irqchip/sifive-plic: Add ACPI support

Add ACPI support in PLIC driver. Use the mapping created early during
boot to get details about the PLIC.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Co-developed-by: Haibo Xu <haibo1.xu@intel.com>
Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20240812005929.113499-18-sunilvl@ventanamicro.com
[ rjw: Rebase on top of recent irqchip changes ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 4d9ea718086d30a87aefe2644e99c5dc97e1e100..2f6ef5c495bdaa4c34a76e1f9575c54a8eade95a 100644 (file)
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2018 Christoph Hellwig
  */
 #define pr_fmt(fmt) "riscv-plic: " fmt
+#include <linux/acpi.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -71,6 +72,8 @@ struct plic_priv {
        unsigned long plic_quirks;
        unsigned int nr_irqs;
        unsigned long *prio_save;
+       u32 gsi_base;
+       int acpi_plic_id;
 };
 
 struct plic_handler {
@@ -325,6 +328,10 @@ static int plic_irq_domain_translate(struct irq_domain *d,
 {
        struct plic_priv *priv = d->host_data;
 
+       /* For DT, gsi_base is always zero. */
+       if (fwspec->param[0] >= priv->gsi_base)
+               fwspec->param[0] = fwspec->param[0] - priv->gsi_base;
+
        if (test_bit(PLIC_QUIRK_EDGE_INTERRUPT, &priv->plic_quirks))
                return irq_domain_translate_twocell(d, fwspec, hwirq, type);
 
@@ -426,17 +433,36 @@ static const struct of_device_id plic_match[] = {
        {}
 };
 
+#ifdef CONFIG_ACPI
+
+static const struct acpi_device_id plic_acpi_match[] = {
+       { "RSCV0001", 0 },
+       {}
+};
+MODULE_DEVICE_TABLE(acpi, plic_acpi_match);
+
+#endif
 static int plic_parse_nr_irqs_and_contexts(struct fwnode_handle *fwnode,
-                                          u32 *nr_irqs, u32 *nr_contexts)
+                                          u32 *nr_irqs, u32 *nr_contexts,
+                                          u32 *gsi_base, u32 *id)
 {
        int rc;
 
-       /*
-        * Currently, only OF fwnode is supported so extend this
-        * function for ACPI support.
-        */
-       if (!is_of_node(fwnode))
-               return -EINVAL;
+       if (!is_of_node(fwnode)) {
+               rc = riscv_acpi_get_gsi_info(fwnode, gsi_base, id, nr_irqs, NULL);
+               if (rc) {
+                       pr_err("%pfwP: failed to find GSI mapping\n", fwnode);
+                       return rc;
+               }
+
+               *nr_contexts = acpi_rintc_get_plic_nr_contexts(*id);
+               if (WARN_ON(!*nr_contexts)) {
+                       pr_err("%pfwP: no PLIC context available\n", fwnode);
+                       return -EINVAL;
+               }
+
+               return 0;
+       }
 
        rc = of_property_read_u32(to_of_node(fwnode), "riscv,ndev", nr_irqs);
        if (rc) {
@@ -450,22 +476,28 @@ static int plic_parse_nr_irqs_and_contexts(struct fwnode_handle *fwnode,
                return -EINVAL;
        }
 
+       *gsi_base = 0;
+       *id = 0;
+
        return 0;
 }
 
 static int plic_parse_context_parent(struct fwnode_handle *fwnode, u32 context,
-                                    u32 *parent_hwirq, int *parent_cpu)
+                                    u32 *parent_hwirq, int *parent_cpu, u32 id)
 {
        struct of_phandle_args parent;
        unsigned long hartid;
        int rc;
 
-       /*
-        * Currently, only OF fwnode is supported so extend this
-        * function for ACPI support.
-        */
-       if (!is_of_node(fwnode))
-               return -EINVAL;
+       if (!is_of_node(fwnode)) {
+               hartid = acpi_rintc_ext_parent_to_hartid(id, context);
+               if (hartid == INVALID_HARTID)
+                       return -EINVAL;
+
+               *parent_cpu = riscv_hartid_to_cpuid(hartid);
+               *parent_hwirq = RV_IRQ_EXT;
+               return 0;
+       }
 
        rc = of_irq_parse_one(to_of_node(fwnode), context, &parent);
        if (rc)
@@ -489,6 +521,8 @@ static int plic_probe(struct fwnode_handle *fwnode)
        struct plic_priv *priv;
        irq_hw_number_t hwirq;
        void __iomem *regs;
+       int id, context_id;
+       u32 gsi_base;
 
        if (is_of_node(fwnode)) {
                const struct of_device_id *id;
@@ -501,10 +535,12 @@ static int plic_probe(struct fwnode_handle *fwnode)
                if (!regs)
                        return -ENOMEM;
        } else {
-               return -ENODEV;
+               regs = devm_platform_ioremap_resource(to_platform_device(fwnode->dev), 0);
+               if (IS_ERR(regs))
+                       return PTR_ERR(regs);
        }
 
