sparc32: genirq support

The conversion of sparc32 to genirq is based on original work done
by David S. Miller.
Daniel Hellstrom has helped in the conversion and implemented
the shutdowm functionality.
Marcel van Nies <morcles@gmail.com> has tested this on Sparc Station 20

Test status:
sun4c      - not tested
sun4m,pci  - not tested
sun4m,sbus - tested (Sparc Classic, Sparc Station 5, Sparc Station 20)
sun4d      - not tested
leon       - tested on various combinations of leon boards,
             including SMP variants

generic
   Introduce use of GENERIC_HARDIRQS and GENERIC_IRQ_SHOW
   Allocate 64 IRQs - which is enough even for SS2000
   Use a table of irq_bucket to maintain uses IRQs
      irq_bucket is also used to chain several irq's that
      must be called when the same intrrupt is asserted
   Use irq_link to link a interrupt source to the irq
   All plafforms must now supply their own build_device_irq method
   handler_irq rewriten to use generic irq support

floppy
   Read FLOPPY_IRQ from platform device
   Use generic request_irq to register the floppy interrupt
   Rewrote sparc_floppy_irq to use the generic irq support

pcic:
   Introduce irq_chip
   Store mask in chip_data for use in mask/unmask functions
   Add build_device_irq for pcic
   Use pcic_build_device_irq in pci_time_init
   allocate virtual irqs in pcic_fill_irq

sun4c:
   Introduce irq_chip
   Store mask in chip_data for use in mask/unmask functions
   Add build_device_irq for sun4c
   Use sun4c_build_device_irq in sun4c_init_timers

sun4m:
   Introduce irq_chip
   Introduce dedicated mask/unmask methods
   Introduce sun4m_handler_data that allow easy access to necessary
     data in the mask/unmask functions
   Add a helper method to enable profile_timer (used from smp)
   Added sun4m_build_device_irq
   Use sun4m_build_device_irq in sun4m_init_timers

   TODO:
      There is no replacement for smp_rotate that always scheduled
      next CPU as interrupt target upon an interrupt

sun4d:
   Introduce irq_chip
   Introduce dedicated mask/unmask methods
   Introduce sun4d_handler_data that allow easy access to
   necessary data in mask/unmask fuctions
   Rewrote sun4d_handler_irq to use generic irq support

   TODO:
      The original implmentation of enable/disable had:

          if (irq < NR_IRQS)
               return;

      The new implmentation does not distingush between SBUS and cpu
      interrupts.
      I am no sure what is right here. I assume we need to do
      something for the cpu interrupts.

      I have not succeeded booting my sun4d box (with or without this patch)
      and my understanding of this platfrom is limited.
      So I would be a bit suprised if this works.

leon:
   Introduce irq_chip
   Store mask in chip_data for use in mask/unmask functions
   Add build_device_irq for leon
   Use leon_build_device_irq in leon_init_timers

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Daniel Hellstrom <daniel@gaisler.com>
Tested-by: Daniel Hellstrom <daniel@gaisler.com>
Tested-by: Marcel van Nies <morcles@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 164 insertions, 308 deletions

diff --git a/arch/sparc/kernel/sun4d_irq.c b/arch/sparc/kernel/sun4d_irq.c
index ee35c45ffb89..14a043531dcb 100644
--- a/arch/sparc/kernel/sun4d_irq.c
+++ b/arch/sparc/kernel/sun4d_irq.c
@@ -22,22 +22,20 @@
  * 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.
+ * SBUS interrupts are encodes as a combination of board, level and slot.
  */
 
+struct sun4d_handler_data {
+	unsigned int cpuid;    /* target cpu */
+	unsigned int real_irq; /* interrupt level */
+};
+
+
+static unsigned int sun4d_encode_irq(int board, int lvl, int slot)
+{
+	return (board + 1) << 5 | (lvl << 2) | slot;
+}
+
 struct sun4d_timer_regs {
 	u32	l10_timer_limit;
 	u32	l10_cur_countx;
@@ -48,22 +46,13 @@ struct sun4d_timer_regs {
 
 static struct sun4d_timer_regs __iomem *sun4d_timers;
 
-#define TIMER_IRQ	10
-
-#define MAX_STATIC_ALLOC	4
+#define SUN4D_TIMER_IRQ        10
 
