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Message-ID: <86d12cg13b.wl-marc.zyngier@arm.com>
Date: Sun, 14 Jan 2018 10:56:56 +0000
From: Marc Zyngier <marc.zyngier@....com>
To: Derek Basehore <dbasehore@...omium.org>
Cc: linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
rafael.j.wysocki@...el.com, tglx@...utronix.de,
briannorris@...omium.org
Subject: Re: [PATCH 6/8] irqchip/gic-v3-its: add ability to resend MAPC on resume
On Fri, 12 Jan 2018 21:24:20 +0000,
Derek Basehore wrote:
>
> This adds a DT-binding to resend the MAPC command to an ITS node on
This isn't a DT binding. That's the driver implementation. The binding
is what you put in Documentation/device-tree...
> resume. If the ITS is powered down during suspend and the collections
> are not backed by memory, the ITS will lose that state. This just sets
> up the known state for the collections after the ITS is restored.
>
> Change-Id: I4fe7f3f16500e1d3b14368262f03a43509c0049b
> Signed-off-by: Derek Basehore <dbasehore@...omium.org>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 85 ++++++++++++++++++++++------------------
> 1 file changed, 47 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 5cb808e3d0bf..6d2688a2ee67 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_RESEND_MAPC_ON_RESUME (1ULL << 3)
>
> #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
>
> @@ -1949,52 +1950,53 @@ static void its_cpu_init_lpis(void)
> dsb(sy);
> }
>
> -static void its_cpu_init_collection(void)
> +static void its_cpu_init_collection(struct its_node *its)
> {
> - struct its_node *its;
> - int cpu;
> -
> - spin_lock(&its_lock);
> - cpu = smp_processor_id();
> -
> - list_for_each_entry(its, &its_nodes, entry) {
> - u64 target;
> + int cpu = smp_processor_id();
> + u64 target;
>
> - /* avoid cross node collections and its mapping */
> - if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
> - struct device_node *cpu_node;
> + /* avoid cross node collections and its mapping */
> + if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
> + struct device_node *cpu_node;
>
> - cpu_node = of_get_cpu_node(cpu, NULL);
> - if (its->numa_node != NUMA_NO_NODE &&
> - its->numa_node != of_node_to_nid(cpu_node))
> - continue;
> - }
> + cpu_node = of_get_cpu_node(cpu, NULL);
> + if (its->numa_node != NUMA_NO_NODE &&
> + its->numa_node != of_node_to_nid(cpu_node))
> + return;
> + }
>
> + /*
> + * We now have to bind each collection to its target
> + * redistributor.
> + */
> + if (gic_read_typer(its->base + GITS_TYPER) & GITS_TYPER_PTA) {
> /*
> - * We now have to bind each collection to its target
> + * This ITS wants the physical address of the
> * redistributor.
> */
> - if (gic_read_typer(its->base + GITS_TYPER) & GITS_TYPER_PTA) {
> - /*
> - * This ITS wants the physical address of the
> - * redistributor.
> - */
> - target = gic_data_rdist()->phys_base;
> - } else {
> - /*
> - * This ITS wants a linear CPU number.
> - */
> - target = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
> - target = GICR_TYPER_CPU_NUMBER(target) << 16;
> - }
> + target = gic_data_rdist()->phys_base;
> + } else {
> + /* This ITS wants a linear CPU number. */
> + target = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
> + target = GICR_TYPER_CPU_NUMBER(target) << 16;
> + }
>
> - /* Perform collection mapping */
> - its->collections[cpu].target_address = target;
> - its->collections[cpu].col_id = cpu;
> + /* Perform collection mapping */
> + its->collections[cpu].target_address = target;
> + its->collections[cpu].col_id = cpu;
>
> - its_send_mapc(its, &its->collections[cpu], 1);
> - its_send_invall(its, &its->collections[cpu]);
> - }
> + its_send_mapc(its, &its->collections[cpu], 1);
> + its_send_invall(its, &its->collections[cpu]);
> +}
> +
> +static void its_cpu_init_collections(void)
> +{
> + struct its_node *its;
> +
> + spin_lock(&its_lock);
> +
> + list_for_each_entry(its, &its_nodes, entry)
> + its_cpu_init_collection(its);
>
> spin_unlock(&its_lock);
> }
> @@ -3089,6 +3091,9 @@ void its_restore_enable(void)
> its_write_baser(its, &its->tables[i],
> its->tables[i].val);
> writel_relaxed(ctx->ctlr, base + GITS_CTLR);
> +
> + if (its->flags & ITS_FLAGS_RESEND_MAPC_ON_RESUME)
> + its_cpu_init_collection(its);
> }
> spin_unlock(&its_lock);
> }
> @@ -3312,6 +3317,10 @@ static int __init its_probe_one(struct resource *res,
> ctlr |= GITS_CTLR_ImDe;
> writel_relaxed(ctlr, its->base + GITS_CTLR);
>
> + if (fwnode_property_present(its->fwnode_handle,
> + "resend-mapc-on-resume"))
> + its->flags |= ITS_FLAGS_RESEND_MAPC_ON_RESUME;
This function is firmware agnostic, and I really don't want to make
this thing a general purpose property.
Please set this as a quirk when you detect some particular combination
of HW and firmware (in your case, GIC500 + this property). And again,
the property name is totally backward. IT should be something like
"collection-state-lost-on-suspend".
> +
> err = its_init_domain(handle, its);
> if (err)
> goto out_free_tables;
> @@ -3347,7 +3356,7 @@ int its_cpu_init(void)
> return -ENXIO;
> }
> its_cpu_init_lpis();
> - its_cpu_init_collection();
> + its_cpu_init_collections();
> }
>
> return 0;
> --
> 2.16.0.rc1.238.g530d649a79-goog
>
Thanks,
M.
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