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MIPS: Add EIC support for GIC.
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Add support to use an external interrupt controller with the GIC.

Signed-off-by: Steven J. Hill <sjhill@mips.com>
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Steven J. Hill committed Sep 13, 2012
1 parent 2299c49 commit 98b67c3
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Showing 2 changed files with 95 additions and 8 deletions.
5 changes: 5 additions & 0 deletions arch/mips/kernel/cevt-r4k.c
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
#include <asm/smtc_ipi.h>
#include <asm/time.h>
#include <asm/cevt-r4k.h>
#include <asm/gic.h>

/*
* The SMTC Kernel for the 34K, 1004K, et. al. replaces several
Expand Down Expand Up @@ -98,6 +99,10 @@ void mips_event_handler(struct clock_event_device *dev)
*/
static int c0_compare_int_pending(void)
{
#ifdef CONFIG_IRQ_GIC
if (cpu_has_veic)
return gic_get_timer_pending();
#endif
return (read_c0_cause() >> cp0_compare_irq_shift) & (1ul << CAUSEB_IP);
}

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98 changes: 90 additions & 8 deletions arch/mips/kernel/irq-gic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,8 @@

#include <asm/io.h>
#include <asm/gic.h>
#include <asm/setup.h>
#include <asm/traps.h>
#include <asm/gcmpregs.h>
#include <linux/hardirq.h>
#include <asm-generic/bitops/find.h>
Expand All @@ -21,22 +23,71 @@ unsigned long _gic_base;
unsigned int gic_irq_base;
unsigned int gic_irq_flags[GIC_NUM_INTRS];

/* The index into this array is the vector # of the interrupt. */
struct gic_shared_intr_map gic_shared_intr_map[GIC_NUM_INTRS];

static struct gic_pcpu_mask pcpu_masks[NR_CPUS];
static struct gic_pending_regs pending_regs[NR_CPUS];
static struct gic_intrmask_regs intrmask_regs[NR_CPUS];

unsigned int gic_get_timer_pending(void)
{
unsigned int vpe_pending;

GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), 0);
GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_PEND), vpe_pending);
return (vpe_pending & GIC_VPE_PEND_TIMER_MSK);
}

void gic_bind_eic_interrupt(int irq, int set)
{
/* Convert irq vector # to hw int # */
irq -= GIC_PIN_TO_VEC_OFFSET;

/* Set irq to use shadow set */
GICWRITE(GIC_REG_ADDR(VPE_LOCAL, GIC_VPE_EIC_SS(irq)), set);
}

void gic_send_ipi(unsigned int intr)
{
GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
}

static void gic_eic_irq_dispatch(void)
{
unsigned int cause = read_c0_cause();
int irq;

irq = (cause & ST0_IM) >> STATUSB_IP2;
if (irq == 0)
irq = -1;

if (irq >= 0)
do_IRQ(gic_irq_base + irq);
else
spurious_interrupt();
}

static void __init vpe_local_setup(unsigned int numvpes)
{
unsigned long timer_interrupt = GIC_INT_TMR;
unsigned long perf_interrupt = GIC_INT_PERFCTR;
unsigned long timer_intr = GIC_INT_TMR;
unsigned long perf_intr = GIC_INT_PERFCTR;
unsigned int vpe_ctl;
int i;

if (cpu_has_veic) {
/*
* GIC timer interrupt -> CPU HW Int X (vector X+2) ->
* map to pin X+2-1 (since GIC adds 1)
*/
timer_intr += (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
/*
* GIC perfcnt interrupt -> CPU HW Int X (vector X+2) ->
* map to pin X+2-1 (since GIC adds 1)
*/
perf_intr += (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
}

