linux/arch/unicore32
Peter Zijlstra 6137fed082 arch/tlb: Clean up simple architectures
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>
2019-04-03 10:32:54 +02:00
..
boot unicore32: simplify linker script generation for decompressor 2019-03-14 02:39:11 +09:00
configs unicore32: use the new LED disk activity trigger 2016-06-27 08:58:42 +02:00
include arch/tlb: Clean up simple architectures 2019-04-03 10:32:54 +02:00
kernel treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
lib License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
.gitignore
Kconfig arch/tlb: Clean up simple architectures 2019-04-03 10:32:54 +02:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile unicore32: Use full path in KBUILD_IMAGE definition 2017-03-20 22:42:21 +09:00