arch/powerpc/platforms/celleb/interrupt.c

   1 /*
   2  * Celleb/Beat Interrupt controller
   3  *
   4  * (C) Copyright 2006-2007 TOSHIBA CORPORATION
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/irq.h>
  24 #include <linux/percpu.h>
  25 #include <linux/types.h>
  26
  27 #include <asm/machdep.h>
  28
  29 #include "interrupt.h"
  30 #include "beat_wrapper.h"
  31
  32 #define MAX_IRQS        NR_IRQS
  33 static DEFINE_SPINLOCK(beatic_irq_mask_lock);
  34 static uint64_t beatic_irq_mask_enable[(MAX_IRQS+255)/64];
  35 static uint64_t beatic_irq_mask_ack[(MAX_IRQS+255)/64];
  36
  37 static struct irq_host *beatic_host = NULL;
  38
  39 /*
  40  * In this implementation, "virq" == "IRQ plug number",
  41  * "(irq_hw_number_t)hwirq" == "IRQ outlet number".
  42  */
  43
  44 /* assumption: locked */
  45 static inline void beatic_update_irq_mask(unsigned int irq_plug)
  46 {
  47         int off;
  48         unsigned long masks[4];
  49
  50         off = (irq_plug / 256) * 4;
  51         masks[0] = beatic_irq_mask_enable[off + 0]
  52                    & beatic_irq_mask_ack[off + 0];
  53         masks[1] = beatic_irq_mask_enable[off + 1]
  54                    & beatic_irq_mask_ack[off + 1];
  55         masks[2] = beatic_irq_mask_enable[off + 2]
  56                    & beatic_irq_mask_ack[off + 2];
  57         masks[3] = beatic_irq_mask_enable[off + 3]
  58                    & beatic_irq_mask_ack[off + 3];
  59         if (beat_set_interrupt_mask(irq_plug&~255UL,
  60                 masks[0], masks[1], masks[2], masks[3]) != 0)
  61                 panic("Failed to set mask IRQ!");
  62 }
  63
  64 static void beatic_mask_irq(unsigned int irq_plug)
  65 {
  66         unsigned long flags;
  67
  68         spin_lock_irqsave(&beatic_irq_mask_lock, flags);
  69         beatic_irq_mask_enable[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));
  70         beatic_update_irq_mask(irq_plug);
  71         spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
  72 }
  73
  74 static void beatic_unmask_irq(unsigned int irq_plug)
  75 {
  76         unsigned long flags;
  77
  78         spin_lock_irqsave(&beatic_irq_mask_lock, flags);
  79         beatic_irq_mask_enable[irq_plug/64] |= 1UL << (63 - (irq_plug%64));
  80         beatic_update_irq_mask(irq_plug);
  81         spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
  82 }
  83
  84 static void beatic_ack_irq(unsigned int irq_plug)
  85 {
  86         unsigned long flags;
  87
  88         spin_lock_irqsave(&beatic_irq_mask_lock, flags);
  89         beatic_irq_mask_ack[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));
  90         beatic_update_irq_mask(irq_plug);
  91         spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
  92 }
  93
  94 static void beatic_end_irq(unsigned int irq_plug)
  95 {
  96         s64 err;
  97         unsigned long flags;
  98
  99         if ((err = beat_downcount_of_interrupt(irq_plug)) != 0) {
 100                 if ((err & 0xFFFFFFFF) != 0xFFFFFFF5) /* -11: wrong state */
 101                         panic("Failed to downcount IRQ! Error = %16lx", err);
 102
 103                 printk(KERN_ERR "IRQ over-downcounted, plug %d\n", irq_plug);
 104         }
 105         spin_lock_irqsave(&beatic_irq_mask_lock, flags);
 106         beatic_irq_mask_ack[irq_plug/64] |= 1UL << (63 - (irq_plug%64));
 107         beatic_update_irq_mask(irq_plug);
 108         spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
 109 }
 110
 111 static struct irq_chip beatic_pic = {
 112         .typename = " CELL-BEAT ",
 113         .unmask = beatic_unmask_irq,
 114         .mask = beatic_mask_irq,
 115         .eoi = beatic_end_irq,
 116 };
 117
 118 /*
 119  * Dispose binding hardware IRQ number (hw) and Virtuql IRQ number (virq),
 120  * update flags.
 121  *
 122  * Note that the number (virq) is already assigned at upper layer.
 123  */
 124 static void beatic_pic_host_unmap(struct irq_host *h, unsigned int virq)
 125 {
 126         beat_destruct_irq_plug(virq);
 127 }
 128
 129 /*
 130  * Create or update binding hardware IRQ number (hw) and Virtuql
 131  * IRQ number (virq). This is called only once for a given mapping.
 132  *
 133  * Note that the number (virq) is already assigned at upper layer.
