Hi Nicolas, Dave, On Wed, Jan 17, 2018 at 4:46 PM, Chen-Yu Tsai <wens@xxxxxxxx> wrote: > This is v4 of my sun9i SMP/hotplug support series which was started > over two years ago [1]. We've tried to implement PSCI for both the A80 > and A83T. Results were not promising. The issue is that these two chips > have a broken security extensions implementation. If a specific bit is > not burned in its e-fuse, most if not all security protections don't > work [2]. Even worse, non-secure access to the GIC become secure. This > requires a crazy workaround in the GIC driver which probably doesn't work > in all cases [3]. > > Version 3 completely did away with the MCPM framework, instead just > implementing a set of smp_ops. Most of the code from the previous > version was reused, so the structure still has some traces of MCPM. > As our hardware has CCI-400, we still need some sort of MMU/cache > disabled trampoline code to enable cache coherency. Code for this > was adapted from the MCPM framework. This and the entry code are done > in inline assembly. Most of the other sunxi-specific code is derived > from Allwinner code and documentation, with some references to the > other MCPM implementations, as well as the Cortex's Technical Reference > Manuals for the power sequencing stuff. > > In version 4, all traces of MCPM have been removed, except in the > comments for atttributing code sources. Thumb2 mode is also fixed. > It failed due to an unaligned word access. Any more comments on this series? Or is it OK for you guys now that there are no traces of MCPM? :) We'll merge this series later this week for 4.17 if nothing else. Thanks ChenYu > > Hope we can get this version merged. A83T SMP support will be built on > it. > > Regards > ChenYu > > Changes since v3: > - Renamed all "MCPM" occurrences to "MC_SMP", as the MCPM framework > is no longer used > - Thumb2 mode fixed > > Changes since v2: > - Do away with the MCPM framework, directly implement smp_ops > - Some debug messages were clarified > - New ARCH_SUNXI_MCPM Kconfig symbol for this feature > > Changes since v1: > > - Leading zeroes for device node addresses removed > - Added device tree binding for SMP SRAM > - Simplified Kconfig options > - Switched to SPDX license identifier > - Map CPU to device tree node and check compatible to see if it's > Cortex-A15 or Cortex-A7 > - Fix incorrect CPUCFG cluster status macro that prevented cluster > 0 L2 cache WFI detection > - Fixed reversed bit for turning off cluster > - Put cluster in reset before turning off power (or it hangs) > - Added dedicated workqueue for turning off power to cpus and clusters > - Request CPUCFG and SRAM MMIO ranges > - Some comments fixed or added > - Some debug messages added > > [1] http://www.spinics.net/lists/arm-kernel/msg418350.html > [2] https://lists.denx.de/pipermail/u-boot/2017-June/294637.html > [3] https://github.com/wens/linux/commit/c48654c1f737116e7a7660183c8c74fa91970528 > > Chen-Yu Tsai (8): > ARM: sun9i: Support SMP bring-up on A80 > ARM: dts: sun9i: Add CCI-400 device nodes for A80 > ARM: dts: sun9i: Add CPUCFG device node for A80 dtsi > ARM: dts: sun9i: Add PRCM device node for the A80 dtsi > ARM: sun9i: smp: Support CPU/cluster power down and hotplugging for > cpu1~7 > dt-bindings: ARM: sunxi: Document A80 SoC secure SRAM usage by SMP > hotplug > ARM: sun9i: smp: Support cpu0 hotplug > ARM: dts: sun9i: Add secure SRAM node used for SMP hotplug > > .../devicetree/bindings/arm/sunxi/smp-sram.txt | 44 ++ > arch/arm/boot/dts/sun9i-a80.dtsi | 75 ++ > arch/arm/mach-sunxi/Kconfig | 7 + > arch/arm/mach-sunxi/Makefile | 1 + > arch/arm/mach-sunxi/mc_smp.c | 791 +++++++++++++++++++++ > 5 files changed, 918 insertions(+) > create mode 100644 Documentation/devicetree/bindings/arm/sunxi/smp-sram.txt > create mode 100644 arch/arm/mach-sunxi/mc_smp.c > > -- > 2.15.1 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
