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original_kernel/arch/mips/sibyte/sb1250/irq.c

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/*
* Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/kernel_stat.h>
#include <asm/errno.h>
#include <asm/signal.h>
#include <asm/system.h>
#include <asm/ptrace.h>
#include <asm/io.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
#include <asm/sibyte/sb1250_uart.h>
#include <asm/sibyte/sb1250_scd.h>
#include <asm/sibyte/sb1250.h>
/*
* These are the routines that handle all the low level interrupt stuff.
* Actions handled here are: initialization of the interrupt map, requesting of
* interrupt lines by handlers, dispatching if interrupts to handlers, probing
* for interrupt lines
*/
#define shutdown_sb1250_irq disable_sb1250_irq
static void end_sb1250_irq(unsigned int irq);
static void enable_sb1250_irq(unsigned int irq);
static void disable_sb1250_irq(unsigned int irq);
static unsigned int startup_sb1250_irq(unsigned int irq);
static void ack_sb1250_irq(unsigned int irq);
#ifdef CONFIG_SMP
static void sb1250_set_affinity(unsigned int irq, cpumask_t mask);
#endif
#ifdef CONFIG_SIBYTE_HAS_LDT
extern unsigned long ldt_eoi_space;
#endif
#ifdef CONFIG_KGDB
static int kgdb_irq;
/* Default to UART1 */
int kgdb_port = 1;
#ifdef CONFIG_SIBYTE_SB1250_DUART
extern char sb1250_duart_present[];
#endif
#endif
static struct irq_chip sb1250_irq_type = {
.typename = "SB1250-IMR",
.startup = startup_sb1250_irq,
.shutdown = shutdown_sb1250_irq,
.enable = enable_sb1250_irq,
.disable = disable_sb1250_irq,
.ack = ack_sb1250_irq,
.end = end_sb1250_irq,
#ifdef CONFIG_SMP
.set_affinity = sb1250_set_affinity
#endif
};
/* Store the CPU id (not the logical number) */
int sb1250_irq_owner[SB1250_NR_IRQS];
DEFINE_SPINLOCK(sb1250_imr_lock);
void sb1250_mask_irq(int cpu, int irq)
{
unsigned long flags;
u64 cur_ints;
spin_lock_irqsave(&sb1250_imr_lock, flags);
cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
R_IMR_INTERRUPT_MASK));
cur_ints |= (((u64) 1) << irq);
____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
R_IMR_INTERRUPT_MASK));
spin_unlock_irqrestore(&sb1250_imr_lock, flags);
}
void sb1250_unmask_irq(int cpu, int irq)
{
unsigned long flags;
u64 cur_ints;
spin_lock_irqsave(&sb1250_imr_lock, flags);
cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
R_IMR_INTERRUPT_MASK));
cur_ints &= ~(((u64) 1) << irq);
____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
R_IMR_INTERRUPT_MASK));
spin_unlock_irqrestore(&sb1250_imr_lock, flags);
}
#ifdef CONFIG_SMP
static void sb1250_set_affinity(unsigned int irq, cpumask_t mask)
{
int i = 0, old_cpu, cpu, int_on;
u64 cur_ints;
struct irq_desc *desc = irq_desc + irq;
unsigned long flags;
i = first_cpu(mask);
if (cpus_weight(mask) > 1) {
printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
return;
}
/* Convert logical CPU to physical CPU */
cpu = cpu_logical_map(i);
/* Protect against other affinity changers and IMR manipulation */
spin_lock_irqsave(&desc->lock, flags);
spin_lock(&sb1250_imr_lock);
/* Swizzle each CPU's IMR (but leave the IP selection alone) */
old_cpu = sb1250_irq_owner[irq];
cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(old_cpu) +
R_IMR_INTERRUPT_MASK));
int_on = !(cur_ints & (((u64) 1) << irq));
if (int_on) {
/* If it was on, mask it */
cur_ints |= (((u64) 1) << irq);
____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) +
R_IMR_INTERRUPT_MASK));
}
sb1250_irq_owner[irq] = cpu;
if (int_on) {
/* unmask for the new CPU */
cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
R_IMR_INTERRUPT_MASK));
cur_ints &= ~(((u64) 1) << irq);
____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
R_IMR_INTERRUPT_MASK));
}
spin_unlock(&sb1250_imr_lock);
spin_unlock_irqrestore(&desc->lock, flags);
}
#endif
/*****************************************************************************/
static unsigned int startup_sb1250_irq(unsigned int irq)
{
sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
return 0; /* never anything pending */
}
static void disable_sb1250_irq(unsigned int irq)
{
sb1250_mask_irq(sb1250_irq_owner[irq], irq);
}
static void enable_sb1250_irq(unsigned int irq)
{
sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
}
static void ack_sb1250_irq(unsigned int irq)
{
#ifdef CONFIG_SIBYTE_HAS_LDT
u64 pending;
/*
* If the interrupt was an HT interrupt, now is the time to
* clear it. NOTE: we assume the HT bridge was set up to
* deliver the interrupts to all CPUs (which makes affinity
* changing easier for us)
*/
pending = __raw_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq],
R_IMR_LDT_INTERRUPT)));
pending &= ((u64)1 << (irq));
if (pending) {
int i;
for (i=0; i<NR_CPUS; i++) {
int cpu;
#ifdef CONFIG_SMP
cpu = cpu_logical_map(i);
#else
cpu = i;
#endif
/*
* Clear for all CPUs so an affinity switch
* doesn't find an old status
*/
__raw_writeq(pending,
IOADDR(A_IMR_REGISTER(cpu,
R_IMR_LDT_INTERRUPT_CLR)));
}
/*
* Generate EOI. For Pass 1 parts, EOI is a nop. For
* Pass 2, the LDT world may be edge-triggered, but
* this EOI shouldn't hurt. If they are
* level-sensitive, the EOI is required.
