1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef __LINUX_CACHE_H 3#define __LINUX_CACHE_H 4 5#include <uapi/linux/kernel.h> 6#include <asm/cache.h> 7 8#ifndef L1_CACHE_ALIGN 9#define L1_CACHE_ALIGN(x) __ALIGN_KERNEL(x, L1_CACHE_BYTES) 10#endif 11 12#ifndef SMP_CACHE_BYTES 13#define SMP_CACHE_BYTES L1_CACHE_BYTES 14#endif 15 16/* 17 * __read_mostly is used to keep rarely changing variables out of frequently 18 * updated cachelines. If an architecture doesn't support it, ignore the 19 * hint. 20 */ 21#ifndef __read_mostly 22#define __read_mostly 23#endif 24 25/* 26 * __ro_after_init is used to mark things that are read-only after init (i.e. 27 * after mark_rodata_ro() has been called). These are effectively read-only, 28 * but may get written to during init, so can't live in .rodata (via "const"). 29 */ 30#ifndef __ro_after_init 31#define __ro_after_init __attribute__((__section__(".data..ro_after_init"))) 32#endif 33 34#ifndef ____cacheline_aligned 35#define ____cacheline_aligned __attribute__((__aligned__(SMP_CACHE_BYTES))) 36#endif 37 38#ifndef ____cacheline_aligned_in_smp 39#ifdef CONFIG_SMP 40#define ____cacheline_aligned_in_smp ____cacheline_aligned 41#else 42#define ____cacheline_aligned_in_smp 43#endif /* CONFIG_SMP */ 44#endif 45 46#ifndef __cacheline_aligned 47#define __cacheline_aligned \ 48 __attribute__((__aligned__(SMP_CACHE_BYTES), \ 49 __section__(".data..cacheline_aligned"))) 50#endif /* __cacheline_aligned */ 51 52#ifndef __cacheline_aligned_in_smp 53#ifdef CONFIG_SMP 54#define __cacheline_aligned_in_smp __cacheline_aligned 55#else 56#define __cacheline_aligned_in_smp 57#endif /* CONFIG_SMP */ 58#endif 59 60/* 61 * The maximum alignment needed for some critical structures 62 * These could be inter-node cacheline sizes/L3 cacheline 63 * size etc. Define this in asm/cache.h for your arch 64 */ 65#ifndef INTERNODE_CACHE_SHIFT 66#define INTERNODE_CACHE_SHIFT L1_CACHE_SHIFT 67#endif 68 69#if !defined(____cacheline_internodealigned_in_smp) 70#if defined(CONFIG_SMP) 71#define ____cacheline_internodealigned_in_smp \ 72 __attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT)))) 73#else 74#define ____cacheline_internodealigned_in_smp 75#endif 76#endif 77 78#ifndef CONFIG_ARCH_HAS_CACHE_LINE_SIZE 79#define cache_line_size() L1_CACHE_BYTES 80#endif 81 82#endif /* __LINUX_CACHE_H */ 83