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Message-ID: <21a0183b-bf4b-1895-d10b-8287dbff930a@arm.com>
Date: Thu, 8 Nov 2018 11:26:02 +0000
From: Julien Thierry <julien.thierry@....com>
To: Robert Richter <rrichter@...ium.com>,
Marc Zyngier <marc.zyngier@....com>,
Thomas Gleixner <tglx@...utronix.de>,
Jason Cooper <jason@...edaemon.net>
Cc: "linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Stuart Yoder <stuyoder@...il.com>,
Laurentiu Tudor <laurentiu.tudor@....com>,
Matthias Brugger <matthias.bgg@...il.com>,
Will Deacon <will.deacon@....com>,
Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
"Richter, Robert" <Robert.Richter@...ium.com>
Subject: Re: [PATCH 08/10] irqchip/gic-v3-its: Decouple its initialization
from gic
On 07/11/18 22:03, Robert Richter wrote:
> This patch separates its initialization from the gic. Probing and
> initialization of its nodes is separate now. There is an own cpu
> notifier for its now.
>
> Signed-off-by: Robert Richter <rrichter@...ium.com>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 58 +++++++++++++++++++++++++-------------
> drivers/irqchip/irq-gic-v3.c | 14 ++++-----
> include/linux/cpuhotplug.h | 1 +
> include/linux/irqchip/arm-gic-v3.h | 2 +-
> 4 files changed, 48 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index c28f4158ff70..fd8561fcfdf3 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -167,6 +167,7 @@ static struct {
> } vpe_proxy;
>
> static LIST_HEAD(its_nodes);
> +static LIST_HEAD(its_probed);
> static DEFINE_RAW_SPINLOCK(its_lock);
> static struct rdists *gic_rdists;
> static struct irq_domain *its_parent;
> @@ -3482,20 +3483,13 @@ static int __init its_compute_its_list_map(struct its_node *its)
>
> static void its_free(struct its_node *its)
> {
> - raw_spin_lock(&its_lock);
> - list_del(&its->entry);
> - raw_spin_unlock(&its_lock);
> -
> kfree(its);
> }
>
> -static int __init its_init_one(struct its_node *its);
> -
> static int __init its_probe_one(struct resource *res,
> struct fwnode_handle *handle, int numa_node)
> {
> struct its_node *its;
> - int err;
>
> its = kzalloc(sizeof(*its), GFP_KERNEL);
> if (!its)
> @@ -3510,16 +3504,12 @@ static int __init its_probe_one(struct resource *res,
> its->numa_node = numa_node;
>
> raw_spin_lock(&its_lock);
> - list_add_tail(&its->entry, &its_nodes);
> + list_add_tail(&its->entry, &its_probed);
> raw_spin_unlock(&its_lock);
>
> pr_info("ITS %pR\n", res);
>
> - err = its_init_one(its);
> - if (err)
> - its_free(its);
> -
> - return err;
> + return 0;
> }
>
> static int __init its_init_one(struct its_node *its)
> @@ -3717,7 +3707,7 @@ static int redist_disable_lpis(void)
> return 0;
> }
>
> -int its_cpu_init(void)
> +static int its_cpu_init(unsigned int cpu)
> {
> if (!list_empty(&its_nodes)) {
> int ret;
> @@ -3913,8 +3903,6 @@ static void __init its_acpi_probe(void)
> static void __init its_acpi_probe(void) { }
> #endif
>
> -static int __init its_init(void);
> -
> int __init its_probe(struct fwnode_handle *handle, struct rdists *rdists,
> struct irq_domain *parent_domain)
> {
> @@ -3929,23 +3917,51 @@ int __init its_probe(struct fwnode_handle *handle, struct rdists *rdists,
>
> gic_rdists = rdists;
>
> - return its_init();
> + return 0;
> }
>
> -static int __init its_init(void)
> +int __init its_init(void)
> {
> struct its_node *its;
> bool has_v4 = false;
> int err;
>
> + if (list_empty(&its_probed))
> + return 0;
> +
> + raw_spin_lock(&its_lock);
> +redo:
> + list_for_each_entry(its, &its_probed, entry) {
> + list_del_init(&its->entry);
> +
> + raw_spin_unlock(&its_lock);
> +
> + /* Needs to be called in non-atomic context */
> + err = its_init_one(its);
> + if (err)
> + its_free(its);
> +
> + raw_spin_lock(&its_lock);
> +
> + if (!err)
> + list_add_tail(&its->entry, &its_nodes);
> +
> + goto redo;
Again, you're starting a loop only to work on the first element and then
restarting the loop.
