Hi all,
This RFC patch series leverages the existing APMU support for R-Car Gen2
and RZ/G1 SoCs to enable SMP support on R-Mobile APE6. This allows me
to enjoy the 4 Cortex-A15 CPU cores on the APE6-EVM development board.
The core APE6-specific code was lifted from an old series by Magnus[1].
Known issues:
- While initial secondary CPU bring-up during boot works, CPU cores
fail to come online after offlining/onlining them using the sysfs
interface ("echo [01] > /sys/*/*/cpu/cpu[0-9]*{off,on}line").
- This breaks detection of the CFI FLASH. I traced this back to
setting the SBAR_BAREN bit in the SYSC.CA15BAR register.
Presumably this affects the LBSC in some way?
To do:
- Call into rmobile-sysc instead of hardcoding the SYSC mapping,
- Describe CCI-400 in DT and call cci_enable_port_by_index()?
- Let pm-rcar-gen2.c call into rcar-rst instead of hardcoding the RST
mapping,
- Abstract SYSC vs. RST access and merge with pm-rcar-gen2.c?
Questions:
- Do we want to bring up the Cortex-A7 cores, too? We don't on R-Car
H2 neither.
Thanks for your comments!
[1] [PATCH 00/02] ARM: shmobile: Initial r8a73a4 APMU SMP code
https://lore.kernel.org/linux-arm-kernel/20130807225531.9856.18974.sendpatchset@w520/
Geert Uytterhoeven (6):
soc: renesas: Introduce RENESAS_APMU Kconfig option
dt-bindings: power: renesas,apmu: Document R-Mobile APE6 support
ARM: dts: r8a73a4: Add secondary CPU nodes
ARM: dts: r8a73a4: Add Media RAM for SMP jump stub
ARM: dts: r8a73a4: Add APMU nodes
[WIP] ARM: shmobile: r8a73a4: Add SMP support
.../bindings/power/renesas,apmu.yaml | 6 +-
arch/arm/boot/dts/r8a73a4.dtsi | 96 +++++++++++
arch/arm/mach-shmobile/Makefile | 6 +-
arch/arm/mach-shmobile/platsmp-apmu.c | 15 +-
arch/arm/mach-shmobile/pm-r8a73a4.c | 152 ++++++++++++++++++
arch/arm/mach-shmobile/r8a73a4.h | 7 +
drivers/soc/renesas/Kconfig | 5 +
7 files changed, 281 insertions(+), 6 deletions(-)
create mode 100644 arch/arm/mach-shmobile/pm-r8a73a4.c
create mode 100644 arch/arm/mach-shmobile/r8a73a4.h
--
2.25.1
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
