static void mcip_ipi_clear(int irq)
{
unsigned int cpu, c;
unsigned long flags;
if (unlikely(irq == SOFTIRQ_IRQ)) {
arc_softirq_clear(irq);
return;
}
raw_spin_lock_irqsave(&mcip_lock, flags);
/* Who sent the IPI */
__mcip_cmd(CMD_INTRPT_CHECK_SOURCE, 0);
cpu = read_aux_reg(ARC_REG_MCIP_READBACK); /* 1,2,4,8... */
/*
* In rare case, multiple concurrent IPIs sent to same target can
* possibly be coalesced by MCIP into 1 asserted IRQ, so @cpus can be
* "vectored" (multiple bits sets) as opposed to typical single bit
*/
do {
c = __ffs(cpu); /* 0,1,2,3 */
__mcip_cmd(CMD_INTRPT_GENERATE_ACK, c);
cpu &= ~(1U << c);
} while (cpu);
raw_spin_unlock_irqrestore(&mcip_lock, flags);
}
static void mcip_ipi_clear(int irq)
{
unsigned int cpu, c;
unsigned long flags;
unsigned int __maybe_unused copy;
raw_spin_lock_irqsave(&mcip_lock, flags);
/* Who sent the IPI */
__mcip_cmd(CMD_INTRPT_CHECK_SOURCE, 0);
copy = cpu = read_aux_reg(ARC_REG_MCIP_READBACK); /* 1,2,4,8... */
/*
* In rare case, multiple concurrent IPIs sent to same target can
* possibly be coalesced by MCIP into 1 asserted IRQ, so @cpus can be
* "vectored" (multiple bits sets) as opposed to typical single bit
*/
do {
c = __ffs(cpu); /* 0,1,2,3 */
__mcip_cmd(CMD_INTRPT_GENERATE_ACK, c);
cpu &= ~(1U << c);
} while (cpu);
raw_spin_unlock_irqrestore(&mcip_lock, flags);
#ifdef CONFIG_ARC_IPI_DBG
if (c != __ffs(copy))
pr_info("IPIs from %x coalesced to %x\n",
copy, raw_smp_processor_id());
#endif
}
static void mcip_ipi_send(int cpu)
{
unsigned long flags;
int ipi_was_pending;
/* ARConnect can only send IPI to others */
if (unlikely(cpu == raw_smp_processor_id())) {
arc_softirq_trigger(SOFTIRQ_IRQ);
return;
}
raw_spin_lock_irqsave(&mcip_lock, flags);
/*
* If receiver already has a pending interrupt, elide sending this one.
* Linux cross core calling works well with concurrent IPIs
* coalesced into one
* see arch/arc/kernel/smp.c: ipi_send_msg_one()
*/
__mcip_cmd(CMD_INTRPT_READ_STATUS, cpu);
ipi_was_pending = read_aux_reg(ARC_REG_MCIP_READBACK);
if (!ipi_was_pending)
__mcip_cmd(CMD_INTRPT_GENERATE_IRQ, cpu);
raw_spin_unlock_irqrestore(&mcip_lock, flags);
}
static void mcip_ipi_send(int cpu)
{
unsigned long flags;
int ipi_was_pending;
/*
* NOTE: We must spin here if the other cpu hasn't yet
* serviced a previous message. This can burn lots
* of time, but we MUST follows this protocol or
* ipi messages can be lost!!!
* Also, we must release the lock in this loop because
* the other side may get to this same loop and not
* be able to ack -- thus causing deadlock.
