summaryrefslogtreecommitdiff
path: root/arch/mips/sgi-ip30/ip30-irq.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/sgi-ip30/ip30-irq.c')
-rw-r--r--arch/mips/sgi-ip30/ip30-irq.c328
1 files changed, 328 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip30/ip30-irq.c b/arch/mips/sgi-ip30/ip30-irq.c
new file mode 100644
index 000000000000..d46655b914f1
--- /dev/null
+++ b/arch/mips/sgi-ip30/ip30-irq.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip30-irq.c: Highlevel interrupt handling for IP30 architecture.
+ */
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+#include <linux/tick.h>
+#include <linux/types.h>
+
+#include <asm/irq_cpu.h>
+#include <asm/sgi/heart.h>
+
+struct heart_irq_data {
+ u64 *irq_mask;
+ int cpu;
+};
+
+static DECLARE_BITMAP(heart_irq_map, HEART_NUM_IRQS);
+
+static DEFINE_PER_CPU(unsigned long, irq_enable_mask);
+
+static inline int heart_alloc_int(void)
+{
+ int bit;
+
+again:
+ bit = find_first_zero_bit(heart_irq_map, HEART_NUM_IRQS);
+ if (bit >= HEART_NUM_IRQS)
+ return -ENOSPC;
+
+ if (test_and_set_bit(bit, heart_irq_map))
+ goto again;
+
+ return bit;
+}
+
+static void ip30_error_irq(struct irq_desc *desc)
+{
+ u64 pending, mask, cause, error_irqs, err_reg;
+ int cpu = smp_processor_id();
+ int i;
+
+ pending = heart_read(&heart_regs->isr);
+ mask = heart_read(&heart_regs->imr[cpu]);
+ cause = heart_read(&heart_regs->cause);
+ error_irqs = (pending & HEART_L4_INT_MASK & mask);
+
+ /* Bail if there's nothing to process (how did we get here, then?) */
+ if (unlikely(!error_irqs))
+ return;
+
+ /* Prevent any of the error IRQs from firing again. */
+ heart_write(mask & ~(pending), &heart_regs->imr[cpu]);
+
+ /* Ack all error IRQs. */
+ heart_write(HEART_L4_INT_MASK, &heart_regs->clear_isr);
+
+ /*
+ * If we also have a cause value, then something happened, so loop
+ * through the error IRQs and report a "heart attack" for each one
+ * and print the value of the HEART cause register. This is really
+ * primitive right now, but it should hopefully work until a more
+ * robust error handling routine can be put together.
+ *
+ * Refer to heart.h for the HC_* macros to work out the cause
+ * that got us here.
+ */
+ if (cause) {
+ pr_alert("IP30: CPU%d: HEART ATTACK! ISR = 0x%.16llx, IMR = 0x%.16llx, CAUSE = 0x%.16llx\n",
+ cpu, pending, mask, cause);
+
+ if (cause & HC_COR_MEM_ERR) {
+ err_reg = heart_read(&heart_regs->mem_err_addr);
+ pr_alert(" HEART_MEMERR_ADDR = 0x%.16llx\n", err_reg);
+ }
+
+ /* i = 63; i >= 51; i-- */
+ for (i = HEART_ERR_MASK_END; i >= HEART_ERR_MASK_START; i--)
+ if ((pending >> i) & 1)
+ pr_alert(" HEART Error IRQ #%d\n", i);
+
+ /* XXX: Seems possible to loop forever here, so panic(). */
+ panic("IP30: Fatal Error !\n");
+ }
+
+ /* Unmask the error IRQs. */
+ heart_write(mask, &heart_regs->imr[cpu]);
+}
+
+static void ip30_normal_irq(struct irq_desc *desc)
+{
+ int cpu = smp_processor_id();
+ struct irq_domain *domain;
+ u64 pend, mask;
+ int irq;
+
+ pend = heart_read(&heart_regs->isr);
+ mask = (heart_read(&heart_regs->imr[cpu]) &
+ (HEART_L0_INT_MASK | HEART_L1_INT_MASK | HEART_L2_INT_MASK));
