arch/mips/kernel/irq-gic.c

   1 #undef DEBUG
   2
   3 #include <linux/bitmap.h>
   4 #include <linux/init.h>
   5 #include <linux/smp.h>
   6 #include <linux/irq.h>
   7
   8 #include <asm/io.h>
   9 #include <asm/gic.h>
  10 #include <asm/gcmpregs.h>
  11 #include <linux/hardirq.h>
  12 #include <asm-generic/bitops/find.h>
  13
  14
  15 static unsigned long _gic_base;
  16 static unsigned int _irqbase;
  17 static unsigned int gic_irq_flags[GIC_NUM_INTRS];
  18 #define GIC_IRQ_FLAG_EDGE      0x0001
  19
  20 struct gic_pcpu_mask pcpu_masks[NR_CPUS];
  21 static struct gic_pending_regs pending_regs[NR_CPUS];
  22 static struct gic_intrmask_regs intrmask_regs[NR_CPUS];
  23
  24 void gic_send_ipi(unsigned int intr)
  25 {
  26         pr_debug("CPU%d: %s status %08x\n", smp_processor_id(), __func__,
  27                  read_c0_status());
  28         GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
  29 }
  30
  31 /* This is Malta specific and needs to be exported */
  32 static void __init vpe_local_setup(unsigned int numvpes)
  33 {
  34         int i;
  35         unsigned long timer_interrupt = 5, perf_interrupt = 5;
  36         unsigned int vpe_ctl;
  37
  38         /*
  39          * Setup the default performance counter timer interrupts
  40          * for all VPEs
  41          */
  42         for (i = 0; i < numvpes; i++) {
  43                 GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), i);
  44
  45                 /* Are Interrupts locally routable? */
  46                 GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_CTL), vpe_ctl);
  47                 if (vpe_ctl & GIC_VPE_CTL_TIMER_RTBL_MSK)
  48                         GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP),
  49                                  GIC_MAP_TO_PIN_MSK | timer_interrupt);
  50
  51                 if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
  52                         GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
  53                                  GIC_MAP_TO_PIN_MSK | perf_interrupt);
  54         }
  55 }
  56
  57 unsigned int gic_get_int(void)
  58 {
  59         unsigned int i;
  60         unsigned long *pending, *intrmask, *pcpu_mask;
  61         unsigned long *pending_abs, *intrmask_abs;
  62
  63         /* Get per-cpu bitmaps */
  64         pending = pending_regs[smp_processor_id()].pending;
  65         intrmask = intrmask_regs[smp_processor_id()].intrmask;
  66         pcpu_mask = pcpu_masks[smp_processor_id()].pcpu_mask;
  67
  68         pending_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
  69                                                          GIC_SH_PEND_31_0_OFS);
  70         intrmask_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
  71                                                           GIC_SH_MASK_31_0_OFS);
  72
  73         for (i = 0; i < BITS_TO_LONGS(GIC_NUM_INTRS); i++) {
  74                 GICREAD(*pending_abs, pending[i]);
  75                 GICREAD(*intrmask_abs, intrmask[i]);
  76                 pending_abs++;
  77                 intrmask_abs++;
  78         }
  79
  80         bitmap_and(pending, pending, intrmask, GIC_NUM_INTRS);
  81         bitmap_and(pending, pending, pcpu_mask, GIC_NUM_INTRS);
  82
  83         i = find_first_bit(pending, GIC_NUM_INTRS);
  84
  85         pr_debug("CPU%d: %s pend=%d\n", smp_processor_id(), __func__, i);
  86
  87         return i;
  88 }
  89
  90 static void gic_irq_ack(struct irq_data *d)
  91 {
  92         unsigned int irq = d->irq - _irqbase;
  93
  94         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
  95         GIC_CLR_INTR_MASK(irq);
  96
  97         if (gic_irq_flags[irq] & GIC_IRQ_FLAG_EDGE)
  98                 GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), irq);
  99 }
 100
 101 static void gic_mask_irq(struct irq_data *d)
 102 {
 103         unsigned int irq = d->irq - _irqbase;
 104         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
 105         GIC_CLR_INTR_MASK(irq);
 106 }
 107
 108 static void gic_unmask_irq(struct irq_data *d)
 109 {
 110         unsigned int irq = d->irq - _irqbase;
 111         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
 112         GIC_SET_INTR_MASK(irq);
 113 }
 114
 115 #ifdef CONFIG_SMP
 116
 117 static DEFINE_SPINLOCK(gic_lock);
 118
 119 static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
 120                             bool force)
 121 {
 122         unsigned int irq = d->irq - _irqbase;
 123         cpumask_t       tmp = CPU_MASK_NONE;
 124         unsigned long   flags;
 125         int             i;
 126
 127         pr_debug("%s(%d) called\n", __func__, irq);
 128         cpumask_and(&tmp, cpumask, cpu_online_mask);
 129         if (cpus_empty(tmp))
 130                 return -1;
 131
 132         /* Assumption : cpumask refers to a single CPU */
 133         spin_lock_irqsave(&gic_lock, flags);
 134         for (;;) {
 135                 /* Re-route this IRQ */