 /* Specify which cpu handle interrupts from which board.
  * Index is board - value is cpu.
  */
 static unsigned char board_to_cpu[32];
 
-static struct irqaction *irq_action[NR_IRQS];
-
-static struct sbus_action {
-	struct irqaction *action;
-	/* For SMP this needs to be extended */
-} *sbus_actions;
-
 static int pil_to_sbus[] = {
 	0,
 	0,
@@ -83,152 +72,81 @@ static int pil_to_sbus[] = {
 	0,
 };
 
-static int sbus_to_pil[] = {
-	0,
-	2,
-	3,
-	5,
-	7,
-	9,
-	11,
-	13,
-};
-
-static int nsbi;
-
 /* Exported for sun4d_smp.c */
 DEFINE_SPINLOCK(sun4d_imsk_lock);
 
-int show_sun4d_interrupts(struct seq_file *p, void *v)
+/* 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.
+ *
+ * 3) Call the genreric IRQ support.
+ */
+static void sun4d_sbus_handler_irq(int sbusl)
 {
-	int i = *(loff_t *) v, j = 0, k = 0, sbusl;
-	struct irqaction *action;
-	unsigned long flags;
-#ifdef CONFIG_SMP
-	int x;
-#endif
-
-	spin_lock_irqsave(&irq_action_lock, flags);
-	if (i < NR_IRQS) {
-		sbusl = pil_to_sbus[i];
-		if (!sbusl) {
-			action = *(i + irq_action);
-			if (!action)
-				goto out_unlock;
-		} else {
-			for (j = 0; j < nsbi; j++) {
-				for (k = 0; k < 4; k++)
-					action = sbus_actions[(j << 5) + (sbusl << 2) + k].action;
-					if (action)
-						goto found_it;
-			}
-			goto out_unlock;
-		}
-found_it:	seq_printf(p, "%3d: ", i);
-#ifndef CONFIG_SMP
-		seq_printf(p, "%10u ", kstat_irqs(i));
-#else
-		for_each_online_cpu(x)
-			seq_printf(p, "%10u ",
-			       kstat_cpu(cpu_logical_map(x)).irqs[i]);
-#endif
-		seq_printf(p, "%c %s",
-			(action->flags & IRQF_DISABLED) ? '+' : ' ',
-			action->name);
-		action = action->next;
-		for (;;) {
-			for (; action; action = action->next) {
-				seq_printf(p, ",%s %s",
-					(action->flags & IRQF_DISABLED) ? " +" : "",
-					action->name);
-			}
-			if (!sbusl)
-				break;
-			k++;
-			if (k < 4) {
-				action = sbus_actions[(j << 5) + (sbusl << 2) + k].action;
-			} else {
-				j++;
-				if (j == nsbi)
-					break;
-				k = 0;
-				action = sbus_actions[(j << 5) + (sbusl << 2)].action;
+	unsigned int bus_mask;
+	unsigned int sbino, slot;
+	unsigned int sbil;
+
+	bus_mask = bw_get_intr_mask(sbusl) & 0x3ffff;
+	bw_clear_intr_mask(sbusl, bus_mask);
+
+	sbil = (sbusl << 2);
+	/* Loop for each pending SBI */
+	for (sbino = 0; bus_mask; sbino++) {
+		unsigned int idx, mask;
+
+		bus_mask >>= 1;
+		if (!(bus_mask & 1))
+			continue;
+		/* XXX This seems to ACK the irq twice.  acquire_sbi()
+		 * XXX uses swap, therefore this writes 0xf << sbil,
+		 * XXX then later release_sbi() will write the individual
+		 * XXX bits which were set again.
+		 */
+		mask = acquire_sbi(SBI2DEVID(sbino), 0xf << sbil);
+		mask &= (0xf << sbil);
+
+		/* Loop for each pending SBI slot */
+		idx = 0;
+		slot = (1 << sbil);
+		while (mask != 0) {
+			unsigned int pil;
+			struct irq_bucket *p;
+
+			idx++;
+			slot <<= 1;
+			if (!(mask & slot))
+				continue;
+
+			mask &= ~slot;
+			pil = sun4d_encode_irq(sbino, sbil, idx);
+
+			p = irq_map[pil];
+			while (p) {
+				struct irq_bucket *next;
+
+				next = p->next;
+				generic_handle_irq(p->irq);
+				p = next;
 			}
+			release_sbi(SBI2DEVID(sbino), slot);
 		}
-		seq_putc(p, '\n');
-	}
-out_unlock:
-	spin_unlock_irqrestore(&irq_action_lock, flags);
-	return 0;
-}
-
-void sun4d_free_irq(unsigned int irq, void *dev_id)
-{
-	struct irqaction *action, **actionp;
-	struct irqaction *tmp = NULL;
-	unsigned long flags;
-
-	spin_lock_irqsave(&irq_action_lock, flags);
-	if (irq < 15)
-		actionp = irq + irq_action;
-	else
-		actionp = &(sbus_actions[irq - (1 << 5)].action);
-	action = *actionp;
-	if (!action) {
-		printk(KERN_ERR "Trying to free free IRQ%d\n", irq);
-		goto out_unlock;
-	}
-	if (dev_id) {
-		for (; action; action = action->next) {
-			if (action->dev_id == dev_id)
-				break;
-			tmp = action;
-		}
-		if (!action) {
-			printk(KERN_ERR "Trying to free free shared IRQ%d\n",
-			       irq);
-			goto out_unlock;
-		}
-	} else if (action->flags & IRQF_SHARED) {
-		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
-		 * so it is a bad idea to free it.
-		 */
-		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
-		*actionp = action->next;
-
-	spin_unlock_irqrestore(&irq_action_lock, flags);
-
-	synchronize_irq(irq);
-
-	spin_lock_irqsave(&irq_action_lock, flags);
-
-	kfree(action);
-
-	if (!(*actionp))
-		__disable_irq(irq);
-
-out_unlock:
-	spin_unlock_irqrestore(&irq_action_lock, flags);
 }
 
