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-rw-r--r--arch/parisc/kernel/irq.c582
1 files changed, 582 insertions, 0 deletions
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
new file mode 100644
index 000000000..9ddb2e397
--- /dev/null
+++ b/arch/parisc/kernel/irq.c
@@ -0,0 +1,582 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Code to handle x86 style IRQs plus some generic interrupt stuff.
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
+ * Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
+ * Copyright (C) 1999-2000 Grant Grundler
+ * Copyright (c) 2005 Matthew Wilcox
+ */
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/seq_file.h>
+#include <linux/types.h>
+#include <linux/sched/task_stack.h>
+#include <asm/io.h>
+
+#include <asm/softirq_stack.h>
+#include <asm/smp.h>
+#include <asm/ldcw.h>
+
+#undef PARISC_IRQ_CR16_COUNTS
+
+extern irqreturn_t timer_interrupt(int, void *);
+extern irqreturn_t ipi_interrupt(int, void *);
+
+#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
+
+/* Bits in EIEM correlate with cpu_irq_action[].
+** Numbered *Big Endian*! (ie bit 0 is MSB)
+*/
+static volatile unsigned long cpu_eiem = 0;
+
+/*
+** local ACK bitmap ... habitually set to 1, but reset to zero
+** between ->ack() and ->end() of the interrupt to prevent
+** re-interruption of a processing interrupt.
+*/
+static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL;
+
+static void cpu_mask_irq(struct irq_data *d)
+{
+ unsigned long eirr_bit = EIEM_MASK(d->irq);
+
+ cpu_eiem &= ~eirr_bit;
+ /* Do nothing on the other CPUs. If they get this interrupt,
+ * The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
+ * handle it, and the set_eiem() at the bottom will ensure it
+ * then gets disabled */
+}
+
+static void __cpu_unmask_irq(unsigned int irq)
+{
+ unsigned long eirr_bit = EIEM_MASK(irq);
+
+ cpu_eiem |= eirr_bit;
+
+ /* This is just a simple NOP IPI. But what it does is cause
+ * all the other CPUs to do a set_eiem(cpu_eiem) at the end
+ * of the interrupt handler */
+ smp_send_all_nop();
+}
+
+static void cpu_unmask_irq(struct irq_data *d)
+{
+ __cpu_unmask_irq(d->irq);
+}
+
+void cpu_ack_irq(struct irq_data *d)
+{
+ unsigned long mask = EIEM_MASK(d->irq);
+ int cpu = smp_processor_id();
+
+ /* Clear in EIEM so we can no longer process */
+ per_cpu(local_ack_eiem, cpu) &= ~mask;
+
+ /* disable the interrupt */
+ set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
+
+ /* and now ack it */
+ mtctl(mask, 23);
+}
+
+void cpu_eoi_irq(struct irq_data *d)
+{
+ unsigned long mask = EIEM_MASK(d->irq);
+ int cpu = smp_processor_id();
+
+ /* set it in the eiems---it's no longer in process */
+ per_cpu(local_ack_eiem, cpu) |= mask;
+
+ /* enable the interrupt */
+ set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
+}
+
+#ifdef CONFIG_SMP
+int cpu_check_affinity(struct irq_data *d, const struct cpumask *dest)
+{
+ int cpu_dest;
+
+ /* timer and ipi have to always be received on all CPUs */
+ if (irqd_is_per_cpu(d))
+ return -EINVAL;
+
+ cpu_dest = cpumask_first_and(dest, cpu_online_mask);
+ if (cpu_dest >= nr_cpu_ids)
+ cpu_dest = cpumask_first(cpu_online_mask);
+
+ return cpu_dest;
+}
+#endif
+
+static struct irq_chip cpu_interrupt_type = {
+ .name = "CPU",
+ .irq_mask = cpu_mask_irq,
+ .irq_unmask = cpu_unmask_irq,
+ .irq_ack = cpu_ack_irq,
+ .irq_eoi = cpu_eoi_irq,
+ /* XXX: Needs to be written. We managed without it so far, but
+ * we really ought to write it.
