linux/arch
Nicholas Piggin 59dc5bfca0 powerpc/64s: avoid reloading (H)SRR registers if they are still valid
When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).

This improves the performance of interrupt returns.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fixup patch from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-06-25 00:06:55 +10:00
..
alpha Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
arc ARC: mm: Use max_high_pfn as a HIGHMEM zone border 2021-05-10 12:38:59 -07:00
arm xen/swiotlb: check if the swiotlb has already been initialized 2021-05-14 15:52:11 +02:00
arm64 xen: branch for v5.13-rc2 2021-05-16 09:39:04 -07:00
csky arch/csky patches for 5.13-rc1 2021-05-03 12:58:31 -07:00
h8300 arch: rearrange headers inclusion order in asm/bitops for m68k, sh and h8300 2021-05-06 19:24:11 -07:00
hexagon Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
ia64 Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
m68k Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
microblaze tracing updates for 5.13 2021-05-03 11:19:54 -07:00
mips Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
nds32 tracing updates for 5.13 2021-05-03 11:19:54 -07:00
nios2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-05-02 09:14:01 -07:00
openrisc drivers/char: remove /dev/kmem for good 2021-05-07 00:26:34 -07:00
parisc Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
powerpc powerpc/64s: avoid reloading (H)SRR registers if they are still valid 2021-06-25 00:06:55 +10:00
riscv riscv: remove unused handle_exception symbol 2021-05-06 09:40:16 -07:00
s390 Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
sh sh: Remove unused variable 2021-05-10 23:23:04 +02:00
sparc Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
um Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
x86 Two fixes for timers: 2021-05-16 09:42:13 -07:00
xtensa Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
Kconfig Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00