1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Bit operations for the Hexagon architecture 4 * 5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. 6 */ 7 8 #ifndef _ASM_BITOPS_H 9 #define _ASM_BITOPS_H 10 11 #include <linux/compiler.h> 12 #include <asm/byteorder.h> 13 #include <asm/atomic.h> 14 #include <asm/barrier.h> 15 16 #ifdef __KERNEL__ 17 18 /* 19 * The offset calculations for these are based on BITS_PER_LONG == 32 20 * (i.e. I get to shift by #5-2 (32 bits per long, 4 bytes per access), 21 * mask by 0x0000001F) 22 * 23 * Typically, R10 is clobbered for address, R11 bit nr, and R12 is temp 24 */ 25 26 /** 27 * test_and_clear_bit - clear a bit and return its old value 28 * @nr: bit number to clear 29 * @addr: pointer to memory 30 */ 31 static inline int test_and_clear_bit(int nr, volatile void *addr) 32 { 33 int oldval; 34 35 __asm__ __volatile__ ( 36 " {R10 = %1; R11 = asr(%2,#5); }\n" 37 " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" 38 "1: R12 = memw_locked(R10);\n" 39 " { P0 = tstbit(R12,R11); R12 = clrbit(R12,R11); }\n" 40 " memw_locked(R10,P1) = R12;\n" 41 " {if (!P1) jump 1b; %0 = mux(P0,#1,#0);}\n" 42 : "=&r" (oldval) 43 : "r" (addr), "r" (nr) 44 : "r10", "r11", "r12", "p0", "p1", "memory" 45 ); 46 47 return oldval; 48 } 49 50 /** 51 * test_and_set_bit - set a bit and return its old value 52 * @nr: bit number to set 53 * @addr: pointer to memory 54 */ 55 static inline int test_and_set_bit(int nr, volatile void *addr) 56 { 57 int oldval; 58 59 __asm__ __volatile__ ( 60 " {R10 = %1; R11 = asr(%2,#5); }\n" 61 " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" 62 "1: R12 = memw_locked(R10);\n" 63 " { P0 = tstbit(R12,R11); R12 = setbit(R12,R11); }\n" 64 " memw_locked(R10,P1) = R12;\n" 65 " {if (!P1) jump 1b; %0 = mux(P0,#1,#0);}\n" 66 : "=&r" (oldval) 67 : "r" (addr), "r" (nr) 68 : "r10", "r11", "r12", "p0", "p1", "memory" 69 ); 70 71 72 return oldval; 73 74 } 75 76 /** 77 * test_and_change_bit - toggle a bit and return its old value 78 * @nr: bit number to set 79 * @addr: pointer to memory 80 */ 81 static inline int test_and_change_bit(int nr, volatile void *addr) 82 { 83 int oldval; 84 85 __asm__ __volatile__ ( 86 " {R10 = %1; R11 = asr(%2,#5); }\n" 87 " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" 88 "1: R12 = memw_locked(R10);\n" 89 " { P0 = tstbit(R12,R11); R12 = togglebit(R12,R11); }\n" 90 " memw_locked(R10,P1) = R12;\n" 91 " {if (!P1) jump 1b; %0 = mux(P0,#1,#0);}\n" 92 : "=&r" (oldval) 93 : "r" (addr), "r" (nr) 94 : "r10", "r11", "r12", "p0", "p1", "memory" 95 ); 96 97 return oldval; 98 99 } 100 101 /* 102 * Atomic, but doesn't care about the return value. 103 * Rewrite later to save a cycle or two. 104 */ 105 106 static inline void clear_bit(int nr, volatile void *addr) 107 { 108 test_and_clear_bit(nr, addr); 109 } 110 111 static inline void set_bit(int nr, volatile void *addr) 112 { 113 test_and_set_bit(nr, addr); 114 } 115 116 static inline void change_bit(int nr, volatile void *addr) 117 { 118 test_and_change_bit(nr, addr); 119 } 120 121 122 /* 123 * These are allowed to be non-atomic. In fact the generic flavors are 124 * in non-atomic.h. Would it be better to use intrinsics for this? 125 * 126 * OK, writes in our architecture do not invalidate LL/SC, so this has to 127 * be atomic, particularly for things like slab_lock and slab_unlock. 