drivers/irqchip/irq-armada-370-xp.c

   1 /*
   2  * Marvell Armada 370 and Armada XP SoC IRQ handling
   3  *
   4  * Copyright (C) 2012 Marvell
   5  *
   6  * Lior Amsalem <alior@marvell.com>
   7  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   8  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   9  * Ben Dooks <ben.dooks@codethink.co.uk>
  10  *
  11  * This file is licensed under the terms of the GNU General Public
  12  * License version 2.  This program is licensed "as is" without any
  13  * warranty of any kind, whether express or implied.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/irq.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/io.h>
  22 #include <linux/of_address.h>
  23 #include <linux/of_irq.h>
  24 #include <linux/irqdomain.h>
  25 #include <asm/mach/arch.h>
  26 #include <asm/exception.h>
  27 #include <asm/smp_plat.h>
  28 #include <asm/mach/irq.h>
  29
  30 #include "irqchip.h"
  31
  32 /* Interrupt Controller Registers Map */
  33 #define ARMADA_370_XP_INT_SET_MASK_OFFS         (0x48)
  34 #define ARMADA_370_XP_INT_CLEAR_MASK_OFFS       (0x4C)
  35
  36 #define ARMADA_370_XP_INT_CONTROL               (0x00)
  37 #define ARMADA_370_XP_INT_SET_ENABLE_OFFS       (0x30)
  38 #define ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS     (0x34)
  39 #define ARMADA_370_XP_INT_SOURCE_CTL(irq)       (0x100 + irq*4)
  40
  41 #define ARMADA_370_XP_CPU_INTACK_OFFS           (0x44)
  42
  43 #define ARMADA_370_XP_SW_TRIG_INT_OFFS           (0x4)
  44 #define ARMADA_370_XP_IN_DRBEL_MSK_OFFS          (0xc)
  45 #define ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS        (0x8)
  46
  47 #define ARMADA_370_XP_MAX_PER_CPU_IRQS          (28)
  48
  49 #define ARMADA_370_XP_TIMER0_PER_CPU_IRQ        (5)
  50
  51 #define IPI_DOORBELL_START                      (0)
  52 #define IPI_DOORBELL_END                        (8)
  53 #define IPI_DOORBELL_MASK                       0xFF
  54
  55 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
  56
  57 static void __iomem *per_cpu_int_base;
  58 static void __iomem *main_int_base;
  59 static struct irq_domain *armada_370_xp_mpic_domain;
  60
  61 /*
  62  * In SMP mode:
  63  * For shared global interrupts, mask/unmask global enable bit
  64  * For CPU interrtups, mask/unmask the calling CPU's bit
  65  */
  66 static void armada_370_xp_irq_mask(struct irq_data *d)
  67 {
  68 #ifdef CONFIG_SMP
  69         irq_hw_number_t hwirq = irqd_to_hwirq(d);
  70
  71         if (hwirq != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
  72                 writel(hwirq, main_int_base +
  73                                 ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
  74         else
  75                 writel(hwirq, per_cpu_int_base +
  76                                 ARMADA_370_XP_INT_SET_MASK_OFFS);
  77 #else
  78         writel(irqd_to_hwirq(d),
  79                per_cpu_int_base + ARMADA_370_XP_INT_SET_MASK_OFFS);
  80 #endif
  81 }
  82
  83 static void armada_370_xp_irq_unmask(struct irq_data *d)
  84 {
  85 #ifdef CONFIG_SMP
  86         irq_hw_number_t hwirq = irqd_to_hwirq(d);
  87
  88         if (hwirq != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
  89                 writel(hwirq, main_int_base +
  90                                 ARMADA_370_XP_INT_SET_ENABLE_OFFS);
  91         else
  92                 writel(hwirq, per_cpu_int_base +
  93                                 ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
  94 #else
  95         writel(irqd_to_hwirq(d),
  96                per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
  97 #endif
  98 }
  99
 100 #ifdef CONFIG_SMP
 101 static int armada_xp_set_affinity(struct irq_data *d,
 102                                   const struct cpumask *mask_val, bool force)
 103 {
 104         unsigned long reg;
 105         unsigned long new_mask = 0;
 106         unsigned long online_mask = 0;
 107         unsigned long count = 0;
 108         irq_hw_number_t hwirq = irqd_to_hwirq(d);
 109         int cpu;
 110
 111         for_each_cpu(cpu, mask_val) {
 112                 new_mask |= 1 << cpu_logical_map(cpu);
 113                 count++;
 114         }
 115
 116         /*
 117          * Forbid mutlicore interrupt affinity
 118          * This is required since the MPIC HW doesn't limit
 119          * several CPUs from acknowledging the same interrupt.