/*
* Setup the default performance counter timer interrupts
* for all VPEs
Expand All @@ -48,11 +99,20 @@ static void __init vpe_local_setup(unsigned int numvpes)
GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_CTL), vpe_ctl);
if (vpe_ctl & GIC_VPE_CTL_TIMER_RTBL_MSK)
GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP),
GIC_MAP_TO_PIN_MSK | timer_interrupt);
GIC_MAP_TO_PIN_MSK | timer_intr);
if (cpu_has_veic) {
set_vi_handler(timer_intr + GIC_PIN_TO_VEC_OFFSET,
gic_eic_irq_dispatch);
gic_shared_intr_map[timer_intr + GIC_PIN_TO_VEC_OFFSET].local_intr_mask |= GIC_VPE_RMASK_TIMER_MSK;
}

if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
GIC_MAP_TO_PIN_MSK | perf_interrupt);
GIC_MAP_TO_PIN_MSK | perf_intr);
if (cpu_has_veic) {
set_vi_handler(perf_intr + GIC_PIN_TO_VEC_OFFSET, gic_eic_irq_dispatch);
gic_shared_intr_map[perf_intr + GIC_PIN_TO_VEC_OFFSET].local_intr_mask |= GIC_VPE_RMASK_PERFCNT_MSK;
}
}
}

Expand Down Expand Up @@ -145,6 +205,8 @@ static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,
unsigned int pin, unsigned int polarity, unsigned int trigtype,
unsigned int flags)
{
struct gic_shared_intr_map *map_ptr;

/* Setup Intr to Pin mapping */
if (pin & GIC_MAP_TO_NMI_MSK) {
GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
Expand All @@ -159,6 +221,14 @@ static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,
GIC_MAP_TO_PIN_MSK | pin);
/* Setup Intr to CPU mapping */
GIC_SH_MAP_TO_VPE_SMASK(intr, cpu);
if (cpu_has_veic) {
set_vi_handler(pin + GIC_PIN_TO_VEC_OFFSET,
gic_eic_irq_dispatch);
map_ptr = &gic_shared_intr_map[pin + GIC_PIN_TO_VEC_OFFSET];
if (map_ptr->num_shared_intr >= GIC_MAX_SHARED_INTR)
BUG();
map_ptr->intr_list[map_ptr->num_shared_intr++] = intr;
}
}

/* Setup Intr Polarity */
Expand All @@ -169,11 +239,10 @@ static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,

/* Init Intr Masks */
GIC_CLR_INTR_MASK(intr);

/* Initialise per-cpu Interrupt software masks */
if (flags & GIC_FLAG_IPI)
set_bit(intr, pcpu_masks[cpu].pcpu_mask);
if (flags & GIC_FLAG_TRANSPARENT)
if ((flags & GIC_FLAG_TRANSPARENT) && (cpu_has_veic == 0))
GIC_SET_INTR_MASK(intr);
if (trigtype == GIC_TRIG_EDGE)
gic_irq_flags[intr] |= GIC_TRIG_EDGE;
Expand All @@ -183,16 +252,29 @@ static void __init gic_basic_init(int numintrs, int numvpes,
struct gic_intr_map *intrmap, int mapsize)
{
unsigned int i, cpu;
unsigned int pin_offset = 0;

board_bind_eic_interrupt = &gic_bind_eic_interrupt;

/* Setup defaults */
for (i = 0; i < numintrs; i++) {
GIC_SET_POLARITY(i, GIC_POL_POS);
GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
GIC_CLR_INTR_MASK(i);
if (i < GIC_NUM_INTRS)
if (i < GIC_NUM_INTRS) {
gic_irq_flags[i] = 0;
gic_shared_intr_map[i].num_shared_intr = 0;
gic_shared_intr_map[i].local_intr_mask = 0;
}
}

/*
* In EIC mode, the HW_INT# is offset by (2-1). Need to subtract
* one because the GIC will add one (since 0=no intr).
*/
if (cpu_has_veic)
pin_offset = (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);

/* Setup specifics */
for (i = 0; i < mapsize; i++) {
cpu = intrmap[i].cpunum;
Expand All @@ -202,7 +284,7 @@ static void __init gic_basic_init(int numintrs, int numvpes,
continue;
gic_setup_intr(i,
intrmap[i].cpunum,
intrmap[i].pin,
intrmap[i].pin + pin_offset,
intrmap[i].polarity,
intrmap[i].trigtype,
intrmap[i].flags);
Expand Down

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