arm64: hibernate: reduce TLB maintenance scope

In break_before_make_ttbr_switch we perform broadcast TLB maintenance
for the inner shareable domain, and use a DSB ISH to complete this.
However, at the point we execute this, secondary CPUs are either
physically offline, or executing code outside of the kernel. Upon
entering the kernel, secondary CPUs will invalidate their TLBs before
enabling their MMUs.

Thus we do not need to invalidate TLBs of other CPUs, and as with
idmap_cpu_replace_ttbr1 we can reduce the scope of maintenance to the
TLBs of the local CPU. This keeps our TLB maintenance code consistent,
and is a minor optimisation.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Mark Rutland 2016-08-08 11:12:07 +01:00 committed by Will Deacon
parent fa8410b355
commit 0a7d87a777

View File

@ -36,8 +36,8 @@
.macro break_before_make_ttbr_switch zero_page, page_table
msr ttbr1_el1, \zero_page
isb
tlbi vmalle1is
dsb ish
tlbi vmalle1
dsb nsh
msr ttbr1_el1, \page_table
isb
.endm