+ */
+ .irq_retrigger = NULL,
+};
+
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+#define irq_stats(x) (&per_cpu(irq_stat, x))
+
+/*
+ * /proc/interrupts printing for arch specific interrupts
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+ int j;
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+ seq_printf(p, "%*s: ", prec, "STK");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage);
+ seq_puts(p, " Kernel stack usage\n");
+# ifdef CONFIG_IRQSTACKS
+ seq_printf(p, "%*s: ", prec, "IST");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_stack_usage);
+ seq_puts(p, " Interrupt stack usage\n");
+# endif
+#endif
+#ifdef CONFIG_SMP
+ if (num_online_cpus() > 1) {
+ seq_printf(p, "%*s: ", prec, "RES");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
+ seq_puts(p, " Rescheduling interrupts\n");
+ seq_printf(p, "%*s: ", prec, "CAL");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
+ seq_puts(p, " Function call interrupts\n");
+ }
+#endif
+ seq_printf(p, "%*s: ", prec, "UAH");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_unaligned_count);
+ seq_puts(p, " Unaligned access handler traps\n");
+ seq_printf(p, "%*s: ", prec, "FPA");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_fpassist_count);
+ seq_puts(p, " Floating point assist traps\n");
+ seq_printf(p, "%*s: ", prec, "TLB");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
+ seq_puts(p, " TLB shootdowns\n");
+ return 0;
+}
+
+int show_interrupts(struct seq_file *p, void *v)
+{
+ int i = *(loff_t *) v, j;
+ unsigned long flags;
+
+ if (i == 0) {
+ seq_puts(p, " ");
+ for_each_online_cpu(j)
+ seq_printf(p, " CPU%d", j);
+
+#ifdef PARISC_IRQ_CR16_COUNTS
+ seq_printf(p, " [min/avg/max] (CPU cycle counts)");
+#endif
+ seq_putc(p, '\n');
+ }
+
+ if (i < NR_IRQS) {
+ struct irq_desc *desc = irq_to_desc(i);
+ struct irqaction *action;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ action = desc->action;
+ if (!action)
+ goto skip;
+ seq_printf(p, "%3d: ", i);
+
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, j));
+
+ seq_printf(p, " %14s", irq_desc_get_chip(desc)->name);
+#ifndef PARISC_IRQ_CR16_COUNTS
+ seq_printf(p, " %s", action->name);
+
+ while ((action = action->next))
+ seq_printf(p, ", %s", action->name);
+#else
+ for ( ;action; action = action->next) {
+ unsigned int k, avg, min, max;
+
+ min = max = action->cr16_hist[0];
+
+ for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
+ int hist = action->cr16_hist[k];
+
+ if (hist) {
+ avg += hist;
+ } else
+ break;
+
+ if (hist > max) max = hist;
+ if (hist < min) min = hist;
+ }
+
+ avg /= k;
+ seq_printf(p, " %s[%d/%d/%d]", action->name,
+ min,avg,max);
+ }
+#endif
+
+ seq_putc(p, '\n');
+ skip:
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
+
+ if (i == NR_IRQS)
+ arch_show_interrupts(p, 3);
+
+ return 0;
+}
+
+
+
+/*
+** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
+** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
+**
+** To use txn_XXX() interfaces, get a Virtual IRQ first.
+** Then use that to get the Transaction address and data.
+*/
+
+int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data)
+{
+ if (irq_has_action(irq))
+ return -EBUSY;
+ if (irq_get_chip(irq) != &cpu_interrupt_type)
+ return -EBUSY;
+
+ /* for iosapic interrupts */
+ if (type) {
+ irq_set_chip_and_handler(irq, type, handle_percpu_irq);
+ irq_set_chip_data(irq, data);
+ __cpu_unmask_irq(irq);
+ }
+ return 0;
+}
+
+int txn_claim_irq(int irq)
+{
+ return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
+}
+
+/*
+ * The bits_wide parameter accommodates the limitations of the HW/SW which
+ * use these bits:
+ * Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
+ * V-class (EPIC): 6 bits
+ * N/L/A-class (iosapic): 8 bits
+ * PCI 2.2 MSI: 16 bits
+ * Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
+ *
+ * On the service provider side:
+ * o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
+ * o PA 2.0 wide mode 6-bits (per processor)
+ * o IA64 8-bits (0-256 total)
+ *
+ * So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
+ * by the processor...and the N/L-class I/O subsystem supports more bits than
+ * PA2.0 has. The first case is the problem.
