linux/arch/mips/sgi-ip27/ip27-irq.c
Thomas Bogendoerfer 78691e4f17
MIPS: SGI-IP27: Only reserve interrupts used in Linux
Reduce number of reserved interrupts by removing bits copied from IRIX
and not used by Linux.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paulburton@kernel.org>
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
2020-01-09 15:30:04 -08:00

315 lines
7.4 KiB
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
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#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/sn/addrs.h>
#include <asm/sn/agent.h>
#include <asm/sn/arch.h>
#include <asm/sn/intr.h>
#include <asm/sn/irq_alloc.h>
struct hub_irq_data {
u64 *irq_mask[2];
cpuid_t cpu;
};
static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT);
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(d->hwirq, 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(d->hwirq, mask);
__raw_writeq(mask[0], hd->irq_mask[0]);
__raw_writeq(mask[1], hd->irq_mask[1]);
}
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);
if (cpu >= nr_cpu_ids)
cpu = cpumask_any(cpu_online_mask);
nasid = 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);
}
}
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))
enable_hub_irq(d);
irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
return 0;
}
static struct irq_chip hub_irq_type = {
.name = "HUB",
.irq_mask = disable_hub_irq,
.irq_unmask = enable_hub_irq,
.irq_set_affinity = set_affinity_hub_irq,
};
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;
if (nr_irqs > 1 || !info)
return -EINVAL;
hd = kzalloc(sizeof(*hd), GFP_KERNEL);
if (!hd)
return -ENOMEM;
swlevel = alloc_level();
if (unlikely(swlevel < 0)) {
kfree(hd);
return -EAGAIN;
}
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(info->nasid);
setup_hub_mask(hd, &hub->h_cpus);
info->nasid = cpu_to_node(hd->cpu);
/* 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 0;
}
static void hub_domain_free(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs)
{
struct irq_data *irqd;
if (nr_irqs > 1)
return;
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
* to service, we must mask _all_ these interrupts; firstly, to make
* sure the same intr does not intr again, causing recursion that
* can lead to stack overflow. Secondly, we can not just mask the
* one intr we are do_IRQing, because the non-masked intrs in the
* first set might intr again, causing multiple servicings of the
* same intr. This effect is mostly seen for intercpu intrs.
* Kanoj 05.13.00
*/
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);
pend0 &= mask[0]; /* Pick intrs we should look at */
if (!pend0)
return;
#ifdef CONFIG_SMP
if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
scheduler_ipi();
} else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ);
scheduler_ipi();
} else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
generic_smp_call_function_interrupt();
} else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
generic_smp_call_function_interrupt();
} else
#endif
{
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);
}
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);
pend1 &= mask[1]; /* Pick intrs we should look at */
if (!pend1)
return;
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);
}
void install_ipi(void)
{
int cpu = smp_processor_id();
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, mask);
LOCAL_HUB_CLR_INTR(resched);
call = CPU_CALL_A_IRQ + slice;
set_bit(call, mask);
LOCAL_HUB_CLR_INTR(call);
if (slice == 0) {
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, mask[0]);
LOCAL_HUB_S(PI_INT_MASK1_B, mask[1]);
}
}
void __init arch_init_irq(void)
{
struct irq_domain *domain;
struct fwnode_handle *fn;
int i;
mips_cpu_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 <= CPU_CALL_B_IRQ; i++)
set_bit(i, 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_and_data(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0,
domain);
irq_set_percpu_devid(IP27_HUB_PEND1_IRQ);
irq_set_chained_handler_and_data(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1,
domain);
}