-       error = plic_parse_nr_irqs_and_contexts(fwnode, &nr_irqs, &nr_contexts);
+       error = plic_parse_nr_irqs_and_contexts(fwnode, &nr_irqs, &nr_contexts, &gsi_base, &id);
        if (error)
                goto fail_free_regs;
 
@@ -518,6 +554,8 @@ static int plic_probe(struct fwnode_handle *fwnode)
        priv->plic_quirks = plic_quirks;
        priv->nr_irqs = nr_irqs;
        priv->regs = regs;
+       priv->gsi_base = gsi_base;
+       priv->acpi_plic_id = id;
 
        priv->prio_save = bitmap_zalloc(nr_irqs, GFP_KERNEL);
        if (!priv->prio_save) {
@@ -526,12 +564,23 @@ static int plic_probe(struct fwnode_handle *fwnode)
        }
 
        for (i = 0; i < nr_contexts; i++) {
-               error = plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu);
+               error = plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu,
+                                                 priv->acpi_plic_id);
                if (error) {
                        pr_warn("%pfwP: hwirq for context%d not found\n", fwnode, i);
                        continue;
                }
 
+               if (is_of_node(fwnode)) {
+                       context_id = i;
+               } else {
+                       context_id = acpi_rintc_get_plic_context(priv->acpi_plic_id, i);
+                       if (context_id == INVALID_CONTEXT) {
+                               pr_warn("%pfwP: invalid context id for context%d\n", fwnode, i);
+                               continue;
+                       }
+               }
+
                /*
                 * Skip contexts other than external interrupts for our
                 * privilege level.
@@ -569,10 +618,10 @@ static int plic_probe(struct fwnode_handle *fwnode)
                cpumask_set_cpu(cpu, &priv->lmask);
                handler->present = true;
                handler->hart_base = priv->regs + CONTEXT_BASE +
-                       i * CONTEXT_SIZE;
+                       context_id * CONTEXT_SIZE;
                raw_spin_lock_init(&handler->enable_lock);
                handler->enable_base = priv->regs + CONTEXT_ENABLE_BASE +
-                       i * CONTEXT_ENABLE_SIZE;
+                       context_id * CONTEXT_ENABLE_SIZE;
                handler->priv = priv;
 
                handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs, 32),
@@ -588,8 +637,8 @@ done:
                nr_handlers++;
        }
 
-       priv->irqdomain = irq_domain_add_linear(to_of_node(fwnode), nr_irqs + 1,
-                                               &plic_irqdomain_ops, priv);
+       priv->irqdomain = irq_domain_create_linear(fwnode, nr_irqs + 1,
+                                                  &plic_irqdomain_ops, priv);
        if (WARN_ON(!priv->irqdomain))
                goto fail_cleanup_contexts;
 
@@ -626,13 +675,18 @@ done:
                }
        }
 
+#ifdef CONFIG_ACPI
+       if (!acpi_disabled)
+               acpi_dev_clear_dependencies(ACPI_COMPANION(fwnode->dev));
+#endif
+
        pr_info("%pfwP: mapped %d interrupts with %d handlers for %d contexts.\n",
                fwnode, nr_irqs, nr_handlers, nr_contexts);
        return 0;
 
 fail_cleanup_contexts:
        for (i = 0; i < nr_contexts; i++) {
-               if (plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu))
+               if (plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu, priv->acpi_plic_id))
                        continue;
                if (parent_hwirq != RV_IRQ_EXT || cpu < 0)
                        continue;
@@ -663,6 +717,7 @@ static struct platform_driver plic_driver = {
                .name           = "riscv-plic",
                .of_match_table = plic_match,
                .suppress_bind_attrs = true,
+               .acpi_match_table = ACPI_PTR(plic_acpi_match),
        },
        .probe = plic_platform_probe,
 };