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

arch/mips/Kconfig

@@ -675,6 +675,7 @@ config SGI_IP27
 	select DEFAULT_SGI_PARTITION
 	select SYS_HAS_EARLY_PRINTK
 	select HAVE_PCI
+	select IRQ_MIPS_CPU
 	select NR_CPUS_DEFAULT_64
 	select SYS_HAS_CPU_R10000
 	select SYS_SUPPORTS_64BIT_KERNEL

arch/mips/include/asm/mach-ip27/irq.h

@@ -10,13 +10,15 @@
 #ifndef __ASM_MACH_IP27_IRQ_H
 #define __ASM_MACH_IP27_IRQ_H
 
-/*
- * A hardwired interrupt number is completely stupid for this system - a
- * large configuration might have thousands if not tenthousands of
- * interrupts.
- */
 #define NR_IRQS 256
 
 #include_next <irq.h>
 
+#define IP27_HUB_PEND0_IRQ	(MIPS_CPU_IRQ_BASE + 2)
+#define IP27_HUB_PEND1_IRQ	(MIPS_CPU_IRQ_BASE + 3)
+#define IP27_RT_TIMER_IRQ	(MIPS_CPU_IRQ_BASE + 4)
+
+#define IP27_HUB_IRQ_BASE	(MIPS_CPU_IRQ_BASE + 8)
+#define IP27_HUB_IRQ_COUNT	128
+
 #endif /* __ASM_MACH_IP27_IRQ_H */

arch/mips/include/asm/mach-ip27/mmzone.h

@@ -8,20 +8,11 @@
 
 #define pa_to_nid(addr)		NASID_TO_COMPACT_NODEID(NASID_GET(addr))
 
-#define LEVELS_PER_SLICE	128
-
-struct slice_data {
-	unsigned long irq_enable_mask[2];
-	int level_to_irq[LEVELS_PER_SLICE];
-};
-
 struct hub_data {
 	kern_vars_t	kern_vars;
 	DECLARE_BITMAP(h_bigwin_used, HUB_NUM_BIG_WINDOW);
 	cpumask_t	h_cpus;
 	unsigned long slice_map;
-	unsigned long irq_alloc_mask[2];
-	struct slice_data slice[2];
 };
 
 struct node_data {

arch/mips/include/asm/pci/bridge.h

@@ -808,7 +808,6 @@ struct bridge_controller {
 	struct bridge_regs	*base;
 	nasid_t			nasid;
 	unsigned int		widget_id;
-	unsigned int		irq_cpu;
 	u64			baddr;
 	unsigned int		pci_int[8];
 };
@@ -823,8 +822,7 @@ struct bridge_controller {
 #define bridge_clr(bc, reg, val)	\
 	__raw_writel(__raw_readl(&bc->base->reg) & ~(val), &bc->base->reg)
 
-extern void register_bridge_irq(unsigned int irq);
-extern int request_bridge_irq(struct bridge_controller *bc);
+extern int request_bridge_irq(struct bridge_controller *bc, int pin);
 
 extern struct pci_ops bridge_pci_ops;
 

arch/mips/pci/pci-ip27.c

@@ -23,23 +23,12 @@
  */
 #define MAX_PCI_BUSSES		40
 
-/*
- * Max #PCI devices (like scsi controllers) we handle on a bus.
- */
-#define MAX_DEVICES_PER_PCIBUS	8
-
 /*
  * XXX: No kmalloc available when we do our crosstalk scan,
  *	we should try to move it later in the boot process.
  */
 static struct bridge_controller bridges[MAX_PCI_BUSSES];
 
-/*
- * Translate from irq to software PCI bus number and PCI slot.
- */
-struct bridge_controller *irq_to_bridge[MAX_PCI_BUSSES * MAX_DEVICES_PER_PCIBUS];
-int irq_to_slot[MAX_PCI_BUSSES * MAX_DEVICES_PER_PCIBUS];
-
 extern struct pci_ops bridge_pci_ops;
 
 int bridge_probe(nasid_t nasid, int widget_id, int masterwid)
@@ -77,7 +66,6 @@ int bridge_probe(nasid_t nasid, int widget_id, int masterwid)
 	bc->io.end		= ~0UL;
 	bc->io.flags		= IORESOURCE_IO;
 
-	bc->irq_cpu = smp_processor_id();
 	bc->widget_id = widget_id;
 	bc->nasid = nasid;
 
