irqchip/gic-v2m: acpi: Introducing GICv2m ACPI support

This patch introduces gicv2m_acpi_init(), which uses information
in MADT GIC MSI frames structure to initialize GICv2m driver.
It also exposes gicv2m_init() function, which simplifies callers
to a single GICv2m init function.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Duc Dang <dhdang@apm.com>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

2 files changed, 114 insertions, 2 deletions

diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
index 779c3906a22e..7e2975df4473 100644
--- a/drivers/irqchip/irq-gic-v2m.c
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -15,9 +15,11 @@
 
 #define pr_fmt(fmt) "GICv2m: " fmt
 
+#include <linux/acpi.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
+#include <linux/msi.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
 #include <linux/slab.h>
@@ -138,6 +140,11 @@ static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
                 fwspec.param[0] = 0;
                 fwspec.param[1] = hwirq - 32;
                 fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+        } else if (is_fwnode_irqchip(domain->parent->fwnode)) {
+                fwspec.fwnode = domain->parent->fwnode;
+                fwspec.param_count = 2;
+                fwspec.param[0] = hwirq;
+                fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
         } else {
                 return -EINVAL;
         }
@@ -255,6 +262,8 @@ static void gicv2m_teardown(void)
                 kfree(v2m->bm);
                 iounmap(v2m->base);
                 of_node_put(to_of_node(v2m->fwnode));
+                if (is_fwnode_irqchip(v2m->fwnode))
+                        irq_domain_free_fwnode(v2m->fwnode);
                 kfree(v2m);
         }
 }
@@ -373,9 +382,11 @@ static struct of_device_id gicv2m_device_id[] = {
         {},
 };
 
-int __init gicv2m_of_init(struct device_node *node, struct irq_domain *parent)
+static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
+                                 struct irq_domain *parent)
 {
         int ret = 0;
+        struct device_node *node = to_of_node(parent_handle);
         struct device_node *child;
 
         for (child = of_find_matching_node(node, gicv2m_device_id); child;
@@ -411,3 +422,100 @@ int __init gicv2m_of_init(struct device_node *node, struct irq_domain *parent)
                 gicv2m_teardown();
         return ret;
 }
+
+#ifdef CONFIG_ACPI
+static int acpi_num_msi;
+
+static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
+{
+        struct v2m_data *data;
+
+        if (WARN_ON(acpi_num_msi <= 0))
+                return NULL;
+
+        /* We only return the fwnode of the first MSI frame. */
+        data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
+        if (!data)
+                return NULL;
+
+        return data->fwnode;
+}
+
+static int __init
+acpi_parse_madt_msi(struct acpi_subtable_header *header,
+                    const unsigned long end)
+{
+        int ret;
+        struct resource res;
+        u32 spi_start = 0, nr_spis = 0;
+        struct acpi_madt_generic_msi_frame *m;
+        struct fwnode_handle *fwnode;
+
+        m = (struct acpi_madt_generic_msi_frame *)header;
+        if (BAD_MADT_ENTRY(m, end))
+                return -EINVAL;
+
+        res.start = m->base_address;
+        res.end = m->base_address + SZ_4K;
+
+        if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
+                spi_start = m->spi_base;
+                nr_spis = m->spi_count;
+
+                pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
+                        spi_start, nr_spis);
+        }
+
+        fwnode = irq_domain_alloc_fwnode((void *)m->base_address);
+        if (!fwnode) {
+                pr_err("Unable to allocate GICv2m domain token\n");
+                return -EINVAL;
+        }
+
+        ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res);
+        if (ret)
+                irq_domain_free_fwnode(fwnode);
+
+        return ret;
+}
+
+static int __init gicv2m_acpi_init(struct irq_domain *parent)
+{
+        int ret;
+
+        if (acpi_num_msi > 0)
+                return 0;
+
+        acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
+                                      acpi_parse_madt_msi, 0);
+
+        if (acpi_num_msi <= 0)
+                goto err_out;
+
+        ret = gicv2m_allocate_domains(parent);
+        if (ret)
+                goto err_out;
+
+        pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
+
+        return 0;
+
+err_out:
+        gicv2m_teardown();
+        return -EINVAL;
+}
+#else /* CONFIG_ACPI */
+static int __init gicv2m_acpi_init(struct irq_domain *parent)
+{
+        return -EINVAL;
+}
+#endif /* CONFIG_ACPI */
+
+int __init gicv2m_init(struct fwnode_handle *parent_handle,
+                       struct irq_domain *parent)
+{
+        if (is_of_node(parent_handle))
+                return gicv2m_of_init(parent_handle, parent);
+
+        return gicv2m_acpi_init(parent);
+}
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index fcd327f49e8e..644e8bbe130c 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1234,7 +1234,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
         }
 
         if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
-                gicv2m_of_init(node, gic_data[gic_cnt].domain);
+                gicv2m_init(&node->fwnode, gic_data[gic_cnt].domain);
 
         gic_cnt++;
         return 0;
@@ -1359,6 +1359,10 @@ static int __init gic_v2_acpi_init(struct acpi_subtable_header *header,
         __gic_init_bases(0, -1, dist_base, cpu_base, 0, domain_handle);
 
         acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);
+
+        if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
+                gicv2m_init(NULL, gic_data[0].domain);
+
         return 0;
 }
 IRQCHIP_ACPI_DECLARE(gic_v2, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,