {R10 = %1; R11 = asr(%2,#5); }\n" 53 " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" 54 "1: R12 = memw_locked(R10);\n" 55 " { P0 = tstbit(R12,R11); R12 = clrbit(R12,R11); }\n" 56 " memw_locked(R10,P1) = R12;\n" 57 " {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n" 58 : "=&r" (oldval) 59 : "r" (addr), "r" (nr) 60 : "r10", "r11", "r12", "p0", "p1", "memory" 61 ); 62 63 return oldval; 64 } 65 66 /** 67 * test_and_set_bit - set a bit and return its old value 68 * @nr: bit number to set 69 * @addr: pointer to memory 70 */ 71 static inline int test_and_set_bit(int nr, volatile void *addr) 72 { 73 int oldval; 74 75 __asm__ __volatile__ ( 76 " {R10 = %1; R11 = asr(%2,#5); }\n" 77 " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" 78 "1: R12 = memw_locked(R10);\n" 79 " { P0 = tstbit(R12,R11); R12 = setbit(R12,R11); }\n" 80 " memw_locked(R10,P1) = R12;\n" 81 " {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n" 82 : "=&r" (oldval) 83 : "r" (addr), "r" (nr) 84 : "r10", "r11", "r12", "p0", "p1", "memory" 85 ); 86 87 88 return oldval; 89 90 } 91 92 /** 93 * test_and_change_bit - toggle a bit and return its old value 94 * @nr: bit number to set 95 * @addr: pointer to memory 96 */ 97 static inline int test_and_change_bit(int nr, volatile void *addr) 98 { 99 int oldval; 100 101 __asm__ __volatile__ ( 102 " {R10 = %1; R11 = asr(%2,#5); }\n" 103 " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" 104 "1: R12 = memw_locked(R10);\n" 105 " { P0 = tstbit(R12,R11); R12 = togglebit(R12,R11); }\n" 106 " memw_locked(R10,P1) = R12;\n" 107 " {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n" 108 : "=&r" (oldval) 109 : "r" (addr), "r" (nr) 110 : "r10", "r11", "r12", "p0", "p1", "memory" 111 ); 112 113 return oldval; 114 115 } 116 117 /* 118 * Atomic, but doesn't care about the return value. 119 * Rewrite later to save a cycle or two. 120 */ 121 122 static inline void clear_bit(int nr, volatile void *addr) 123 { 124 test_and_clear_bit(nr, addr); 125 } 126 127 static inline void set_bit(int nr, volatile void *addr) 128 { 129 test_and_set_bit(nr, addr); 130 } 131 132 static inline void change_bit(int nr, volatile void *addr) 133 { 134 test_and_change_bit(nr, addr); 135 } 136 137 138 /* 139 * These are allowed to be non-atomic. In fact the generic flavors are 140 * in non-atomic.h. Would it be better to use intrinsics for this? 141 * 142 * OK, writes in our architecture do not invalidate LL/SC, so this has to 143 * be atomic, particularly for things like slab_lock and slab_unlock. 144 * 145 */ 146 static inline void __clear_bit(int nr, volatile unsigned long *addr) 147 { 148 test_and_clear_bit(nr, addr); 149 } 150 151 static inline void __set_bit(int nr, volatile unsigned long *addr) 152 { 153 test_and_set_bit(nr, addr); 154 } 155 156 static inline void __change_bit(int nr, volatile unsigned long *addr) 157 { 158 test_and_change_bit(nr, addr); 159 } 160 161 /* Apparently, at least some of these are allowed to be non-atomic */ 162 static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) 163 { 164 return test_and_clear_bit(nr, addr); 165 } 166 167 static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) 168 { 169 return test_and_set_bit(nr, addr); 170 } 171 172 static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) 173 { 174 return test_and_change_bit(nr, addr); 175 } 176 177 static inline int __test_bit(int nr, const volatile unsigned long *addr) 178 { 179 int retval; 180 181 asm volatile( 182 "{P0 = tstbit(%1,%2); if (P0.new) %0 = #1; if (!P0.new) %0 = #0;}\n" 183 : "=&r" (retval) 184 : "r" (addr[BIT_WORD(nr)]), "r" (nr % BITS_PER_LONG) 185 : "p0" 186 ); 187 188 return retval; 189 } 190 191 #define test_bit(nr, addr) __test_bit(nr, addr) 192 193 /* 194 * ffz - find first zero in word. 195 * @word: The word to search 196 * 197 * Undefined if no zero exists, so code should check against ~0UL first. 198 */ 199 static inline long ffz(int x) 200 { 201 int r; 202 203 asm("%0 = ct1(%1);\n" 204 : "=&r" (r) 205 : "r" (x)); 206 return r; 207 } 208 209 /* 210 * fls - find last (most-significant) bit set 211 * @x: the word to search 212 * 213 * This is defined the same way as ffs. 214 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 215 */ 216 static inline long fls(int x) 217 { 218 int r; 219 220 asm("{ %0 = cl0(%1);}\n" 221 "%0 = sub(#32,%0);\n" 222 : "=&r" (r) 223 : "r" (x) 224 : "p0"); 225 226 return r; 227 } 228 229 /* 230 * ffs - find first bit set 231 * @x: the word to search 232 * 233 * This is defined the same way as 234 * the libc and compiler builtin ffs routines, therefore 235 * differs in spirit from the above ffz (man ffs). 236 */ 237 static inline long ffs(int x) 238 { 239 int r; 240 241 asm("{ P0 = cmp.eq(%1,#0); %0 = ct0(%1);}\n" 242 "{ if P0 %0 = #0; if !P0 %0 = add(%0,#1);}\n" 243 : "=&r" (r) 244 : "r" (x) 245 : "p0"); 246 247 return r; 248 } 249 250 /* 251 * __ffs - find first bit in word. 252 * @word: The word to search 253 * 254 * Undefined if no bit exists, so code should check against 0 first. 255 * 256 * bits_per_long assumed to be 32 257 * numbering starts at 0 I think (instead of 1 like ffs) 258 */ 259 static inline unsigned long __ffs(unsigned long word) 260 { 261 int num; 262 263 asm("%0 = ct0(%1);\n" 264 : "=&r" (num) 265 : "r" (word)); 266 267 return num; 268 } 269 270 /* 271 * __fls - find last (most-significant) set bit in a long word 272 * @word: the word to search 273 * 274 * Undefined if no set bit exists, so code should check against 0 first. 275 * bits_per_long assumed to be 32 276 */ 277 static inline unsigned long __fls(unsigned long word) 278 { 279 int num; 280 281 asm("%0 = cl0(%1);\n" 282 "%0 = sub(#31,%0);\n" 283 : "=&r" (num) 284 : "r" (word)); 285 286 return num; 287 } 288 289 #include <asm-generic/bitops/lock.h> 290 #include <asm-generic/bitops/find.h> 291 292 #include <asm-generic/bitops/fls64.h> 293 #include <asm-generic/bitops/sched.h> 294 #include <asm-generic/bitops/hweight.h> 295 296 #include <asm-generic/bitops/le.h> 297 #include <asm-generic/bitops/ext2-atomic.h> 298 299 #endif /* __KERNEL__ */ 300 #endif 301