// SPDX-License-Identifier: GPL-2.0
/*
* ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
* found on INDY and Indigo2 workstations.
*
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
* Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
* Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
* - Indigo2 changes
* - Interrupt handling fixes
* Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org)
*/
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/ftrace.h>
#include <asm/irq_cpu.h>
#include <asm/sgi/hpc3.h>
#include <asm/sgi/ip22.h>
/* So far nothing hangs here */
#undef USE_LIO3_IRQ
struct sgint_regs *sgint;
static char lc0msk_to_irqnr[256];
static char lc1msk_to_irqnr[256];
static char lc2msk_to_irqnr[256];
static char lc3msk_to_irqnr[256];
extern int ip22_eisa_init(void);
static void enable_local0_irq(struct irq_data *d)
{
/* don't allow mappable interrupt to be enabled from setup_irq,
* we have our own way to do so */
if (d->irq != SGI_MAP_0_IRQ)
sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0));
}
static void disable_local0_irq(struct irq_data *d)
{
sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0));
}
static struct irq_chip ip22_local0_irq_type = {
.name = "IP22 local 0",
.irq_mask = disable_local0_irq,
.irq_unmask = enable_local0_irq,
};
static void enable_local1_irq(struct irq_data *d)
{
/* don't allow mappable interrupt to be enabled from setup_irq,
* we have our own way to do so */
if (d->irq != SGI_MAP_1_IRQ)
sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1));
}
static void disable_local1_irq(struct irq_data *d)
{
sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1));
}
static struct irq_chip ip22_local1_irq_type = {
.name = "IP22 local 1",
.irq_mask = disable_local1_irq,
.irq_unmask = enable_local1_irq,
};
static void enable_local2_irq(struct irq_data *d)
{
sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2));
}
static void disable_local2_irq(struct irq_data *d)
{
sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2));
if (!sgint->cmeimask0)
sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
}
static struct irq_chip ip22_local2_irq_type = {
.name = "IP22 local 2",
.irq_mask = disable_local2_irq,
.irq_unmask = enable_local2_irq,
};
static void enable_local3_irq(struct irq_data *d)
{
sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3));
}
static void disable_local3_irq(struct irq_data *d)
{
sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3));
if (!sgint->cmeimask1)
sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
}
static struct irq_chip ip22_local3_irq_type = {
.name = "IP22 local 3",
.irq_mask = disable_local3_irq,
.irq_unmask = enable_local3_irq,
};
static void indy_local0_irqdispatch(void)
{
u8 mask = sgint->istat0 & sgint->imask0;
u8 mask2;
int irq;
if (mask & SGINT_ISTAT0_LIO2) {
mask2 = sgint->vmeistat & sgint->cmeimask0;
irq = lc2msk_to_irqnr[mask2];
} else
irq = lc0msk_to_irqnr[mask];
/*
* workaround for INT2 bug; if irq == 0, INT2 has seen a fifo full
* irq, but failed to latch it into status register
*/
if (irq)
do_IRQ(irq);
else
do_IRQ(SGINT_LOCAL0 + 0);
}
static void indy_local1_irqdispatch(void)
{
u8 mask = sgint->istat1 & sgint->imask1;
u8 mask2;
int irq;
if (mask & SGINT_ISTAT1_LIO3) {
mask2 = sgint->vmeistat & sgint->cmeimask1;
irq = lc3msk_to_irqnr[mask2];
} else
irq = lc1msk_to_irqnr[mask];
/* if irq == 0, then the interrupt has already been cleared */
if (irq)
do_IRQ(irq);
}
extern void ip22_be_interrupt(int irq);
static void __irq_entry indy_buserror_irq(void)
{
int irq = SGI_BUSERR_IRQ;
irq_enter();
kstat_incr_irq_this_cpu(irq);
ip22_be_interrupt(irq);
irq_exit();
}
#ifdef USE_LIO3_IRQ
#define SGI_INTERRUPTS SGINT_END
#else
#define SGI_INTERRUPTS SGINT_LOCAL3
#endif
extern void indy_8254timer_irq(void);
/*
* IRQs on the INDY look basically (barring software IRQs which we don't use
* at all) like:
*
* MIPS IRQ Source
* -------- ------
* 0 Software (ignored)
* 1 Software (ignored)
* 2 Local IRQ level zero
* 3 Local IRQ level one
* 4 8254 Timer zero
* 5 8254 Timer one
* 6 Bus Error
* 7 R4k timer (what we use)
*
* We handle the IRQ according to _our_ priority which is:
*
* Highest ---- R4k Timer
* Local IRQ zero
* Local IRQ one
* Bus Error
* 8254 Timer zero
* Lowest ---- 8254 Timer one
*
* then we just return, if multiple IRQs are pending then we will just take
* another exception, big deal.