+ */
+int txn_alloc_irq(unsigned int bits_wide)
+{
+ int irq;
+
+ /* never return irq 0 cause that's the interval timer */
+ for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
+ if (cpu_claim_irq(irq, NULL, NULL) < 0)
+ continue;
+ if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
+ continue;
+ return irq;
+ }
+
+ /* unlikely, but be prepared */
+ return -1;
+}
+
+
+unsigned long txn_affinity_addr(unsigned int irq, int cpu)
+{
+#ifdef CONFIG_SMP
+ struct irq_data *d = irq_get_irq_data(irq);
+ irq_data_update_affinity(d, cpumask_of(cpu));
+#endif
+
+ return per_cpu(cpu_data, cpu).txn_addr;
+}
+
+
+unsigned long txn_alloc_addr(unsigned int virt_irq)
+{
+ static int next_cpu = -1;
+
+ next_cpu++; /* assign to "next" CPU we want this bugger on */
+
+ /* validate entry */
+ while ((next_cpu < nr_cpu_ids) &&
+ (!per_cpu(cpu_data, next_cpu).txn_addr ||
+ !cpu_online(next_cpu)))
+ next_cpu++;
+
+ if (next_cpu >= nr_cpu_ids)
+ next_cpu = 0; /* nothing else, assign monarch */
+
+ return txn_affinity_addr(virt_irq, next_cpu);
+}
+
+
+unsigned int txn_alloc_data(unsigned int virt_irq)
+{
+ return virt_irq - CPU_IRQ_BASE;
+}
+
+static inline int eirr_to_irq(unsigned long eirr)
+{
+ int bit = fls_long(eirr);
+ return (BITS_PER_LONG - bit) + TIMER_IRQ;
+}
+
+#ifdef CONFIG_IRQSTACKS
+/*
+ * IRQ STACK - used for irq handler
+ */
+#ifdef CONFIG_64BIT
+#define IRQ_STACK_SIZE (4096 << 4) /* 64k irq stack size */
+#else
+#define IRQ_STACK_SIZE (4096 << 3) /* 32k irq stack size */
+#endif
+
+union irq_stack_union {
+ unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)];
+ volatile unsigned int slock[4];
+ volatile unsigned int lock[1];
+};
+
+static DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = {
+ .slock = { 1,1,1,1 },
+ };
+#endif
+
+
+int sysctl_panic_on_stackoverflow = 1;
+
+static inline void stack_overflow_check(struct pt_regs *regs)
+{
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+ #define STACK_MARGIN (256*6)
+
+ unsigned long stack_start = (unsigned long) task_stack_page(current);
+ unsigned long sp = regs->gr[30];
+ unsigned long stack_usage;
+ unsigned int *last_usage;
+ int cpu = smp_processor_id();
+
+ /* if sr7 != 0, we interrupted a userspace process which we do not want
+ * to check for stack overflow. We will only check the kernel stack. */
+ if (regs->sr[7])
+ return;
+
+ /* exit if already in panic */
+ if (sysctl_panic_on_stackoverflow < 0)
+ return;
+
+ /* calculate kernel stack usage */
+ stack_usage = sp - stack_start;
+#ifdef CONFIG_IRQSTACKS
+ if (likely(stack_usage <= THREAD_SIZE))
+ goto check_kernel_stack; /* found kernel stack */
+
+ /* check irq stack usage */
+ stack_start = (unsigned long) &per_cpu(irq_stack_union, cpu).stack;
+ stack_usage = sp - stack_start;
+
+ last_usage = &per_cpu(irq_stat.irq_stack_usage, cpu);
+ if (unlikely(stack_usage > *last_usage))
+ *last_usage = stack_usage;
+
+ if (likely(stack_usage < (IRQ_STACK_SIZE - STACK_MARGIN)))
+ return;
+
+ pr_emerg("stackcheck: %s will most likely overflow irq stack "
+ "(sp:%lx, stk bottom-top:%lx-%lx)\n",
+ current->comm, sp, stack_start, stack_start + IRQ_STACK_SIZE);
+ goto panic_check;
+
+check_kernel_stack:
+#endif
+
+ /* check kernel stack usage */
+ last_usage = &per_cpu(irq_stat.kernel_stack_usage, cpu);
+
+ if (unlikely(stack_usage > *last_usage))
+ *last_usage = stack_usage;
