Re: [PATCH v3 08/16] irqchip/gic: Configure SGIs as standard interrupts

[Marc Zyngier <maz@kernel.org>]

Marek,

On 2020-09-14 14:26, Marek Szyprowski wrote:
> Hi Marc,
> 
> On 14.09.2020 15:13, Marc Zyngier wrote:
>> On 2020-09-14 14:06, Marek Szyprowski wrote:
>>> On 01.09.2020 16:43, Marc Zyngier wrote:
>>>> Change the way we deal with GIC SGIs by turning them into proper
>>>> IRQs, and calling into the arch code to register the interrupt range
>>>> instead of a callback.
>>>> 
>>>> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
>>>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>>> This patch landed in linux next-20200914 as commit ac063232d4b0
>>> ("irqchip/gic: Configure SGIs as standard interrupts"). Sadly it 
>>> breaks
>>> booting of all Samsung Exynos 4210/4412 based boards (dual/quad ARM
>>> Cortex A9 based). Here are the last lines from the bootlog:
>>> 
>>> [    0.106322] CPU: Testing write buffer coherency: ok
>>> [    0.109895] CPU0: Spectre v2: using BPIALL workaround
>>> [    0.116057] CPU0: thread -1, cpu 0, socket 9, mpidr 80000900
>>> [    0.123885] Setting up static identity map for 0x40100000 -
>>> 0x40100060
>>> [    0.130191] rcu: Hierarchical SRCU implementation.
>>> [    0.137195] soc soc0: Exynos: CPU[EXYNOS4210] PRO_ID[0x43210211]
>>> REV[0x11] Detected
>>> [    0.145129] smp: Bringing up secondary CPUs ...
>>> [    0.156279] CPU1: thread -1, cpu 1, socket 9, mpidr 80000901
>>> [    0.156291] CPU1: Spectre v2: using BPIALL workaround
>>> [    2.716379] random: fast init done
>> 
>> Thanks for the report. Is this the funky non-banked GIC?
> 
> Both Exynos 4210 and 4412 use non-zero cpu-offset in GIC node in
> device-tree: arch/arm/boot/dts/exynos{4210,4412}.dtsi, so I assume that
> the GIC registers are not banked.

Annoyingly, it seems to work correctly in QEMU:

root@unassigned-hostname:~# cat /proc/interrupts
            CPU0       CPU1
  40:          0          0     GIC-0  89 Level     mct_comp_irq
  41:      16144          0     GIC-0  74 Level     mct_tick0
  42:          0      15205     GIC-0  80 Level     mct_tick1
  43:          0          0  COMBINER  18 Edge      arm-pmu
  44:          0          0  COMBINER  26 Edge      arm-pmu
  46:       2270          0     GIC-0 107 Level     mmc0
  48:        878          0     GIC-0  84 Level     13800000.serial
  52:          0          0     GIC-0  90 Level     13860000.i2c
  54:          0          0     GIC-0  67 Level     12680000.pdma
  55:          0          0     GIC-0  68 Level     12690000.pdma
  56:          0          0     GIC-0  66 Level     12850000.mdma
  59:          0          0  COMBINER  45 Edge      13620000.sysmmu
  60:          0          0  COMBINER  46 Edge      13630000.sysmmu
  61:          0          0  COMBINER  44 Edge      12e20000.sysmmu
  62:          0          0  COMBINER  34 Edge      11a20000.sysmmu
  63:          0          0  COMBINER  35 Edge      11a30000.sysmmu
  64:          0          0  COMBINER  36 Edge      11a40000.sysmmu
  65:          0          0  COMBINER  37 Edge      11a50000.sysmmu
  66:          0          0  COMBINER  38 Edge      11a60000.sysmmu
  67:          0          0  COMBINER  40 Edge      12a30000.sysmmu
  68:          0          0  COMBINER  42 Edge      11e20000.sysmmu
  74:          0          0     GIC-0  79 Level     11400000.pinctrl
  75:          0          0     GIC-0  78 Level     11000000.pinctrl
  77:          0          0  COMBINER  39 Edge      12a20000.sysmmu
  78:          0          0  COMBINER  43 Edge      12220000.sysmmu
IPI0:          0          1  CPU wakeup interrupts
IPI1:          0          0  Timer broadcast interrupts
IPI2:         32         63  Rescheduling interrupts
IPI3:       3925       5381  Function call interrupts
IPI4:          0          0  CPU stop interrupts
IPI5:       4375       3778  IRQ work interrupts
IPI6:          0          0  completion interrupts
Err:          0

Do you happen to know whether the QEMU emulation is trustworthy?

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...