[PATCH 2/2] irqchip/riscv-aplic: Save and restore APLIC registers
Nick Hu
nick.hu at sifive.com
Thu Jul 17 00:26:59 PDT 2025
On Thu, Jul 17, 2025 at 1:15 PM Anup Patel <anup at brainfault.org> wrote:
>
> On Wed, Jul 9, 2025 at 8:26 AM Nick Hu <nick.hu at sifive.com> wrote:
> >
> > The APLIC may be powered down when the CPUs enter a deep sleep state.
> > Therefore adding the APLIC save and restore functions to save and
> > restore the states of APLIC.
> >
> > Signed-off-by: Nick Hu <nick.hu at sifive.com>
> > Reviewed-by: Yong-Xuan Wang <yongxuan.wang at sifive.com>
> > Reviewed-by: Cyan Yang <cyan.yang at sifive.com>
> > ---
> > drivers/irqchip/irq-riscv-aplic-direct.c | 14 ++-
> > drivers/irqchip/irq-riscv-aplic-main.c | 143 +++++++++++++++++++++++
> > drivers/irqchip/irq-riscv-aplic-main.h | 12 ++
> > drivers/irqchip/irq-riscv-aplic-msi.c | 3 +-
> > 4 files changed, 170 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> > index 205ad61d15e4..df42f979d02c 100644
> > --- a/drivers/irqchip/irq-riscv-aplic-direct.c
> > +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> > @@ -8,6 +8,7 @@
> > #include <linux/bitfield.h>
> > #include <linux/bitops.h>
> > #include <linux/cpu.h>
> > +#include <linux/cpumask.h>
> > #include <linux/interrupt.h>
> > #include <linux/irqchip.h>
> > #include <linux/irqchip/chained_irq.h>
> > @@ -171,6 +172,16 @@ static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> > writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> > }
> >
> > +void aplic_direct_restore(struct aplic_priv *priv)
> > +{
> > + struct aplic_direct *direct =
> > + container_of(priv, struct aplic_direct, priv);
> > + int cpu;
> > +
> > + for_each_cpu(cpu, &direct->lmask)
> > + aplic_idc_set_delivery(per_cpu_ptr(&aplic_idcs, cpu), true);
> > +}
> > +
> > static int aplic_direct_dying_cpu(unsigned int cpu)
> > {
> > if (aplic_direct_parent_irq)
> > @@ -343,5 +354,6 @@ int aplic_direct_setup(struct device *dev, void __iomem *regs)
> > dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> > priv->nr_irqs, priv->nr_idcs);
> >
> > - return 0;
> > + /* Add the aplic_priv to the list */
> > + return aplic_add(dev, priv);
> > }
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > index 93e7c51f944a..9054ce7a7256 100644
> > --- a/drivers/irqchip/irq-riscv-aplic-main.c
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> > @@ -12,10 +12,130 @@
> > #include <linux/of.h>
> > #include <linux/of_irq.h>
> > #include <linux/platform_device.h>
> > +#include <linux/pm_domain.h>
> > +#include <linux/pm_runtime.h>
> > #include <linux/printk.h>
> > +#include <linux/syscore_ops.h>
> >
> > #include "irq-riscv-aplic-main.h"
> >
> > +static LIST_HEAD(aplics);
> > +
> > +static void aplic_restore(struct aplic_priv *priv)
> > +{
> > + int i;
> > + u32 clrip;
> > +
> > + writel(priv->saved_domaincfg, priv->regs + APLIC_DOMAINCFG);
> > +#ifdef CONFIG_RISCV_M_MODE
> > + writel(priv->saved_msiaddr, priv->regs + APLIC_xMSICFGADDR);
> > + writel(priv->saved_msiaddrh, priv->regs + APLIC_xMSICFGADDRH);
