ACPI: RISC-V: Initialize GSI mapping structures

RISC-V has PLIC and APLIC in MADT as well as namespace devices.
Initialize the list of those structures using MADT and namespace devices
to create mapping between the ACPI handle and the GSI ranges. This will
be used later to add dependencies.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://patch.msgid.link/20240812005929.113499-12-sunilvl@ventanamicro.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
index 8e10a94430a2c2bc6228ac7141f16ba832b474c0..44a0b128c60280e41064274e88dac3e402c560df 100644 (file)
--- a/arch/riscv/include/asm/irq.h
+++ b/arch/riscv/include/asm/irq.h
@@ -16,4 +16,26 @@ void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void));
 
 struct fwnode_handle *riscv_get_intc_hwnode(void);
 
+#ifdef CONFIG_ACPI
+
+enum riscv_irqchip_type {
+       ACPI_RISCV_IRQCHIP_INTC         = 0x00,
+       ACPI_RISCV_IRQCHIP_IMSIC        = 0x01,
+       ACPI_RISCV_IRQCHIP_PLIC         = 0x02,
+       ACPI_RISCV_IRQCHIP_APLIC        = 0x03,
+};
+
+int riscv_acpi_get_gsi_info(struct fwnode_handle *fwnode, u32 *gsi_base,
+                           u32 *id, u32 *nr_irqs, u32 *nr_idcs);
+struct fwnode_handle *riscv_acpi_get_gsi_domain_id(u32 gsi);
+
+#else
+static inline int riscv_acpi_get_gsi_info(struct fwnode_handle *fwnode, u32 *gsi_base,
+                                         u32 *id, u32 *nr_irqs, u32 *nr_idcs)
+{
+       return 0;
+}
+
+#endif /* CONFIG_ACPI */
+
 #endif /* _ASM_RISCV_IRQ_H */

diff --git a/drivers/acpi/riscv/init.c b/drivers/acpi/riscv/init.c
index a875a76aa44cdba0bda38f00d9a5c8452c65d1db..5ef97905a72759ea2aab3195e56b7ee580eded96 100644 (file)
--- a/drivers/acpi/riscv/init.c
+++ b/drivers/acpi/riscv/init.c
@@ -5,7 +5,9 @@
  */
 
 #include <linux/acpi.h>
+#include "init.h"
 
 void __init acpi_riscv_init(void)
 {
+       riscv_acpi_init_gsi_mapping();
 }

diff --git a/drivers/acpi/riscv/init.h b/drivers/acpi/riscv/init.h
new file mode 100644 (file)
index 0000000..0b9a07e
--- /dev/null
+++ b/drivers/acpi/riscv/init.h
@@ -0,0 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <linux/init.h>
+
+void __init riscv_acpi_init_gsi_mapping(void);

diff --git a/drivers/acpi/riscv/irq.c b/drivers/acpi/riscv/irq.c
index 835eb6eccd5300652cbb53786c85e6f546f4d9fe..9028787c73a7da7e6cc7d587ff20f76f921bd494 100644 (file)
--- a/drivers/acpi/riscv/irq.c
+++ b/drivers/acpi/riscv/irq.c
@@ -6,6 +6,21 @@
 
 #include <linux/acpi.h>
 #include <linux/sort.h>
+#include <linux/irq.h>
+
+#include "init.h"
+
+struct riscv_ext_intc_list {
+       acpi_handle             handle;
+       u32                     gsi_base;
+       u32                     nr_irqs;
+       u32                     nr_idcs;
+       u32                     id;
+       u32                     type;
+       struct list_head        list;
+};
+
+LIST_HEAD(ext_intc_list);
 