+
+ pend &= mask;
+ if (unlikely(!pend))
+ return;
+
+#ifdef CONFIG_SMP
+ if (pend & BIT_ULL(HEART_L2_INT_RESCHED_CPU_0)) {
+ heart_write(BIT_ULL(HEART_L2_INT_RESCHED_CPU_0),
+ &heart_regs->clear_isr);
+ scheduler_ipi();
+ } else if (pend & BIT_ULL(HEART_L2_INT_RESCHED_CPU_1)) {
+ heart_write(BIT_ULL(HEART_L2_INT_RESCHED_CPU_1),
+ &heart_regs->clear_isr);
+ scheduler_ipi();
+ } else if (pend & BIT_ULL(HEART_L2_INT_CALL_CPU_0)) {
+ heart_write(BIT_ULL(HEART_L2_INT_CALL_CPU_0),
+ &heart_regs->clear_isr);
+ generic_smp_call_function_interrupt();
+ } else if (pend & BIT_ULL(HEART_L2_INT_CALL_CPU_1)) {
+ heart_write(BIT_ULL(HEART_L2_INT_CALL_CPU_1),
+ &heart_regs->clear_isr);
+ generic_smp_call_function_interrupt();
+ } else
+#endif
+ {
+ domain = irq_desc_get_handler_data(desc);
+ irq = irq_linear_revmap(domain, __ffs(pend));
+ if (irq)
+ generic_handle_irq(irq);
+ else
+ spurious_interrupt();
+ }
+}
+
+static void ip30_ack_heart_irq(struct irq_data *d)
+{
+ heart_write(BIT_ULL(d->hwirq), &heart_regs->clear_isr);
+}
+
+static void ip30_mask_heart_irq(struct irq_data *d)
+{
+ struct heart_irq_data *hd = irq_data_get_irq_chip_data(d);
+ unsigned long *mask = &per_cpu(irq_enable_mask, hd->cpu);
+
+ clear_bit(d->hwirq, mask);
+ heart_write(*mask, &heart_regs->imr[hd->cpu]);
+}
+
+static void ip30_mask_and_ack_heart_irq(struct irq_data *d)
+{
+ struct heart_irq_data *hd = irq_data_get_irq_chip_data(d);
+ unsigned long *mask = &per_cpu(irq_enable_mask, hd->cpu);
+
+ clear_bit(d->hwirq, mask);
+ heart_write(*mask, &heart_regs->imr[hd->cpu]);
+ heart_write(BIT_ULL(d->hwirq), &heart_regs->clear_isr);
+}
+
+static void ip30_unmask_heart_irq(struct irq_data *d)
+{
+ struct heart_irq_data *hd = irq_data_get_irq_chip_data(d);
+ unsigned long *mask = &per_cpu(irq_enable_mask, hd->cpu);
+
+ set_bit(d->hwirq, mask);
+ heart_write(*mask, &heart_regs->imr[hd->cpu]);
+}
+
+static int ip30_set_heart_irq_affinity(struct irq_data *d,
+ const struct cpumask *mask, bool force)
+{
+ struct heart_irq_data *hd = irq_data_get_irq_chip_data(d);
+
+ if (!hd)
+ return -EINVAL;
+
+ if (irqd_is_started(d))
+ ip30_mask_and_ack_heart_irq(d);
+
+ hd->cpu = cpumask_first_and(mask, cpu_online_mask);
+
+ if (irqd_is_started(d))
+ ip30_unmask_heart_irq(d);
+
+ irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
+
+ return 0;
+}
+
+static struct irq_chip heart_irq_chip = {
+ .name = "HEART",
+ .irq_ack = ip30_ack_heart_irq,
+ .irq_mask = ip30_mask_heart_irq,
+ .irq_mask_ack = ip30_mask_and_ack_heart_irq,
+ .irq_unmask = ip30_unmask_heart_irq,
+ .irq_set_affinity = ip30_set_heart_irq_affinity,
+};
+
+static int heart_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct irq_alloc_info *info = arg;
+ struct heart_irq_data *hd;
+ int hwirq;
+
+ if (nr_irqs > 1 || !info)
+ return -EINVAL;
+
+ hd = kzalloc(sizeof(*hd), GFP_KERNEL);
+ if (!hd)
+ return -ENOMEM;
+
+ hwirq = heart_alloc_int();
+ if (hwirq < 0) {
+ kfree(hd);
+ return -EAGAIN;
+ }
+ irq_domain_set_info(domain, virq, hwirq, &heart_irq_chip, hd,
+ handle_level_irq, NULL, NULL);
+
+ return 0;
+}
+
