riscv: mm: Always use an ASID to flush mm contexts

Even if multiple ASIDs are not supported, using the single-ASID variant
of the sfence.vma instruction preserves TLB entries for global (kernel)
pages. So it is always more efficient to use the single-ASID code path.

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240327045035.368512-14-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Samuel Holland 2024-03-26 21:49:54 -07:00 committed by Palmer Dabbelt
parent 8fc21cc672
commit daef19263f
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@ -109,8 +109,7 @@ static void __flush_tlb_range(struct cpumask *cmask, unsigned long asid,
static inline unsigned long get_mm_asid(struct mm_struct *mm)
{
return static_branch_unlikely(&use_asid_allocator) ?
cntx2asid(atomic_long_read(&mm->context.id)) : FLUSH_TLB_NO_ASID;
return cntx2asid(atomic_long_read(&mm->context.id));
}
void flush_tlb_mm(struct mm_struct *mm)