root/arch/sparc/kernel/irq_32.c

DEFINITIONS

1. arch_local_irq_save
2. arch_local_irq_enable
3. arch_local_irq_restore
4. irq_alloc
5. irq_link
6. irq_unlink
7. arch_show_interrupts
8. handler_irq
9. sparc_floppy_request_irq
10. sparc_floppy_irq
11. init_IRQ

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Interrupt request handling routines. On the
   4  * Sparc the IRQs are basically 'cast in stone'
   5  * and you are supposed to probe the prom's device
   6  * node trees to find out who's got which IRQ.
   7  *
   8  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   9  *  Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)
  10  *  Copyright (C) 1995,2002 Pete A. Zaitcev (zaitcev@yahoo.com)
  11  *  Copyright (C) 1996 Dave Redman (djhr@tadpole.co.uk)
  12  *  Copyright (C) 1998-2000 Anton Blanchard (anton@samba.org)
  13  */
  14 
  15 #include <linux/kernel_stat.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/export.h>
  18 
  19 #include <asm/cacheflush.h>
  20 #include <asm/cpudata.h>
  21 #include <asm/setup.h>
  22 #include <asm/pcic.h>
  23 #include <asm/leon.h>
  24 
  25 #include "kernel.h"
  26 #include "irq.h"
  27 
  28 /* platform specific irq setup */
  29 struct sparc_config sparc_config;
  30 
  31 unsigned long arch_local_irq_save(void)
  32 {
  33         unsigned long retval;
  34         unsigned long tmp;
  35 
  36         __asm__ __volatile__(
  37                 "rd     %%psr, %0\n\t"
  38                 "or     %0, %2, %1\n\t"
  39                 "wr     %1, 0, %%psr\n\t"
  40                 "nop; nop; nop\n"
  41                 : "=&r" (retval), "=r" (tmp)
  42                 : "i" (PSR_PIL)
  43                 : "memory");
  44 
  45         return retval;
  46 }
  47 EXPORT_SYMBOL(arch_local_irq_save);
  48 
  49 void arch_local_irq_enable(void)
  50 {
  51         unsigned long tmp;
  52 
  53         __asm__ __volatile__(
  54                 "rd     %%psr, %0\n\t"
  55                 "andn   %0, %1, %0\n\t"
  56                 "wr     %0, 0, %%psr\n\t"
  57                 "nop; nop; nop\n"
  58                 : "=&r" (tmp)
  59                 : "i" (PSR_PIL)
  60                 : "memory");
  61 }
  62 EXPORT_SYMBOL(arch_local_irq_enable);
  63 
  64 void arch_local_irq_restore(unsigned long old_psr)
  65 {
  66         unsigned long tmp;
  67 
  68         __asm__ __volatile__(
  69                 "rd     %%psr, %0\n\t"
  70                 "and    %2, %1, %2\n\t"
  71                 "andn   %0, %1, %0\n\t"
  72                 "wr     %0, %2, %%psr\n\t"
  73                 "nop; nop; nop\n"
  74                 : "=&r" (tmp)
  75                 : "i" (PSR_PIL), "r" (old_psr)
  76                 : "memory");
  77 }
  78 EXPORT_SYMBOL(arch_local_irq_restore);
  79 
  80 /*
  81  * Dave Redman (djhr@tadpole.co.uk)
  82  *
  83  * IRQ numbers.. These are no longer restricted to 15..
  84  *
  85  * this is done to enable SBUS cards and onboard IO to be masked
  86  * correctly. using the interrupt level isn't good enough.
  87  *
  88  * For example:
  89  *   A device interrupting at sbus level6 and the Floppy both come in
  90  *   at IRQ11, but enabling and disabling them requires writing to
  91  *   different bits in the SLAVIO/SEC.
  92  *
  93  * As a result of these changes sun4m machines could now support
  94  * directed CPU interrupts using the existing enable/disable irq code
  95  * with tweaks.
  96  *
  97  * Sun4d complicates things even further.  IRQ numbers are arbitrary
  98  * 32-bit values in that case.  Since this is similar to sparc64,
  99  * we adopt a virtual IRQ numbering scheme as is done there.
 100  * Virutal interrupt numbers are allocated by build_irq().  So NR_IRQS
 101  * just becomes a limit of how many interrupt sources we can handle in
 102  * a single system.  Even fully loaded SS2000 machines top off at
 103  * about 32 interrupt sources or so, therefore a NR_IRQS value of 64
 104  * is more than enough.
 105   *
 106  * We keep a map of per-PIL enable interrupts.  These get wired
 107  * up via the irq_chip->startup() method which gets invoked by
 108  * the generic IRQ layer during request_irq().
