linux/arch/riscv/include/asm/cacheflush.h
Alexandre Ghiti 7a92fc8b4d mm: Introduce flush_cache_vmap_early()
The pcpu setup when using the page allocator sets up a new vmalloc
mapping very early in the boot process, so early that it cannot use the
flush_cache_vmap() function which may depend on structures not yet
initialized (for example in riscv, we currently send an IPI to flush
other cpus TLB).

But on some architectures, we must call flush_cache_vmap(): for example,
in riscv, some uarchs can cache invalid TLB entries so we need to flush
the new established mapping to avoid taking an exception.

So fix this by introducing a new function flush_cache_vmap_early() which
is called right after setting the new page table entry and before
accessing this new mapping. This new function implements a local flush
tlb on riscv and is no-op for other architectures (same as today).

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
2023-12-14 00:23:17 -08:00

77 lines
2.0 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_folio(struct folio *folio)
{
if (test_bit(PG_dcache_clean, &folio->flags))
clear_bit(PG_dcache_clean, &folio->flags);
}
#define flush_dcache_folio flush_dcache_folio
#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
static inline void flush_dcache_page(struct page *page)
{
flush_dcache_folio(page_folio(page));
}
/*
* 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)
#ifdef CONFIG_64BIT
#define flush_cache_vmap(start, end) flush_tlb_kernel_range(start, end)
#define flush_cache_vmap_early(start, end) local_flush_tlb_kernel_range(start, end)
#endif
#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 */
extern unsigned int riscv_cbom_block_size;
extern unsigned int riscv_cboz_block_size;
void riscv_init_cbo_blocksizes(void);
#ifdef CONFIG_RISCV_DMA_NONCOHERENT
void riscv_noncoherent_supported(void);
void __init riscv_set_dma_cache_alignment(void);
#else
static inline void riscv_noncoherent_supported(void) {}
static inline void riscv_set_dma_cache_alignment(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 */