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| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
|---|---|
| 2 | #ifndef _ASM_WORD_AT_A_TIME_H |
| 3 | #define _ASM_WORD_AT_A_TIME_H |
| 4 | |
| 5 | #include <linux/bitops.h> |
| 6 | #include <linux/wordpart.h> |
| 7 | #include <asm/asm-extable.h> |
| 8 | #include <asm/bitsperlong.h> |
| 9 | |
| 10 | struct word_at_a_time { |
| 11 | const unsigned long bits; |
| 12 | }; |
| 13 | |
| 14 | #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x7f) } |
| 15 | |
| 16 | static inline unsigned long prep_zero_mask(unsigned long val, unsigned long data, const struct word_at_a_time *c) |
| 17 | { |
| 18 | return data; |
| 19 | } |
| 20 | |
| 21 | static inline unsigned long create_zero_mask(unsigned long data) |
| 22 | { |
| 23 | return __fls(data); |
| 24 | } |
| 25 | |
| 26 | static inline unsigned long find_zero(unsigned long data) |
| 27 | { |
| 28 | return (data ^ (BITS_PER_LONG - 1)) >> 3; |
| 29 | } |
| 30 | |
| 31 | static inline unsigned long has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c) |
| 32 | { |
| 33 | unsigned long mask = (val & c->bits) + c->bits; |
| 34 | |
| 35 | *data = ~(mask | val | c->bits); |
| 36 | return *data; |
| 37 | } |
| 38 | |
| 39 | static inline unsigned long zero_bytemask(unsigned long data) |
| 40 | { |
| 41 | return ~1UL << data; |
| 42 | } |
| 43 | |
| 44 | /* |
| 45 | * Load an unaligned word from kernel space. |
| 46 | * |
| 47 | * In the (very unlikely) case of the word being a page-crosser |
| 48 | * and the next page not being mapped, take the exception and |
| 49 | * return zeroes in the non-existing part. |
| 50 | */ |
| 51 | static inline unsigned long load_unaligned_zeropad(const void *addr) |
| 52 | { |
| 53 | unsigned long data; |
| 54 | |
| 55 | asm_inline volatile( |
| 56 | "0: lg %[data],0(%[addr])\n" |
| 57 | "1: nopr %%r7\n" |
| 58 | EX_TABLE_ZEROPAD(0b, 1b, %[data], %[addr]) |
| 59 | EX_TABLE_ZEROPAD(1b, 1b, %[data], %[addr]) |
| 60 | : [data] "=d" (data) |
| 61 | : [addr] "a" (addr), "m" (*(unsigned long *)addr)); |
| 62 | return data; |
| 63 | } |
| 64 | |
| 65 | #endif /* _ASM_WORD_AT_A_TIME_H */ |
| 66 |
Warning: This file is not a C or C++ file. It does not have highlighting.