1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2023-2024, Ventana Micro Systems Inc 4 * Author: Sunil V L <sunilvl@ventanamicro.com> 5 */ 6 7 #include <linux/acpi.h> 8 #include <linux/sort.h> 9 #include <linux/irq.h> 10 11 #include "init.h" 12 13 struct riscv_ext_intc_list { 14 acpi_handle handle; 15 u32 gsi_base; 16 u32 nr_irqs; 17 u32 nr_idcs; 18 u32 id; 19 u32 type; 20 struct list_head list; 21 }; 22 23 LIST_HEAD(ext_intc_list); 24 25 static int irqchip_cmp_func(const void *in0, const void *in1) 26 { 27 struct acpi_probe_entry *elem0 = (struct acpi_probe_entry *)in0; 28 struct acpi_probe_entry *elem1 = (struct acpi_probe_entry *)in1; 29 30 return (elem0->type > elem1->type) - (elem0->type < elem1->type); 31 } 32 33 /* 34 * On RISC-V, RINTC structures in MADT should be probed before any other 35 * interrupt controller structures and IMSIC before APLIC. The interrupt 36 * controller subtypes in MADT of ACPI spec for RISC-V are defined in 37 * the incremental order like RINTC(24)->IMSIC(25)->APLIC(26)->PLIC(27). 38 * Hence, simply sorting the subtypes in incremental order will 39 * establish the required order. 40 */ 41 void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr) 42 { 43 struct acpi_probe_entry *ape = ap_head; 44 45 if (nr == 1 || !ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) 46 return; 47 sort(ape, nr, sizeof(*ape), irqchip_cmp_func, NULL); 48 } 49 50 static acpi_status riscv_acpi_update_gsi_handle(u32 gsi_base, acpi_handle handle) 51 { 52 struct riscv_ext_intc_list *ext_intc_element; 53 struct list_head *i, *tmp; 54 55 list_for_each_safe(i, tmp, &ext_intc_list) { 56 ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list); 57 if (gsi_base == ext_intc_element->gsi_base) { 58 ext_intc_element->handle = handle; 59 return AE_OK; 60 } 61 } 62 63 return AE_NOT_FOUND; 64 } 65 66 int riscv_acpi_get_gsi_info(struct fwnode_handle *fwnode, u32 *gsi_base, 67 u32 *id, u32 *nr_irqs, u32 *nr_idcs) 68 { 69 struct riscv_ext_intc_list *ext_intc_element; 70 struct list_head *i; 71 72 list_for_each(i, &ext_intc_list) { 73 ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list); 74 if (ext_intc_element->handle == ACPI_HANDLE_FWNODE(fwnode)) { 75 *gsi_base = ext_intc_element->gsi_base; 76 *id = ext_intc_element->id; 77 *nr_irqs = ext_intc_element->nr_irqs; 78 if (nr_idcs) 79 *nr_idcs = ext_intc_element->nr_idcs; 80 81 return 0; 82 } 83 } 84 85 return -ENODEV; 86 } 87 88 struct fwnode_handle *riscv_acpi_get_gsi_domain_id(u32 gsi) 89 { 90 struct riscv_ext_intc_list *ext_intc_element; 91 struct acpi_device *adev; 92 struct list_head *i; 93 94 list_for_each(i, &ext_intc_list) { 95 ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list); 96 if (gsi >= ext_intc_element->gsi_base && 97 gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs)) { 98 adev = acpi_fetch_acpi_dev(ext_intc_element->handle); 99 if (!adev) 100 return NULL; 101 102 return acpi_fwnode_handle(adev); 103 } 104 } 105 106 return NULL; 107 } 108 109 static int __init riscv_acpi_register_ext_intc(u32 gsi_base, u32 nr_irqs, u32 nr_idcs, 110 u32 id, u32 type) 111 { 112 struct riscv_ext_intc_list *ext_intc_element; 113 114 ext_intc_element = kzalloc(sizeof(*ext_intc_element), GFP_KERNEL); 115 if (!ext_intc_element) 116 return -ENOMEM; 117 118 ext_intc_element->gsi_base = gsi_base; 119 ext_intc_element->nr_irqs = nr_irqs; 120 ext_intc_element->nr_idcs = nr_idcs; 121 ext_intc_element->id = id; 122 list_add_tail(&ext_intc_element->list, &ext_intc_list); 123 return 0; 124 } 125 126 static acpi_status __init riscv_acpi_create_gsi_map(acpi_handle handle, u32 level, 127 void *context, void **return_value) 128 { 129 acpi_status status; 130 u64 gbase; 131 132 if (!acpi_has_method(handle, "_GSB")) { 133 acpi_handle_err(handle, "_GSB method not found\n"); 134 return AE_ERROR; 135 } 136 137 status = acpi_evaluate_integer(handle, "_GSB", NULL, &gbase); 138 if (ACPI_FAILURE(status)) { 139 acpi_handle_err(handle, "failed to evaluate _GSB method\n"); 140 return status; 141 } 142 143 status = riscv_acpi_update_gsi_handle((u32)gbase, handle); 144 if (ACPI_FAILURE(status)) { 145 acpi_handle_err(handle, "failed to find the GSI mapping entry\n"); 146 return status; 147 } 148 149 return AE_OK; 150 } 151 152 static int __init riscv_acpi_aplic_parse_madt(union acpi_subtable_headers *header, 153 const unsigned long end) 154 { 155 struct acpi_madt_aplic *aplic = (struct acpi_madt_aplic *)header; 156 157 return riscv_acpi_register_ext_intc(aplic->gsi_base, aplic->num_sources, aplic->num_idcs, 158 aplic->id, ACPI_RISCV_IRQCHIP_APLIC); 159 } 160 161 static int __init riscv_acpi_plic_parse_madt(union acpi_subtable_headers *header, 162 const unsigned long end) 163 { 164 struct acpi_madt_plic *plic = (struct acpi_madt_plic *)header; 165 166 return riscv_acpi_register_ext_intc(plic->gsi_base, plic->num_irqs, 0, 167 plic->id, ACPI_RISCV_IRQCHIP_PLIC); 168 } 169 170 void __init riscv_acpi_init_gsi_mapping(void) 171 { 172 /* There can be either PLIC or APLIC */ 173 if (acpi_table_parse_madt(ACPI_MADT_TYPE_PLIC, riscv_acpi_plic_parse_madt, 0) > 0) { 174 acpi_get_devices("RSCV0001", riscv_acpi_create_gsi_map, NULL, NULL); 175 return; 176 } 177 178 if (acpi_table_parse_madt(ACPI_MADT_TYPE_APLIC, riscv_acpi_aplic_parse_madt, 0) > 0) 179 acpi_get_devices("RSCV0002", riscv_acpi_create_gsi_map, NULL, NULL); 180 } 181