/* * Copyright (C) 2013 ARM Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License 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, see . */ #ifndef __ASM_WORD_AT_A_TIME_H #define __ASM_WORD_AT_A_TIME_H #include #ifndef __AARCH64EB__ #include struct word_at_a_time { const unsigned long one_bits, high_bits; }; #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) } static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c) { unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits; *bits = mask; return mask; } #define prep_zero_mask(a, bits, c) (bits) static inline unsigned long create_zero_mask(unsigned long bits) { bits = (bits - 1) & ~bits; return bits >> 7; } static inline unsigned long find_zero(unsigned long mask) { return fls64(mask) >> 3; } #define zero_bytemask(mask) (mask) #else /* __AARCH64EB__ */ #include #endif /* * Load an unaligned word from kernel space. * * In the (very unlikely) case of the word being a page-crosser * and the next page not being mapped, take the exception and * return zeroes in the non-existing part. */ static inline unsigned long load_unaligned_zeropad(const void *addr) { unsigned long ret, tmp; /* Load word from unaligned pointer addr */ asm( "1: ldr %0, %3\n" "2:\n" " .pushsection .fixup,\"ax\"\n" " .align 2\n" "3: bic %1, %2, #0x7\n" " ldr %0, [%1]\n" " and %1, %2, #0x7\n" " lsl %1, %1, #0x3\n" #ifndef __AARCH64EB__ " lsr %0, %0, %1\n" #else " lsl %0, %0, %1\n" #endif " b 2b\n" " .popsection\n" _ASM_EXTABLE(1b, 3b) : "=&r" (ret), "=&r" (tmp) : "r" (addr), "Q" (*(unsigned long *)addr)); return ret; } #endif /* __ASM_WORD_AT_A_TIME_H */