drivers/irqchip/irq-loongarch-cpu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/kernel.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqchip.h>
  11 #include <linux/irqdomain.h>
  12
  13 #include <asm/loongarch.h>
  14 #include <asm/setup.h>
  15
  16 static struct irq_domain *irq_domain;
  17 struct fwnode_handle *cpuintc_handle;
  18
  19 static u32 lpic_gsi_to_irq(u32 gsi)
  20 {
  21         /* Only pch irqdomain transferring is required for LoongArch. */
  22         if (gsi >= GSI_MIN_PCH_IRQ && gsi <= GSI_MAX_PCH_IRQ)
  23                 return acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH);
  24
  25         return 0;
  26 }
  27
  28 static struct fwnode_handle *lpic_get_gsi_domain_id(u32 gsi)
  29 {
  30         int id;
  31         struct fwnode_handle *domain_handle = NULL;
  32
  33         switch (gsi) {
  34         case GSI_MIN_CPU_IRQ ... GSI_MAX_CPU_IRQ:
  35                 if (liointc_handle)
  36                         domain_handle = liointc_handle;
  37                 break;
  38
  39         case GSI_MIN_LPC_IRQ ... GSI_MAX_LPC_IRQ:
  40                 if (pch_lpc_handle)
  41                         domain_handle = pch_lpc_handle;
  42                 break;
  43
  44         case GSI_MIN_PCH_IRQ ... GSI_MAX_PCH_IRQ:
  45                 id = find_pch_pic(gsi);
  46                 if (id >= 0 && pch_pic_handle[id])
  47                         domain_handle = pch_pic_handle[id];
  48                 break;
  49         }
  50
  51         return domain_handle;
  52 }
  53
  54 static void mask_loongarch_irq(struct irq_data *d)
  55 {
  56         clear_csr_ecfg(ECFGF(d->hwirq));
  57 }
  58
  59 static void unmask_loongarch_irq(struct irq_data *d)
  60 {
  61         set_csr_ecfg(ECFGF(d->hwirq));
  62 }
  63
  64 static struct irq_chip cpu_irq_controller = {
  65         .name           = "CPUINTC",
  66         .irq_mask       = mask_loongarch_irq,
  67         .irq_unmask     = unmask_loongarch_irq,
  68 };
  69
  70 static void handle_cpu_irq(struct pt_regs *regs)
  71 {
  72         int hwirq;
  73         unsigned int estat = read_csr_estat() & CSR_ESTAT_IS;
  74
  75         while ((hwirq = ffs(estat))) {
  76                 estat &= ~BIT(hwirq - 1);
  77                 generic_handle_domain_irq(irq_domain, hwirq - 1);
  78         }
  79 }
  80
  81 static int loongarch_cpu_intc_map(struct irq_domain *d, unsigned int irq,
  82                              irq_hw_number_t hwirq)
  83 {
  84         irq_set_noprobe(irq);
  85         irq_set_chip_and_handler(irq, &cpu_irq_controller, handle_percpu_irq);
  86
  87         return 0;
  88 }
  89
  90 static const struct irq_domain_ops loongarch_cpu_intc_irq_domain_ops = {
  91         .map = loongarch_cpu_intc_map,
  92         .xlate = irq_domain_xlate_onecell,
  93 };
  94
  95 static int __init
  96 liointc_parse_madt(union acpi_subtable_headers *header,
  97                        const unsigned long end)
  98 {
  99         struct acpi_madt_lio_pic *liointc_entry = (struct acpi_madt_lio_pic *)header;
 100
 101         return liointc_acpi_init(irq_domain, liointc_entry);
 102 }
 103
 104 static int __init
 105 eiointc_parse_madt(union acpi_subtable_headers *header,
 106                        const unsigned long end)
 107 {
 108         struct acpi_madt_eio_pic *eiointc_entry = (struct acpi_madt_eio_pic *)header;
 109
 110         return eiointc_acpi_init(irq_domain, eiointc_entry);
 111 }
 112
 113 static int __init acpi_cascade_irqdomain_init(void)
 114 {
 115         acpi_table_parse_madt(ACPI_MADT_TYPE_LIO_PIC,
 116                               liointc_parse_madt, 0);
 117         acpi_table_parse_madt(ACPI_MADT_TYPE_EIO_PIC,
 118                               eiointc_parse_madt, 0);
 119         return 0;
 120 }
 121
 122 static int __init cpuintc_acpi_init(union acpi_subtable_headers *header,
 123                                    const unsigned long end)
 124 {
 125         if (irq_domain)
 126                 return 0;
 127
 128         /* Mask interrupts. */
 129         clear_csr_ecfg(ECFG0_IM);
 130         clear_csr_estat(ESTATF_IP);
 131
 132         cpuintc_handle = irq_domain_alloc_fwnode(NULL);
 133         irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
 134                                         &loongarch_cpu_intc_irq_domain_ops, NULL);
 135
 136         if (!irq_domain)
 137                 panic("Failed to add irqdomain for LoongArch CPU");
 138
 139         set_handle_irq(&handle_cpu_irq);
 140         acpi_set_irq_model(ACPI_IRQ_MODEL_LPIC, lpic_get_gsi_domain_id);
 141         acpi_set_gsi_to_irq_fallback(lpic_gsi_to_irq);
 142         acpi_cascade_irqdomain_init();
 143
 144         return 0;
 145 }
 146
 147 IRQCHIP_ACPI_DECLARE(cpuintc_v1, ACPI_MADT_TYPE_CORE_PIC,
 148                 NULL, ACPI_MADT_CORE_PIC_VERSION_V1, cpuintc_acpi_init);