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 struct irq_host_ops beatic_pic_host_ops = {
 179         .map = beatic_pic_host_map,
 180         .remap = beatic_pic_host_remap,
 181         .unmap = beatic_pic_host_unmap,
 182         .xlate = beatic_pic_host_xlate,
 183 };
 184
 185 /*
 186  * Get an IRQ number
 187  * Note: returns VIRQ
 188  */
 189 static inline unsigned int beatic_get_irq_plug(void)
 190 {
 191         int i;
 192         uint64_t        pending[4], ub;
 193
 194         for (i = 0; i < MAX_IRQS; i += 256) {
 195                 beat_detect_pending_interrupts(i, pending);
 196                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 197                         "r"(pending[0] & beatic_irq_mask_enable[i/64+0]
 198                                        & beatic_irq_mask_ack[i/64+0]));
 199                 if (ub != 64)
 200                         return i + ub + 0;
 201                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 202                         "r"(pending[1] & beatic_irq_mask_enable[i/64+1]
 203                                        & beatic_irq_mask_ack[i/64+1]));
 204                 if (ub != 64)
 205                         return i + ub + 64;
 206                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 207                         "r"(pending[2] & beatic_irq_mask_enable[i/64+2]
 208                                        & beatic_irq_mask_ack[i/64+2]));
 209                 if (ub != 64)
 210                         return i + ub + 128;
 211                 __asm__ ("cntlzd %0,%1":"=r"(ub):
 212                         "r"(pending[3] & beatic_irq_mask_enable[i/64+3]
 213                                        & beatic_irq_mask_ack[i/64+3]));
 214                 if (ub != 64)
 215                         return i + ub + 192;
 216         }
 217
 218         return NO_IRQ;
 219 }
 220 unsigned int beatic_get_irq(void)
 221 {
 222         unsigned int ret;
 223
 224         ret = beatic_get_irq_plug();
 225         if (ret != NO_IRQ)
 226                 beatic_ack_irq(ret);
 227         return ret;
 228 }
 229
 230 /*
 231  */
 232 void __init beatic_init_IRQ(void)
 233 {
 234         int     i;
 235
 236         memset(beatic_irq_mask_enable, 0, sizeof(beatic_irq_mask_enable));
 237         memset(beatic_irq_mask_ack, 255, sizeof(beatic_irq_mask_ack));
 238         for (i = 0; i < MAX_IRQS; i += 256)
 239                 beat_set_interrupt_mask(i, 0L, 0L, 0L, 0L);
 240
 241         /* Set out get_irq function */
 242         ppc_md.get_irq = beatic_get_irq;
 243
 244         /* Allocate an irq host */
 245         beatic_host = irq_alloc_host(IRQ_HOST_MAP_NOMAP, 0,
 246                                          &beatic_pic_host_ops,
 247                                          0);
 248         BUG_ON(beatic_host == NULL);
 249         irq_set_default_host(beatic_host);
 250 }
 251
 252 #ifdef CONFIG_SMP
 253
 254 /* Nullified to compile with SMP mode */
 255 void beatic_setup_cpu(int cpu)
 256 {
 257 }
 258
 259 void beatic_cause_IPI(int cpu, int mesg)
 260 {
 261 }
 262
 263 void beatic_request_IPIs(void)
 264 {
 265 }
 266 #endif /* CONFIG_SMP */
 267
 268 void beatic_deinit_IRQ(void)
 269 {
 270         int     i;
 271
 272         for (i = 1; i < NR_IRQS; i++)
 273                 beat_destruct_irq_plug(i);
 274 }