linux/arch/powerpc/sysdev/xive
Cédric Le Goater e2cf43d595 powerpc/xive: Introduce XIVE_IPI_HW_IRQ
The XIVE driver deals with CPU IPIs in a peculiar way. Each CPU has
its own XIVE IPI interrupt allocated at the HW level, for PowerNV, or
at the hypervisor level for pSeries. In practice, these interrupts are
not always used. pSeries/PowerVM prefers local doorbells for local
threads since they are faster. On PowerNV, global doorbells are also
preferred for the same reason.

The mapping in the Linux is reduced to a single interrupt using HW
interrupt number 0 and a custom irq_chip to handle EOI. This can cause
performance issues in some benchmark (ipistorm) on multichip systems.

Clarify the use of the 0 value, it will help in improving multichip
support.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-4-clg@kaod.org
2020-12-11 09:34:07 +11:00
..
common.c powerpc/xive: Introduce XIVE_IPI_HW_IRQ 2020-12-11 09:34:07 +11:00
Kconfig powerpc: remove redundant 'default n' from Kconfig-s 2018-10-13 22:21:25 +11:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
native.c powerpc/xive: Ignore kmemleak false positives 2020-06-22 10:37:57 +10:00
spapr.c powerpc: fix function annotations to avoid section mismatch warnings with gcc-10 2020-07-30 10:50:07 +10:00
xive-internal.h powerpc/xive: Introduce XIVE_IPI_HW_IRQ 2020-12-11 09:34:07 +11:00