@@ -165,16 +153,12 @@ int pcibios_plat_dev_init(struct pci_dev *dev)
 
 	irq = bc->pci_int[slot];
 	if (irq == -1) {
-		irq = request_bridge_irq(bc);
+		irq = request_bridge_irq(bc, slot);
 		if (irq < 0)
 			return irq;
 
 		bc->pci_int[slot] = irq;
 	}
-
-	irq_to_bridge[irq] = bc;
-	irq_to_slot[irq] = slot;
-
 	dev->irq = irq;
 
 	return 0;

arch/mips/sgi-ip27/Makefile

@@ -3,10 +3,9 @@
 # Makefile for the IP27 specific kernel interface routines under Linux.
 #
 
-obj-y	:= ip27-berr.o ip27-irq.o ip27-irqno.o ip27-init.o ip27-klconfig.o \
+obj-y	:= ip27-berr.o ip27-irq.o ip27-init.o ip27-klconfig.o \
 	   ip27-klnuma.o ip27-memory.o ip27-nmi.o ip27-reset.o ip27-timer.o \
 	   ip27-hubio.o ip27-xtalk.o
 
 obj-$(CONFIG_EARLY_PRINTK)	+= ip27-console.o
-obj-$(CONFIG_PCI)		+= ip27-irq-pci.o
 obj-$(CONFIG_SMP)		+= ip27-smp.o

arch/mips/sgi-ip27/ip27-init.c

@@ -56,7 +56,6 @@ static void per_hub_init(cnodeid_t cnode)
 {
 	struct hub_data *hub = hub_data(cnode);
 	nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode);
-	int i;
 
 	cpumask_set_cpu(smp_processor_id(), &hub->h_cpus);
 
@@ -87,24 +86,6 @@ static void per_hub_init(cnodeid_t cnode)
 		__flush_cache_all();
 	}
 #endif
-
-	/*
-	 * 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_alloc_mask);
-		LOCAL_HUB_CLR_INTR(INT_PEND0_BASELVL + i);
-	}
-
-	__set_bit(IP_PEND0_6_63, hub->irq_alloc_mask);
-	LOCAL_HUB_S(PI_INT_PEND_MOD, IP_PEND0_6_63);
-
-	for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++) {
-		__set_bit(i, hub->irq_alloc_mask);
-		LOCAL_HUB_CLR_INTR(INT_PEND1_BASELVL + i);
-	}
 }
 
 void per_cpu_init(void)
@@ -113,8 +94,6 @@ void per_cpu_init(void)
 	int slice = LOCAL_HUB_L(PI_CPU_NUM);
 	cnodeid_t cnode = get_compact_nodeid();
 	struct hub_data *hub = hub_data(cnode);
-	struct slice_data *si = hub->slice + slice;
-	int i;
 
 	if (test_and_set_bit(slice, &hub->slice_map))
 		return;
@@ -123,22 +102,14 @@ void per_cpu_init(void)
 
 	per_hub_init(cnode);
 
-	for (i = 0; i < LEVELS_PER_SLICE; i++)
-		si->level_to_irq[i] = -1;
-
-	/*
-	 * We use this so we can find the local hub's data as fast as only
-	 * possible.
-	 */
-	cpu_data[cpu].data = si;
-
 	cpu_time_init();
 	install_ipi();
 
 	/* Install our NMI handler if symmon hasn't installed one. */
 	install_cpu_nmi_handler(cputoslice(cpu));
 
-	set_c0_status(SRB_DEV0 | SRB_DEV1);
+	enable_percpu_irq(IP27_HUB_PEND0_IRQ, IRQ_TYPE_NONE);
+	enable_percpu_irq(IP27_HUB_PEND1_IRQ, IRQ_TYPE_NONE);
 }
 
