linux-stable/arch/x86/include/asm/tlb.h
Peter Zijlstra 1e9fdf21a4 mmu_gather: Remove per arch tlb_{start,end}_vma()
Scattered across the archs are 3 basic forms of tlb_{start,end}_vma().
Provide two new MMU_GATHER_knobs to enumerate them and remove the per
arch tlb_{start,end}_vma() implementations.

 - MMU_GATHER_NO_FLUSH_CACHE indicates the arch has flush_cache_range()
   but does *NOT* want to call it for each VMA.

 - MMU_GATHER_MERGE_VMAS indicates the arch wants to merge the
   invalidate across multiple VMAs if possible.

With these it is possible to capture the three forms:

  1) empty stubs;
     select MMU_GATHER_NO_FLUSH_CACHE and MMU_GATHER_MERGE_VMAS

  2) start: flush_cache_range(), end: empty;
     select MMU_GATHER_MERGE_VMAS

  3) start: flush_cache_range(), end: flush_tlb_range();
     default

Obviously, if the architecture does not have flush_cache_range() then
it also doesn't need to select MMU_GATHER_NO_FLUSH_CACHE.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-21 10:50:13 -07:00

37 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_TLB_H
#define _ASM_X86_TLB_H
#define tlb_flush tlb_flush
static inline void tlb_flush(struct mmu_gather *tlb);
#include <asm-generic/tlb.h>
static inline void tlb_flush(struct mmu_gather *tlb)
{
unsigned long start = 0UL, end = TLB_FLUSH_ALL;
unsigned int stride_shift = tlb_get_unmap_shift(tlb);
if (!tlb->fullmm && !tlb->need_flush_all) {
start = tlb->start;
end = tlb->end;
}
flush_tlb_mm_range(tlb->mm, start, end, stride_shift, tlb->freed_tables);
}
/*
* While x86 architecture in general requires an IPI to perform TLB
* shootdown, enablement code for several hypervisors overrides
* .flush_tlb_others hook in pv_mmu_ops and implements it by issuing
* a hypercall. To keep software pagetable walkers safe in this case we
* switch to RCU based table free (MMU_GATHER_RCU_TABLE_FREE). See the comment
* below 'ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE' in include/asm-generic/tlb.h
* for more details.
*/
static inline void __tlb_remove_table(void *table)
{
free_page_and_swap_cache(table);
}
#endif /* _ASM_X86_TLB_H */