[PATCH] drivers/irqchip: gicv3: add workaround for Synquacer pre-ITS
Robin Murphy
robin.murphy at arm.com
Thu Oct 5 05:19:33 PDT 2017
On 05/10/17 12:43, Ard Biesheuvel wrote:
> The Socionext Synquacer SoC's implementation of GICv3 has a so-called
> 'pre-ITS', which maps 32-bit writes targeted at a separate window of
> size '4 << device_id_bits' onto writes to GITS_TRANSLATER with device
> ID taken from bits [device_id_bits + 1:2] of the window offset.
> Writes that target GITS_TRANSLATER directly are reported as originating
> from device ID #0.
>
> So add a workaround for this. Given that this breaks isolation, clear
> the IRQ_DOMAIN_FLAG_MSI_REMAP flag as well.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---
> Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt | 4 ++
> arch/arm64/Kconfig | 8 ++++
> drivers/irqchip/irq-gic-v3-its.c | 50 ++++++++++++++++++--
> 3 files changed, 58 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> index 4c29cdab0ea5..112ebb286728 100644
> --- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> @@ -75,6 +75,10 @@ These nodes must have the following properties:
> - reg: Specifies the base physical address and size of the ITS
> registers.
>
> +Optional:
> +- socionext,synquacer-pre-its: (u64, u64) tuple describing the PCI address
> + and size of the pre-ITS window.
> +
> The main GIC node must contain the appropriate #address-cells,
> #size-cells and ranges properties for the reg property of all ITS
> nodes.
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index dfd908630631..081722240936 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -538,6 +538,14 @@ config QCOM_QDF2400_ERRATUM_0065
>
> If unsure, say Y.
>
> +config SOCIONEXT_SYNQUACER_PREITS
> + bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
> + default y
> + help
> + Socionext Synquacer SoCs implement a separate h/w block to generate
> + MSI doorbell writes with non-zero values for the device ID.
> +
> + If unsure, say Y.
> endmenu
>
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 284738add89b..fb86b15fa10d 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -45,6 +45,7 @@
> #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_SOCIONEXT_PREITS (1ULL << 3)
>
> #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
>
> @@ -85,6 +86,10 @@ struct its_node {
> struct its_collection *collections;
> struct list_head its_device_list;
> u64 flags;
> +#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS
> + u64 pre_its_base;
> + u64 pre_its_size;
> +#endif
> u32 ite_size;
> u32 device_ids;
> int numa_node;
> @@ -654,6 +659,23 @@ static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
> return IRQ_SET_MASK_OK_DONE;
> }
>
> +static u64 its_irq_get_msi_base(struct its_node *its)
> +{
> +#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS
> + if (its->flags & ITS_FLAGS_WORKAROUND_SOCIONEXT_PREITS)
> +
> + /*
> + * The Socionext Synquacer SoC has a so-called 'pre-ITS',
> + * which maps 32-bit writes targeted at a separate window of
> + * size '4 << device_id_bits' onto writes to GITS_TRANSLATER
> + * with device ID taken from bits [device_id_bits + 1:2] of
> + * the window offset.
> + */
> + return its->pre_its_base + (its_dev->device_id << 2);
> +#endif
> + return its->phys_base + GITS_TRANSLATER;
> +}
> +
> static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
> {
> struct its_device *its_dev = irq_data_get_irq_chip_data(d);
> @@ -661,12 +683,15 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
> u64 addr;
>
> its = its_dev->its;
> - addr = its->phys_base + GITS_TRANSLATER;
> + addr = its_irq_get_msi_base(its);
>
> msg->address_lo = lower_32_bits(addr);
> msg->address_hi = upper_32_bits(addr);
> msg->data = its_get_event_id(d);
>
> + if (its->flags & ITS_FLAGS_WORKAROUND_SOCIONEXT_PREITS)
> + return;
Oh, goody. If the pre-ITS is in front of SMMU translation as well then
we're really going to need that generic IOMMU reserved region binding.
Does this thing plan to support ACPI booting as well?
Robin.
> +
> iommu_dma_map_msi_msg(d->irq, msg);
> }
>
> @@ -1044,6 +1069,11 @@ static int its_alloc_tables(struct its_node *its)
> ids = 0x14; /* 20 bits, 8MB */
> }
>
> +#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS
> + if (its->flags & ITS_FLAGS_WORKAROUND_SOCIONEXT_PREITS)
> + ids = ilog2(its->pre_its_size) - 2;
> +#endif
> +
> its->device_ids = ids;
>
> for (i = 0; i < GITS_BASER_NR_REGS; i++) {
> @@ -1640,11 +1670,21 @@ static const struct gic_quirk its_quirks[] = {
> }
> };
>
> -static void its_enable_quirks(struct its_node *its)
> +static void its_enable_quirks(struct its_node *its,
> + struct fwnode_handle *handle)
> {
> u32 iidr = readl_relaxed(its->base + GITS_IIDR);
>
> gic_enable_quirks(iidr, its_quirks, its);
> +
> +#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS
> + if (!fwnode_property_read_u64_array(handle,
> + "socionext,synquacer-pre-its",
> + &its->pre_its_base, 2)) {
> + its->flags |= ITS_FLAGS_WORKAROUND_SOCIONEXT_PREITS;
> + pr_info("ITS: enabling workaround for Socionext Synquacer pre-ITS\n");
> + }
> +#endif
> }
>
> static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
> @@ -1664,7 +1704,9 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
>
> inner_domain->parent = its_parent;
> irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
> - inner_domain->flags |= IRQ_DOMAIN_FLAG_MSI_REMAP;
> +
> + if (!(its->flags & ITS_FLAGS_WORKAROUND_SOCIONEXT_PREITS))
> + inner_domain->flags |= IRQ_DOMAIN_FLAG_MSI_REMAP;
> info->ops = &its_msi_domain_ops;
> info->data = its;
> inner_domain->host_data = info;
> @@ -1724,7 +1766,7 @@ static int __init its_probe_one(struct resource *res,
> }
> its->cmd_write = its->cmd_base;
>
> - its_enable_quirks(its);
> + its_enable_quirks(its, handle);
>
> err = its_alloc_tables(its);
> if (err)
>
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