[PATCH v3 2/2] drivers/irqchip: gicv3: add workaround for Synquacer pre-ITS
Ard Biesheuvel
ard.biesheuvel at linaro.org
Thu Oct 12 12:11:52 PDT 2017
On 12 October 2017 at 19:32, Ard Biesheuvel <ard.biesheuvel at linaro.org> 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 | 63 +++++++++++++++++++-
> 3 files changed, 72 insertions(+), 3 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..0798a61bbf99 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: (u32, u32) tuple describing the host address
> + and size of the pre-ITS window, as implemented on the Socionext Synquacer SoC
> +
> 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 0df64a6a56d4..c4361dff2b74 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -539,6 +539,14 @@ 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 891de07fd4cc..2fc4fba0cc4c 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -97,12 +97,18 @@ struct its_node {
> struct its_cmd_block *cmd_write;
> struct its_baser tables[GITS_BASER_NR_REGS];
> struct its_collection *collections;
> + struct fwnode_handle *fwnode_handle;
> struct list_head its_device_list;
> u64 flags;
> u32 ite_size;
> u32 device_ids;
> int numa_node;
> + unsigned int msi_domain_flag_mask;
> bool is_v4;
> +
> + /* for Socionext Synquacer pre-ITS */
> + u32 pre_its_base;
> + u32 pre_its_size;
> };
>
> #define ITS_ITT_ALIGN SZ_256
> @@ -1095,14 +1101,29 @@ 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_device *its_dev)
> +{
> + struct its_node *its = its_dev->its;
> +
> + if (unlikely(its->pre_its_size > 0))
> + /*
> + * 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);
> +
> + 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);
> - struct its_node *its;
> u64 addr;
>
> - its = its_dev->its;
> - addr = its->phys_base + GITS_TRANSLATER;
> + addr = its_irq_get_msi_base(its_dev);
>
> msg->address_lo = lower_32_bits(addr);
> msg->address_hi = upper_32_bits(addr);
> @@ -2752,6 +2773,27 @@ static void __maybe_unused its_enable_quirk_qdf2400_e0065(void *data)
> its->ite_size = 16;
> }
>
> +static void __maybe_unused its_enable_quirk_socionext_synquacer(void *data)
> +{
> + struct its_node *its = data;
> + u32 pre_its_window[2];
> + u32 ids;
> +
> + if (!fwnode_property_read_u32_array(its->fwnode_handle,
> + "socionext,synquacer-pre-its",
> + pre_its_window,
> + ARRAY_SIZE(pre_its_window))) {
> + its->pre_its_base = pre_its_window[0];
> + its->pre_its_size = pre_its_window[1];
> +
> + ids = ilog2(its->pre_its_size) - 2;
> + if (its->device_ids > ids)
> + its->device_ids = ids;
> +
> + its->msi_domain_flag_mask = ~IRQ_DOMAIN_FLAG_MSI_REMAP;
> + }
> +}
> +
> static const struct gic_quirk its_quirks[] = {
> #ifdef CONFIG_CAVIUM_ERRATUM_22375
> {
> @@ -2777,6 +2819,19 @@ static const struct gic_quirk its_quirks[] = {
> .init = its_enable_quirk_qdf2400_e0065,
> },
> #endif
> +#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS
> + {
> + /*
> + * The Socionext Synquacer SoC incorporates ARM's own GIC-500
> + * implementation, but with a 'pre-ITS' added that requires
> + * special handling in software.
> + */
> + .desc = "ITS: Socionext Synquacer pre-ITS",
> + .iidr = 0x0001143b,
> + .mask = 0xffffffff,
> + .init = its_enable_quirk_socionext_synquacer,
> + },
> +#endif
> {
> }
> };
> @@ -2806,6 +2861,7 @@ 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;
> + inner_domain->flags &= its->msi_domain_flag_mask;
Oops. its->msi_domain_flag_mask defaults to 0, so this breaks other platforms.
Unless there are better suggestions, I will move the ~ from the
assignment to here.
> info->ops = &its_msi_domain_ops;
> info->data = its;
> inner_domain->host_data = info;
> @@ -2959,6 +3015,7 @@ static int __init its_probe_one(struct resource *res,
> goto out_free_its;
> }
> its->cmd_write = its->cmd_base;
> + its->fwnode_handle = handle;
>
> its_enable_quirks(its);
>
> --
> 2.11.0
>
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