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2017-08-28ARC: [plat-eznps] handle extra aux regs #1: save/restore on context switchNoam Camus
save EFLAGS, and GPA1 auxiliary registers during context switch, since they may be changed by the new task in kernel mode, while using atomic ops e.g. cmpxchg. Signed-off-by: Noam Camus <noamc@ezchip.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-08-28ARC: [plat-eznps] avoid toggling of DPC registerElad Kanfi
HW bug description: in case of HW thread context switch the dpc configuration of the exiting thread is dragged one cycle into the next thread. In order to avoid the consequences of this bug, the DPC register is set to an initial value, and not changed afterwards. Signed-off-by: Elad Kanfi <eladkan@mellanox.com> Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-08-28ARC: [plat-eznps] Update the init sequence of aux regs per cpu.Liav Rehana
This commit add new configuration that enables us to distinguish between building the kernel for platforms that have a different set of auxiliary registers for each cpu and platforms that have a shared set of auxiliary registers across every thread in each core. On platforms that implement a different set of auxiliary registers disabling this configuration insures that we initialize registers on every cpu and not just for the first thread of the core. Example for non shared registers is working with EZsim (non silicon) Signed-off-by: Liav Rehana <liavr@mellanox.com> Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-08-28ARC: [plat-eznps] new command line argument for HW scheduler at MTMNoam Camus
We add ability for all cores at NPS SoC to control the number of cycles HW thread can execute before it is replace with another eligible HW thread within the same core. The replacement is done by the HW scheduler. Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: simplified handlign of out of range argument value]
2017-08-28ARC: [plat-eznps] Handle user memory error same in simulation and siliconNoam Camus
On ARC700 (and nSIM), user mode memory error triggers an L2 interrupt which is handled gracefully by kernel (or it tries to despite this being imprecise, and error could get charged to kernel itself). The offending task is killed and kernel moves on. NPS hardware however raises a Machine Check exception for same error which is NOT recoverable by kernel. This patch aligns kernel handling for nSIM case, to same as hardware by overriding the default user space bus error handler. Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Elad Kanfi <eladkan@mellanox.com> [vgupta: rewrote changelog] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-08-28ARC: [plat-eznps] use schd.wft instruction instead of sleep at idle taskNoam Camus
When HW threads are active we want CPU to enter idle state only for the calling HW thread and not to put on sleep all HW threads sharing this core. For this need the NPS400 got dedicated instruction so only calling thread is entring sleep and all other are still awake and can execute instructions. Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: reworked patch to not use inline ifdef but a new function itself]
2017-08-28ARC: [plat-eznps] disabled stall counter due to a HW bugNoam Camus
This counter represents threshold for consecutive stall which would trigger HW threads scheduling. However when enabled, low threshhold values cause performance degradation and in the worst case even livelock. So disable it by resorting to HW reset value Signed-off-by: Noam Camus <noamca@mellanox.com> Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: fixed changelog]
2017-08-28ARC: [plat-eznps] typo fix at KconfigNoam Camus
Signed-off-by: Noam Camus <noamca@mellanox.com> Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-02-06ARC: [plat-*] ARC_HAS_COH_CACHES no longer relevantVineet Gupta
A typical SMP system expects cache coherency. Initial NPS platform support was slated to be SMP w/o cache coherency. However it seems the platform now selects that option, so there is no point in keeping it around. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30soc: Support for NPS HW schedulingNoam Camus
This new header file is for NPS400 SoC (part of ARC architecture). The header file includes macros for save/restore of HW scheduling. The control of HW scheduling is achieved by writing core registers. This code was moved from arc/plat-eznps so it can be used from drivers/clocksource/, available only for CONFIG_EZNPS_MTM_EXT. Signed-off-by: Noam Camus <noamca@mellanox.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2016-11-08ARC: [plat-eznps] remove IPI clear from SMP operationsNoam Camus
Today we register to plat_smp_ops.clear() method which actually is acking the IPI. However this is already taking care by our irqchip driver specifically by the irq_chip.irq_eoi() method. This is perfect timing where it should be done and no special handling is needed at plat_smp_ops.clear(). Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-05-09ARC: [plat-eznps] Use dedicated identity auxiliary register.Noam Camus
With generic "identity" num of CPUs is limited to 256 (8 bit). We use our alternative AUX register GLOBAL_ID (12 bit). Now we can support up to 4096 CPUs. Signed-off-by: Noam Camus <noamc@ezchip.com>
2016-05-09ARC: [plat-eznps] Add eznps platformNoam Camus
This platform include boards: Hardware Emulator (HE) Simulator based upon nSIM. Signed-off-by: Noam Camus <noamc@ezchip.com>