+static void heart_domain_free(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs)
+{
+ struct irq_data *irqd;
+
+ if (nr_irqs > 1)
+ return;
+
+ irqd = irq_domain_get_irq_data(domain, virq);
+ clear_bit(irqd->hwirq, heart_irq_map);
+ if (irqd && irqd->chip_data)
+ kfree(irqd->chip_data);
+}
+
+static const struct irq_domain_ops heart_domain_ops = {
+ .alloc = heart_domain_alloc,
+ .free = heart_domain_free,
+};
+
+void __init ip30_install_ipi(void)
+{
+ int cpu = smp_processor_id();
+ unsigned long *mask = &per_cpu(irq_enable_mask, cpu);
+
+ set_bit(HEART_L2_INT_RESCHED_CPU_0 + cpu, mask);
+ heart_write(BIT_ULL(HEART_L2_INT_RESCHED_CPU_0 + cpu),
+ &heart_regs->clear_isr);
+ set_bit(HEART_L2_INT_CALL_CPU_0 + cpu, mask);
+ heart_write(BIT_ULL(HEART_L2_INT_CALL_CPU_0 + cpu),
+ &heart_regs->clear_isr);
+
+ heart_write(*mask, &heart_regs->imr[cpu]);
+}
+
+void __init arch_init_irq(void)
+{
+ struct irq_domain *domain;
+ struct fwnode_handle *fn;
+ unsigned long *mask;
+ int i;
+
+ mips_cpu_irq_init();
+
+ /* Mask all IRQs. */
+ heart_write(HEART_CLR_ALL_MASK, &heart_regs->imr[0]);
+ heart_write(HEART_CLR_ALL_MASK, &heart_regs->imr[1]);
+ heart_write(HEART_CLR_ALL_MASK, &heart_regs->imr[2]);
+ heart_write(HEART_CLR_ALL_MASK, &heart_regs->imr[3]);
+
+ /* Ack everything. */
+ heart_write(HEART_ACK_ALL_MASK, &heart_regs->clear_isr);
+
+ /* Enable specific HEART error IRQs for each CPU. */
+ mask = &per_cpu(irq_enable_mask, 0);
+ *mask |= HEART_CPU0_ERR_MASK;
+ heart_write(*mask, &heart_regs->imr[0]);
+ mask = &per_cpu(irq_enable_mask, 1);
+ *mask |= HEART_CPU1_ERR_MASK;
+ heart_write(*mask, &heart_regs->imr[1]);
+
+ /*
+ * Some HEART bits are reserved by hardware or by software convention.
+ * Mark these as reserved right away so they won't be accidentally
+ * used later.
+ */
+ set_bit(HEART_L0_INT_GENERIC, heart_irq_map);
+ set_bit(HEART_L0_INT_FLOW_CTRL_HWTR_0, heart_irq_map);
+ set_bit(HEART_L0_INT_FLOW_CTRL_HWTR_1, heart_irq_map);
+ set_bit(HEART_L2_INT_RESCHED_CPU_0, heart_irq_map);
+ set_bit(HEART_L2_INT_RESCHED_CPU_1, heart_irq_map);
+ set_bit(HEART_L2_INT_CALL_CPU_0, heart_irq_map);
+ set_bit(HEART_L2_INT_CALL_CPU_1, heart_irq_map);
+ set_bit(HEART_L3_INT_TIMER, heart_irq_map);
+
+ /* Reserve the error interrupts (#51 to #63). */
+ for (i = HEART_L4_INT_XWID_ERR_9; i <= HEART_L4_INT_HEART_EXCP; i++)
+ set_bit(i, heart_irq_map);
+
+ fn = irq_domain_alloc_named_fwnode("HEART");
+ WARN_ON(fn == NULL);
+ if (!fn)
+ return;
+ domain = irq_domain_create_linear(fn, HEART_NUM_IRQS,
+ &heart_domain_ops, NULL);
+ WARN_ON(domain == NULL);
+ if (!domain)
+ return;
+
+ irq_set_default_host(domain);
+
+ irq_set_percpu_devid(IP30_HEART_L0_IRQ);
+ irq_set_chained_handler_and_data(IP30_HEART_L0_IRQ, ip30_normal_irq,
+ domain);
+ irq_set_percpu_devid(IP30_HEART_L1_IRQ);
+ irq_set_chained_handler_and_data(IP30_HEART_L1_IRQ, ip30_normal_irq,
+ domain);
+ irq_set_percpu_devid(IP30_HEART_L2_IRQ);
+ irq_set_chained_handler_and_data(IP30_HEART_L2_IRQ, ip30_normal_irq,
+ domain);
+ irq_set_percpu_devid(IP30_HEART_ERR_IRQ);
+ irq_set_chained_handler_and_data(IP30_HEART_ERR_IRQ, ip30_error_irq,
+ domain);
+}