> > +#endif
> > + for (i = 1; i <= priv->nr_irqs; i++) {
> > + writel(priv->saved_sourcecfg[i - 1],
> > + priv->regs + APLIC_SOURCECFG_BASE +
> > + (i - 1) * sizeof(u32));
> > + writel(priv->saved_target[i - 1],
> > + priv->regs + APLIC_TARGET_BASE +
> > + (i - 1) * sizeof(u32));
> > + }
> > +
> > + for (i = 0; i <= priv->nr_irqs; i += 32) {
> > + writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> > + (i / 32) * sizeof(u32));
> > + writel(priv->saved_ie[i / 32],
> > + priv->regs + APLIC_SETIE_BASE +
> > + (i / 32) * sizeof(u32));
> > + }
> > +
> > + if (priv->nr_idcs) {
> > + aplic_direct_restore(priv);
> > + } else {
> > + /* Re-trigger the interrupts */
> > + for (i = 0; i <= priv->nr_irqs; i += 32) {
> > + clrip = readl(priv->regs + APLIC_CLRIP_BASE +
> > + (i / 32) * sizeof(u32));
> > + writel(clrip, priv->regs + APLIC_SETIP_BASE +
> > + (i / 32) * sizeof(u32));
> > + }
> > + }
> > +}
> > +
> > +static void aplic_save(struct aplic_priv *priv)
> > +{
> > + int i;
> > +
> > + for (i = 1; i <= priv->nr_irqs; i++) {
> > + priv->saved_target[i - 1] = readl(priv->regs +
> > + APLIC_TARGET_BASE +
> > + (i - 1) * sizeof(u32));
> > + }
> > +
> > + for (i = 0; i <= priv->nr_irqs; i += 32) {
> > + priv->saved_ie[i / 32] = readl(priv->regs +
> > + APLIC_SETIE_BASE +
> > + (i / 32) * sizeof(u32));
> > + }
> > +}
> > +
> > +static int aplic_syscore_suspend(void)
> > +{
> > + struct aplic_priv *priv;
> > +
> > + list_for_each_entry(priv, &aplics, list) {
> > + aplic_save(priv);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static void aplic_syscore_resume(void)
> > +{
> > + struct aplic_priv *priv;
> > +
> > + list_for_each_entry(priv, &aplics, list) {
> > + aplic_restore(priv);
> > + }
> > +}
> > +
> > +static struct syscore_ops aplic_syscore_ops = {
> > + .suspend = aplic_syscore_suspend,
> > + .resume = aplic_syscore_resume,
> > +};
> > +
> > +static int aplic_notifier(struct notifier_block *nb, unsigned long action,
> > + void *data)
>
> s/aplic_notifier/aplic_pm_notifier/
>
> The "void *data" parameter can be on the same line as function declaration.
>
> > +{
> > + struct aplic_priv *priv = container_of(nb, struct aplic_priv, genpd_nb);
> > +
> > + switch (action) {
> > + case GENPD_NOTIFY_PRE_OFF:
> > + aplic_save(priv);
> > + break;
> > + case GENPD_NOTIFY_ON:
> > + aplic_restore(priv);
> > + break;
> > + default:
> > + break;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +int aplic_add(struct device *dev, struct aplic_priv *priv)
> > +{
> > + int ret;
> > +
> > + list_add(&priv->list, &aplics);
> > + /* Add genpd notifier */
> > + priv->genpd_nb.notifier_call = aplic_notifier;
> > + ret = dev_pm_genpd_add_notifier(dev, &priv->genpd_nb);
> > + if (!ret)
> > + return devm_pm_runtime_enable(dev);
> > +
> > + return ret == -ENODEV || ret == -EOPNOTSUPP ? 0 : ret;
> > +}
> > +
>
> Make aplic_add() as static and directly call it from aplic_setup_priv().
>
> To cleanup upon device removal, use devm_add_action_or_reset().
