linux/arch/powerpc
Christophe Leroy 70428da94c powerpc/32s: Save content of sr0 to avoid 'mfsr'
Calling 'mfsr' to get the content of segment registers is heavy,
in addition it requires clearing of the 'reserved' bits.

In order to avoid this operation, save it in mm context and in
thread struct.

The saved sr0 is the one used by kernel, this means that on
locking entry it can be used as is.

For unlocking, the only thing to do is to clear SR_NX.

This improves null_syscall selftest by 12 cycles, ie 4%.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b02baf2ed8f09bad910dfaeeb7353b2ae6830525.1634627931.git.christophe.leroy@csgroup.eu
2021-12-09 22:41:17 +11:00
..
boot powerpc: flexible GPR range save/restore macros 2021-11-29 23:15:20 +11:00
configs powerpc/microwatt: add POWER9_CPU, clear PPC_64S_HASH_MMU 2021-12-09 22:41:16 +11:00
crypto powerpc: flexible GPR range save/restore macros 2021-11-29 23:15:20 +11:00
include powerpc/32s: Save content of sr0 to avoid 'mfsr' 2021-12-09 22:41:17 +11:00
kernel powerpc/32s: Save content of sr0 to avoid 'mfsr' 2021-12-09 22:41:17 +11:00
kexec powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU 2021-12-09 22:41:13 +11:00
kvm powerpc/64s: Make hash MMU support configurable 2021-12-09 22:40:24 +11:00
lib powerpc: flexible GPR range save/restore macros 2021-11-29 23:15:20 +11:00
math-emu powerpc/64s: avoid reloading (H)SRR registers if they are still valid 2021-06-25 00:06:55 +10:00
mm powerpc/32s: Save content of sr0 to avoid 'mfsr' 2021-12-09 22:41:17 +11:00
net bpf ppc32: Access only if addr is kernel address 2021-11-25 11:25:32 +11:00
perf powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC 2021-11-30 17:15:49 +11:00
platforms powerpc/book3e: Activate KUEP at all time 2021-12-09 22:41:17 +11:00
purgatory
sysdev powerpc/xive: Fix compile when !CONFIG_PPC_POWERNV. 2021-12-02 10:40:38 +11:00
tools powerpc/head_check: Fix shellcheck errors 2021-08-17 22:52:02 +10:00
xmon powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU 2021-12-09 22:41:13 +11:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU 2021-12-09 22:41:13 +11:00
Kconfig.debug powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP 2021-08-25 13:35:48 +10:00
Makefile Kbuild updates for v5.16 2021-11-08 09:15:45 -08:00
Makefile.postlink