linux/arch/powerpc/platforms/pasemi
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
..
dma_lib.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
gpio_mdio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
idle.c powerpc/64s: avoid reloading (H)SRR registers if they are still valid 2021-06-25 00:06:55 +10:00
iommu.c powerpc/iommu: Do not immediately panic when failed IOMMU table allocation 2021-04-23 01:38:04 +10:00
Kconfig PCI: consolidate PCI config entry in drivers/pci 2018-11-23 11:45:34 +09:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
misc.c powerpc: use for_each_child_of_node() macro 2020-07-29 22:30:33 +10:00
msi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
pasemi.h powerpc: use time64_t in read_persistent_clock 2018-06-03 20:43:33 +10:00
pci.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
powersave.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
setup.c powerpc/pasemi: Move PHB discovery 2021-02-09 00:02:07 +11:00
time.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00