/* * Bit operations for the Hexagon architecture * * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. */ #ifndef _ASM_BITOPS_H #define _ASM_BITOPS_H #include #include #include #include #ifdef __KERNEL__ /* * The offset calculations for these are based on BITS_PER_LONG == 32 * (i.e. I get to shift by #5-2 (32 bits per long, 4 bytes per access), * mask by 0x0000001F) * * Typically, R10 is clobbered for address, R11 bit nr, and R12 is temp */ /** * test_and_clear_bit - clear a bit and return its old value * @nr: bit number to clear * @addr: pointer to memory */ static inline int test_and_clear_bit(int nr, volatile void *addr) { int oldval; __asm__ __volatile__ ( " {R10 = %1; R11 = asr(%2,#5); }\n" " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" "1: R12 = memw_locked(R10);\n" " { P0 = tstbit(R12,R11); R12 = clrbit(R12,R11); }\n" " memw_locked(R10,P1) = R12;\n" " {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n" : "=&r" (oldval) : "r" (addr), "r" (nr) : "r10", "r11", "r12", "p0", "p1", "memory" ); return oldval; } /** * test_and_set_bit - set a bit and return its old value * @nr: bit number to set * @addr: pointer to memory */ static inline int test_and_set_bit(int nr, volatile void *addr) { int oldval; __asm__ __volatile__ ( " {R10 = %1; R11 = asr(%2,#5); }\n" " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" "1: R12 = memw_locked(R10);\n" " { P0 = tstbit(R12,R11); R12 = setbit(R12,R11); }\n" " memw_locked(R10,P1) = R12;\n" " {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n" : "=&r" (oldval) : "r" (addr), "r" (nr) : "r10", "r11", "r12", "p0", "p1", "memory" ); return oldval; } /** * test_and_change_bit - toggle a bit and return its old value * @nr: bit number to set * @addr: pointer to memory */ static inline int test_and_change_bit(int nr, volatile void *addr) { int oldval; __asm__ __volatile__ ( " {R10 = %1; R11 = asr(%2,#5); }\n" " {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n" "1: R12 = memw_locked(R10);\n" " { P0 = tstbit(R12,R11); R12 = togglebit(R12,R11); }\n" " memw_locked(R10,P1) = R12;\n" " {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n" : "=&r" (oldval) : "r" (addr), "r" (nr) : "r10", "r11", "r12", "p0", "p1", "memory" ); return oldval; } /* * Atomic, but doesn't care about the return value. * Rewrite later to save a cycle or two. */ static inline void clear_bit(int nr, volatile void *addr) { test_and_clear_bit(nr, addr); } static inline void set_bit(int nr, volatile void *addr) { test_and_set_bit(nr, addr); } static inline void change_bit(int nr, volatile void *addr) { test_and_change_bit(nr, addr); } /* * These are allowed to be non-atomic. In fact the generic flavors are * in non-atomic.h. Would it be better to use intrinsics for this? * * OK, writes in our architecture do not invalidate LL/SC, so this has to * be atomic, particularly for things like slab_lock and slab_unlock. * */ static inline void __clear_bit(int nr, volatile unsigned long *addr) { test_and_clear_bit(nr, addr); } static inline void __set_bit(int nr, volatile unsigned long *addr) { test_and_set_bit(nr, addr); } static inline void __change_bit(int nr, volatile unsigned long *addr) { test_and_change_bit(nr, addr); } /* Apparently, at least some of these are allowed to be non-atomic */ static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) { return test_and_clear_bit(nr, addr); } static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) { return test_and_set_bit(nr, addr); } static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) { return test_and_change_bit(nr, addr); } static inline int __test_bit(int nr, const volatile unsigned long *addr) { int retval; asm volatile( "{P0 = tstbit(%1,%2); if (P0.new) %0 = #1; if (!P0.new) %0 = #0;}\n" : "=&r" (retval) : "r" (addr[BIT_WORD(nr)]), "r" (nr % BITS_PER_LONG) : "p0" ); return retval; } #define test_bit(nr, addr) __test_bit(nr, addr) /* * ffz - find first zero in word. * @word: The word to search * * Undefined if no zero exists, so code should check against ~0UL first. */ static inline long ffz(int x) { int r; asm("%0 = ct1(%1);\n" : "=&r" (r) : "r" (x)); return r; } /* * fls - find last (most-significant) bit set * @x: the word to search * * This is defined the same way as ffs. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. */ static inline long fls(int x) { int r; asm("{ %0 = cl0(%1);}\n" "%0 = sub(#32,%0);\n" : "=&r" (r) : "r" (x) : "p0"); return r; } /* * ffs - find first bit set * @x: the word to search * * This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */ static inline long ffs(int x) { int r; asm("{ P0 = cmp.eq(%1,#0); %0 = ct0(%1);}\n" "{ if P0 %0 = #0; if !P0 %0 = add(%0,#1);}\n" : "=&r" (r) : "r" (x) : "p0"); return r; } /* * __ffs - find first bit in word. * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. * * bits_per_long assumed to be 32 * numbering starts at 0 I think (instead of 1 like ffs) */ static inline unsigned long __ffs(unsigned long word) { int num; asm("%0 = ct0(%1);\n" : "=&r" (num) : "r" (word)); return num; } /* * __fls - find last (most-significant) set bit in a long word * @word: the word to search * * Undefined if no set bit exists, so code should check against 0 first. * bits_per_long assumed to be 32 */ static inline unsigned long __fls(unsigned long word) { int num; asm("%0 = cl0(%1);\n" "%0 = sub(#31,%0);\n" : "=&r" (num) : "r" (word)); return num; } #include #include #include #include #include #include #include #endif /* __KERNEL__ */ #endif