 static int irqchip_cmp_func(const void *in0, const void *in1)
 {
@@ -31,3 +46,135 @@ void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr)
                return;
        sort(ape, nr, sizeof(*ape), irqchip_cmp_func, NULL);
 }
+
+static acpi_status riscv_acpi_update_gsi_handle(u32 gsi_base, acpi_handle handle)
+{
+       struct riscv_ext_intc_list *ext_intc_element;
+       struct list_head *i, *tmp;
+
+       list_for_each_safe(i, tmp, &ext_intc_list) {
+               ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+               if (gsi_base == ext_intc_element->gsi_base) {
+                       ext_intc_element->handle = handle;
+                       return AE_OK;
+               }
+       }
+
+       return AE_NOT_FOUND;
+}
+
+int riscv_acpi_get_gsi_info(struct fwnode_handle *fwnode, u32 *gsi_base,
+                           u32 *id, u32 *nr_irqs, u32 *nr_idcs)
+{
+       struct riscv_ext_intc_list *ext_intc_element;
+       struct list_head *i;
+
+       list_for_each(i, &ext_intc_list) {
+               ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+               if (ext_intc_element->handle == ACPI_HANDLE_FWNODE(fwnode)) {
+                       *gsi_base = ext_intc_element->gsi_base;
+                       *id = ext_intc_element->id;
+                       *nr_irqs = ext_intc_element->nr_irqs;
+                       if (nr_idcs)
+                               *nr_idcs = ext_intc_element->nr_idcs;
+
+                       return 0;
+               }
+       }
+
+       return -ENODEV;
+}
+
+struct fwnode_handle *riscv_acpi_get_gsi_domain_id(u32 gsi)
+{
+       struct riscv_ext_intc_list *ext_intc_element;
+       struct acpi_device *adev;
+       struct list_head *i;
+
+       list_for_each(i, &ext_intc_list) {
+               ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+               if (gsi >= ext_intc_element->gsi_base &&
+                   gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs)) {
+                       adev = acpi_fetch_acpi_dev(ext_intc_element->handle);
+                       if (!adev)
+                               return NULL;
+
+                       return acpi_fwnode_handle(adev);
+               }
+       }
+
+       return NULL;
+}
+
+static int __init riscv_acpi_register_ext_intc(u32 gsi_base, u32 nr_irqs, u32 nr_idcs,
+                                              u32 id, u32 type)
+{
+       struct riscv_ext_intc_list *ext_intc_element;
+
+       ext_intc_element = kzalloc(sizeof(*ext_intc_element), GFP_KERNEL);
+       if (!ext_intc_element)
+               return -ENOMEM;
+
+       ext_intc_element->gsi_base = gsi_base;
+       ext_intc_element->nr_irqs = nr_irqs;
+       ext_intc_element->nr_idcs = nr_idcs;
+       ext_intc_element->id = id;
+       list_add_tail(&ext_intc_element->list, &ext_intc_list);
+       return 0;
+}
+
+static acpi_status __init riscv_acpi_create_gsi_map(acpi_handle handle, u32 level,
+                                                   void *context, void **return_value)
+{
+       acpi_status status;
+       u64 gbase;
+
+       if (!acpi_has_method(handle, "_GSB")) {
+               acpi_handle_err(handle, "_GSB method not found\n");
+               return AE_ERROR;
+       }
+
+       status = acpi_evaluate_integer(handle, "_GSB", NULL, &gbase);
+       if (ACPI_FAILURE(status)) {
+               acpi_handle_err(handle, "failed to evaluate _GSB method\n");
+               return status;
+       }
+
+       status = riscv_acpi_update_gsi_handle((u32)gbase, handle);
+       if (ACPI_FAILURE(status)) {
+               acpi_handle_err(handle, "failed to find the GSI mapping entry\n");
+               return status;
+       }
+
+       return AE_OK;
+}
+
+static int __init riscv_acpi_aplic_parse_madt(union acpi_subtable_headers *header,
+                                             const unsigned long end)
+{
+       struct acpi_madt_aplic *aplic = (struct acpi_madt_aplic *)header;
+
+       return riscv_acpi_register_ext_intc(aplic->gsi_base, aplic->num_sources, aplic->num_idcs,
+                                           aplic->id, ACPI_RISCV_IRQCHIP_APLIC);
+}
+
+static int __init riscv_acpi_plic_parse_madt(union acpi_subtable_headers *header,
+                                            const unsigned long end)
+{
+       struct acpi_madt_plic *plic = (struct acpi_madt_plic *)header;
+
+       return riscv_acpi_register_ext_intc(plic->gsi_base, plic->num_irqs, 0,
+                                           plic->id, ACPI_RISCV_IRQCHIP_PLIC);
+}
+
+void __init riscv_acpi_init_gsi_mapping(void)
+{
+       /* There can be either PLIC or APLIC */
+       if (acpi_table_parse_madt(ACPI_MADT_TYPE_PLIC, riscv_acpi_plic_parse_madt, 0) > 0) {
+               acpi_get_devices("RSCV0001", riscv_acpi_create_gsi_map, NULL, NULL);
+               return;
+       }
+
+       if (acpi_table_parse_madt(ACPI_MADT_TYPE_APLIC, riscv_acpi_aplic_parse_madt, 0) > 0)
+               acpi_get_devices("RSCV0002", riscv_acpi_create_gsi_map, NULL, NULL);
+}