Hi All. The clock controller module in the Zynq platform has the ability to halt and reset arbitrary devices, including the CPU. We use this feature to implement SMP Linux - the kernel halts CPU1 then rewrites the vector table to the secondary entry point and unhalts.
The clock controller however is reasonable generic, in that in has the ability to halt and reset any arbitrary device in the Zynq SoC. The interface for doing this is reasonably consistent. So im looking for unified way to halt and reset arbitrary devices CPUs included. So given we already have reset() defined on the TYPE_DEVICE level, i've added halt as well. This series is based on v3 of the current qom-cpu queue to pick up the move of cpu halt out of the env. From this I attach the cpu::halted bit to the Device::(un)halt function. Next up, CPUs seem to have a different reset path to normal devices. So I have trivially hooked up CPU::Reset to Device::Reset. This means that anyone who holds a DeviceState pointer to the CPU can reset it properly without actually knowing its a CPU. With the halt API I played with changing an existing device over to use it in place of the CPU halted bit (sun4m). I then finally add SMP support to the Zynq machine, and patch the Zynq SLCR (my clock controller) to have DeviceState pointers to the CPUs. device_reset() and device_halt() is where the magic happens. Future work, more devices in Zynq will have halt and reset. My agenda for abstracting away the fact that attached device is a CPU is to allow for consistent implementation and a single code path for the clock controlled devices. Peter A. G. Crosthwaite (3): xilinx_zynq: added smp support zynq_slcr: Add links to the CPUs zynq_slcr: Implement CPU reset and halting Peter Crosthwaite (4): qdev: Define halting API qom/cpu.c: Encapsulate cpu halting qom/cpu.c: Hook CPU reset up to device reset sun4m: Use halting API to halt/unhalt CPUs hw/qdev-core.h | 17 ++++++++++++++ hw/qdev.c | 18 ++++++++++++++ hw/sun4m.c | 24 +++++++++--------- hw/xilinx_zynq.c | 66 ++++++++++++++++++++++++++++++++++++++++++++--------- hw/zynq_slcr.c | 30 ++++++++++++++++++++++++ qom/cpu.c | 22 ++++++++++++++++++ 6 files changed, 153 insertions(+), 24 deletions(-)
