sparc32, sun4d: add comment in empty statement in sun4d_request_irq()
[pandora-kernel.git] / arch / sparc / kernel / sun4d_irq.c
index e11b461..609a13c 100644 (file)
@@ -1,50 +1,42 @@
 /*
- *  arch/sparc/kernel/sun4d_irq.c:
- *                     SS1000/SC2000 interrupt handling.
+ * SS1000/SC2000 interrupt handling.
  *
  *  Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
  *  Heavily based on arch/sparc/kernel/irq.c.
  */
 
-#include <linux/errno.h>
-#include <linux/linkage.h>
 #include <linux/kernel_stat.h>
-#include <linux/signal.h>
-#include <linux/sched.h>
-#include <linux/ptrace.h>
-#include <linux/interrupt.h>
-#include <linux/slab.h>
-#include <linux/random.h>
-#include <linux/init.h>
-#include <linux/smp.h>
-#include <linux/spinlock.h>
 #include <linux/seq_file.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
-
-#include <asm/ptrace.h>
-#include <asm/processor.h>
-#include <asm/system.h>
-#include <asm/psr.h>
-#include <asm/smp.h>
-#include <asm/vaddrs.h>
+
 #include <asm/timer.h>
-#include <asm/openprom.h>
-#include <asm/oplib.h>
 #include <asm/traps.h>
 #include <asm/irq.h>
 #include <asm/io.h>
-#include <asm/pgalloc.h>
-#include <asm/pgtable.h>
 #include <asm/sbi.h>
 #include <asm/cacheflush.h>
-#include <asm/irq_regs.h>
 
 #include "kernel.h"
 #include "irq.h"
 
-/* If you trust current SCSI layer to handle different SCSI IRQs, enable this. I don't trust it... -jj */
-/* #define DISTRIBUTE_IRQS */
+/* Sun4d interrupts fall roughly into two categories.  SBUS and
+ * cpu local.  CPU local interrupts cover the timer interrupts
+ * and whatnot, and we encode those as normal PILs between
+ * 0 and 15.
+ *
+ * SBUS interrupts are encoded integers including the board number
+ * (plus one), the SBUS level, and the SBUS slot number.  Sun4D
+ * IRQ dispatch is done by:
+ *
+ * 1) Reading the BW local interrupt table in order to get the bus
+ *    interrupt mask.
+ *
+ *    This table is indexed by SBUS interrupt level which can be
+ *    derived from the PIL we got interrupted on.
+ *
+ * 2) For each bus showing interrupt pending from #1, read the
+ *    SBI interrupt state register.  This will indicate which slots
+ *    have interrupts pending for that SBUS interrupt level.
+ */
 
 struct sun4d_timer_regs {
        u32     l10_timer_limit;
@@ -59,11 +51,9 @@ static struct sun4d_timer_regs __iomem *sun4d_timers;
 #define TIMER_IRQ      10
 
 #define MAX_STATIC_ALLOC       4
-extern int static_irq_count;
 static unsigned char sbus_tid[32];
 
 static struct irqaction *irq_action[NR_IRQS];
-extern spinlock_t irq_action_lock;
 
 static struct sbus_action {
        struct irqaction *action;
@@ -71,11 +61,33 @@ static struct sbus_action {
 } *sbus_actions;
 
 static int pil_to_sbus[] = {
-       0, 0, 1, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 0,
+       0,
+       0,
+       1,
+       2,
+       0,
+       3,
+       0,
+       4,
+       0,
+       5,
+       0,
+       6,
+       0,
+       7,
+       0,
+       0,
 };
 
 static int sbus_to_pil[] = {
-       0, 2, 3, 5, 7, 9, 11, 13,
+       0,
+       2,
+       3,
+       5,
+       7,
+       9,
+       11,
+       13,
 };
 
