android_kernel_xiaomi_sm8350/arch/riscv/include/asm/tlbflush.h
Paul Walmsley 4c8eb19cf9 riscv: tlbflush: remove confusing comment on local_flush_tlb_all()
Remove a confusing comment on our local_flush_tlb_all()
implementation.  Per an internal discussion with Andrew, while it's
true that the fence.i is not necessary, it's not the case that an
sfence.vma implies a fence.i.  We also drop the section about
"flush[ing] the entire local TLB" to better align with the language in
section 4.2.1 "Supervisor Memory-Management Fence Instruction" of the
RISC-V Privileged Specification v20190608.

Fixes: c901e45a99 ("RISC-V: `sfence.vma` orderes the instruction cache")
Reported-by: Alan Kao <alankao@andestech.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-14 12:35:36 -07:00

51 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
* Copyright (C) 2012 Regents of the University of California
*/
#ifndef _ASM_RISCV_TLBFLUSH_H
#define _ASM_RISCV_TLBFLUSH_H
#include <linux/mm_types.h>
#include <asm/smp.h>
static inline void local_flush_tlb_all(void)
{
__asm__ __volatile__ ("sfence.vma" : : : "memory");
}
/* Flush one page from local TLB */
static inline void local_flush_tlb_page(unsigned long addr)
{
__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory");
}
#ifdef CONFIG_SMP
void flush_tlb_all(void);
void flush_tlb_mm(struct mm_struct *mm);
void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end);
#else /* CONFIG_SMP */
#define flush_tlb_all() local_flush_tlb_all()
#define flush_tlb_page(vma, addr) local_flush_tlb_page(addr)
static inline void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
local_flush_tlb_all();
}
#define flush_tlb_mm(mm) flush_tlb_all()
#endif /* CONFIG_SMP */
/* Flush a range of kernel pages */
static inline void flush_tlb_kernel_range(unsigned long start,
unsigned long end)
{
flush_tlb_all();
}
#endif /* _ASM_RISCV_TLBFLUSH_H */