arch/mips/pmcs-msp71xx/msp_irq_cic.c

   1 /*
   2  * Copyright 2010 PMC-Sierra, Inc, derived from irq_cpu.c
   3  *
   4  * This file define the irq handler for MSP CIC subsystem interrupts.
   5  *
   6  * This program is free software; you can redistribute  it and/or modify it
   7  * under  the terms of  the GNU General  Public License as published by the
   8  * Free Software Foundation;  either version 2 of the  License, or (at your
   9  * option) any later version.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/bitops.h>
  16 #include <linux/irq.h>
  17
  18 #include <asm/mipsregs.h>
  19
  20 #include <msp_cic_int.h>
  21 #include <msp_regs.h>
  22
  23 /*
  24  * External API
  25  */
  26 extern void msp_per_irq_init(void);
  27 extern void msp_per_irq_dispatch(void);
  28
  29
  30 /*
  31  * Convenience Macro.  Should be somewhere generic.
  32  */
  33 #define get_current_vpe()   \
  34         ((read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE)
  35
  36 #ifdef CONFIG_SMP
  37
  38 #define LOCK_VPE(flags, mtflags) \
  39 do {                            \
  40         local_irq_save(flags);  \
  41         mtflags = dmt();        \
  42 } while (0)
  43
  44 #define UNLOCK_VPE(flags, mtflags) \
  45 do {                            \
  46         emt(mtflags);           \
  47         local_irq_restore(flags);\
  48 } while (0)
  49
  50 #define LOCK_CORE(flags, mtflags) \
  51 do {                            \
  52         local_irq_save(flags);  \
  53         mtflags = dvpe();       \
  54 } while (0)
  55
  56 #define UNLOCK_CORE(flags, mtflags)             \
  57 do {                            \
  58         evpe(mtflags);          \
  59         local_irq_restore(flags);\
  60 } while (0)
  61
  62 #else
  63
  64 #define LOCK_VPE(flags, mtflags)
  65 #define UNLOCK_VPE(flags, mtflags)
  66 #endif
  67
  68 /* ensure writes to cic are completed */
  69 static inline void cic_wmb(void)
  70 {
  71         const volatile void __iomem *cic_mem = CIC_VPE0_MSK_REG;
  72         volatile u32 dummy_read;
  73
  74         wmb();
  75         dummy_read = __raw_readl(cic_mem);
  76         dummy_read++;
  77 }
  78
  79 static void unmask_cic_irq(struct irq_data *d)
  80 {
  81         volatile u32   *cic_msk_reg = CIC_VPE0_MSK_REG;
  82         int vpe;
  83 #ifdef CONFIG_SMP
  84         unsigned int mtflags;
  85         unsigned long  flags;
  86
  87         /*
  88         * Make sure we have IRQ affinity.  It may have changed while
  89         * we were processing the IRQ.
  90         */
  91         if (!cpumask_test_cpu(smp_processor_id(), d->affinity))
  92                 return;
  93 #endif
  94
  95         vpe = get_current_vpe();
  96         LOCK_VPE(flags, mtflags);
  97         cic_msk_reg[vpe] |= (1 << (d->irq - MSP_CIC_INTBASE));
  98         UNLOCK_VPE(flags, mtflags);
  99         cic_wmb();
 100 }
 101
 102 static void mask_cic_irq(struct irq_data *d)
 103 {
 104         volatile u32 *cic_msk_reg = CIC_VPE0_MSK_REG;
 105         int     vpe = get_current_vpe();
 106 #ifdef CONFIG_SMP
 107         unsigned long flags, mtflags;
 108 #endif
 109         LOCK_VPE(flags, mtflags);
 110         cic_msk_reg[vpe] &= ~(1 << (d->irq - MSP_CIC_INTBASE));
 111         UNLOCK_VPE(flags, mtflags);
 112         cic_wmb();
 113 }
 114 static void msp_cic_irq_ack(struct irq_data *d)
 115 {
 116         mask_cic_irq(d);
 117         /*
 118         * Only really necessary for 18, 16-14 and sometimes 3:0