 void sun4d_handler_irq(int pil, struct pt_regs *regs)
 {
 	struct pt_regs *old_regs;
-	struct irqaction *action;
-	int cpu = smp_processor_id();
 	/* SBUS IRQ level (1 - 7) */
 	int sbusl = pil_to_sbus[pil];
 
@@ -239,158 +157,85 @@ void sun4d_handler_irq(int pil, struct pt_regs *regs)
 
 	old_regs = set_irq_regs(regs);
 	irq_enter();
-	kstat_cpu(cpu).irqs[pil]++;
-	if (!sbusl) {
-		action = *(pil + irq_action);
-		if (!action)
-			unexpected_irq(pil, NULL, regs);
-		do {
-			action->handler(pil, action->dev_id);
-			action = action->next;
-		} while (action);
+	if (sbusl == 0) {
+		/* cpu interrupt */
+		struct irq_bucket *p;
+
+		p = irq_map[pil];
+		while (p) {
+			struct irq_bucket *next;
+
+			next = p->next;
+			generic_handle_irq(p->irq);
+			p = next;
+		}
 	} else {
-		int bus_mask = bw_get_intr_mask(sbusl) & 0x3ffff;
-		int sbino;
-		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) {
-				mask = acquire_sbi(SBI2DEVID(sbino), 0xf << sbil);
-				mask &= (0xf << sbil);
-				actionp = sbus_actions + (sbino << 5) + (sbil);
-				/* Loop for each pending SBI slot */
-				for (slot = (1 << sbil); mask; slot <<= 1, actionp++)
-					if (mask & slot) {
-						mask &= ~slot;
-						action = actionp->action;
-
-						if (!action)
-							unexpected_irq(pil, NULL, regs);
-						do {
-							action->handler(pil, action->dev_id);
-							action = action->next;
-						} while (action);
-						release_sbi(SBI2DEVID(sbino), slot);
-					}
-			}
+		/* SBUS interrupt */
+		sun4d_sbus_handler_irq(sbusl);
 	}
 	irq_exit();
 	set_irq_regs(old_regs);
 }
 
