[PATCH v3 00/13] OpenRISC SMP Support

[Stafford Horne]

Hello Again,

(sorry for a bit of delay getting this version out, gdb and qemu patches
 have been keeping me busy)

This series adds SMP support for OpenRISC.  The OpenRISC multi-core
platform and SMP linux support is based on the work that Stefan
Kristiansson did around 2012 implemented in Verilog and run on FPGAs.  I
have been working to upstream this work. I have additionally tested this on
QEMU, which I patched for OpenRISC multi-core support, as well as FPGA.

I have documented the architecture in the OpenRISC 1.2 specification
proposal available here:
  https://github.com/stffrdhrn/doc/raw/arch-1.2-proposal/openrisc-arch-1.2-rev0.pdf

The QEMU patches are still under review but are available here for testers
and anyone interested:
  https://github.com/stffrdhrn/qemu.git openrisc-smp-v1

This series contains a bit of a mix of patches to get everything working.
 o First the "use shadow registers" and "define CPU_BIG_ENDIAN as true" get
   the architecture ready for SMP.
 o The "add 1 and 2 byte cmpxchg support" and "use qspinlocks and qrwlocks"
   add the SMP locking infrastructure as needed.  Using the qspinlocks and
   qrwlocks as suggested by Peter Z while reviewing the original spinlocks
   implementation.
 o The "support for ompic" adds a new irqchip device which is used for IPI
   communication to support SMP.  (Perhaps this patch should go via another
   route but included here for completeness - confirmed this is ok)
 o The "initial SMP support" adds smp.c and makes changes to all of the
   necessary data-structures to be per-cpu.
 o The remaining patches are bug fixes and debug helpers which I wanted
   to keep separate from the "initial SMP support" in order to allow them
   to be reviewed on their own. This includes:
    - add cacheflush support to fix icache aliasing
    - fix initial preempt state for secondary cpu tasks
    - sleep instead of spin on secondary wait
    - support framepointers and STACKTRACE_SUPPORT
    - enable LOCKDEP_SUPPORT and irqflags tracing
    - timer sync: Add tick timer sync logic

--

Changes since v2
  - Dropped BIG_ENDIAN patch as its upstream already
  - Fix typos with multi-core throughout the series suggested by Rob
    Herring.
  - Fix issues with static functions throughout the series suggested by
    Marc Zyngier.
  - Suggestions on DT docs from Rob Herring:
    > Fix 'interrupt-controller@98000000' naming issue.
    > Add back #interrupt-cells.

Changes since v1
  - refactor of timer headers to not require extern openrisc_timer_init()
    in smp.c
  - check for power management unit when sleeping on secondary cpu wait
  - fixed cpuinfo to print online CPUs only
  - cleanups for the ompic suggested by Marc Zyngier and Mark Rutland
    > don't say size is arbitrary, it's 8 bytes per CPU
    > validate register size vs cpus
    > add validations for all initialization failures
    > use percpu for percpu ipi ops
    > remove SMP and OF #ifdefs
    > document details about OpenRISC implied barriers
    > use vendor prefix openrisc,
    > removed #interrupt-cells as this will not be a parent
    > added some architecture documentation into the source
  - enforce shadow register usage for SMP as suggested by Geert
  - DTS updates suggested by Mark Rutland
    > Add and use vendor prefix openrisc, for ompic
    > Use stdout-path

-Stafford

Jan Henrik Weinstock (1):
  openrisc: add cacheflush support to fix icache aliasing

Stafford Horne (8):
  openrisc: add 1 and 2 byte cmpxchg support
  openrisc: use qspinlocks and qrwlocks
  dt-bindings: add openrisc to vendor prefixes list
  openrisc: fix initial preempt state for secondary cpu tasks
  openrisc: sleep instead of spin on secondary wait
  openrisc: support framepointers and STACKTRACE_SUPPORT
  openrisc: enable LOCKDEP_SUPPORT and irqflags tracing
  openrisc: add tick timer multi-core sync logic