 static int nsbi;
@@ -86,7 +98,7 @@ DEFINE_SPINLOCK(sun4d_imsk_lock);
 int show_sun4d_interrupts(struct seq_file *p, void *v)
 {
        int i = *(loff_t *) v, j = 0, k = 0, sbusl;
-       struct irqaction * action;
+       struct irqaction *action;
        unsigned long flags;
 #ifdef CONFIG_SMP
        int x;
@@ -96,13 +108,14 @@ int show_sun4d_interrupts(struct seq_file *p, void *v)
        if (i < NR_IRQS) {
                sbusl = pil_to_sbus[i];
                if (!sbusl) {
-                       action = *(i + irq_action);
-                       if (!action) 
-                               goto out_unlock;
+                       action = *(i + irq_action);
+                       if (!action)
+                               goto out_unlock;
                } else {
                        for (j = 0; j < nsbi; j++) {
                                for (k = 0; k < 4; k++)
-                                       if ((action = sbus_actions [(j << 5) + (sbusl << 2) + k].action))
+                                       action = sbus_actions[(j << 5) + (sbusl << 2) + k].action;
+                                       if (action)
                                                goto found_it;
                        }
                        goto out_unlock;
@@ -125,15 +138,17 @@ found_it: seq_printf(p, "%3d: ", i);
                                        (action->flags & IRQF_DISABLED) ? " +" : "",
                                        action->name);
                        }
-                       if (!sbusl) break;
+                       if (!sbusl)
+                               break;
                        k++;
-                       if (k < 4)
-                               action = sbus_actions [(j << 5) + (sbusl << 2) + k].action;
-                       else {
+                       if (k < 4) {
+                               action = sbus_actions[(j << 5) + (sbusl << 2) + k].action;
+                       else {
                                j++;
-                               if (j == nsbi) break;
+                               if (j == nsbi)
+                                       break;
                                k = 0;
-                               action = sbus_actions [(j << 5) + (sbusl << 2)].action;
+                               action = sbus_actions[(j << 5) + (sbusl << 2)].action;
                        }
                }
                seq_putc(p, '\n');
@@ -147,7 +162,7 @@ void sun4d_free_irq(unsigned int irq, void *dev_id)
 {
        struct irqaction *action, **actionp;
        struct irqaction *tmp = NULL;
-        unsigned long flags;
+       unsigned long flags;
 
        spin_lock_irqsave(&irq_action_lock, flags);
        if (irq < 15)
@@ -156,7 +171,7 @@ void sun4d_free_irq(unsigned int irq, void *dev_id)
                actionp = &(sbus_actions[irq - (1 << 5)].action);
        action = *actionp;
        if (!action) {
-               printk("Trying to free free IRQ%d\n",irq);
+               printk(KERN_ERR "Trying to free free IRQ%d\n", irq);
                goto out_unlock;
        }
        if (dev_id) {
@@ -166,23 +181,25 @@ void sun4d_free_irq(unsigned int irq, void *dev_id)
                        tmp = action;
                }
                if (!action) {
-                       printk("Trying to free free shared IRQ%d\n",irq);
+                       printk(KERN_ERR "Trying to free free shared IRQ%d\n",
+                              irq);
                        goto out_unlock;
                }
        } else if (action->flags & IRQF_SHARED) {
-               printk("Trying to free shared IRQ%d with NULL device ID\n", irq);
+               printk(KERN_ERR "Trying to free shared IRQ%d with NULL device ID\n",
+                      irq);
                goto out_unlock;
        }
-       if (action->flags & SA_STATIC_ALLOC)
-       {
-               /* This interrupt is marked as specially allocated
+       if (action->flags & SA_STATIC_ALLOC) {
+               /*
+                * This interrupt is marked as specially allocated
                 * so it is a bad idea to free it.
                 */
-               printk("Attempt to free statically allocated IRQ%d (%s)\n",
+               printk(KERN_ERR "Attempt to free statically allocated IRQ%d (%s)\n",
                       irq, action->name);
                goto out_unlock;
        }
-       
+
        if (tmp)
                tmp->next = action->next;
        else
@@ -203,30 +220,28 @@ out_unlock:
        spin_unlock_irqrestore(&irq_action_lock, flags);
 }
 