*/
asmlinkage void plat_irq_dispatch(void)
{
unsigned int pending = read_c0_status() & read_c0_cause();
/*
* First we check for r4k counter/timer IRQ.
*/
if (pending & CAUSEF_IP7)
do_IRQ(SGI_TIMER_IRQ);
else if (pending & CAUSEF_IP2)
indy_local0_irqdispatch();
else if (pending & CAUSEF_IP3)
indy_local1_irqdispatch();
else if (pending & CAUSEF_IP6)
indy_buserror_irq();
else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
indy_8254timer_irq();
}
void __init arch_init_irq(void)
{
int i;
/* Init local mask --> irq tables. */
for (i = 0; i < 256; i++) {
if (i & 0x80) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
} else if (i & 0x40) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
} else if (i & 0x20) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
} else if (i & 0x10) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
} else if (i & 0x08) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
} else if (i & 0x04) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
} else if (i & 0x02) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
} else if (i & 0x01) {
lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
} else {
lc0msk_to_irqnr[i] = 0;
lc1msk_to_irqnr[i] = 0;
lc2msk_to_irqnr[i] = 0;
lc3msk_to_irqnr[i] = 0;
}
}
/* Mask out all interrupts. */
sgint->imask0 = 0;
sgint->imask1 = 0;
sgint->cmeimask0 = 0;
sgint->cmeimask1 = 0;
/* init CPU irqs */
mips_cpu_irq_init();
for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
struct irq_chip *handler;
if (i < SGINT_LOCAL1)
handler = &ip22_local0_irq_type;
else if (i < SGINT_LOCAL2)
handler = &ip22_local1_irq_type;
else if (i < SGINT_LOCAL3)
handler = &ip22_local2_irq_type;
else
handler = &ip22_local3_irq_type;
irq_set_chip_and_handler(i, handler, handle_level_irq);
}
/* vector handler. this register the IRQ as non-sharable */
if (request_irq(SGI_LOCAL_0_IRQ, no_action, IRQF_NO_THREAD,
"local0 cascade", NULL))
pr_err("Failed to register local0 cascade interrupt\n");
if (request_irq(SGI_LOCAL_1_IRQ, no_action, IRQF_NO_THREAD,
"local1 cascade", NULL))
pr_err("Failed to register local1 cascade interrupt\n");
if (request_irq(SGI_BUSERR_IRQ, no_action, IRQF_NO_THREAD,
"Bus Error", NULL))
pr_err("Failed to register Bus Error interrupt\n");
/* cascade in cascade. i love Indy ;-) */
if (request_irq(SGI_MAP_0_IRQ, no_action, IRQF_NO_THREAD,
"mapable0 cascade", NULL))
pr_err("Failed to register mapable0 cascade interrupt\n");
#ifdef USE_LIO3_IRQ
if (request_irq(SGI_MAP_1_IRQ, no_action, IRQF_NO_THREAD,
"mapable1 cascade", NULL))
pr_err("Failed to register mapable1 cascade interrupt\n");
#endif
#ifdef CONFIG_EISA
if (ip22_is_fullhouse()) /* Only Indigo-2 has EISA stuff */
ip22_eisa_init();
#endif
}