 119         * (since these can be edge sensitive) but it doesn't
 120         * hurt for the others
 121         */
 122         *CIC_STS_REG = (1 << (d->irq - MSP_CIC_INTBASE));
 123 }
 124
 125 /* Note: Limiting to VSMP.  */
 126
 127 #ifdef CONFIG_MIPS_MT_SMP
 128 static int msp_cic_irq_set_affinity(struct irq_data *d,
 129                                     const struct cpumask *cpumask, bool force)
 130 {
 131         int cpu;
 132         unsigned long flags;
 133         unsigned int  mtflags;
 134         unsigned long imask = (1 << (d->irq - MSP_CIC_INTBASE));
 135         volatile u32 *cic_mask = (volatile u32 *)CIC_VPE0_MSK_REG;
 136
 137         /* timer balancing should be disabled in kernel code */
 138         BUG_ON(d->irq == MSP_INT_VPE0_TIMER || d->irq == MSP_INT_VPE1_TIMER);
 139
 140         LOCK_CORE(flags, mtflags);
 141         /* enable if any of each VPE's TCs require this IRQ */
 142         for_each_online_cpu(cpu) {
 143                 if (cpumask_test_cpu(cpu, cpumask))
 144                         cic_mask[cpu] |= imask;
 145                 else
 146                         cic_mask[cpu] &= ~imask;
 147
 148         }
 149
 150         UNLOCK_CORE(flags, mtflags);
 151         return 0;
 152
 153 }
 154 #endif
 155
 156 static struct irq_chip msp_cic_irq_controller = {
 157         .name = "MSP_CIC",
 158         .irq_mask = mask_cic_irq,
 159         .irq_mask_ack = msp_cic_irq_ack,
 160         .irq_unmask = unmask_cic_irq,
 161         .irq_ack = msp_cic_irq_ack,
 162 #ifdef CONFIG_MIPS_MT_SMP
 163         .irq_set_affinity = msp_cic_irq_set_affinity,
 164 #endif
 165 };
 166
 167 void __init msp_cic_irq_init(void)
 168 {
 169         int i;
 170         /* Mask/clear interrupts. */
 171         *CIC_VPE0_MSK_REG = 0x00000000;
 172         *CIC_VPE1_MSK_REG = 0x00000000;
 173         *CIC_STS_REG      = 0xFFFFFFFF;
 174         /*
 175         * The MSP7120 RG and EVBD boards use IRQ[6:4] for PCI.
 176         * These inputs map to EXT_INT_POL[6:4] inside the CIC.
 177         * They are to be active low, level sensitive.
 178         */
 179         *CIC_EXT_CFG_REG &= 0xFFFF8F8F;
 180
 181         /* initialize all the IRQ descriptors */
 182         for (i = MSP_CIC_INTBASE ; i < MSP_CIC_INTBASE + 32 ; i++) {
 183                 irq_set_chip_and_handler(i, &msp_cic_irq_controller,
 184                                          handle_level_irq);
 185         }
 186
 187         /* Initialize the PER interrupt sub-system */
 188          msp_per_irq_init();
 189 }
 190
 191 /* CIC masked by CIC vector processing before dispatch called */
 192 void msp_cic_irq_dispatch(void)
 193 {
 194         volatile u32    *cic_msk_reg = (volatile u32 *)CIC_VPE0_MSK_REG;
 195         u32     cic_mask;
 196         u32      pending;
 197         int     cic_status = *CIC_STS_REG;
 198         cic_mask = cic_msk_reg[get_current_vpe()];
 199         pending = cic_status & cic_mask;
 200         if (pending & (1 << (MSP_INT_VPE0_TIMER - MSP_CIC_INTBASE))) {
 201                 do_IRQ(MSP_INT_VPE0_TIMER);
 202         } else if (pending & (1 << (MSP_INT_VPE1_TIMER - MSP_CIC_INTBASE))) {
 203                 do_IRQ(MSP_INT_VPE1_TIMER);
 204         } else if (pending & (1 << (MSP_INT_PER - MSP_CIC_INTBASE))) {
 205                 msp_per_irq_dispatch();
 206         } else if (pending) {
 207                 do_IRQ(ffs(pending) + MSP_CIC_INTBASE - 1);
 208         } else{
 209                 spurious_interrupt();
 210         }
 211 }