MIPS: SGI-IP27: abstract chipset irq from bridge

Bridge ASIC is widely used in different SGI systems, but the connected
chipset is either HUB, HEART or BEDROCK. This commit switches to
irq domain hierarchy for hub and bridge interrupts to get bridge
setup out of hub interrupt code.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
[paul.burton@mips.com:
  Resolve conflict with commit 69a07a41d908 ("MIPS: SGI-IP27: rework HUB
  interrupts").]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

1 files changed, 84 insertions, 107 deletions

diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 710a59764b01..37be04975831 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -12,22 +12,20 @@
 #include <linux/ioport.h>
 #include <linux/kernel.h>
 #include <linux/bitops.h>
+#include <linux/sched.h>
 
 #include <asm/io.h>
 #include <asm/irq_cpu.h>
-#include <asm/pci/bridge.h>
 #include <asm/sn/addrs.h>
 #include <asm/sn/agent.h>
 #include <asm/sn/arch.h>
 #include <asm/sn/hub.h>
 #include <asm/sn/intr.h>
+#include <asm/sn/irq_alloc.h>
 
 struct hub_irq_data {
-	struct bridge_controller *bc;
 	u64	*irq_mask[2];
 	cpuid_t	cpu;
-	int	bit;
-	int	pin;
 };
 
 static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT);
@@ -54,7 +52,7 @@ static void enable_hub_irq(struct irq_data *d)
 	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
 	unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
 
-	set_bit(hd->bit, mask);
+	set_bit(d->hwirq, mask);
 	__raw_writeq(mask[0], hd->irq_mask[0]);
 	__raw_writeq(mask[1], hd->irq_mask[1]);
 }
@@ -64,72 +62,11 @@ static void disable_hub_irq(struct irq_data *d)
 	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
 	unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
 
-	clear_bit(hd->bit, mask);
+	clear_bit(d->hwirq, mask);
 	__raw_writeq(mask[0], hd->irq_mask[0]);
 	__raw_writeq(mask[1], hd->irq_mask[1]);
 }
 
-static unsigned int startup_bridge_irq(struct irq_data *d)
-{
-	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
-	struct bridge_controller *bc;
-	nasid_t nasid;
-	u32 device;
-	int pin;
-
-	if (!hd)
-		return -EINVAL;
-
-	pin = hd->pin;
-	bc = hd->bc;
-
-	nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(hd->cpu));
-	bridge_write(bc, b_int_addr[pin].addr,
-		     (0x20000 | hd->bit | (nasid << 8)));
-	bridge_set(bc, b_int_enable, (1 << pin));
-	bridge_set(bc, b_int_enable, 0x7ffffe00); /* more stuff in int_enable */
-
-	/*
-	 * Enable sending of an interrupt clear packt to the hub on a high to
-	 * low transition of the interrupt pin.
-	 *
-	 * IRIX sets additional bits in the address which are documented as
-	 * reserved in the bridge docs.
-	 */
-	bridge_set(bc, b_int_mode, (1UL << pin));
-
-	/*
-	 * We assume the bridge to have a 1:1 mapping between devices
-	 * (slots) and intr pins.
-	 */
-	device = bridge_read(bc, b_int_device);
-	device &= ~(7 << (pin*3));
-	device |= (pin << (pin*3));
-	bridge_write(bc, b_int_device, device);
-
-	bridge_read(bc, b_wid_tflush);
-
-	enable_hub_irq(d);
-
-	return 0;	/* Never anything pending.  */
-}
-
-static void shutdown_bridge_irq(struct irq_data *d)
-{
-	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
-	struct bridge_controller *bc;
-	int pin = hd->pin;
-
-	if (!hd)
-		return;
-
-	disable_hub_irq(d);
-
-	bc = hd->bc;
-	bridge_clr(bc, b_int_enable, (1 << pin));
-	bridge_read(bc, b_wid_tflush);
-}
-
 static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
 {
 	nasid_t nasid;
@@ -145,9 +82,6 @@ static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
 		hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_B);
 		hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_B);
 	}
-
-	/* Make sure it's not already pending when we connect it. */
-	REMOTE_HUB_CLR_INTR(nasid, hd->bit);
 }
 