 /*

arch/mips/sgi-ip27/ip27-irq-pci.c

-// SPDX-License-Identifier: GPL-2.0
-/*
- * ip27-irq.c: Highlevel interrupt handling for IP27 architecture.
- *
- * Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
- * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
- * Copyright (C) 1999 - 2001 Kanoj Sarcar
- */
-
-#undef DEBUG
-
-#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/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/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.
- */
-
-extern struct bridge_controller *irq_to_bridge[];
-extern int irq_to_slot[];
-
-/*
- * use these macros to get the encoded nasid and widget id
- * from the irq value
- */
-#define IRQ_TO_BRIDGE(i)		irq_to_bridge[(i)]
-#define SLOT_FROM_PCI_IRQ(i)		irq_to_slot[i]
-
-static inline int alloc_level(int cpu, int irq)
-{
-	struct hub_data *hub = hub_data(cpu_to_node(cpu));
-	struct slice_data *si = cpu_data[cpu].data;
-	int level;
-
-	level = find_first_zero_bit(hub->irq_alloc_mask, LEVELS_PER_SLICE);
-	if (level >= LEVELS_PER_SLICE)
-		panic("Cpu %d flooded with devices", cpu);
-
-	__set_bit(level, hub->irq_alloc_mask);
-	si->level_to_irq[level] = irq;
-
-	return level;
-}
-
-static inline int find_level(cpuid_t *cpunum, int irq)
-{
-	int cpu, i;
-
-	for_each_online_cpu(cpu) {
-		struct slice_data *si = cpu_data[cpu].data;
-
-		for (i = BASE_PCI_IRQ; i < LEVELS_PER_SLICE; i++)
-			if (si->level_to_irq[i] == irq) {
-				*cpunum = cpu;
-
-				return i;
-			}
-	}
-
-	panic("Could not identify cpu/level for irq %d", irq);
-}
-
-static int intr_connect_level(int cpu, int bit)
-{
-	nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
-	struct slice_data *si = cpu_data[cpu].data;
-
-	set_bit(bit, si->irq_enable_mask);
-
-	if (!cputoslice(cpu)) {
-		REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]);
-		REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]);
-	} else {
-		REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]);
-		REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]);
-	}
-
-	return 0;
-}
-
-static int intr_disconnect_level(int cpu, int bit)
-{
-	nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
-	struct slice_data *si = cpu_data[cpu].data;
-
-	clear_bit(bit, si->irq_enable_mask);
-
-	if (!cputoslice(cpu)) {
-		REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]);
-		REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]);
-	} else {
-		REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]);
-		REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]);
-	}
-
-	return 0;
-}
-
-/* Startup one of the (PCI ...) IRQs routes over a bridge.  */
-static unsigned int startup_bridge_irq(struct irq_data *d)
-{
-	struct bridge_controller *bc;
-	int pin, swlevel;
-	cpuid_t cpu;
-	u64 device;
-
-	pin = SLOT_FROM_PCI_IRQ(d->irq);
-	bc = IRQ_TO_BRIDGE(d->irq);
-
-	pr_debug("bridge_startup(): irq= 0x%x  pin=%d\n", d->irq, pin);
-	/*
-	 * "map" irq to a swlevel greater than 6 since the first 6 bits
-	 * of INT_PEND0 are taken
-	 */
-	swlevel = find_level(&cpu, d->irq);
-	bridge_write(bc, b_int_addr[pin].addr,
-		     (0x20000 | swlevel | (bc->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);
-
-	intr_connect_level(cpu, swlevel);
-
-	return 0;	/* Never anything pending.  */
-}
-
-/* Shutdown one of the (PCI ...) IRQs routes over a bridge.  */
-static void shutdown_bridge_irq(struct irq_data *d)
-{
-	struct bridge_controller *bc = IRQ_TO_BRIDGE(d->irq);
-	int pin, swlevel;
-	cpuid_t cpu;
-
-	pr_debug("bridge_shutdown: irq 0x%x\n", d->irq);
-	pin = SLOT_FROM_PCI_IRQ(d->irq);
-
-	/*
-	 * map irq to a swlevel greater than 6 since the first 6 bits
-	 * of INT_PEND0 are taken
-	 */
-	swlevel = find_level(&cpu, d->irq);
-	intr_disconnect_level(cpu, swlevel);
-
-	bridge_clr(bc, b_int_enable, (1 << pin));
-	bridge_read(bc, b_wid_tflush);
-}
-
-static inline void enable_bridge_irq(struct irq_data *d)
-{
-	cpuid_t cpu;
-	int swlevel;
-
-	swlevel = find_level(&cpu, d->irq);	/* Criminal offence */
-	intr_connect_level(cpu, swlevel);
-}
-
-static inline void disable_bridge_irq(struct irq_data *d)
-{
-	cpuid_t cpu;
-	int swlevel;
-
-	swlevel = find_level(&cpu, d->irq);	/* Criminal offence */
-	intr_disconnect_level(cpu, swlevel);
-}
-
-static struct irq_chip bridge_irq_type = {
-	.name		= "bridge",
-	.irq_startup	= startup_bridge_irq,
-	.irq_shutdown	= shutdown_bridge_irq,
-	.irq_mask	= disable_bridge_irq,
-	.irq_unmask	= enable_bridge_irq,
-};
-
-void register_bridge_irq(unsigned int irq)
-{
-	irq_set_chip_and_handler(irq, &bridge_irq_type, handle_level_irq);
-}
-
-int request_bridge_irq(struct bridge_controller *bc)
-{
-	int irq = allocate_irqno();
-	int swlevel, cpu;
-	nasid_t nasid;
-
-	if (irq < 0)
-		return irq;
-
-	/*
-	 * "map" irq to a swlevel greater than 6 since the first 6 bits
-	 * of INT_PEND0 are taken
-	 */
-	cpu = bc->irq_cpu;
-	swlevel = alloc_level(cpu, irq);
-	if (unlikely(swlevel < 0)) {
-		free_irqno(irq);
-
-		return -EAGAIN;
-	}
-
-	/* Make sure it's not already pending when we connect it. */
-	nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
-	REMOTE_HUB_CLR_INTR(nasid, swlevel);
-
-	intr_connect_level(cpu, swlevel);
-
-	register_bridge_irq(irq);
-
-	return irq;
-}

