On 18/01/18 05:28, Ganapatrao Kulkarni wrote:
> This erratum is observed on the ThunderX2 GICv3 ITS. When a
> MOVI command is used to change affinity of a LPI to a collection/cpu
> on another node, the LPI is not delivered to the cpu.
> An additional INV command is required after the MOVI to deliver
> the LPI to the new destination.
>
> If we add INV after MOVI, there is a chance that we lose LPIs which
> are raised when the affinity is changed. So for now, adding workaround fix
> to disable inter node affinity change.
>
> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@xxxxxxxxxx>
> ---
>
> v2: Added workaround to avoid inter node affinity change.
>
> v1: Initial patch
>
> Documentation/arm64/silicon-errata.txt | 1 +
> arch/arm64/Kconfig | 10 ++++++++++
> drivers/irqchip/irq-gic-v3-its.c | 21 ++++++++++++++++++++-
> 3 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
> index fc1c884..fb27cb5 100644
> --- a/Documentation/arm64/silicon-errata.txt
> +++ b/Documentation/arm64/silicon-errata.txt
> @@ -63,6 +63,7 @@ stable kernels.
> | Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456 |
> | Cavium | ThunderX Core | #30115 | CAVIUM_ERRATUM_30115 |
> | Cavium | ThunderX SMMUv2 | #27704 | N/A |
> +| Cavium | ThunderX2 ITS | #174 | CAVIUM_ERRATUM_174 |
> | Cavium | ThunderX2 SMMUv3| #74 | N/A |
> | Cavium | ThunderX2 SMMUv3| #126 | N/A |
> | | | | |
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index c9a7e9e..0dbf3bd 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -461,6 +461,16 @@ config ARM64_ERRATUM_843419
>
> If unsure, say Y.
>
> +config CAVIUM_ERRATUM_174
> + bool "Cavium ThunderX2 erratum 174"
> + default y
> + help
> + Cavium ThunderX2 dual socket systems may loose interrupts
> + on affinity change to a cpu on other node.
> + This workaround fix avoids inter node affinity change.
> +
> + If unsure, say Y.
> +
> config CAVIUM_ERRATUM_22375
> bool "Cavium erratum 22375, 24313"
> default y
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 06f025f..b0cb528 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -46,6 +46,7 @@
> #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0)
> #define ITS_FLAGS_WORKAROUND_CAVIUM_22375 (1ULL << 1)
> #define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2)
> +#define ITS_FLAGS_WORKAROUND_CAVIUM_174 (1ULL << 3)
Instead of inventing a new flag, please rename the existing one to
ITS_FLAG_WORKAROUND_RESTRICT_NODE_AFFINITY (or something similar). There
is really no need to have two flags that do the exact same thing,
>
> #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
>
> @@ -1102,7 +1103,8 @@ static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
> return -EINVAL;
>
> /* lpi cannot be routed to a redistributor that is on a foreign node */
> - if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
> + if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144 ||
> + its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_174) {
> if (its_dev->its->numa_node >= 0) {
> cpu_mask = cpumask_of_node(its_dev->its->numa_node);
> if (!cpumask_intersects(mask_val, cpu_mask))
> @@ -2904,6 +2906,15 @@ static int its_force_quiescent(void __iomem *base)
> }
> }
>
> +static bool __maybe_unused its_enable_quirk_cavium_174(void *data)
> +{
> + struct its_node *its = data;
> +
> + its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_174;
> +
> + return true;
> +}
> +
> static bool __maybe_unused its_enable_quirk_cavium_22375(void *data)
> {
> struct its_node *its = data;
> @@ -3031,6 +3042,14 @@ static const struct gic_quirk its_quirks[] = {
> .init = its_enable_quirk_hip07_161600802,
> },
> #endif
> +#ifdef CONFIG_CAVIUM_ERRATUM_174
> + {
> + .desc = "ITS: Cavium ThunderX2 erratum 174",
> + .iidr = 0x13f, /* ThunderX2 pass A1/A2/B0 */
> + .mask = 0xffffffff,
> + .init = its_enable_quirk_cavium_174,
> + },
> +#endif
> {
> }
> };
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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