-extern void unexpected_irq(int, void *, struct pt_regs *);
-
-void sun4d_handler_irq(int irq, struct pt_regs * regs)
+void sun4d_handler_irq(int pil, struct pt_regs *regs)
 {
        struct pt_regs *old_regs;
-       struct irqaction * action;
+       struct irqaction *action;
        int cpu = smp_processor_id();
        /* SBUS IRQ level (1 - 7) */
-       int sbusl = pil_to_sbus[irq];
-       
+       int sbusl = pil_to_sbus[pil];
+
        /* FIXME: Is this necessary?? */
        cc_get_ipen();
-       
-       cc_set_iclr(1 << irq);
-       
+
+       cc_set_iclr(1 << pil);
+
        old_regs = set_irq_regs(regs);
        irq_enter();
-       kstat_cpu(cpu).irqs[irq]++;
+       kstat_cpu(cpu).irqs[pil]++;
        if (!sbusl) {
-               action = *(irq + irq_action);
+               action = *(pil + irq_action);
                if (!action)
-                       unexpected_irq(irq, NULL, regs);
+                       unexpected_irq(pil, NULL, regs);
                do {
-                       action->handler(irq, action->dev_id);
+                       action->handler(pil, action->dev_id);
                        action = action->next;
                } while (action);
        } else {
@@ -235,9 +250,9 @@ void sun4d_handler_irq(int irq, struct pt_regs * regs)
                struct sbus_action *actionp;
                unsigned mask, slot;
                int sbil = (sbusl << 2);
-               
+
                bw_clear_intr_mask(sbusl, bus_mask);
-               
+
                /* Loop for each pending SBI */
                for (sbino = 0; bus_mask; sbino++, bus_mask >>= 1)
                        if (bus_mask & 1) {
@@ -249,11 +264,11 @@ void sun4d_handler_irq(int irq, struct pt_regs * regs)
                                        if (mask & slot) {
                                                mask &= ~slot;
                                                action = actionp->action;
-                                               
+
                                                if (!action)
-                                                       unexpected_irq(irq, NULL, regs);
+                                                       unexpected_irq(pil, NULL, regs);
                                                do {
-                                                       action->handler(irq, action->dev_id);
+                                                       action->handler(pil, action->dev_id);
                                                        action = action->next;
                                                } while (action);
                                                release_sbi(SBI2DEVID(sbino), slot);
@@ -266,13 +281,13 @@ void sun4d_handler_irq(int irq, struct pt_regs * regs)
 
 int sun4d_request_irq(unsigned int irq,
                irq_handler_t handler,
-               unsigned long irqflags, const char * devname, void *dev_id)
+               unsigned long irqflags, const char *devname, void *dev_id)
 {
        struct irqaction *action, *tmp = NULL, **actionp;
        unsigned long flags;
        int ret;
-       
-       if(irq > 14 && irq < (1 << 5)) {
+
+       if (irq > 14 && irq < (1 << 5)) {
                ret = -EINVAL;
                goto out;
        }
@@ -289,16 +304,18 @@ int sun4d_request_irq(unsigned int irq,
        else
                actionp = irq + irq_action;
        action = *actionp;
-       
+
        if (action) {
                if ((action->flags & IRQF_SHARED) && (irqflags & IRQF_SHARED)) {
-                       for (tmp = action; tmp->next; tmp = tmp->next);
+                       for (tmp = action; tmp->next; tmp = tmp->next)
+                               /* find last entry - tmp used below */;
                } else {
                        ret = -EBUSY;
                        goto out_unlock;
                }
                if ((action->flags & IRQF_DISABLED) ^ (irqflags & IRQF_DISABLED)) {
-                       printk("Attempt to mix fast and slow interrupts on IRQ%d denied\n", irq);
+                       printk(KERN_ERR "Attempt to mix fast and slow interrupts on IRQ%d denied\n",
+                              irq);
                        ret = -EBUSY;
                        goto out_unlock;
                }
@@ -312,14 +329,14 @@ int sun4d_request_irq(unsigned int irq,
                if (static_irq_count < MAX_STATIC_ALLOC)
                        action = &static_irqaction[static_irq_count++];
                else
-                       printk("Request for IRQ%d (%s) SA_STATIC_ALLOC failed using kmalloc\n", irq, devname);
+                       printk(KERN_ERR "Request for IRQ%d (%s) SA_STATIC_ALLOC failed using kmalloc\n",
+                              irq, devname);
        }
-       
+
        if (action == NULL)
-               action = kmalloc(sizeof(struct irqaction),
-                                                    GFP_ATOMIC);
-       
-       if (!action) { 
+               action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
+
+       if (!action) {
                ret = -ENOMEM;
                goto out_unlock;
        }
@@ -334,7 +351,7 @@ int sun4d_request_irq(unsigned int irq,
                tmp->next = action;
        else
                *actionp = action;
-               
+
        __enable_irq(irq);
 
        ret = 0;
@@ -348,7 +365,7 @@ static void sun4d_disable_irq(unsigned int irq)
 {
        int tid = sbus_tid[(irq >> 5) - 1];
        unsigned long flags;
-       
+
        if (irq < NR_IRQS)
                return;
 
@@ -361,7 +378,7 @@ static void sun4d_enable_irq(unsigned int irq)
 {
        int tid = sbus_tid[(irq >> 5) - 1];
        unsigned long flags;
-       
+
        if (irq < NR_IRQS)
                return;
 
@@ -389,44 +406,6 @@ void __init sun4d_distribute_irqs(void)
 {
        struct device_node *dp;
 
