[PATCH v4 5/5] irqchip, gicv3-its: Workaround for Cavium ThunderX errata 22375, 24313

Marc Zyngier
2015-09-07T16:32:25Z

On 14/08/15 19:28, Robert Richter wrote:
> From: Robert Richter <rrichter@cavium.com>
>
> This implements two gicv3-its errata workarounds for ThunderX. Both
> with small impact affecting only ITS table allocation.
>
> erratum 22375: only alloc 8MB table size
> erratum 24313: ignore memory access type
>
> The fixes are in ITS initialization and basically ignore memory access
> type and table size provided by the TYPER and BASER registers.
>
> v3:
> * fix erratum to be dependend from iidr
>
> Signed-off-by: Robert Richter <rrichter@cavium.com>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 35 +++++++++++++++++++++++++++++++----
> 1 file changed, 31 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 697421e834ee..30459df2ee2c 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -39,7 +39,8 @@
> #include "irq-gic-common.h"
> #include "irqchip.h"
>
> -#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1 << 0)
> +#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0)
> +#define ITS_FLAGS_CAVIUM_THUNDERX (1ULL << 1)

I think you might need something slightly more explicit, as I'd expect
some ulterior revision of ThunderX to be eventually fixed...
ITS_FLAGS_THUNDERX_BOGUS_TYPER? Or something based on the errata numbers?

>
> #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
>
> @@ -803,9 +804,22 @@ static int its_alloc_tables(struct its_node *its)
> int i;
> int psz = SZ_64K;
> u64 shr = GITS_BASER_InnerShareable;
> - u64 cache = GITS_BASER_WaWb;
> - u64 typer = readq_relaxed(its->base + GITS_TYPER);
> - u32 ids = GITS_TYPER_DEVBITS(typer);
> + u64 cache;
> + u64 typer;
> + u32 ids;
> +
> + if (its->flags & ITS_FLAGS_CAVIUM_THUNDERX) {
> + /*
> + * erratum 22375: only alloc 8MB table size
> + * erratum 24313: ignore memory access type
> + */
> + cache = 0;
> + ids = 0x13; /* 20 bits, 8MB */
> + } else {

You can move the typer definition here, as it is only used here.

> + cache = GITS_BASER_WaWb;
> + typer = readq_relaxed(its->base + GITS_TYPER);
> + ids = GITS_TYPER_DEVBITS(typer);
> + }
>
> for (i = 0; i < GITS_BASER_NR_REGS; i++) {
> u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
> @@ -1391,8 +1405,21 @@ static int its_force_quiescent(void __iomem *base)
> }
> }
>
> +static void its_enable_cavium_thunderx(void *data)
> +{
> + struct its_node *its = data;
> +
> + its->flags |= ITS_FLAGS_CAVIUM_THUNDERX;
> +}
> +
> static const struct gic_capabilities its_errata[] = {
> {
> + .desc = "ITS: Cavium errata 22375, 24313",
> + .iidr = 0xa100034c, /* ThunderX pass 1.x */
> + .mask = 0xffff0fff,
> + .init = its_enable_cavium_thunderx,
> + },
> + {
> }
> };
>
>

Otherwise looks OK to me.

Thanks,

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