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
   7 #include <asm/io.h>
   8 #include <asm/gic.h>
   9 #include <asm/gcmpregs.h>
  10 #include <asm/mips-boards/maltaint.h>
  11 #include <asm/irq.h>
  12 #include <linux/hardirq.h>
  13 #include <asm-generic/bitops/find.h>
  14
  15
  16 static unsigned long _gic_base;
  17 static unsigned int _irqbase, _mapsize, numvpes, numintrs;
  18 static struct gic_intr_map *_intrmap;
  19
  20 static 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 #define gic_wedgeb2bok 0        /*
  25                                  * Can GIC handle b2b writes to wedge register?
  26                                  */
  27 #if gic_wedgeb2bok == 0
  28 static DEFINE_SPINLOCK(gic_wedgeb2b_lock);
  29 #endif
  30
  31 void gic_send_ipi(unsigned int intr)
  32 {
  33 #if gic_wedgeb2bok == 0
  34         unsigned long flags;
  35 #endif
  36         pr_debug("CPU%d: %s status %08x\n", smp_processor_id(), __func__,
  37                  read_c0_status());
  38         if (!gic_wedgeb2bok)
  39                 spin_lock_irqsave(&gic_wedgeb2b_lock, flags);
  40         GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
  41         if (!gic_wedgeb2bok) {
  42                 (void) GIC_REG(SHARED, GIC_SH_CONFIG);
  43                 spin_unlock_irqrestore(&gic_wedgeb2b_lock, flags);
  44         }
  45 }
  46
  47 /* This is Malta specific and needs to be exported */
  48 static void vpe_local_setup(unsigned int numvpes)
  49 {
  50         int i;
  51         unsigned long timer_interrupt = 5, perf_interrupt = 5;
  52         unsigned int vpe_ctl;
  53
  54         /*
  55          * Setup the default performance counter timer interrupts
  56          * for all VPEs
  57          */
  58         for (i = 0; i < numvpes; i++) {
  59                 GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), i);
  60
  61                 /* Are Interrupts locally routable? */
  62                 GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_CTL), vpe_ctl);
  63                 if (vpe_ctl & GIC_VPE_CTL_TIMER_RTBL_MSK)
  64                         GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP),
  65                                  GIC_MAP_TO_PIN_MSK | timer_interrupt);
  66
  67                 if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
  68                         GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
  69                                  GIC_MAP_TO_PIN_MSK | perf_interrupt);
  70         }
  71 }
  72
  73 unsigned int gic_get_int(void)
  74 {
  75         unsigned int i;
  76         unsigned long *pending, *intrmask, *pcpu_mask;
  77         unsigned long *pending_abs, *intrmask_abs;
  78
  79         /* Get per-cpu bitmaps */
  80         pending = pending_regs[smp_processor_id()].pending;
  81         intrmask = intrmask_regs[smp_processor_id()].intrmask;
  82         pcpu_mask = pcpu_masks[smp_processor_id()].pcpu_mask;
  83
  84         pending_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
  85                                                          GIC_SH_PEND_31_0_OFS);
  86         intrmask_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
  87                                                           GIC_SH_MASK_31_0_OFS);
  88
  89         for (i = 0; i < BITS_TO_LONGS(GIC_NUM_INTRS); i++) {
  90                 GICREAD(*pending_abs, pending[i]);
  91                 GICREAD(*intrmask_abs, intrmask[i]);
  92                 pending_abs++;
  93                 intrmask_abs++;
  94         }
  95
  96         bitmap_and(pending, pending, intrmask, GIC_NUM_INTRS);
  97         bitmap_and(pending, pending, pcpu_mask, GIC_NUM_INTRS);
  98
  99         i = find_first_bit(pending, GIC_NUM_INTRS);
 100
 101         pr_debug("CPU%d: %s pend=%d\n", smp_processor_id(), __func__, i);
 102
 103         return i;
 104 }
 105
 106 static unsigned int gic_irq_startup(unsigned int irq)
 107 {
 108         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
 109         irq -= _irqbase;
 110         GIC_SET_INTR_MASK(irq, 1);
 111         return 0;
 112 }
 113
 114 static void gic_irq_ack(unsigned int irq)
 115 {
 116 #if gic_wedgeb2bok == 0
 117         unsigned long flags;
 118 #endif
 119         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
 120         irq -= _irqbase;
 121         GIC_CLR_INTR_MASK(irq, 1);
 122
 123         if (_intrmap[irq].trigtype == GIC_TRIG_EDGE) {
 124                 if (!gic_wedgeb2bok)
 125                         spin_lock_irqsave(&gic_wedgeb2b_lock, flags);
 126                 GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), irq);
 127                 if (!gic_wedgeb2bok) {
 128                         (void) GIC_REG(SHARED, GIC_SH_CONFIG);
 129                         spin_unlock_irqrestore(&gic_wedgeb2b_lock, flags);
 130                 }
 131         }
 132 }
 133
 134 static void gic_mask_irq(unsigned int irq)
 135 {
 136         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
 137         irq -= _irqbase;
 138         GIC_CLR_INTR_MASK(irq, 1);
 139 }
 140
 141 static void gic_unmask_irq(unsigned int irq)
 142 {
 143         pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
 144         irq -= _irqbase;
 145         GIC_SET_INTR_MASK(irq, 1);
 146 }
 147
 148 #ifdef CONFIG_SMP
 149
 150 static DEFINE_SPINLOCK(gic_lock);
 151
 152 static int gic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 153 {