 134  */
 135 static int beatic_pic_host_map(struct irq_host *h, unsigned int virq,
 136                                irq_hw_number_t hw)
 137 {
 138         struct irq_desc *desc = get_irq_desc(virq);
 139         int64_t err;
 140
 141         if ((err = beat_construct_and_connect_irq_plug(virq, hw)) < 0)
 142                 return -EIO;
 143
 144         desc->status |= IRQ_LEVEL;
 145         set_irq_chip_and_handler(virq, &beatic_pic, handle_fasteoi_irq);
 146         return 0;
 147 }
 148
 149 /*
 150  * Update binding hardware IRQ number (hw) and Virtuql
 151  * IRQ number (virq). This is called only once for a given mapping.
 152  */
 153 static void beatic_pic_host_remap(struct irq_host *h, unsigned int virq,
 154                                irq_hw_number_t hw)
 155 {
 156         beat_construct_and_connect_irq_plug(virq, hw);
 157 }
 158
 159 /*
 160  * Translate device-tree interrupt spec to irq_hw_number_t style (ulong),
 161  * to pass away to irq_create_mapping().
 162  *
 163  * Called from irq_create_of_mapping() only.
 164  * Note: We have only 1 entry to translate.
 165  */
 166 static int beatic_pic_host_xlate(struct irq_host *h, struct device_node *ct,
 167                                  u32 *intspec, unsigned int intsize,
 168                                  irq_hw_number_t *out_hwirq,
 169                                  unsigned int *out_flags)
 170 {
 171         u64 *intspec2 = (u64 *)intspec;
 172
 173         *out_hwirq = *intspec2;
 174         *out_flags |= IRQ_TYPE_LEVEL_LOW;
 175         return 0;
 176 }
 177
 178 static int beatic_pic_host_match(struct irq_host *h, struct device_node *np)
 179 {
 180         /* Match all */
 181         return 1;
 182 }
 183
 184 static struct irq_host_ops beatic_pic_host_ops = {
 185         .map = beatic_pic_host_map,
 186         .remap = beatic_pic_host_remap,
 187         .unmap = beatic_pic_host_unmap,
 188         .xlate = beatic_pic_host_xlate,
 189         .match = beatic_pic_host_match,
 190 };
 191
 192 /*
 193  * Get an IRQ number
 194  * Note: returns VIRQ
 195  */
 196 static inline unsigned int beatic_get_irq_plug(void)
 197 {
 198         int i;
 199         uint64_t        pending[4], ub;
 200
 201         for (i = 0; i < MAX_IRQS; i += 256) {
 202                 beat_detect_pending_interrupts(i, pending);
 203                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 204                         "r"(pending[0] & beatic_irq_mask_enable[i/64+0]
 205                                        & beatic_irq_mask_ack[i/64+0]));
 206                 if (ub != 64)
 207                         return i + ub + 0;
 208                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 209                         "r"(pending[1] & beatic_irq_mask_enable[i/64+1]
 210                                        & beatic_irq_mask_ack[i/64+1]));
 211                 if (ub != 64)
 212                         return i + ub + 64;
 213                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 214                         "r"(pending[2] & beatic_irq_mask_enable[i/64+2]
 215                                        & beatic_irq_mask_ack[i/64+2]));
 216                 if (ub != 64)
 217                         return i + ub + 128;
 218                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 219                         "r"(pending[3] & beatic_irq_mask_enable[i/64+3]
 220                                        & beatic_irq_mask_ack[i/64+3]));
 221                 if (ub != 64)
 222                         return i + ub + 192;
 223         }
 224
 225         return NO_IRQ;
 226 }
 227 unsigned int beatic_get_irq(void)
 228 {
 229         unsigned int ret;
 230
 231         ret = beatic_get_irq_plug();
 232         if (ret != NO_IRQ)
 233                 beatic_ack_irq(ret);
 234         return ret;
 235 }
 236
 237 /*
 238  */
 239 void __init beatic_init_IRQ(void)
 240 {
 241         int     i;
 242
 243         memset(beatic_irq_mask_enable, 0, sizeof(beatic_irq_mask_enable));
 244         memset(beatic_irq_mask_ack, 255, sizeof(beatic_irq_mask_ack));
 245         for (i = 0; i < MAX_IRQS; i += 256)
 246                 beat_set_interrupt_mask(i, 0L, 0L, 0L, 0L);
 247
 248         /* Set out get_irq function */
 249         ppc_md.get_irq = beatic_get_irq;
 250
 251         /* Allocate an irq host */
 252         beatic_host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
 253                                          &beatic_pic_host_ops,
 254                                          0);
 255         BUG_ON(beatic_host == NULL);
 256         irq_set_default_host(beatic_host);
 257 }
 258
 259 #ifdef CONFIG_SMP
 260
 261 /* Nullified to compile with SMP mode */
 262 void beatic_setup_cpu(int cpu)
 263 {
 264 }
 265
 266 void beatic_cause_IPI(int cpu, int mesg)
 267 {
 268 }
 269
 270 void beatic_request_IPIs(void)
 271 {
 272 }
 273 #endif /* CONFIG_SMP */
 274
 275 void beatic_deinit_IRQ(void)
 276 {
 277         int     i;
 278
 279         for (i = 1; i < NR_IRQS; i++)
 280                 beat_destruct_irq_plug(i);
 281 }