-int sun4d_request_irq(unsigned int irq,
-		irq_handler_t handler,
-		unsigned long irqflags, const char *devname, void *dev_id)
+
+static void sun4d_mask_irq(struct irq_data *data)
 {
-	struct irqaction *action, *tmp = NULL, **actionp;
+	struct sun4d_handler_data *handler_data = data->handler_data;
+	unsigned int real_irq;
+#ifdef CONFIG_SMP
+	int cpuid = handler_data->cpuid;
 	unsigned long flags;
-	int ret;
-
-	if (irq > 14 && irq < (1 << 5)) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (!handler) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	spin_lock_irqsave(&irq_action_lock, flags);
-
-	if (irq >= (1 << 5))
-		actionp = &(sbus_actions[irq - (1 << 5)].action);
-	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)
-				/* find last entry - tmp used below */;
-		} else {
-			ret = -EBUSY;
-			goto out_unlock;
-		}
-		if ((action->flags & IRQF_DISABLED) ^ (irqflags & IRQF_DISABLED)) {
-			printk(KERN_ERR "Attempt to mix fast and slow interrupts on IRQ%d denied\n",
-			       irq);
-			ret = -EBUSY;
-			goto out_unlock;
-		}
-		action = NULL;		/* Or else! */
-	}
-
-	/* If this is flagged as statically allocated then we use our
-	 * private struct which is never freed.
-	 */
-	if (irqflags & SA_STATIC_ALLOC) {
-		if (static_irq_count < MAX_STATIC_ALLOC)
-			action = &static_irqaction[static_irq_count++];
-		else
-			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) {
-		ret = -ENOMEM;
-		goto out_unlock;
-	}
-
-	action->handler = handler;
-	action->flags = irqflags;
-	action->name = devname;
-	action->next = NULL;
-	action->dev_id = dev_id;
-
-	if (tmp)
-		tmp->next = action;
-	else
-		*actionp = action;
-
-	__enable_irq(irq);
-
-	ret = 0;
-out_unlock:
-	spin_unlock_irqrestore(&irq_action_lock, flags);
-out:
-	return ret;
+#endif
+	real_irq = handler_data->real_irq;
+#ifdef CONFIG_SMP
+	spin_lock_irqsave(&sun4d_imsk_lock, flags);
+	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) | (1 << real_irq));
+	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
+#else
+	cc_set_imsk(cc_get_imsk() | (1 << real_irq));
+#endif
 }
 
-static void sun4d_disable_irq(unsigned int irq)
+static void sun4d_unmask_irq(struct irq_data *data)
 {
-	int tid = board_to_cpu[(irq >> 5) - 1];
+	struct sun4d_handler_data *handler_data = data->handler_data;
+	unsigned int real_irq;
+#ifdef CONFIG_SMP
+	int cpuid = handler_data->cpuid;
 	unsigned long flags;
+#endif
+	real_irq = handler_data->real_irq;
 
-	if (irq < NR_IRQS)
-		return;
-
+#ifdef CONFIG_SMP
 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
-	cc_set_imsk_other(tid, cc_get_imsk_other(tid) | (1 << sbus_to_pil[(irq >> 2) & 7]));
+	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) | ~(1 << real_irq));
 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
+#else
+	cc_set_imsk(cc_get_imsk() | ~(1 << real_irq));
+#endif
 }
 
-static void sun4d_enable_irq(unsigned int irq)
+static unsigned int sun4d_startup_irq(struct irq_data *data)
 {
-	int tid = board_to_cpu[(irq >> 5) - 1];
-	unsigned long flags;
-
-	if (irq < NR_IRQS)
-		return;
+	irq_link(data->irq);
+	sun4d_unmask_irq(data);
+	return 0;
+}
 
-	spin_lock_irqsave(&sun4d_imsk_lock, flags);
-	cc_set_imsk_other(tid, cc_get_imsk_other(tid) & ~(1 << sbus_to_pil[(irq >> 2) & 7]));
-	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
+static void sun4d_shutdown_irq(struct irq_data *data)
+{
+	sun4d_mask_irq(data);
+	irq_unlink(data->irq);
 }
 