arch/mips/sgi-ip27/ip27-irqno.c

-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-#include <linux/init.h>
-#include <linux/irq.h>
-#include <linux/types.h>
-
-#include <asm/barrier.h>
-
-static DECLARE_BITMAP(irq_map, NR_IRQS);
-
-int allocate_irqno(void)
-{
-	int irq;
-
-again:
-	irq = find_first_zero_bit(irq_map, NR_IRQS);
-
-	if (irq >= NR_IRQS)
-		return -ENOSPC;
-
-	if (test_and_set_bit(irq, irq_map))
-		goto again;
-
-	return irq;
-}
-
-/*
- * Allocate the 16 legacy interrupts for i8259 devices.	 This happens early
- * in the kernel initialization so treating allocation failure as BUG() is
- * ok.
- */
-void __init alloc_legacy_irqno(void)
-{
-	int i;
-
-	for (i = 0; i <= 16; i++)
-		BUG_ON(test_and_set_bit(i, irq_map));
-}
-
-void free_irqno(unsigned int irq)
-{
-	smp_mb__before_atomic();
-	clear_bit(irq, irq_map);
-	smp_mb__after_atomic();
-}

arch/mips/sgi-ip27/ip27-timer.c

@@ -38,20 +38,6 @@
 #include <asm/sn/sn0/hubio.h>
 #include <asm/pci/bridge.h>
 
-static void enable_rt_irq(struct irq_data *d)
-{
-}
-
-static void disable_rt_irq(struct irq_data *d)
-{
-}
-
-static struct irq_chip rt_irq_type = {
-	.name		= "SN HUB RT timer",
-	.irq_mask	= disable_rt_irq,
-	.irq_unmask	= enable_rt_irq,
-};
-
 static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
 {
 	unsigned int cpu = smp_processor_id();
@@ -65,8 +51,6 @@ static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
 	return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
 }
 
-unsigned int rt_timer_irq;
-
 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
 static DEFINE_PER_CPU(char [11], hub_rt_name);
 
@@ -87,6 +71,7 @@ static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
 
 struct irqaction hub_rt_irqaction = {
 	.handler	= hub_rt_counter_handler,
+	.percpu_dev_id	= &hub_rt_clockevent,
 	.flags		= IRQF_PERCPU | IRQF_TIMER,
 	.name		= "hub-rt",
 };
@@ -107,7 +92,6 @@ void hub_rt_clock_event_init(void)
 	unsigned int cpu = smp_processor_id();
 	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
 	unsigned char *name = per_cpu(hub_rt_name, cpu);
-	int irq = rt_timer_irq;
 
 	sprintf(name, "hub-rt %d", cpu);
 	cd->name		= name;
@@ -118,29 +102,19 @@ void hub_rt_clock_event_init(void)
 	cd->min_delta_ns	= clockevent_delta2ns(0x300, cd);
 	cd->min_delta_ticks	= 0x300;
 	cd->rating		= 200;
-	cd->irq			= irq;
+	cd->irq			= IP27_RT_TIMER_IRQ;
 	cd->cpumask		= cpumask_of(cpu);
 	cd->set_next_event	= rt_next_event;
 	clockevents_register_device(cd);
+
+	enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE);
 }
 
 static void __init hub_rt_clock_event_global_init(void)
 {
-	int irq;
-
-	do {
-		smp_wmb();
-		irq = rt_timer_irq;
-		if (irq)
-			break;
-
-		irq = allocate_irqno();
-		if (irq < 0)
-			panic("Allocation of irq number for timer failed");
-	} while (xchg(&rt_timer_irq, irq));
-
-	irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
-	setup_irq(irq, &hub_rt_irqaction);
+	irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq);
+	irq_set_percpu_devid(IP27_RT_TIMER_IRQ);
+	setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction);
 }
 
 static u64 hub_rt_read(struct clocksource *cs)
@@ -194,8 +168,6 @@ void cpu_time_init(void)
 		panic("No information about myself?");
 
 	printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
-
-	set_c0_status(SRB_TIMOCLK);
 }
 
 void hub_rtc_init(cnodeid_t cnode)