 136                 GIC_SH_MAP_TO_VPE_SMASK(irq, first_cpu(tmp));
 137
 138                 /* Update the pcpu_masks */
 139                 for (i = 0; i < NR_CPUS; i++)
 140                         clear_bit(irq, pcpu_masks[i].pcpu_mask);
 141                 set_bit(irq, pcpu_masks[first_cpu(tmp)].pcpu_mask);
 142
 143         }
 144         cpumask_copy(d->affinity, cpumask);
 145         spin_unlock_irqrestore(&gic_lock, flags);
 146
 147         return IRQ_SET_MASK_OK_NOCOPY;
 148 }
 149 #endif
 150
 151 static struct irq_chip gic_irq_controller = {
 152         .name                   =       "MIPS GIC",
 153         .irq_ack                =       gic_irq_ack,
 154         .irq_mask               =       gic_mask_irq,
 155         .irq_mask_ack           =       gic_mask_irq,
 156         .irq_unmask             =       gic_unmask_irq,
 157         .irq_eoi                =       gic_unmask_irq,
 158 #ifdef CONFIG_SMP
 159         .irq_set_affinity       =       gic_set_affinity,
 160 #endif
 161 };
 162
 163 static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,
 164         unsigned int pin, unsigned int polarity, unsigned int trigtype,
 165         unsigned int flags)
 166 {
 167         /* Setup Intr to Pin mapping */
 168         if (pin & GIC_MAP_TO_NMI_MSK) {
 169                 GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
 170                 /* FIXME: hack to route NMI to all cpu's */
 171                 for (cpu = 0; cpu < NR_CPUS; cpu += 32) {
 172                         GICWRITE(GIC_REG_ADDR(SHARED,
 173                                           GIC_SH_MAP_TO_VPE_REG_OFF(intr, cpu)),
 174                                  0xffffffff);
 175                 }
 176         } else {
 177                 GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)),
 178                          GIC_MAP_TO_PIN_MSK | pin);
 179                 /* Setup Intr to CPU mapping */
 180                 GIC_SH_MAP_TO_VPE_SMASK(intr, cpu);
 181         }
 182
 183         /* Setup Intr Polarity */
 184         GIC_SET_POLARITY(intr, polarity);
 185
 186         /* Setup Intr Trigger Type */
 187         GIC_SET_TRIGGER(intr, trigtype);
 188
 189         /* Init Intr Masks */
 190         GIC_CLR_INTR_MASK(intr);
 191         /* Initialise per-cpu Interrupt software masks */
 192         if (flags & GIC_FLAG_IPI)
 193                 set_bit(intr, pcpu_masks[cpu].pcpu_mask);
 194         if (flags & GIC_FLAG_TRANSPARENT)
 195                 GIC_SET_INTR_MASK(intr);
 196         if (trigtype == GIC_TRIG_EDGE)
 197                 gic_irq_flags[intr] |= GIC_IRQ_FLAG_EDGE;
 198 }
 199
 200 static void __init gic_basic_init(int numintrs, int numvpes,
 201                         struct gic_intr_map *intrmap, int mapsize)
 202 {
 203         unsigned int i, cpu;
 204
 205         /* Setup defaults */
 206         for (i = 0; i < numintrs; i++) {
 207                 GIC_SET_POLARITY(i, GIC_POL_POS);
 208                 GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
 209                 GIC_CLR_INTR_MASK(i);
 210                 if (i < GIC_NUM_INTRS)
 211                         gic_irq_flags[i] = 0;
 212         }
 213
 214         /* Setup specifics */
 215         for (i = 0; i < mapsize; i++) {
 216                 cpu = intrmap[i].cpunum;
 217                 if (cpu == GIC_UNUSED)
 218                         continue;
 219                 if (cpu == 0 && i != 0 && intrmap[i].flags == 0)
 220                         continue;
 221                 gic_setup_intr(i,
 222                         intrmap[i].cpunum,
 223                         intrmap[i].pin,
 224                         intrmap[i].polarity,
 225                         intrmap[i].trigtype,
 226                         intrmap[i].flags);
 227         }
 228
 229         vpe_local_setup(numvpes);
 230
 231         for (i = _irqbase; i < (_irqbase + numintrs); i++)
 232                 irq_set_chip(i, &gic_irq_controller);
 233 }
 234
 235 void __init gic_init(unsigned long gic_base_addr,
 236                      unsigned long gic_addrspace_size,
 237                      struct gic_intr_map *intr_map, unsigned int intr_map_size,
 238                      unsigned int irqbase)
 239 {
 240         unsigned int gicconfig;
 241         int numvpes, numintrs;
 242
 243         _gic_base = (unsigned long) ioremap_nocache(gic_base_addr,
 244                                                     gic_addrspace_size);
 245         _irqbase = irqbase;
 246
 247         GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), gicconfig);
 248         numintrs = (gicconfig & GIC_SH_CONFIG_NUMINTRS_MSK) >>
 249                    GIC_SH_CONFIG_NUMINTRS_SHF;
 250         numintrs = ((numintrs + 1) * 8);
 251
 252         numvpes = (gicconfig & GIC_SH_CONFIG_NUMVPES_MSK) >>
 253                   GIC_SH_CONFIG_NUMVPES_SHF;
 254
 255         pr_debug("%s called\n", __func__);
 256
 257         gic_basic_init(numintrs, numvpes, intr_map, intr_map_size);
 258 }