+struct irq_chip sun4d_irq = {
+	.name		= "sun4d",
+	.irq_startup	= sun4d_startup_irq,
+	.irq_shutdown	= sun4d_shutdown_irq,
+	.irq_unmask	= sun4d_unmask_irq,
+	.irq_mask	= sun4d_mask_irq,
+};
+
 #ifdef CONFIG_SMP
 static void sun4d_set_cpu_int(int cpu, int level)
 {
@@ -447,15 +292,16 @@ static void __init sun4d_load_profile_irqs(void)
 unsigned int sun4d_build_device_irq(struct platform_device *op,
                                     unsigned int real_irq)
 {
-	static int pil_to_sbus[] = {
-		0, 0, 1, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 0,
-	};
 	struct device_node *dp = op->dev.of_node;
 	struct device_node *io_unit, *sbi = dp->parent;
 	const struct linux_prom_registers *regs;
+	struct sun4d_handler_data *handler_data;
+	unsigned int pil;
+	unsigned int irq;
 	int board, slot;
 	int sbusl;
 
+	irq = 0;
 	while (sbi) {
 		if (!strcmp(sbi->name, "sbi"))
 			break;
@@ -488,7 +334,28 @@ unsigned int sun4d_build_device_irq(struct platform_device *op,
 
 	sbusl = pil_to_sbus[real_irq];
 	if (sbusl)
-		return (((board + 1) << 5) + (sbusl << 2) + slot);
+		pil = sun4d_encode_irq(board, sbusl, slot);
+	else
+		pil = real_irq;
+
+	irq = irq_alloc(real_irq, pil);
+	if (irq == 0)
+		goto err_out;
+
+	handler_data = irq_get_handler_data(irq);
+	if (unlikely(handler_data))
+		goto err_out;
+
+	handler_data = kzalloc(sizeof(struct sun4d_handler_data), GFP_ATOMIC);
+	if (unlikely(!handler_data)) {
+		prom_printf("IRQ: kzalloc(sun4d_handler_data) failed.\n");
+		prom_halt();
+	}
+	handler_data->cpuid    = board_to_cpu[board];
+	handler_data->real_irq = real_irq;
+	irq_set_chip_and_handler_name(irq, &sun4d_irq,
+	                              handle_level_irq, "level");
+	irq_set_handler_data(irq, handler_data);
 
 err_out:
 	return real_irq;
@@ -522,6 +389,7 @@ static void __init sun4d_init_timers(irq_handler_t counter_fn)
 {
 	struct device_node *dp;
 	struct resource res;
+	unsigned int irq;
 	const u32 *reg;
 	int err;
 
@@ -556,9 +424,8 @@ static void __init sun4d_init_timers(irq_handler_t counter_fn)
 
 	master_l10_counter = &sun4d_timers->l10_cur_count;
 
-	err = request_irq(TIMER_IRQ, counter_fn,
-			  (IRQF_DISABLED | SA_STATIC_ALLOC),
-			  "timer", NULL);
+	irq = sun4d_build_device_irq(NULL, SUN4D_TIMER_IRQ);
+	err = request_irq(irq, counter_fn, IRQF_TIMER, "timer", NULL);
 	if (err) {
 		prom_printf("sun4d_init_timers: request_irq() failed with %d\n",
 		             err);
@@ -576,15 +443,6 @@ void __init sun4d_init_sbi_irq(void)
 #ifdef CONFIG_SMP
 	target_cpu = boot_cpu_id;
 #endif
-
-	nsbi = 0;
-	for_each_node_by_name(dp, "sbi")
-		nsbi++;
-	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();
-	}
 	for_each_node_by_name(dp, "sbi") {
 		int devid = of_getintprop_default(dp, "device-id", 0);
 		int board = of_getintprop_default(dp, "board#", 0);
@@ -607,12 +465,10 @@ void __init sun4d_init_IRQ(void)
 {
 	local_irq_disable();
 
-	BTFIXUPSET_CALL(enable_irq, sun4d_enable_irq, BTFIXUPCALL_NORM);
-	BTFIXUPSET_CALL(disable_irq, sun4d_disable_irq, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(clear_clock_irq, sun4d_clear_clock_irq, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(load_profile_irq, sun4d_load_profile_irq, BTFIXUPCALL_NORM);
 
-	sparc_irq_config.init_timers = sun4d_init_timers;
+	sparc_irq_config.init_timers      = sun4d_init_timers;
 	sparc_irq_config.build_device_irq = sun4d_build_device_irq;
 
 #ifdef CONFIG_SMP