 154         cpumask_t       tmp = CPU_MASK_NONE;
 155         unsigned long   flags;
 156         int             i;
 157
 158         pr_debug(KERN_DEBUG "%s called\n", __func__);
 159         irq -= _irqbase;
 160
 161         cpumask_and(&tmp, cpumask, cpu_online_mask);
 162         if (cpus_empty(tmp))
 163                 return -1;
 164
 165         /* Assumption : cpumask refers to a single CPU */
 166         spin_lock_irqsave(&gic_lock, flags);
 167         for (;;) {
 168                 /* Re-route this IRQ */
 169                 GIC_SH_MAP_TO_VPE_SMASK(irq, first_cpu(tmp));
 170
 171                 /*
 172                  * FIXME: assumption that _intrmap is ordered and has no holes
 173                  */
 174
 175                 /* Update the intr_map */
 176                 _intrmap[irq].cpunum = first_cpu(tmp);
 177
 178                 /* Update the pcpu_masks */
 179                 for (i = 0; i < NR_CPUS; i++)
 180                         clear_bit(irq, pcpu_masks[i].pcpu_mask);
 181                 set_bit(irq, pcpu_masks[first_cpu(tmp)].pcpu_mask);
 182
 183         }
 184         cpumask_copy(irq_desc[irq].affinity, cpumask);
 185         spin_unlock_irqrestore(&gic_lock, flags);
 186
 187         return 0;
 188 }
 189 #endif
 190
 191 static struct irq_chip gic_irq_controller = {
 192         .name           =       "MIPS GIC",
 193         .startup        =       gic_irq_startup,
 194         .ack            =       gic_irq_ack,
 195         .mask           =       gic_mask_irq,
 196         .mask_ack       =       gic_mask_irq,
 197         .unmask         =       gic_unmask_irq,
 198         .eoi            =       gic_unmask_irq,
 199 #ifdef CONFIG_SMP
 200         .set_affinity   =       gic_set_affinity,
 201 #endif
 202 };
 203
 204 static void __init setup_intr(unsigned int intr, unsigned int cpu,
 205         unsigned int pin, unsigned int polarity, unsigned int trigtype)
 206 {
 207         /* Setup Intr to Pin mapping */
 208         if (pin & GIC_MAP_TO_NMI_MSK) {
 209                 GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
 210                 /* FIXME: hack to route NMI to all cpu's */
 211                 for (cpu = 0; cpu < NR_CPUS; cpu += 32) {
 212                         GICWRITE(GIC_REG_ADDR(SHARED,
 213                                           GIC_SH_MAP_TO_VPE_REG_OFF(intr, cpu)),
 214                                  0xffffffff);
 215                 }
 216         } else {
 217                 GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)),
 218                          GIC_MAP_TO_PIN_MSK | pin);
 219                 /* Setup Intr to CPU mapping */
 220                 GIC_SH_MAP_TO_VPE_SMASK(intr, cpu);
 221         }
 222
 223         /* Setup Intr Polarity */
 224         GIC_SET_POLARITY(intr, polarity);
 225
 226         /* Setup Intr Trigger Type */
 227         GIC_SET_TRIGGER(intr, trigtype);
 228
 229         /* Init Intr Masks */
 230         GIC_SET_INTR_MASK(intr, 0);
 231 }
 232
 233 static void __init gic_basic_init(void)
 234 {
 235         unsigned int i, cpu;
 236
 237         /* Setup defaults */
 238         for (i = 0; i < GIC_NUM_INTRS; i++) {
 239                 GIC_SET_POLARITY(i, GIC_POL_POS);
 240                 GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
 241                 GIC_SET_INTR_MASK(i, 0);
 242         }
 243
 244         /* Setup specifics */
 245         for (i = 0; i < _mapsize; i++) {
 246                 cpu = _intrmap[i].cpunum;
 247                 if (cpu == X)
 248                         continue;
 249
 250                 if (cpu == 0 && i != 0 && _intrmap[i].intrnum == 0 &&
 251                                         _intrmap[i].ipiflag == 0)
 252                         continue;
 253
 254                 setup_intr(_intrmap[i].intrnum,
 255                                 _intrmap[i].cpunum,
 256                                 _intrmap[i].pin,
 257                                 _intrmap[i].polarity,
 258                                 _intrmap[i].trigtype);
 259                 /* Initialise per-cpu Interrupt software masks */
 260                 if (_intrmap[i].ipiflag)
 261                         set_bit(_intrmap[i].intrnum, pcpu_masks[cpu].pcpu_mask);
 262         }
 263
 264         vpe_local_setup(numvpes);
 265
 266         for (i = _irqbase; i < (_irqbase + numintrs); i++)
 267                 set_irq_chip(i, &gic_irq_controller);
 268 }
 269
 270 void __init gic_init(unsigned long gic_base_addr,
 271                      unsigned long gic_addrspace_size,
 272                      struct gic_intr_map *intr_map, unsigned int intr_map_size,
 273                      unsigned int irqbase)
 274 {
 275         unsigned int gicconfig;
 276
 277         _gic_base = (unsigned long) ioremap_nocache(gic_base_addr,
 278                                                     gic_addrspace_size);
 279         _irqbase = irqbase;
 280         _intrmap = intr_map;
 281         _mapsize = intr_map_size;
 282
 283         GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), gicconfig);
 284         numintrs = (gicconfig & GIC_SH_CONFIG_NUMINTRS_MSK) >>
 285                    GIC_SH_CONFIG_NUMINTRS_SHF;
 286         numintrs = ((numintrs + 1) * 8);
 287
 288         numvpes = (gicconfig & GIC_SH_CONFIG_NUMVPES_MSK) >>
 289                   GIC_SH_CONFIG_NUMVPES_SHF;
 290
 291         pr_debug("%s called\n", __func__);
 292
 293         gic_basic_init();
 294 }