MIPS: SGI-IP27: rework HUB interrupts

This commit rearranges the HUB interrupt code by using MIPS_IRQ_CPU
interrupt handling code and modern Linux IRQ framework features to get
rid of global arrays. It also adds support for irq affinity setting.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
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, 240 insertions, 117 deletions

diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index f37155ef7ed9..710a59764b01 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -7,67 +7,234 @@
  * Copyright (C) 1999 - 2001 Kanoj Sarcar
  */
 
-#undef DEBUG
-
-#include <linux/init.h>
-#include <linux/irq.h>
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/sched.h>
-#include <linux/types.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/ioport.h>
-#include <linux/timex.h>
-#include <linux/smp.h>
-#include <linux/random.h>
 #include <linux/kernel.h>
-#include <linux/kernel_stat.h>
-#include <linux/delay.h>
 #include <linux/bitops.h>
 
-#include <asm/bootinfo.h>
 #include <asm/io.h>
-#include <asm/mipsregs.h>
-
-#include <asm/processor.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>
 
-/*
- * Linux has a controller-independent x86 interrupt architecture.
- * every controller has a 'controller-template', that is used
- * by the main code to do the right thing. Each driver-visible
- * interrupt source is transparently wired to the appropriate
- * controller. Thus drivers need not be aware of the
- * interrupt-controller.
- *
- * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
- * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
- * (IO-APICs assumed to be messaging to Pentium local-APICs)
- *
- * the code is designed to be easily extended with new/different
- * interrupt controllers, without having to do assembly magic.
- */
+struct hub_irq_data {
+	struct bridge_controller *bc;
+	u64	*irq_mask[2];
+	cpuid_t	cpu;
+	int	bit;
+	int	pin;
+};
 
-extern asmlinkage void ip27_irq(void);
+static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT);
 
-/*
- * Find first bit set
- */
-static int ms1bit(unsigned long x)
+static DEFINE_PER_CPU(unsigned long [2], irq_enable_mask);
+
+static inline int alloc_level(void)
+{
+	int level;
+
+again:
+	level = find_first_zero_bit(hub_irq_map, IP27_HUB_IRQ_COUNT);
+	if (level >= IP27_HUB_IRQ_COUNT)
+		return -ENOSPC;
+
+	if (test_and_set_bit(level, hub_irq_map))
+		goto again;
+
+	return level;
+}
+
+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);
+	__raw_writeq(mask[0], hd->irq_mask[0]);
+	__raw_writeq(mask[1], hd->irq_mask[1]);
+}
+
+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);
+	__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;
+	int cpu;
+
+	cpu = cpumask_first_and(mask, cpu_online_mask);
+	nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
+	hd->cpu = cpu;
+	if (!cputoslice(cpu)) {
+		hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_A);
+		hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_A);
+	} else {
+		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,
+				bool force)
+{
+	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
+
+	if (!hd)
+		return -EINVAL;
+
+	if (irqd_is_started(d))
+		disable_hub_irq(d);
+
+	setup_hub_mask(hd, mask);
+
+	if (irqd_is_started(d))
+		startup_bridge_irq(d);
+
+	irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
+
+	return 0;
+}
+
+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)
 {
-	int b = 0, s;
+	struct hub_irq_data *hd;
+	struct hub_data *hub;
+	struct irq_desc *desc;
+	int swlevel;
+	int irq;
+
+	hd = kzalloc(sizeof(*hd), GFP_KERNEL);
+	if (!hd)
+		return -ENOMEM;
+
+	swlevel = alloc_level();
+	if (unlikely(swlevel < 0)) {
+		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);
+
+	/* use CPU connected to nearest hub */
+	hub = hub_data(NASID_TO_COMPACT_NODEID(bc->nasid));
+	setup_hub_mask(hd, &hub->h_cpus);
 
-	s = 16; if (x >> 16 == 0) s = 0; b += s; x >>= s;
-	s =  8; if (x >>  8 == 0) s = 0; b += s; x >>= s;
-	s =  4; if (x >>  4 == 0) s = 0; b += s; x >>= s;
-	s =  2; if (x >>  2 == 0) s = 0; b += s; x >>= s;
-	s =  1; if (x >>  1 == 0) s = 0; b += s;
+	desc = irq_to_desc(irq);
+	desc->irq_common_data.node = bc->nasid;
+	cpumask_copy(desc->irq_common_data.affinity, &hub->h_cpus);
 
-	return b;
+	return irq;
+}
+
+void ip27_hub_irq_init(void)
+{
+	int i;
+
+	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);
+
+	for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
+		set_bit(i, hub_irq_map);
 }
 
 /*
@@ -82,23 +249,19 @@ static int ms1bit(unsigned long x)
  * Kanoj 05.13.00
  */
 
-static void ip27_do_irq_mask0(void)
+static void ip27_do_irq_mask0(struct irq_desc *desc)
 {
-	int irq, swlevel;
-	u64 pend0, mask0;
 	cpuid_t cpu = smp_processor_id();
-	int pi_int_mask0 =
-		(cputoslice(cpu) == 0) ?  PI_INT_MASK0_A : PI_INT_MASK0_B;
+	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	u64 pend0;
 
 	/* copied from Irix intpend0() */
 	pend0 = LOCAL_HUB_L(PI_INT_PEND0);
-	mask0 = LOCAL_HUB_L(pi_int_mask0);
 
-	pend0 &= mask0;		/* Pick intrs we should look at */
+	pend0 &= mask[0];		/* Pick intrs we should look at */
 	if (!pend0)
 		return;
 