 109  */
 110 
 111 
 112 /* Table of allocated irqs. Unused entries has irq == 0 */
 113 static struct irq_bucket irq_table[NR_IRQS];
 114 /* Protect access to irq_table */
 115 static DEFINE_SPINLOCK(irq_table_lock);
 116 
 117 /* Map between the irq identifier used in hw to the irq_bucket. */
 118 struct irq_bucket *irq_map[SUN4D_MAX_IRQ];
 119 /* Protect access to irq_map */
 120 static DEFINE_SPINLOCK(irq_map_lock);
 121 
 122 /* Allocate a new irq from the irq_table */
 123 unsigned int irq_alloc(unsigned int real_irq, unsigned int pil)
 124 {
 125         unsigned long flags;
 126         unsigned int i;
 127 
 128         spin_lock_irqsave(&irq_table_lock, flags);
 129         for (i = 1; i < NR_IRQS; i++) {
 130                 if (irq_table[i].real_irq == real_irq && irq_table[i].pil == pil)
 131                         goto found;
 132         }
 133 
 134         for (i = 1; i < NR_IRQS; i++) {
 135                 if (!irq_table[i].irq)
 136                         break;
 137         }
 138 
 139         if (i < NR_IRQS) {
 140                 irq_table[i].real_irq = real_irq;
 141                 irq_table[i].irq = i;
 142                 irq_table[i].pil = pil;
 143         } else {
 144                 printk(KERN_ERR "IRQ: Out of virtual IRQs.\n");
 145                 i = 0;
 146         }
 147 found:
 148         spin_unlock_irqrestore(&irq_table_lock, flags);
 149 
 150         return i;
 151 }
 152 
 153 /* Based on a single pil handler_irq may need to call several
 154  * interrupt handlers. Use irq_map as entry to irq_table,
 155  * and let each entry in irq_table point to the next entry.
 156  */
 157 void irq_link(unsigned int irq)
 158 {
 159         struct irq_bucket *p;
 160         unsigned long flags;
 161         unsigned int pil;
 162 
 163         BUG_ON(irq >= NR_IRQS);
 164 
 165         spin_lock_irqsave(&irq_map_lock, flags);
 166 
 167         p = &irq_table[irq];
 168         pil = p->pil;
 169         BUG_ON(pil >= SUN4D_MAX_IRQ);
 170         p->next = irq_map[pil];
 171         irq_map[pil] = p;
 172 
 173         spin_unlock_irqrestore(&irq_map_lock, flags);
 174 }
 175 
 176 void irq_unlink(unsigned int irq)
 177 {
 178         struct irq_bucket *p, **pnext;
 179         unsigned long flags;
 180 
 181         BUG_ON(irq >= NR_IRQS);
 182 
 183         spin_lock_irqsave(&irq_map_lock, flags);
 184 
 185         p = &irq_table[irq];
 186         BUG_ON(p->pil >= SUN4D_MAX_IRQ);
 187         pnext = &irq_map[p->pil];
 188         while (*pnext != p)
 189                 pnext = &(*pnext)->next;
 190         *pnext = p->next;
 191 
 192         spin_unlock_irqrestore(&irq_map_lock, flags);
 193 }
 194 
 195 
 196 /* /proc/interrupts printing */
 197 int arch_show_interrupts(struct seq_file *p, int prec)
 198 {
 199         int j;
 200 
 201 #ifdef CONFIG_SMP
 202         seq_printf(p, "RES: ");
 203         for_each_online_cpu(j)
 204                 seq_printf(p, "%10u ", cpu_data(j).irq_resched_count);
 205         seq_printf(p, "     IPI rescheduling interrupts\n");
 206         seq_printf(p, "CAL: ");
 207         for_each_online_cpu(j)
 208                 seq_printf(p, "%10u ", cpu_data(j).irq_call_count);
 209         seq_printf(p, "     IPI function call interrupts\n");
 210 #endif
 211         seq_printf(p, "NMI: ");
 212         for_each_online_cpu(j)
 213                 seq_printf(p, "%10u ", cpu_data(j).counter);
 214         seq_printf(p, "     Non-maskable interrupts\n");
 215         return 0;
 216 }
 217 
 218 void handler_irq(unsigned int pil, struct pt_regs *regs)
 219 {
 220         struct pt_regs *old_regs;
 221         struct irq_bucket *p;
 222 
 223         BUG_ON(pil > 15);
 224         old_regs = set_irq_regs(regs);
 225         irq_enter();
 226 
 227         p = irq_map[pil];
 228         while (p) {
 229                 struct irq_bucket *next = p->next;
 230 
 231                 generic_handle_irq(p->irq);
 232                 p = next;
 233         }
 234         irq_exit();
 235         set_irq_regs(old_regs);
 236 }
 237 
 238 #if defined(CONFIG_BLK_DEV_FD) || defined(CONFIG_BLK_DEV_FD_MODULE)
 239 static unsigned int floppy_irq;
 240 