>
> > void aplic_irq_unmask(struct irq_data *d)
> > {
> > struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > @@ -59,6 +179,7 @@ int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> > sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> > sourcecfg += (d->hwirq - 1) * sizeof(u32);
> > writel(val, sourcecfg);
> > + priv->saved_sourcecfg[d->hwirq - 1] = val;
> >
> > return 0;
> > }
> > @@ -95,6 +216,8 @@ void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXS, priv->msicfg.hhxs);
> > writel(val, priv->regs + APLIC_xMSICFGADDR);
> > writel(valh, priv->regs + APLIC_xMSICFGADDRH);
> > + priv->saved_msiaddr = val;
> > + priv->saved_msiaddrh = valH;
> > }
> > #endif
> >
> > @@ -106,6 +229,7 @@ void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > writel(val, priv->regs + APLIC_DOMAINCFG);
> > if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> > dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n", val);
> > + priv->saved_domaincfg = val;
> > }
> >
> > static void aplic_init_hw_irqs(struct aplic_priv *priv)
> > @@ -176,6 +300,23 @@ int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *
> > /* Setup initial state APLIC interrupts */
> > aplic_init_hw_irqs(priv);
> >
> > + /* For power management */
> > + priv->saved_target = devm_kzalloc(dev, priv->nr_irqs * sizeof(u32),
> > + GFP_KERNEL);
> > + if (!priv->saved_target)
> > + return -ENOMEM;
> > +
> > + priv->saved_sourcecfg = devm_kzalloc(dev, priv->nr_irqs * sizeof(u32),
> > + GFP_KERNEL);
> > + if (!priv->saved_sourcecfg)
> > + return -ENOMEM;
> > +
> > + priv->saved_ie = devm_kzalloc(dev,
> > + DIV_ROUND_UP(priv->nr_irqs, 32) * sizeof(u32),
> > + GFP_KERNEL);
> > + if (!priv->saved_ie)
> > + return -ENOMEM;
> > +
> > return 0;
> > }
> >
> > @@ -209,6 +350,8 @@ static int aplic_probe(struct platform_device *pdev)
> > if (rc)
> > dev_err_probe(dev, rc, "failed to setup APLIC in %s mode\n",
> > msi_mode ? "MSI" : "direct");
> > + else
> > + register_syscore_ops(&aplic_syscore_ops);
> >
> > #ifdef CONFIG_ACPI
> > if (!acpi_disabled)
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
> > index b0ad8cde69b1..969319242dbc 100644
> > --- a/drivers/irqchip/irq-riscv-aplic-main.h
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.h
> > @@ -31,6 +31,16 @@ struct aplic_priv {
> > u32 acpi_aplic_id;
> > void __iomem *regs;
> > struct aplic_msicfg msicfg;
> > + struct notifier_block genpd_nb;
> > + struct list_head list;
>
> Rename "list" as "head" and make it first variable
> in "struct aplic_priv"
>
> > + u32 *saved_target;
> > + u32 *saved_sourcecfg;
> > + u32 *saved_ie;
> > + u32 saved_domaincfg;
> > +#ifdef CONFIG_RISCV_M_MODE
> > + u32 saved_msiaddr;
> > + u32 saved_msiaddrh;
> > +#endif
> > };
> >
> > void aplic_irq_unmask(struct irq_data *d);
> > @@ -39,7 +49,9 @@ int aplic_irq_set_type(struct irq_data *d, unsigned int type);
> > int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > unsigned long *hwirq, unsigned int *type);
> > void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
> > +void aplic_direct_restore(struct aplic_priv *priv);
> > int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs);
> > +int aplic_add(struct device *dev, struct aplic_priv *priv);
> > int aplic_direct_setup(struct device *dev, void __iomem *regs);
> > #ifdef CONFIG_RISCV_APLIC_MSI
> > int aplic_msi_setup(struct device *dev, void __iomem *regs);
> > diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c
> > index fb8d1838609f..c9b4f7d5e6ea 100644
> > --- a/drivers/irqchip/irq-riscv-aplic-msi.c
> > +++ b/drivers/irqchip/irq-riscv-aplic-msi.c
> > @@ -281,5 +281,6 @@ int aplic_msi_setup(struct device *dev, void __iomem *regs)
> > pa = priv->msicfg.base_ppn << APLIC_xMSICFGADDR_PPN_SHIFT;
> > dev_info(dev, "%d interrupts forwarded to MSI base %pa\n", priv->nr_irqs, &pa);
> >
> > - return 0;
> > + /* Add the aplic_priv to the list */
> > + return aplic_add(dev, priv);
> > }
> > --
> > 2.17.1
> >
>
> Also, please address the issue reported by the kernel test robot.
>
Will apply the above feedback in the next version. Thanks!
Regards,
Nick
> Regards,
> Anup
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