 120          */
 121         if (count > 1)
 122                 return -EINVAL;
 123
 124         for_each_cpu(cpu, cpu_online_mask)
 125                 online_mask |= 1 << cpu_logical_map(cpu);
 126
 127         raw_spin_lock(&irq_controller_lock);
 128
 129         reg = readl(main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
 130         reg = (reg & (~online_mask)) | new_mask;
 131         writel(reg, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
 132
 133         raw_spin_unlock(&irq_controller_lock);
 134
 135         return 0;
 136 }
 137 #endif
 138
 139 static struct irq_chip armada_370_xp_irq_chip = {
 140         .name           = "armada_370_xp_irq",
 141         .irq_mask       = armada_370_xp_irq_mask,
 142         .irq_mask_ack   = armada_370_xp_irq_mask,
 143         .irq_unmask     = armada_370_xp_irq_unmask,
 144 #ifdef CONFIG_SMP
 145         .irq_set_affinity = armada_xp_set_affinity,
 146 #endif
 147 };
 148
 149 static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
 150                                       unsigned int virq, irq_hw_number_t hw)
 151 {
 152         armada_370_xp_irq_mask(irq_get_irq_data(virq));
 153         writel(hw, main_int_base + ARMADA_370_XP_INT_SET_ENABLE_OFFS);
 154         irq_set_status_flags(virq, IRQ_LEVEL);
 155
 156         if (hw == ARMADA_370_XP_TIMER0_PER_CPU_IRQ) {
 157                 irq_set_percpu_devid(virq);
 158                 irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
 159                                         handle_percpu_devid_irq);
 160
 161         } else {
 162                 irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
 163                                         handle_level_irq);
 164         }
 165         set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
 166
 167         return 0;
 168 }
 169
 170 #ifdef CONFIG_SMP
 171 void armada_mpic_send_doorbell(const struct cpumask *mask, unsigned int irq)
 172 {
 173         int cpu;
 174         unsigned long map = 0;
 175
 176         /* Convert our logical CPU mask into a physical one. */
 177         for_each_cpu(cpu, mask)
 178                 map |= 1 << cpu_logical_map(cpu);
 179
 180         /*
 181          * Ensure that stores to Normal memory are visible to the
 182          * other CPUs before issuing the IPI.
 183          */
 184         dsb();
 185
 186         /* submit softirq */
 187         writel((map << 8) | irq, main_int_base +
 188                 ARMADA_370_XP_SW_TRIG_INT_OFFS);
 189 }
 190
 191 void armada_xp_mpic_smp_cpu_init(void)
 192 {
 193         /* Clear pending IPIs */
 194         writel(0, per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
 195
 196         /* Enable first 8 IPIs */
 197         writel(IPI_DOORBELL_MASK, per_cpu_int_base +
 198                 ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
 199
 200         /* Unmask IPI interrupt */
 201         writel(0, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
 202 }
 203 #endif /* CONFIG_SMP */
 204
 205 static struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
 206         .map = armada_370_xp_mpic_irq_map,
 207         .xlate = irq_domain_xlate_onecell,
 208 };
 209
 210 static asmlinkage void __exception_irq_entry
 211 armada_370_xp_handle_irq(struct pt_regs *regs)
 212 {
 213         u32 irqstat, irqnr;
 214
 215         do {
 216                 irqstat = readl_relaxed(per_cpu_int_base +
 217                                         ARMADA_370_XP_CPU_INTACK_OFFS);
 218                 irqnr = irqstat & 0x3FF;
 219
 220                 if (irqnr > 1022)
 221                         break;
 222
 223                 if (irqnr > 0) {
 224                         irqnr = irq_find_mapping(armada_370_xp_mpic_domain,
 225                                         irqnr);
 226                         handle_IRQ(irqnr, regs);
 227                         continue;
 228                 }
 229 #ifdef CONFIG_SMP
 230                 /* IPI Handling */
 231                 if (irqnr == 0) {
 232                         u32 ipimask, ipinr;
 233
 234                         ipimask = readl_relaxed(per_cpu_int_base +
 235                                                 ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
 236                                 & IPI_DOORBELL_MASK;
 237
 238                         writel(~IPI_DOORBELL_MASK, per_cpu_int_base +
 239                                 ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
 240
 241                         /* Handle all pending doorbells */
 242                         for (ipinr = IPI_DOORBELL_START;
 243                              ipinr < IPI_DOORBELL_END; ipinr++) {
 244                                 if (ipimask & (0x1 << ipinr))
 245                                         handle_IPI(ipinr, regs);
 246                         }
 247                         continue;
 248                 }
 249 #endif
 250
 251         } while (1);
 252 }
 253
 254 static int __init armada_370_xp_mpic_of_init(struct device_node *node,
 255                                              struct device_node *parent)
 256 {
 257         u32 control;
 258
 259         main_int_base = of_iomap(node, 0);
 260         per_cpu_int_base = of_iomap(node, 1);
 261
 262         BUG_ON(!main_int_base);
 263         BUG_ON(!per_cpu_int_base);
 264
 265         control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
 266
 267         armada_370_xp_mpic_domain =
 268                 irq_domain_add_linear(node, (control >> 2) & 0x3ff,
 269                                 &armada_370_xp_mpic_irq_ops, NULL);
 270
 271         if (!armada_370_xp_mpic_domain)
 272                 panic("Unable to add Armada_370_Xp MPIC irq domain (DT)\n");
 273
 274         irq_set_default_host(armada_370_xp_mpic_domain);
 275
 276 #ifdef CONFIG_SMP
 277         armada_xp_mpic_smp_cpu_init();
 278
 279         /*
 280          * Set the default affinity from all CPUs to the boot cpu.
 281          * This is required since the MPIC doesn't limit several CPUs
 282          * from acknowledging the same interrupt.
 283          */
 284         cpumask_clear(irq_default_affinity);
 285         cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
 286
 287 #endif
 288
 289         set_handle_irq(armada_370_xp_handle_irq);
 290
 291         return 0;
 292 }
 293
 294 IRQCHIP_DECLARE(armada_370_xp_mpic, "marvell,mpic", armada_370_xp_mpic_of_init);