-	swlevel = ms1bit(pend0);
 #ifdef CONFIG_SMP
 	if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
 		LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
@@ -108,106 +271,66 @@ static void ip27_do_irq_mask0(void)
 		scheduler_ipi();
 	} else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
 		LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
-		irq_enter();
 		generic_smp_call_function_interrupt();
-		irq_exit();
 	} else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
 		LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
-		irq_enter();
 		generic_smp_call_function_interrupt();
-		irq_exit();
 	} else
 #endif
-	{
-		/* "map" swlevel to irq */
-		struct slice_data *si = cpu_data[cpu].data;
-
-		irq = si->level_to_irq[swlevel];
-		do_IRQ(irq);
-	}
+		generic_handle_irq(__ffs(pend0) + IP27_HUB_IRQ_BASE);
 
 	LOCAL_HUB_L(PI_INT_PEND0);
 }
 
-static void ip27_do_irq_mask1(void)
+static void ip27_do_irq_mask1(struct irq_desc *desc)
 {
-	int irq, swlevel;
-	u64 pend1, mask1;
 	cpuid_t cpu = smp_processor_id();
-	int pi_int_mask1 = (cputoslice(cpu) == 0) ?  PI_INT_MASK1_A : PI_INT_MASK1_B;
-	struct slice_data *si = cpu_data[cpu].data;
+	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	u64 pend1;
 
 	/* copied from Irix intpend0() */
 	pend1 = LOCAL_HUB_L(PI_INT_PEND1);
-	mask1 = LOCAL_HUB_L(pi_int_mask1);
 
-	pend1 &= mask1;		/* Pick intrs we should look at */
+	pend1 &= mask[1];		/* Pick intrs we should look at */
 	if (!pend1)
 		return;
 
-	swlevel = ms1bit(pend1);
-	/* "map" swlevel to irq */
-	irq = si->level_to_irq[swlevel];
-	LOCAL_HUB_CLR_INTR(swlevel);
-	do_IRQ(irq);
+	generic_handle_irq(__ffs(pend1) + IP27_HUB_IRQ_BASE + 64);
 
 	LOCAL_HUB_L(PI_INT_PEND1);
 }
 
-static void ip27_prof_timer(void)
-{
-	panic("CPU %d got a profiling interrupt", smp_processor_id());
-}
-
-static void ip27_hub_error(void)
-{
-	panic("CPU %d got a hub error interrupt", smp_processor_id());
-}
-
-asmlinkage void plat_irq_dispatch(void)
-{
-	unsigned long pending = read_c0_cause() & read_c0_status();
-	extern unsigned int rt_timer_irq;
-
-	if (pending & CAUSEF_IP4)
-		do_IRQ(rt_timer_irq);
-	else if (pending & CAUSEF_IP2)	/* PI_INT_PEND_0 or CC_PEND_{A|B} */
-		ip27_do_irq_mask0();
-	else if (pending & CAUSEF_IP3)	/* PI_INT_PEND_1 */
-		ip27_do_irq_mask1();
-	else if (pending & CAUSEF_IP5)
-		ip27_prof_timer();
-	else if (pending & CAUSEF_IP6)
-		ip27_hub_error();
-}
-
-void __init arch_init_irq(void)
-{
-}
-
 void install_ipi(void)
 {
-	int slice = LOCAL_HUB_L(PI_CPU_NUM);
 	int cpu = smp_processor_id();
-	struct slice_data *si = cpu_data[cpu].data;
-	struct hub_data *hub = hub_data(cpu_to_node(cpu));
+	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	int slice = LOCAL_HUB_L(PI_CPU_NUM);
 	int resched, call;
 
 	resched = CPU_RESCHED_A_IRQ + slice;
-	__set_bit(resched, hub->irq_alloc_mask);
-	__set_bit(resched, si->irq_enable_mask);
+	set_bit(resched, mask);
 	LOCAL_HUB_CLR_INTR(resched);
 
 	call = CPU_CALL_A_IRQ + slice;
-	__set_bit(call, hub->irq_alloc_mask);
-	__set_bit(call, si->irq_enable_mask);
+	set_bit(call, mask);
 	LOCAL_HUB_CLR_INTR(call);
 
 	if (slice == 0) {
-		LOCAL_HUB_S(PI_INT_MASK0_A, si->irq_enable_mask[0]);
-		LOCAL_HUB_S(PI_INT_MASK1_A, si->irq_enable_mask[1]);
+		LOCAL_HUB_S(PI_INT_MASK0_A, mask[0]);
+		LOCAL_HUB_S(PI_INT_MASK1_A, mask[1]);
 	} else {
-		LOCAL_HUB_S(PI_INT_MASK0_B, si->irq_enable_mask[0]);
-		LOCAL_HUB_S(PI_INT_MASK1_B, si->irq_enable_mask[1]);
+		LOCAL_HUB_S(PI_INT_MASK0_B, mask[0]);
+		LOCAL_HUB_S(PI_INT_MASK1_B, mask[1]);
 	}
 }
+
+void __init arch_init_irq(void)
+{
+	mips_cpu_irq_init();
+	ip27_hub_irq_init();
+
+	irq_set_percpu_devid(IP27_HUB_PEND0_IRQ);
+	irq_set_chained_handler(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0);
+	irq_set_percpu_devid(IP27_HUB_PEND1_IRQ);
+	irq_set_chained_handler(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1);
+}