*/
do {
raw_spin_lock_irqsave(&mcip_lock, flags);
__mcip_cmd(CMD_INTRPT_READ_STATUS, cpu);
ipi_was_pending = read_aux_reg(ARC_REG_MCIP_READBACK);
if (ipi_was_pending == 0)
break; /* break out but keep lock */
raw_spin_unlock_irqrestore(&mcip_lock, flags);
} while (1);
__mcip_cmd(CMD_INTRPT_GENERATE_IRQ, cpu);
raw_spin_unlock_irqrestore(&mcip_lock, flags);
#ifdef CONFIG_ARC_IPI_DBG
if (ipi_was_pending)
pr_info("IPI ACK delayed from cpu %d\n", cpu);
#endif
}
static int __init
idu_of_init(struct device_node *intc, struct device_node *parent)
{
struct irq_domain *domain;
/* Read IDU BCR to confirm nr_irqs */
int nr_irqs = of_irq_count(intc);
int i, irq;
if (!idu_detected)
panic("IDU not detected, but DeviceTree using it");
pr_info("MCIP: IDU referenced from Devicetree %d irqs\n", nr_irqs);
domain = irq_domain_add_linear(intc, nr_irqs, &idu_irq_ops, NULL);
/* Parent interrupts (core-intc) are already mapped */
for (i = 0; i < nr_irqs; i++) {
/*
* Return parent uplink IRQs (towards core intc) 24,25,.....
* this step has been done before already
* however we need it to get the parent virq and set IDU handler
* as first level isr
*/
irq = irq_of_parse_and_map(intc, i);
if (!i)
idu_first_irq = irq;
irq_set_chained_handler_and_data(irq, idu_cascade_isr, domain);
}
__mcip_cmd(CMD_IDU_ENABLE, 0);
return 0;
}
static cycle_t arc_read_gfrc(struct clocksource *cs)
{
unsigned long flags;
u32 l, h;
local_irq_save(flags);
__mcip_cmd(CMD_GFRC_READ_LO, 0);
l = read_aux_reg(ARC_REG_MCIP_READBACK);
__mcip_cmd(CMD_GFRC_READ_HI, 0);
h = read_aux_reg(ARC_REG_MCIP_READBACK);
local_irq_restore(flags);
return (((cycle_t)h) << 32) | l;
}
static cycle_t arc_counter_read(struct clocksource *cs)
{
unsigned long flags;
union {
#ifdef CONFIG_CPU_BIG_ENDIAN
struct { u32 h, l; };
#else
struct { u32 l, h; };
#endif
cycle_t full;
} stamp;
local_irq_save(flags);
__mcip_cmd(CMD_GRTC_READ_LO, 0);
stamp.l = read_aux_reg(ARC_REG_MCIP_READBACK);
__mcip_cmd(CMD_GRTC_READ_HI, 0);
stamp.h = read_aux_reg(ARC_REG_MCIP_READBACK);
local_irq_restore(flags);
return stamp.full;
}
static int __init
idu_of_init(struct device_node *intc, struct device_node *parent)
{
struct irq_domain *domain;
int nr_irqs;
int i, virq;
struct mcip_bcr mp;
struct mcip_idu_bcr idu_bcr;
READ_BCR(ARC_REG_MCIP_BCR, mp);
if (!mp.idu)
panic("IDU not detected, but DeviceTree using it");
READ_BCR(ARC_REG_MCIP_IDU_BCR, idu_bcr);
nr_irqs = mcip_idu_bcr_to_nr_irqs(idu_bcr);
pr_info("MCIP: IDU supports %u common irqs\n", nr_irqs);
domain = irq_domain_add_linear(intc, nr_irqs, &idu_irq_ops, NULL);
/* Parent interrupts (core-intc) are already mapped */
for (i = 0; i < nr_irqs; i++) {
/* Mask all common interrupts by default */
idu_irq_mask_raw(i);
/*
* Return parent uplink IRQs (towards core intc) 24,25,.....
* this step has been done before already
* however we need it to get the parent virq and set IDU handler
* as first level isr
*/
virq = irq_create_mapping(NULL, i + FIRST_EXT_IRQ);
BUG_ON(!virq);
irq_set_chained_handler_and_data(virq, idu_cascade_isr, domain);
}
__mcip_cmd(CMD_IDU_ENABLE, 0);
return 0;
}