Just do a while (!list_empty()), and without gotos...
> + }
> +
> + raw_spin_unlock(&its_lock);
> +
> if (list_empty(&its_nodes)) {
> pr_warn("ITS: No ITS available, not enabling LPIs\n");
> return -ENXIO;
> }
>
> err = allocate_lpi_tables();
> - if (err)
> + if (err) {
> + pr_warn("ITS: Failed to initialize (%d), not enabling LPIs\n",
> + err);
> return err;
> + }
>
> list_for_each_entry(its, &its_nodes, entry)
> has_v4 |= its->is_v4;
> @@ -3960,5 +3976,9 @@ static int __init its_init(void)
>
> register_syscore_ops(&its_syscore_ops);
>
> + cpuhp_setup_state(CPUHP_AP_IRQ_GIC_ITS_STARTING,
> + "irqchip/arm/gicv3-its:starting",
> + its_cpu_init, NULL);
> +
> return 0;
> }
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index e04108b7c6b7..d2942efdb6d5 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -685,9 +685,6 @@ static int gic_starting_cpu(unsigned int cpu)
> {
> gic_cpu_init();
>
> - if (gic_dist_supports_lpis())
> - its_cpu_init();
> -
> return 0;
> }
>
> @@ -815,7 +812,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
> #else
> #define gic_set_affinity NULL
> #define gic_smp_init() do { } while(0)
> -#endif
> +#endif /* CONFIG_SMP */
>
> #ifdef CONFIG_CPU_PM
> /* Check whether it's single security state view */
> @@ -1131,10 +1128,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
> gic_cpu_init();
> gic_cpu_pm_init();
>
> - if (gic_dist_supports_lpis()) {
> + if (gic_dist_supports_lpis())
> its_probe(handle, &gic_data.rdists, gic_data.domain);
> - its_cpu_init();
> - }
>
> return 0;
>
> @@ -1327,6 +1322,9 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare
>
> if (static_branch_likely(&supports_deactivate_key))
> gic_of_setup_kvm_info(node);
> +
> + its_init();
> +
> return 0;
>
> out_unmap_rdist:
> @@ -1630,6 +1628,8 @@ gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
> if (static_branch_likely(&supports_deactivate_key))
> gic_acpi_setup_kvm_info();
>
> + its_init();
> +
> return 0;
>
> out_fwhandle_free:
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index e0cd2baa8380..584f73585142 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -96,6 +96,7 @@ enum cpuhp_state {
> CPUHP_AP_SCHED_STARTING,
> CPUHP_AP_RCUTREE_DYING,
> CPUHP_AP_IRQ_GIC_STARTING,
> + CPUHP_AP_IRQ_GIC_ITS_STARTING,
> CPUHP_AP_IRQ_HIP04_STARTING,
> CPUHP_AP_IRQ_ARMADA_XP_STARTING,
> CPUHP_AP_IRQ_BCM2836_STARTING,
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index a6fdb2910f73..f4348fa4260a 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -602,9 +602,9 @@ struct rdists {
>
> struct irq_domain;
> struct fwnode_handle;
> -int its_cpu_init(void);
> int its_probe(struct fwnode_handle *handle, struct rdists *rdists,
> struct irq_domain *domain);
> +int its_init(void);
> int mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent);
>
> static inline bool gic_enable_sre(void)
>
--
Julien Thierry
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