 241 int sparc_floppy_request_irq(unsigned int irq, irq_handler_t irq_handler)
 242 {
 243         unsigned int cpu_irq;
 244         int err;
 245 
 246 
 247         err = request_irq(irq, irq_handler, 0, "floppy", NULL);
 248         if (err)
 249                 return -1;
 250 
 251         /* Save for later use in floppy interrupt handler */
 252         floppy_irq = irq;
 253 
 254         cpu_irq = (irq & (NR_IRQS - 1));
 255 
 256         /* Dork with trap table if we get this far. */
 257 #define INSTANTIATE(table) \
 258         table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_one = SPARC_RD_PSR_L0; \
 259         table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two = \
 260                 SPARC_BRANCH((unsigned long) floppy_hardint, \
 261                              (unsigned long) &table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two);\
 262         table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_three = SPARC_RD_WIM_L3; \
 263         table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_four = SPARC_NOP;
 264 
 265         INSTANTIATE(sparc_ttable)
 266 
 267 #if defined CONFIG_SMP
 268         if (sparc_cpu_model != sparc_leon) {
 269                 struct tt_entry *trap_table;
 270 
 271                 trap_table = &trapbase_cpu1;
 272                 INSTANTIATE(trap_table)
 273                 trap_table = &trapbase_cpu2;
 274                 INSTANTIATE(trap_table)
 275                 trap_table = &trapbase_cpu3;
 276                 INSTANTIATE(trap_table)
 277         }
 278 #endif
 279 #undef INSTANTIATE
 280         /*
 281          * XXX Correct thing whould be to flush only I- and D-cache lines
 282          * which contain the handler in question. But as of time of the
 283          * writing we have no CPU-neutral interface to fine-grained flushes.
 284          */
 285         flush_cache_all();
 286         return 0;
 287 }
 288 EXPORT_SYMBOL(sparc_floppy_request_irq);
 289 
 290 /*
 291  * These variables are used to access state from the assembler
 292  * interrupt handler, floppy_hardint, so we cannot put these in
 293  * the floppy driver image because that would not work in the
 294  * modular case.
 295  */
 296 volatile unsigned char *fdc_status;
 297 EXPORT_SYMBOL(fdc_status);
 298 
 299 char *pdma_vaddr;
 300 EXPORT_SYMBOL(pdma_vaddr);
 301 
 302 unsigned long pdma_size;
 303 EXPORT_SYMBOL(pdma_size);
 304 
 305 volatile int doing_pdma;
 306 EXPORT_SYMBOL(doing_pdma);
 307 
 308 char *pdma_base;
 309 EXPORT_SYMBOL(pdma_base);
 310 
 311 unsigned long pdma_areasize;
 312 EXPORT_SYMBOL(pdma_areasize);
 313 
 314 /* Use the generic irq support to call floppy_interrupt
 315  * which was setup using request_irq() in sparc_floppy_request_irq().
 316  * We only have one floppy interrupt so we do not need to check
 317  * for additional handlers being wired up by irq_link()
 318  */
 319 void sparc_floppy_irq(int irq, void *dev_id, struct pt_regs *regs)
 320 {
 321         struct pt_regs *old_regs;
 322 
 323         old_regs = set_irq_regs(regs);
 324         irq_enter();
 325         generic_handle_irq(floppy_irq);
 326         irq_exit();
 327         set_irq_regs(old_regs);
 328 }
 329 #endif
 330 
 331 /* djhr
 332  * This could probably be made indirect too and assigned in the CPU
 333  * bits of the code. That would be much nicer I think and would also
 334  * fit in with the idea of being able to tune your kernel for your machine
 335  * by removing unrequired machine and device support.
 336  *
 337  */
 338 
 339 void __init init_IRQ(void)
 340 {
 341         switch (sparc_cpu_model) {
 342         case sun4m:
 343                 pcic_probe();
 344                 if (pcic_present())
 345                         sun4m_pci_init_IRQ();
 346                 else
 347                         sun4m_init_IRQ();
 348                 break;
 349 
 350         case sun4d:
 351                 sun4d_init_IRQ();
 352                 break;
 353 
 354         case sparc_leon:
 355                 leon_init_IRQ();
 356                 break;
 357 
 358         default:
 359                 prom_printf("Cannot initialize IRQs on this Sun machine...");
 360                 break;
 361         }
 362 }
 363