mirror_ubuntu-kernels/arch/riscv/include/asm/cacheflush.h
Heiko Stuebner 1631ba1259
riscv: Add support for non-coherent devices using zicbom extension
The Zicbom ISA-extension was ratified in november 2021
and introduces instructions for dcache invalidate, clean
and flush operations.

Implement cache management operations for non-coherent devices
based on them.

Of course not all cores will support this, so implement an
alternative-based mechanism that replaces empty instructions
with ones done around Zicbom instructions.

As discussed in previous versions, assume the platform
being coherent by default so that non-coherent devices need
to get marked accordingly by firmware.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-28 15:30:51 -07:00

64 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2015 Regents of the University of California
*/
#ifndef _ASM_RISCV_CACHEFLUSH_H
#define _ASM_RISCV_CACHEFLUSH_H
#include <linux/mm.h>
static inline void local_flush_icache_all(void)
{
asm volatile ("fence.i" ::: "memory");
}
#define PG_dcache_clean PG_arch_1
static inline void flush_dcache_page(struct page *page)
{
if (test_bit(PG_dcache_clean, &page->flags))
clear_bit(PG_dcache_clean, &page->flags);
}
#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
/*
* RISC-V doesn't have an instruction to flush parts of the instruction cache,
* so instead we just flush the whole thing.
*/
#define flush_icache_range(start, end) flush_icache_all()
#define flush_icache_user_page(vma, pg, addr, len) \
flush_icache_mm(vma->vm_mm, 0)
#ifndef CONFIG_SMP
#define flush_icache_all() local_flush_icache_all()
#define flush_icache_mm(mm, local) flush_icache_all()
#else /* CONFIG_SMP */
void flush_icache_all(void);
void flush_icache_mm(struct mm_struct *mm, bool local);
#endif /* CONFIG_SMP */
#ifdef CONFIG_RISCV_ISA_ZICBOM
void riscv_init_cbom_blocksize(void);
#else
static inline void riscv_init_cbom_blocksize(void) { }
#endif
#ifdef CONFIG_RISCV_DMA_NONCOHERENT
void riscv_noncoherent_supported(void);
#endif
/*
* Bits in sys_riscv_flush_icache()'s flags argument.
*/
#define SYS_RISCV_FLUSH_ICACHE_LOCAL 1UL
#define SYS_RISCV_FLUSH_ICACHE_ALL (SYS_RISCV_FLUSH_ICACHE_LOCAL)
#include <asm-generic/cacheflush.h>
#endif /* _ASM_RISCV_CACHEFLUSH_H */