*/
*(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0;
}
#endif
sb1250_mask_irq(sb1250_irq_owner[irq], irq);
}
static void end_sb1250_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
}
}
void __init init_sb1250_irqs(void)
{
int i;
for (i = 0; i < NR_IRQS; i++) {
irq_desc[i].status = IRQ_DISABLED;
irq_desc[i].action = 0;
irq_desc[i].depth = 1;
if (i < SB1250_NR_IRQS) {
irq_desc[i].chip = &sb1250_irq_type;
sb1250_irq_owner[i] = 0;
} else {
irq_desc[i].chip = &no_irq_chip;
}
}
}
static irqreturn_t sb1250_dummy_handler(int irq, void *dev_id,
struct pt_regs *regs)
{
return IRQ_NONE;
}
static struct irqaction sb1250_dummy_action = {
.handler = sb1250_dummy_handler,
.flags = 0,
.mask = CPU_MASK_NONE,
.name = "sb1250-private",
.next = NULL,
.dev_id = 0
};
int sb1250_steal_irq(int irq)
{
struct irq_desc *desc = irq_desc + irq;
unsigned long flags;
int retval = 0;
if (irq >= SB1250_NR_IRQS)
return -EINVAL;
spin_lock_irqsave(&desc->lock,flags);
/* Don't allow sharing at all for these */
if (desc->action != NULL)
retval = -EBUSY;
else {
desc->action = &sb1250_dummy_action;
desc->depth = 0;
}
spin_unlock_irqrestore(&desc->lock,flags);
return 0;
}
/*
* arch_init_irq is called early in the boot sequence from init/main.c via
* init_IRQ. It is responsible for setting up the interrupt mapper and
* installing the handler that will be responsible for dispatching interrupts
* to the "right" place.
*/
/*
* For now, map all interrupts to IP[2]. We could save
* some cycles by parceling out system interrupts to different
* IP lines, but keep it simple for bringup. We'll also direct
* all interrupts to a single CPU; we should probably route
* PCI and LDT to one cpu and everything else to the other
* to balance the load a bit.
*
* On the second cpu, everything is set to IP5, which is
* ignored, EXCEPT the mailbox interrupt. That one is
* set to IP[2] so it is handled. This is needed so we
* can do cross-cpu function calls, as requred by SMP
*/
#define IMR_IP2_VAL K_INT_MAP_I0
#define IMR_IP3_VAL K_INT_MAP_I1
#define IMR_IP4_VAL K_INT_MAP_I2
#define IMR_IP5_VAL K_INT_MAP_I3
#define IMR_IP6_VAL K_INT_MAP_I4
void __init arch_init_irq(void)
{
unsigned int i;
u64 tmp;
unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
STATUSF_IP1 | STATUSF_IP0;
/* Default everything to IP2 */
for (i = 0; i < SB1250_NR_IRQS; i++) { /* was I0 */
__raw_writeq(IMR_IP2_VAL,
IOADDR(A_IMR_REGISTER(0,
R_IMR_INTERRUPT_MAP_BASE) +
(i << 3)));
__raw_writeq(IMR_IP2_VAL,
IOADDR(A_IMR_REGISTER(1,
R_IMR_INTERRUPT_MAP_BASE) +
(i << 3)));
}
init_sb1250_irqs();
/*
* Map the high 16 bits of the mailbox registers to IP[3], for
* inter-cpu messages
*/
/* Was I1 */
__raw_writeq(IMR_IP3_VAL,
IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
(K_INT_MBOX_0 << 3)));
__raw_writeq(IMR_IP3_VAL,
IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
(K_INT_MBOX_0 << 3)));
/* Clear the mailboxes. The firmware may leave them dirty */
__raw_writeq(0xffffffffffffffffULL,
IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU)));
__raw_writeq(0xffffffffffffffffULL,
IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU)));
/* Mask everything except the mailbox registers for both cpus */
tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0);
__raw_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK)));
__raw_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK)));
sb1250_steal_irq(K_INT_MBOX_0);
/*
* Note that the timer interrupts are also mapped, but this is
* done in sb1250_time_init(). Also, the profiling driver
* does its own management of IP7.