 static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
@@ -164,7 +98,7 @@ static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
 	setup_hub_mask(hd, mask);
 
 	if (irqd_is_started(d))
-		startup_bridge_irq(d);
+		enable_hub_irq(d);
 
 	irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
 
@@ -173,20 +107,22 @@ static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
 
 static struct irq_chip hub_irq_type = {
 	.name		  = "HUB",
-	.irq_startup	  = startup_bridge_irq,
-	.irq_shutdown	  = shutdown_bridge_irq,
 	.irq_mask	  = disable_hub_irq,
 	.irq_unmask	  = enable_hub_irq,
 	.irq_set_affinity = set_affinity_hub_irq,
 };
 
-int request_bridge_irq(struct bridge_controller *bc, int pin)
+static int hub_domain_alloc(struct irq_domain *domain, unsigned int virq,
+			    unsigned int nr_irqs, void *arg)
 {
+	struct irq_alloc_info *info = arg;
 	struct hub_irq_data *hd;
 	struct hub_data *hub;
 	struct irq_desc *desc;
 	int swlevel;
-	int irq;
+
+	if (nr_irqs > 1 || !info)
+		return -EINVAL;
 
 	hd = kzalloc(sizeof(*hd), GFP_KERNEL);
 	if (!hd)
@@ -197,46 +133,41 @@ int request_bridge_irq(struct bridge_controller *bc, int pin)
 		kfree(hd);
 		return -EAGAIN;
 	}
-	irq = swlevel + IP27_HUB_IRQ_BASE;
-
-	hd->bc = bc;
-	hd->bit = swlevel;
-	hd->pin = pin;
-	irq_set_chip_data(irq, hd);
+	irq_domain_set_info(domain, virq, swlevel, &hub_irq_type, hd,
+			    handle_level_irq, NULL, NULL);
 
 	/* use CPU connected to nearest hub */
-	hub = hub_data(NASID_TO_COMPACT_NODEID(bc->nasid));
+	hub = hub_data(NASID_TO_COMPACT_NODEID(info->nasid));
 	setup_hub_mask(hd, &hub->h_cpus);
 
-	desc = irq_to_desc(irq);
-	desc->irq_common_data.node = bc->nasid;
+	/* Make sure it's not already pending when we connect it. */
+	REMOTE_HUB_CLR_INTR(info->nasid, swlevel);
+
+	desc = irq_to_desc(virq);
+	desc->irq_common_data.node = info->nasid;
 	cpumask_copy(desc->irq_common_data.affinity, &hub->h_cpus);
 
-	return irq;
+	return 0;
 }
 
-void ip27_hub_irq_init(void)
+static void hub_domain_free(struct irq_domain *domain,
+			    unsigned int virq, unsigned int nr_irqs)
 {
-	int i;
+	struct irq_data *irqd;
 
-	for (i = IP27_HUB_IRQ_BASE;
-	     i < (IP27_HUB_IRQ_BASE + IP27_HUB_IRQ_COUNT); i++)
-		irq_set_chip_and_handler(i, &hub_irq_type, handle_level_irq);
-
-	/*
-	 * Some interrupts are reserved by hardware or by software convention.
-	 * Mark these as reserved right away so they won't be used accidentally
-	 * later.
-	 */
-	for (i = 0; i <= BASE_PCI_IRQ; i++)
-		set_bit(i, hub_irq_map);
-
-	set_bit(IP_PEND0_6_63, hub_irq_map);
+	if (nr_irqs > 1)
+		return;
 
