linux/drivers/irqchip/irq-xtensa-mx.c
Max Filippov e5c86679d5 xtensa: don't use linux IRQ #0
Linux IRQ #0 is reserved for error reporting and may not be used.
Increase NR_IRQS for one additional slot and increase
irq_domain_add_legacy parameter first_irq value to 1, so that linux
IRQ #0 is not associated with hardware IRQ #0 in legacy IRQ domains.
Introduce macro XTENSA_PIC_LINUX_IRQ for static translation of xtensa
PIC hardware IRQ # to linux IRQ #. Use this macro in XTFPGA platform
data definitions.

This fixes inability to use hardware IRQ #0 in configurations that don't
use device tree and allows for non-identity mapping between linux IRQ #
and hardware IRQ #.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-06-05 16:53:10 -07:00

164 lines
4.2 KiB
C

/*
* Xtensa MX interrupt distributor
*
* Copyright (C) 2002 - 2013 Tensilica, Inc.
*
* 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/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/of.h>
#include <asm/mxregs.h>
#define HW_IRQ_IPI_COUNT 2
#define HW_IRQ_MX_BASE 2
#define HW_IRQ_EXTERN_BASE 3
static DEFINE_PER_CPU(unsigned int, cached_irq_mask);
static int xtensa_mx_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
if (hw < HW_IRQ_IPI_COUNT) {
struct irq_chip *irq_chip = d->host_data;
irq_set_chip_and_handler_name(irq, irq_chip,
handle_percpu_irq, "ipi");
irq_set_status_flags(irq, IRQ_LEVEL);
return 0;
}
return xtensa_irq_map(d, irq, hw);
}
/*
* Device Tree IRQ specifier translation function which works with one or
* two cell bindings. First cell value maps directly to the hwirq number.
* Second cell if present specifies whether hwirq number is external (1) or
* internal (0).
*/
static int xtensa_mx_irq_domain_xlate(struct irq_domain *d,
struct device_node *ctrlr,
const u32 *intspec, unsigned int intsize,
unsigned long *out_hwirq, unsigned int *out_type)
{
return xtensa_irq_domain_xlate(intspec, intsize,
intspec[0], intspec[0] + HW_IRQ_EXTERN_BASE,
out_hwirq, out_type);
}
static const struct irq_domain_ops xtensa_mx_irq_domain_ops = {
.xlate = xtensa_mx_irq_domain_xlate,
.map = xtensa_mx_irq_map,
};
void secondary_init_irq(void)
{
__this_cpu_write(cached_irq_mask,
XCHAL_INTTYPE_MASK_EXTERN_EDGE |
XCHAL_INTTYPE_MASK_EXTERN_LEVEL);
set_sr(XCHAL_INTTYPE_MASK_EXTERN_EDGE |
XCHAL_INTTYPE_MASK_EXTERN_LEVEL, intenable);
}
static void xtensa_mx_irq_mask(struct irq_data *d)
{
unsigned int mask = 1u << d->hwirq;
if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
HW_IRQ_MX_BASE), MIENG);
} else {
mask = __this_cpu_read(cached_irq_mask) & ~mask;
__this_cpu_write(cached_irq_mask, mask);
set_sr(mask, intenable);
}
}
static void xtensa_mx_irq_unmask(struct irq_data *d)
{
unsigned int mask = 1u << d->hwirq;
if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
HW_IRQ_MX_BASE), MIENGSET);
} else {
mask |= __this_cpu_read(cached_irq_mask);
__this_cpu_write(cached_irq_mask, mask);
set_sr(mask, intenable);
}
}
static void xtensa_mx_irq_enable(struct irq_data *d)
{
variant_irq_enable(d->hwirq);
xtensa_mx_irq_unmask(d);
}
static void xtensa_mx_irq_disable(struct irq_data *d)
{
xtensa_mx_irq_mask(d);
variant_irq_disable(d->hwirq);
}
static void xtensa_mx_irq_ack(struct irq_data *d)
{
set_sr(1 << d->hwirq, intclear);
}
static int xtensa_mx_irq_retrigger(struct irq_data *d)
{
set_sr(1 << d->hwirq, intset);
return 1;
}
static int xtensa_mx_irq_set_affinity(struct irq_data *d,
const struct cpumask *dest, bool force)
{
unsigned mask = 1u << cpumask_any_and(dest, cpu_online_mask);
set_er(mask, MIROUT(d->hwirq - HW_IRQ_MX_BASE));
return 0;
}
static struct irq_chip xtensa_mx_irq_chip = {
.name = "xtensa-mx",
.irq_enable = xtensa_mx_irq_enable,
.irq_disable = xtensa_mx_irq_disable,
.irq_mask = xtensa_mx_irq_mask,
.irq_unmask = xtensa_mx_irq_unmask,
.irq_ack = xtensa_mx_irq_ack,
.irq_retrigger = xtensa_mx_irq_retrigger,
.irq_set_affinity = xtensa_mx_irq_set_affinity,
};
int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent)
{
struct irq_domain *root_domain =
irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0,
&xtensa_mx_irq_domain_ops,
&xtensa_mx_irq_chip);
irq_set_default_host(root_domain);
secondary_init_irq();
return 0;
}
static int __init xtensa_mx_init(struct device_node *np,
struct device_node *interrupt_parent)
{
struct irq_domain *root_domain =
irq_domain_add_linear(np, NR_IRQS, &xtensa_mx_irq_domain_ops,
&xtensa_mx_irq_chip);
irq_set_default_host(root_domain);
secondary_init_irq();
return 0;
}
IRQCHIP_DECLARE(xtensa_mx_irq_chip, "cdns,xtensa-mx", xtensa_mx_init);