*/
#ifdef CONFIG_KGDB
imask |= STATUSF_IP6;
#endif
/* Enable necessary IPs, disable the rest */
change_c0_status(ST0_IM, imask);
#ifdef CONFIG_KGDB
if (kgdb_flag) {
kgdb_irq = K_INT_UART_0 + kgdb_port;
#ifdef CONFIG_SIBYTE_SB1250_DUART
sb1250_duart_present[kgdb_port] = 0;
#endif
/* Setup uart 1 settings, mapper */
__raw_writeq(M_DUART_IMR_BRK,
IOADDR(A_DUART_IMRREG(kgdb_port)));
sb1250_steal_irq(kgdb_irq);
__raw_writeq(IMR_IP6_VAL,
IOADDR(A_IMR_REGISTER(0,
R_IMR_INTERRUPT_MAP_BASE) +
(kgdb_irq << 3)));
sb1250_unmask_irq(0, kgdb_irq);
}
#endif
}
#ifdef CONFIG_KGDB
#include <linux/delay.h>
#define duart_out(reg, val) csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
#define duart_in(reg) csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
static void sb1250_kgdb_interrupt(struct pt_regs *regs)
{
/*
* Clear break-change status (allow some time for the remote
* host to stop the break, since we would see another
* interrupt on the end-of-break too)
*/
kstat_this_cpu.irqs[kgdb_irq]++;
mdelay(500);
duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
M_DUART_RX_EN | M_DUART_TX_EN);
set_async_breakpoint(&regs->cp0_epc);
}
#endif /* CONFIG_KGDB */
static inline int dclz(unsigned long long x)
{
int lz;
__asm__ (
" .set push \n"
" .set mips64 \n"
" dclz %0, %1 \n"
" .set pop \n"
: "=r" (lz)
: "r" (x));
return lz;
}
extern void sb1250_timer_interrupt(struct pt_regs *regs);
extern void sb1250_mailbox_interrupt(struct pt_regs *regs);
extern void sb1250_kgdb_interrupt(struct pt_regs *regs);
asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
{
unsigned int pending;
#ifdef CONFIG_SIBYTE_SB1250_PROF
/* Set compare to count to silence count/compare timer interrupts */
write_c0_compare(read_c0_count());
#endif
/*
* What a pain. We have to be really careful saving the upper 32 bits
* of any * register across function calls if we don't want them
* trashed--since were running in -o32, the calling routing never saves
* the full 64 bits of a register across a function call. Being the
* interrupt handler, we're guaranteed that interrupts are disabled
* during this code so we don't have to worry about random interrupts
* blasting the high 32 bits.
*/
pending = read_c0_cause();
#ifdef CONFIG_SIBYTE_SB1250_PROF
if (pending & CAUSEF_IP7) /* Cpu performance counter interrupt */
sbprof_cpu_intr(exception_epc(regs));
else
#endif
if (pending & CAUSEF_IP4)
sb1250_timer_interrupt(regs);
#ifdef CONFIG_SMP
else if (pending & CAUSEF_IP3)
sb1250_mailbox_interrupt(regs);
#endif
#ifdef CONFIG_KGDB
else if (pending & CAUSEF_IP6) /* KGDB (uart 1) */
sb1250_kgdb_interrupt(regs);
#endif
else if (pending & CAUSEF_IP2) {
unsigned long long mask;
/*
* Default...we've hit an IP[2] interrupt, which means we've
* got to check the 1250 interrupt registers to figure out what
* to do. Need to detect which CPU we're on, now that
* smp_affinity is supported.
*/
mask = __raw_readq(IOADDR(A_IMR_REGISTER(smp_processor_id(),
R_IMR_INTERRUPT_STATUS_BASE)));
if (mask)
do_IRQ(63 - dclz(mask), regs);
}
}
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