For the architectures that do not implement their own tlb_flush() but
do already use the generic mmu_gather, there are two options:
1) the platform has an efficient flush_tlb_range() and
asm-generic/tlb.h doesn't need any overrides at all.
2) the platform lacks an efficient flush_tlb_range() and
we select MMU_GATHER_NO_RANGE to minimize full invalidates.
Convert all 'simple' architectures to one of these two forms.
alpha: has no range invalidate -> 2
arc: already used flush_tlb_range() -> 1
c6x: has no range invalidate -> 2
hexagon: has an efficient flush_tlb_range() -> 1
(flush_tlb_mm() is in fact a full range invalidate,
so no need to shoot down everything)
m68k: has inefficient flush_tlb_range() -> 2
microblaze: has no flush_tlb_range() -> 2
mips: has efficient flush_tlb_range() -> 1
(even though it currently seems to use flush_tlb_mm())
nds32: already uses flush_tlb_range() -> 1
nios2: has inefficient flush_tlb_range() -> 2
(no limit on range iteration)
openrisc: has inefficient flush_tlb_range() -> 2
(no limit on range iteration)
parisc: already uses flush_tlb_range() -> 1
sparc32: already uses flush_tlb_range() -> 1
unicore32: has inefficient flush_tlb_range() -> 2
(no limit on range iteration)
xtensa: has efficient flush_tlb_range() -> 1
Note this also fixes a bug in the existing code for a number
platforms. Those platforms that did:
tlb_end_vma() -> if (!full_mm) flush_tlb_*()
tlb_flush -> if (full_mm) flush_tlb_mm()
missed the case of shift_arg_pages(), which doesn't have @fullmm set,
nor calls into tlb_*vma(), but still frees page-tables and thus needs
an invalidate. The new code handles this by detecting a non-empty
range, and either issuing the matching range invalidate or a full
invalidate, depending on the capabilities.
No change in behavior intended.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Helge Deller <deller@gmx.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Ley Foon Tan <lftan@altera.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salter <msalter@redhat.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>