Stefan Kristiansson (4):
  openrisc: use shadow registers to save regs on exception
  irqchip: add initial support for ompic
  openrisc: initial SMP support
  openrisc: add simple_smp dts and defconfig for simulators

 .../interrupt-controller/openrisc,ompic.txt        |  22 ++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 MAINTAINERS                                        |   1 +
 arch/openrisc/Kconfig                              |  49 +++-
 arch/openrisc/boot/dts/simple_smp.dts              |  63 +++++
 arch/openrisc/configs/simple_smp_defconfig         |  66 ++++++
 arch/openrisc/include/asm/Kbuild                   |   5 +-
 arch/openrisc/include/asm/cacheflush.h             |  96 ++++++++
 arch/openrisc/include/asm/cmpxchg.h                | 147 +++++++++---
 arch/openrisc/include/asm/cpuinfo.h                |   7 +-
 arch/openrisc/include/asm/mmu_context.h            |   2 +-
 arch/openrisc/include/asm/pgtable.h                |  18 +-
 arch/openrisc/include/asm/serial.h                 |   2 +-
 arch/openrisc/include/asm/smp.h                    |  26 +++
 arch/openrisc/include/asm/spinlock.h               |  12 +-
 arch/openrisc/include/asm/spinlock_types.h         |   7 +
 arch/openrisc/include/asm/spr_defs.h               |  14 ++
 arch/openrisc/include/asm/thread_info.h            |   2 +-
 arch/openrisc/include/asm/time.h                   |  23 ++
 arch/openrisc/include/asm/tlbflush.h               |  25 +-
 arch/openrisc/include/asm/unwinder.h               |  20 ++
 arch/openrisc/kernel/Makefile                      |   4 +-
 arch/openrisc/kernel/dma.c                         |  14 +-
 arch/openrisc/kernel/entry.S                       |  74 +++++-
 arch/openrisc/kernel/head.S                        | 239 ++++++++++++++++---
 arch/openrisc/kernel/setup.c                       | 165 ++++++++-----
 arch/openrisc/kernel/smp.c                         | 259 +++++++++++++++++++++
 arch/openrisc/kernel/stacktrace.c                  |  86 +++++++
 arch/openrisc/kernel/sync-timer.c                  | 120 ++++++++++
 arch/openrisc/kernel/time.c                        |  66 ++++--
 arch/openrisc/kernel/traps.c                       |  54 +----
 arch/openrisc/kernel/unwinder.c                    | 105 +++++++++
 arch/openrisc/lib/delay.c                          |   2 +-
 arch/openrisc/mm/Makefile                          |   2 +-
 arch/openrisc/mm/cache.c                           |  61 +++++
 arch/openrisc/mm/fault.c                           |   4 +-
 arch/openrisc/mm/init.c                            |   2 +-
 arch/openrisc/mm/tlb.c                             |  16 +-
 drivers/irqchip/Kconfig                            |   3 +
 drivers/irqchip/Makefile                           |   1 +
 drivers/irqchip/irq-ompic.c                        | 205 ++++++++++++++++
 41 files changed, 1856 insertions(+), 234 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/openrisc,ompic.txt
 create mode 100644 arch/openrisc/boot/dts/simple_smp.dts
 create mode 100644 arch/openrisc/configs/simple_smp_defconfig
 create mode 100644 arch/openrisc/include/asm/cacheflush.h
 create mode 100644 arch/openrisc/include/asm/smp.h
 create mode 100644 arch/openrisc/include/asm/spinlock_types.h
 create mode 100644 arch/openrisc/include/asm/time.h
 create mode 100644 arch/openrisc/include/asm/unwinder.h
 create mode 100644 arch/openrisc/kernel/smp.c
 create mode 100644 arch/openrisc/kernel/stacktrace.c
 create mode 100644 arch/openrisc/kernel/sync-timer.c
 create mode 100644 arch/openrisc/kernel/unwinder.c
 create mode 100644 arch/openrisc/mm/cache.c
 create mode 100644 drivers/irqchip/irq-ompic.c

-- 
2.13.6