[PATCH v4] irqchip/irq-sifive-plic: Add syscore callbacks for hibernation
Mason Huo
mason.huo at starfivetech.com
Thu Mar 30 03:33:25 PDT 2023
On 2023/3/30 0:44, Emil Renner Berthing wrote:
> On Wed, 8 Mar 2023 at 07:49, Mason Huo <mason.huo at starfivetech.com> wrote:
>>
>> The priority and enable registers of plic will be reset
>> during hibernation power cycle in poweroff mode,
>> add the syscore callbacks to save/restore those registers.
>>
>> Signed-off-by: Mason Huo <mason.huo at starfivetech.com>
>> Reviewed-by: Ley Foon Tan <leyfoon.tan at starfivetech.com>
>> Reviewed-by: Sia Jee Heng <jeeheng.sia at starfivetech.com>
>> Reported-by: Dan Carpenter <error27 at gmail.com>
>> Link: https://lore.kernel.org/r/202302140709.CdkxgtPi-lkp@intel.com/
>> ---
>> drivers/irqchip/irq-sifive-plic.c | 93 ++++++++++++++++++++++++++++++-
>> 1 file changed, 91 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
>> index ff47bd0dec45..2800e7bb149a 100644
>> --- a/drivers/irqchip/irq-sifive-plic.c
>> +++ b/drivers/irqchip/irq-sifive-plic.c
>> @@ -17,6 +17,7 @@
>> #include <linux/of_irq.h>
>> #include <linux/platform_device.h>
>> #include <linux/spinlock.h>
>> +#include <linux/syscore_ops.h>
>> #include <asm/smp.h>
>>
>> /*
>> @@ -67,6 +68,8 @@ struct plic_priv {
>> struct irq_domain *irqdomain;
>> void __iomem *regs;
>> unsigned long plic_quirks;
>> + unsigned int nr_irqs;
>> + unsigned long *prio_save;
>> };
>>
>> struct plic_handler {
>> @@ -78,6 +81,7 @@ struct plic_handler {
>> */
>> raw_spinlock_t enable_lock;
>> void __iomem *enable_base;
>> + u32 *enable_save;
>> struct plic_priv *priv;
>> };
>> static int plic_parent_irq __ro_after_init;
>> @@ -229,6 +233,71 @@ static int plic_irq_set_type(struct irq_data *d, unsigned int type)
>> return IRQ_SET_MASK_OK;
>> }
>>
>> +static int plic_irq_suspend(void)
>> +{
>> + unsigned int i, cpu;
>> + u32 __iomem *reg;
>> + struct plic_priv *priv;
>> +
>> + priv = per_cpu_ptr(&plic_handlers, smp_processor_id())->priv;
>> +
>> + for (i = 0; i < priv->nr_irqs; i++)
>> + if (readl(priv->regs + PRIORITY_BASE + i * PRIORITY_PER_ID))
>> + __set_bit(i, priv->prio_save);
>> + else
>> + __clear_bit(i, priv->prio_save);
>> +
>> + for_each_cpu(cpu, cpu_present_mask) {
>> + struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
>> +
>> + if (!handler->present)
>> + continue;
>> +
>> + raw_spin_lock(&handler->enable_lock);
>> + for (i = 0; i < DIV_ROUND_UP(priv->nr_irqs, 32); i++) {
>> + reg = handler->enable_base + i * sizeof(u32);
>> + handler->enable_save[i] = readl(reg);
>> + }
>> + raw_spin_unlock(&handler->enable_lock);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void plic_irq_resume(void)
>> +{
>> + unsigned int i, index, cpu;
>> + u32 __iomem *reg;
>> + struct plic_priv *priv;
>> +
>> + priv = per_cpu_ptr(&plic_handlers, smp_processor_id())->priv;
>> +
>> + for (i = 0; i < priv->nr_irqs; i++) {
>> + index = (i / BITS_PER_LONG);
>> + writel((priv->prio_save[index] & BIT(i % BITS_PER_LONG)) ? 1 : 0,
>
> This looks like BIT_WORD and test_bit (or at least BIT_MASK).
