2cc029a084
The TCO related routines are used in uaccess methods and load_unaligned_zeropad() but are unrelated to both even if the naming suggest otherwise. Improve the readability of the code moving the away from uaccess.h and pre-pending them with "mte". [andreyknvl@google.com: drop __ from mte_disable/enable_tco names] Link: https://lkml.kernel.org/r/74d26337b2360733956114069e96ff11c296a944.1680114854.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/a48e7adce1248c0f9603a457776d59daa0ef734b.1678491668.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Weizhao Ouyang <ouyangweizhao@zeku.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
74 lines
1.5 KiB
C
74 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2013 ARM Ltd.
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*/
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#ifndef __ASM_WORD_AT_A_TIME_H
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#define __ASM_WORD_AT_A_TIME_H
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#include <linux/uaccess.h>
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#ifndef __AARCH64EB__
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#include <linux/kernel.h>
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struct word_at_a_time {
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const unsigned long one_bits, high_bits;
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};
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#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
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static inline unsigned long has_zero(unsigned long a, unsigned long *bits,
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const struct word_at_a_time *c)
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{
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unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
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*bits = mask;
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return mask;
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}
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#define prep_zero_mask(a, bits, c) (bits)
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static inline unsigned long create_zero_mask(unsigned long bits)
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{
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bits = (bits - 1) & ~bits;
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return bits >> 7;
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}
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static inline unsigned long find_zero(unsigned long mask)
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{
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return fls64(mask) >> 3;
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}
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#define zero_bytemask(mask) (mask)
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#else /* __AARCH64EB__ */
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#include <asm-generic/word-at-a-time.h>
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#endif
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/*
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* Load an unaligned word from kernel space.
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*
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* In the (very unlikely) case of the word being a page-crosser
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* and the next page not being mapped, take the exception and
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* return zeroes in the non-existing part.
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*/
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static inline unsigned long load_unaligned_zeropad(const void *addr)
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{
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unsigned long ret;
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__mte_enable_tco_async();
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/* Load word from unaligned pointer addr */
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asm(
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"1: ldr %0, %2\n"
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"2:\n"
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_ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(1b, 2b, %0, %1)
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: "=&r" (ret)
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: "r" (addr), "Q" (*(unsigned long *)addr));
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__mte_disable_tco_async();
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return ret;
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}
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#endif /* __ASM_WORD_AT_A_TIME_H */
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