-	for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
-		set_bit(i, hub_irq_map);
+	irqd = irq_domain_get_irq_data(domain, virq);
+	if (irqd && irqd->chip_data)
+		kfree(irqd->chip_data);
 }
 
+static const struct irq_domain_ops hub_domain_ops = {
+	.alloc = hub_domain_alloc,
+	.free  = hub_domain_free,
+};
+
 /*
  * This code is unnecessarily complex, because we do
  * intr enabling. Basically, once we grab the set of intrs we need
@@ -253,7 +184,9 @@ static void ip27_do_irq_mask0(struct irq_desc *desc)
 {
 	cpuid_t cpu = smp_processor_id();
 	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	struct irq_domain *domain;
 	u64 pend0;
+	int irq;
 
 	/* copied from Irix intpend0() */
 	pend0 = LOCAL_HUB_L(PI_INT_PEND0);
@@ -277,7 +210,14 @@ static void ip27_do_irq_mask0(struct irq_desc *desc)
 		generic_smp_call_function_interrupt();
 	} else
 #endif
-		generic_handle_irq(__ffs(pend0) + IP27_HUB_IRQ_BASE);
+	{
+		domain = irq_desc_get_handler_data(desc);
+		irq = irq_linear_revmap(domain, __ffs(pend0));
+		if (irq)
+			generic_handle_irq(irq);
+		else
+			spurious_interrupt();
+	}
 
 	LOCAL_HUB_L(PI_INT_PEND0);
 }
@@ -286,7 +226,9 @@ static void ip27_do_irq_mask1(struct irq_desc *desc)
 {
 	cpuid_t cpu = smp_processor_id();
 	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	struct irq_domain *domain;
 	u64 pend1;
+	int irq;
 
 	/* copied from Irix intpend0() */
 	pend1 = LOCAL_HUB_L(PI_INT_PEND1);
@@ -295,7 +237,12 @@ static void ip27_do_irq_mask1(struct irq_desc *desc)
 	if (!pend1)
 		return;
 
-	generic_handle_irq(__ffs(pend1) + IP27_HUB_IRQ_BASE + 64);
+	domain = irq_desc_get_handler_data(desc);
+	irq = irq_linear_revmap(domain, __ffs(pend1) + 64);
+	if (irq)
+		generic_handle_irq(irq);
+	else
+		spurious_interrupt();
 
 	LOCAL_HUB_L(PI_INT_PEND1);
 }
@@ -326,11 +273,41 @@ void install_ipi(void)
 
 void __init arch_init_irq(void)
 {
+	struct irq_domain *domain;
+	struct fwnode_handle *fn;
+	int i;
+
 	mips_cpu_irq_init();
-	ip27_hub_irq_init();
+
+	/*
+	 * Some interrupts are reserved by hardware or by software convention.
+	 * Mark these as reserved right away so they won't be used accidentally
+	 * later.
+	 */
+	for (i = 0; i <= BASE_PCI_IRQ; i++)
+		set_bit(i, hub_irq_map);
+
+	set_bit(IP_PEND0_6_63, hub_irq_map);
+
+	for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
+		set_bit(i, hub_irq_map);
+
+	fn = irq_domain_alloc_named_fwnode("HUB");
+	WARN_ON(fn == NULL);
+	if (!fn)
+		return;
+	domain = irq_domain_create_linear(fn, IP27_HUB_IRQ_COUNT,
+					  &hub_domain_ops, NULL);
+	WARN_ON(domain == NULL);
+	if (!domain)
+		return;
+
+	irq_set_default_host(domain);
 
 	irq_set_percpu_devid(IP27_HUB_PEND0_IRQ);
-	irq_set_chained_handler(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0);
+	irq_set_chained_handler_and_data(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0,
+					 domain);
 	irq_set_percpu_devid(IP27_HUB_PEND1_IRQ);
-	irq_set_chained_handler(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1);
+	irq_set_chained_handler_and_data(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1,
+					 domain);
 }