-#ifdef DISTRIBUTE_IRQS
-       cpumask_t sbus_serving_map;
-
-       sbus_serving_map = cpu_present_map;
-       for_each_node_by_name(dp, "sbi") {
-               int board = of_getintprop_default(dp, "board#", 0);
-
-               if ((board * 2) == boot_cpu_id && cpu_isset(board * 2 + 1, cpu_present_map))
-                       sbus_tid[board] = (board * 2 + 1);
-               else if (cpu_isset(board * 2, cpu_present_map))
-                       sbus_tid[board] = (board * 2);
-               else if (cpu_isset(board * 2 + 1, cpu_present_map))
-                       sbus_tid[board] = (board * 2 + 1);
-               else
-                       sbus_tid[board] = 0xff;
-               if (sbus_tid[board] != 0xff)
-                       cpu_clear(sbus_tid[board], sbus_serving_map);
-       }
-       for_each_node_by_name(dp, "sbi") {
-               int board = of_getintprop_default(dp, "board#", 0);
-               if (sbus_tid[board] == 0xff) {
-                       int i = 31;
-                               
-                       if (cpus_empty(sbus_serving_map))
-                               sbus_serving_map = cpu_present_map;
-                       while (cpu_isset(i, sbus_serving_map))
-                               i--;
-                       sbus_tid[board] = i;
-                       cpu_clear(i, sbus_serving_map);
-               }
-       }
-       for_each_node_by_name(dp, "sbi") {
-               int devid = of_getintprop_default(dp, "device-id", 0);
-               int board = of_getintprop_default(dp, "board#", 0);
-               printk("sbus%d IRQs directed to CPU%d\n", board, sbus_tid[board]);
-               set_sbi_tid(devid, sbus_tid[board] << 3);
-       }
-#else
        int cpuid = cpu_logical_map(1);
 
        if (cpuid == -1)
@@ -437,11 +416,10 @@ void __init sun4d_distribute_irqs(void)
                sbus_tid[board] = cpuid;
                set_sbi_tid(devid, cpuid << 3);
        }
-       printk("All sbus IRQs directed to CPU%d\n", cpuid);
-#endif
+       printk(KERN_ERR "All sbus IRQs directed to CPU%d\n", cpuid);
 }
 #endif
+
 static void sun4d_clear_clock_irq(void)
 {
        sbus_readl(&sun4d_timers->l10_timer_limit);
@@ -466,10 +444,7 @@ static void __init sun4d_fixup_trap_table(void)
 {
 #ifdef CONFIG_SMP
        unsigned long flags;
-       extern unsigned long lvl14_save[4];
        struct tt_entry *trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (14 - 1)];
-       extern unsigned int real_irq_entry[], smp4d_ticker[];
-       extern unsigned int patchme_maybe_smp_msg[];
 
        /* Adjust so that we jump directly to smp4d_ticker */
        lvl14_save[2] += smp4d_ticker - real_irq_entry;
@@ -531,7 +506,8 @@ static void __init sun4d_init_timers(irq_handler_t counter_fn)
                          (IRQF_DISABLED | SA_STATIC_ALLOC),
                          "timer", NULL);
        if (err) {
-               prom_printf("sun4d_init_timers: request_irq() failed with %d\n", err);
+               prom_printf("sun4d_init_timers: request_irq() failed with %d\n",
+                            err);
                prom_halt();
        }
        sun4d_load_profile_irqs();
@@ -550,7 +526,7 @@ void __init sun4d_init_sbi_irq(void)
        nsbi = 0;
        for_each_node_by_name(dp, "sbi")
                nsbi++;
-       sbus_actions = kzalloc (nsbi * 8 * 4 * sizeof(struct sbus_action), GFP_ATOMIC);
+       sbus_actions = kzalloc(nsbi * 8 * 4 * sizeof(struct sbus_action), GFP_ATOMIC);
        if (!sbus_actions) {
                prom_printf("SUN4D: Cannot allocate sbus_actions, halting.\n");
                prom_halt();
@@ -566,7 +542,8 @@ void __init sun4d_init_sbi_irq(void)
                /* Get rid of pending irqs from PROM */
                mask = acquire_sbi(devid, 0xffffffff);
                if (mask) {
-                       printk ("Clearing pending IRQs %08x on SBI %d\n", mask, board);
+                       printk(KERN_ERR "Clearing pending IRQs %08x on SBI %d\n",
+                              mask, board);
                        release_sbi(devid, mask);
                }
        }