drivers/irqchip/irq-csky-mpintc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/kernel.h>
   5 #include <linux/init.h>
   6 #include <linux/of.h>
   7 #include <linux/of_address.h>
   8 #include <linux/module.h>
   9 #include <linux/irqdomain.h>
  10 #include <linux/irqchip.h>
  11 #include <linux/irq.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/smp.h>
  14 #include <linux/io.h>
  15 #include <asm/irq.h>
  16 #include <asm/traps.h>
  17 #include <asm/reg_ops.h>
  18
  19 static struct irq_domain *root_domain;
  20 static void __iomem *INTCG_base;
  21 static void __iomem *INTCL_base;
  22
  23 #define IPI_IRQ         15
  24 #define INTC_IRQS       256
  25 #define COMM_IRQ_BASE   32
  26
  27 #define INTCG_SIZE      0x8000
  28 #define INTCL_SIZE      0x1000
  29
  30 #define INTCG_ICTLR     0x0
  31 #define INTCG_CICFGR    0x100
  32 #define INTCG_CIDSTR    0x1000
  33
  34 #define INTCL_PICTLR    0x0
  35 #define INTCL_SIGR      0x60
  36 #define INTCL_HPPIR     0x68
  37 #define INTCL_RDYIR     0x6c
  38 #define INTCL_SENR      0xa0
  39 #define INTCL_CENR      0xa4
  40 #define INTCL_CACR      0xb4
  41
  42 static DEFINE_PER_CPU(void __iomem *, intcl_reg);
  43
  44 static void csky_mpintc_handler(struct pt_regs *regs)
  45 {
  46         void __iomem *reg_base = this_cpu_read(intcl_reg);
  47
  48         do {
  49                 handle_domain_irq(root_domain,
  50                                   readl_relaxed(reg_base + INTCL_RDYIR),
  51                                   regs);
  52         } while (readl_relaxed(reg_base + INTCL_HPPIR) & BIT(31));
  53 }
  54
  55 static void csky_mpintc_enable(struct irq_data *d)
  56 {
  57         void __iomem *reg_base = this_cpu_read(intcl_reg);
  58
  59         writel_relaxed(d->hwirq, reg_base + INTCL_SENR);
  60 }
  61
  62 static void csky_mpintc_disable(struct irq_data *d)
  63 {
  64         void __iomem *reg_base = this_cpu_read(intcl_reg);
  65
  66         writel_relaxed(d->hwirq, reg_base + INTCL_CENR);
  67 }
  68
  69 static void csky_mpintc_eoi(struct irq_data *d)
  70 {
  71         void __iomem *reg_base = this_cpu_read(intcl_reg);
  72
  73         writel_relaxed(d->hwirq, reg_base + INTCL_CACR);
  74 }
  75
  76 #ifdef CONFIG_SMP
  77 static int csky_irq_set_affinity(struct irq_data *d,
  78                                  const struct cpumask *mask_val,
  79                                  bool force)
  80 {
  81         unsigned int cpu;
  82         unsigned int offset = 4 * (d->hwirq - COMM_IRQ_BASE);
  83
  84         if (!force)
  85                 cpu = cpumask_any_and(mask_val, cpu_online_mask);
  86         else
  87                 cpu = cpumask_first(mask_val);
  88
  89         if (cpu >= nr_cpu_ids)
  90                 return -EINVAL;
  91
  92         /* Enable interrupt destination */
  93         cpu |= BIT(31);
  94
  95         writel_relaxed(cpu, INTCG_base + INTCG_CIDSTR + offset);
  96
  97         irq_data_update_effective_affinity(d, cpumask_of(cpu));
  98
  99         return IRQ_SET_MASK_OK_DONE;
 100 }
 101 #endif
 102
 103 static struct irq_chip csky_irq_chip = {
 104         .name           = "C-SKY SMP Intc",
 105         .irq_eoi        = csky_mpintc_eoi,
 106         .irq_enable     = csky_mpintc_enable,
 107         .irq_disable    = csky_mpintc_disable,
 108 #ifdef CONFIG_SMP
 109         .irq_set_affinity = csky_irq_set_affinity,
 110 #endif
 111 };
 112
 113 static int csky_irqdomain_map(struct irq_domain *d, unsigned int irq,
 114                               irq_hw_number_t hwirq)
 115 {
 116         if (hwirq < COMM_IRQ_BASE) {
 117                 irq_set_percpu_devid(irq);
 118                 irq_set_chip_and_handler(irq, &csky_irq_chip,
 119                                          handle_percpu_irq);
 120         } else {
 121                 irq_set_chip_and_handler(irq, &csky_irq_chip,
 122                                          handle_fasteoi_irq);
 123         }
 124
 125         return 0;
 126 }
 127
 128 static const struct irq_domain_ops csky_irqdomain_ops = {
 129         .map    = csky_irqdomain_map,
 130         .xlate  = irq_domain_xlate_onecell,
 131 };
 132
 133 #ifdef CONFIG_SMP
 134 static void csky_mpintc_send_ipi(const struct cpumask *mask)
 135 {
 136         void __iomem *reg_base = this_cpu_read(intcl_reg);
 137
 138         /*
 139          * INTCL_SIGR[3:0] INTID
 140          * INTCL_SIGR[8:15] CPUMASK
 141          */
 142         writel_relaxed((*cpumask_bits(mask)) << 8 | IPI_IRQ,
 143                                         reg_base + INTCL_SIGR);
 144 }
 145 #endif
 146
 147 /* C-SKY multi processor interrupt controller */
 148 static int __init
 149 csky_mpintc_init(struct device_node *node, struct device_node *parent)
 150 {
 151         int ret;
 152         unsigned int cpu, nr_irq;
 153 #ifdef CONFIG_SMP
 154         unsigned int ipi_irq;
 155 #endif
 156
 157         if (parent)
 158                 return 0;
 159
 160         ret = of_property_read_u32(node, "csky,num-irqs", &nr_irq);
 161         if (ret < 0)
 162                 nr_irq = INTC_IRQS;
 163
 164         if (INTCG_base == NULL) {
 165                 INTCG_base = ioremap(mfcr("cr<31, 14>"),
 166                                      INTCL_SIZE*nr_cpu_ids + INTCG_SIZE);
 167                 if (INTCG_base == NULL)
 168                         return -EIO;
 169
 170                 INTCL_base = INTCG_base + INTCG_SIZE;
 171
 172                 writel_relaxed(BIT(0), INTCG_base + INTCG_ICTLR);
 173         }
 174
 175         root_domain = irq_domain_add_linear(node, nr_irq, &csky_irqdomain_ops,
 176                                             NULL);
 177         if (!root_domain)
 178                 return -ENXIO;
 179
 180         /* for every cpu */
 181         for_each_present_cpu(cpu) {
 182                 per_cpu(intcl_reg, cpu) = INTCL_base + (INTCL_SIZE * cpu);
 183                 writel_relaxed(BIT(0), per_cpu(intcl_reg, cpu) + INTCL_PICTLR);
 184         }
 185
 186         set_handle_irq(&csky_mpintc_handler);
 187
 188 #ifdef CONFIG_SMP
 189         ipi_irq = irq_create_mapping(root_domain, IPI_IRQ);
 190         if (!ipi_irq)
 191                 return -EIO;
 192
 193         set_send_ipi(&csky_mpintc_send_ipi, ipi_irq);
 194 #endif
 195
 196         return 0;
 197 }
 198 IRQCHIP_DECLARE(csky_mpintc, "csky,mpintc", csky_mpintc_init);