nios2: flush_tlb_all use TLBMISC way auto-increment feature (737a3fa2) · Commits · 戴 / test

Writes to TLBACC cause TLBMISC way to be incremented, which can be used to iterate over ways in a set, then wrap back to zero ready for the next set. This reduces register writes significantly. Signed-off-by:

Nicholas Piggin <npiggin@gmail.com> Signed-off-by:

Ley Foon Tan <ley.foon.tan@intel.com>

arch/nios2/mm/tlb.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -242,21 +242,20 @@ void flush_tlb_all(void)
		unsigned long addr = 0;
		unsigned int line;
		unsigned int way;
		unsigned long org_misc, pid_misc, tlbmisc;
		unsigned long org_misc, pid_misc;

		/* remember pid/way until we return */
		get_misc_and_pid(&org_misc, &pid_misc);

		/* Start at way 0, way is auto-incremented after each TLBACC write */
		WRCTL(CTL_TLBMISC, TLBMISC_WE);

		/* Map each TLB entry to physcal address 0 with no-access and a
		bad ptbase */
		for (line = 0; line < cpuinfo.tlb_num_lines; line++) {
		WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));

		for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
		tlbmisc = TLBMISC_WE \| (way << TLBMISC_WAY_SHIFT);
		WRCTL(CTL_TLBMISC, tlbmisc);
		for (way = 0; way < cpuinfo.tlb_num_ways; way++)
		WRCTL(CTL_TLBACC, 0);
		}

		addr += PAGE_SIZE;
		}

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