128 * 129 */ 130 static inline void __clear_bit(int nr, volatile unsigned long *addr) 131 { 132 test_and_clear_bit(nr, addr); 133 } 134 135 static inline void __set_bit(int nr, volatile unsigned long *addr) 136 { 137 test_and_set_bit(nr, addr); 138 } 139 140 static inline void __change_bit(int nr, volatile unsigned long *addr) 141 { 142 test_and_change_bit(nr, addr); 143 } 144 145 /* Apparently, at least some of these are allowed to be non-atomic */ 146 static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) 147 { 148 return test_and_clear_bit(nr, addr); 149 } 150 151 static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) 152 { 153 return test_and_set_bit(nr, addr); 154 } 155 156 static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) 157 { 158 return test_and_change_bit(nr, addr); 159 } 160 161 static inline int __test_bit(int nr, const volatile unsigned long *addr) 162 { 163 int retval; 164 165 asm volatile( 166 "{P0 = tstbit(%1,%2); if (P0.new) %0 = #1; if (!P0.new) %0 = #0;}\n" 167 : "=&r" (retval) 168 : "r" (addr[BIT_WORD(nr)]), "r" (nr % BITS_PER_LONG) 169 : "p0" 170 ); 171 172 return retval; 173 } 174 175 #define test_bit(nr, addr) __test_bit(nr, addr) 176 177 /* 178 * ffz - find first zero in word. 179 * @word: The word to search 180 * 181 * Undefined if no zero exists, so code should check against ~0UL first. 182 */ 183 static inline long ffz(int x) 184 { 185 int r; 186 187 asm("%0 = ct1(%1);\n" 188 : "=&r" (r) 189 : "r" (x)); 190 return r; 191 } 192 193 /* 194 * fls - find last (most-significant) bit set 195 * @x: the word to search 196 * 197 * This is defined the same way as ffs. 198 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 199 */ 200 static inline int fls(unsigned int x) 201 { 202 int r; 203 204 asm("{ %0 = cl0(%1);}\n" 205 "%0 = sub(#32,%0);\n" 206 : "=&r" (r) 207 : "r" (x) 208 : "p0"); 209 210 return r; 211 } 212 213 /* 214 * ffs - find first bit set 215 * @x: the word to search 216 * 217 * This is defined the same way as 218 * the libc and compiler builtin ffs routines, therefore 219 * differs in spirit from the above ffz (man ffs). 220 */ 221 static inline int ffs(int x) 222 { 223 int r; 224 225 asm("{ P0 = cmp.eq(%1,#0); %0 = ct0(%1);}\n" 226 "{ if (P0) %0 = #0; if (!P0) %0 = add(%0,#1);}\n" 227 : "=&r" (r) 228 : "r" (x) 229 : "p0"); 230 231 return r; 232 } 233 234 /* 235 * __ffs - find first bit in word. 236 * @word: The word to search 237 * 238 * Undefined if no bit exists, so code should check against 0 first. 239 * 240 * bits_per_long assumed to be 32 241 * numbering starts at 0 I think (instead of 1 like ffs) 242 */ 243 static inline unsigned long __ffs(unsigned long word) 244 { 245 int num; 246 247 asm("%0 = ct0(%1);\n" 248 : "=&r" (num) 249 : "r" (word)); 250 251 return num; 252 } 253 254 /* 255 * __fls - find last (most-significant) set bit in a long word 256 * @word: the word to search 257 * 258 * Undefined if no set bit exists, so code should check against 0 first. 259 * bits_per_long assumed to be 32 260 */ 261 static inline unsigned long __fls(unsigned long word) 262 { 263 int num; 264 265 asm("%0 = cl0(%1);\n" 266 "%0 = sub(#31,%0);\n" 267 : "=&r" (num) 268 : "r" (word)); 269 270 return num; 271 } 272 273 #include <asm-generic/bitops/lock.h> 274 275 #include <asm-generic/bitops/fls64.h> 276 #include <asm-generic/bitops/sched.h> 277 #include <asm-generic/bitops/hweight.h> 278 279 #include <asm-generic/bitops/le.h> 280 #include <asm-generic/bitops/ext2-atomic.h> 281 282 #endif /* __KERNEL__ */ 283 #endif 284