>
Hi Emil,
Thanks for your review, will replace it.
>> + priv->regs + PRIORITY_BASE + i * PRIORITY_PER_ID);
>> + }
>> +
>> + for_each_cpu(cpu, cpu_present_mask) {
>> + struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
>> +
>> + if (!handler->present)
>> + continue;
>> +
>> + raw_spin_lock(&handler->enable_lock);
>> + for (i = 0; i < DIV_ROUND_UP(priv->nr_irqs, 32); i++) {
>> + reg = handler->enable_base + i * sizeof(u32);
>> + writel(handler->enable_save[i], reg);
>> + }
>> + raw_spin_unlock(&handler->enable_lock);
>> + }
>> +}
>> +
>> +static struct syscore_ops plic_irq_syscore_ops = {
>> + .suspend = plic_irq_suspend,
>> + .resume = plic_irq_resume,
>> +};
>> +
>> static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
>> irq_hw_number_t hwirq)
>> {
>> @@ -345,6 +414,7 @@ static int __init __plic_init(struct device_node *node,
>> u32 nr_irqs;
>> struct plic_priv *priv;
>> struct plic_handler *handler;
>> + unsigned int cpu;
>>
>> priv = kzalloc(sizeof(*priv), GFP_KERNEL);
>> if (!priv)
>> @@ -363,15 +433,21 @@ static int __init __plic_init(struct device_node *node,
>> if (WARN_ON(!nr_irqs))
>> goto out_iounmap;
>>
>> + priv->nr_irqs = nr_irqs;
>> +
>> + priv->prio_save = bitmap_alloc(nr_irqs, GFP_KERNEL);
>> + if (!priv->prio_save)
>> + goto out_free_priority_reg;
>> +
>> nr_contexts = of_irq_count(node);
>> if (WARN_ON(!nr_contexts))
>> - goto out_iounmap;
>> + goto out_free_priority_reg;
>>
>> error = -ENOMEM;
>> priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
>> &plic_irqdomain_ops, priv);
>> if (WARN_ON(!priv->irqdomain))
>> - goto out_iounmap;
>> + goto out_free_priority_reg;
>>
>> for (i = 0; i < nr_contexts; i++) {
>> struct of_phandle_args parent;
>> @@ -441,6 +517,11 @@ static int __init __plic_init(struct device_node *node,
>> handler->enable_base = priv->regs + CONTEXT_ENABLE_BASE +
>> i * CONTEXT_ENABLE_SIZE;
>> handler->priv = priv;
>> +
>> + handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs, 32),
>> + sizeof(*handler->enable_save), GFP_KERNEL);
>> + if (!handler->enable_save)
>> + goto out_free_enable_reg;
>> done:
>> for (hwirq = 1; hwirq <= nr_irqs; hwirq++) {
>> plic_toggle(handler, hwirq, 0);
>> @@ -461,11 +542,19 @@ static int __init __plic_init(struct device_node *node,
>> plic_starting_cpu, plic_dying_cpu);
>> plic_cpuhp_setup_done = true;
>> }
>> + register_syscore_ops(&plic_irq_syscore_ops);
>>
>> pr_info("%pOFP: mapped %d interrupts with %d handlers for"
>> " %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
>> return 0;
>>
>> +out_free_enable_reg:
>> + for_each_cpu(cpu, cpu_present_mask) {
>> + handler = per_cpu_ptr(&plic_handlers, cpu);
>> + kfree(handler->enable_save);
>> + }
>> +out_free_priority_reg:
>> + kfree(priv->prio_save);
>> out_iounmap:
>> iounmap(priv->regs);
>> out_free_priv:
>> --
>> 2.39.2
>>
>>
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