+
+ if (likely(stack_usage < (THREAD_SIZE - STACK_MARGIN)))
+ return;
+
+ pr_emerg("stackcheck: %s will most likely overflow kernel stack "
+ "(sp:%lx, stk bottom-top:%lx-%lx)\n",
+ current->comm, sp, stack_start, stack_start + THREAD_SIZE);
+
+#ifdef CONFIG_IRQSTACKS
+panic_check:
+#endif
+ if (sysctl_panic_on_stackoverflow) {
+ sysctl_panic_on_stackoverflow = -1; /* disable further checks */
+ panic("low stack detected by irq handler - check messages\n");
+ }
+#endif
+}
+
+#ifdef CONFIG_IRQSTACKS
+/* in entry.S: */
+void call_on_stack(unsigned long p1, void *func, unsigned long new_stack);
+
+static void execute_on_irq_stack(void *func, unsigned long param1)
+{
+ union irq_stack_union *union_ptr;
+ unsigned long irq_stack;
+ volatile unsigned int *irq_stack_in_use;
+
+ union_ptr = &per_cpu(irq_stack_union, smp_processor_id());
+ irq_stack = (unsigned long) &union_ptr->stack;
+ irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.slock),
+ FRAME_ALIGN); /* align for stack frame usage */
+
+ /* We may be called recursive. If we are already using the irq stack,
+ * just continue to use it. Use spinlocks to serialize
+ * the irq stack usage.
+ */
+ irq_stack_in_use = (volatile unsigned int *)__ldcw_align(union_ptr);
+ if (!__ldcw(irq_stack_in_use)) {
+ void (*direct_call)(unsigned long p1) = func;
+
+ /* We are using the IRQ stack already.
+ * Do direct call on current stack. */
+ direct_call(param1);
+ return;
+ }
+
+ /* This is where we switch to the IRQ stack. */
+ call_on_stack(param1, func, irq_stack);
+
+ /* free up irq stack usage. */
+ *irq_stack_in_use = 1;
+}
+
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
+void do_softirq_own_stack(void)
+{
+ execute_on_irq_stack(__do_softirq, 0);
+}
+#endif
+#endif /* CONFIG_IRQSTACKS */
+
+/* ONLY called from entry.S:intr_extint() */
+void do_cpu_irq_mask(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs;
+ unsigned long eirr_val;
+ int irq, cpu = smp_processor_id();
+ struct irq_data *irq_data;
+#ifdef CONFIG_SMP
+ cpumask_t dest;
+#endif
+
+ old_regs = set_irq_regs(regs);
+ local_irq_disable();
+ irq_enter();
+
+ eirr_val = mfctl(23) & cpu_eiem & per_cpu(local_ack_eiem, cpu);
+ if (!eirr_val)
+ goto set_out;
+ irq = eirr_to_irq(eirr_val);
+
+ irq_data = irq_get_irq_data(irq);
+
+ /* Filter out spurious interrupts, mostly from serial port at bootup */
+ if (unlikely(!irq_desc_has_action(irq_data_to_desc(irq_data))))
+ goto set_out;
+
+#ifdef CONFIG_SMP
+ cpumask_copy(&dest, irq_data_get_affinity_mask(irq_data));
+ if (irqd_is_per_cpu(irq_data) &&
+ !cpumask_test_cpu(smp_processor_id(), &dest)) {
+ int cpu = cpumask_first(&dest);
+
+ printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
+ irq, smp_processor_id(), cpu);
+ gsc_writel(irq + CPU_IRQ_BASE,
+ per_cpu(cpu_data, cpu).hpa);
+ goto set_out;
+ }
+#endif
+ stack_overflow_check(regs);
+
+#ifdef CONFIG_IRQSTACKS
+ execute_on_irq_stack(&generic_handle_irq, irq);
+#else
+ generic_handle_irq(irq);
+#endif /* CONFIG_IRQSTACKS */
+
+ out:
+ irq_exit();
+ set_irq_regs(old_regs);
+ return;
+
+ set_out:
+ set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
+ goto out;
+}
+
+static void claim_cpu_irqs(void)
+{
+ unsigned long flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL;
+ int i;
+
+ for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
+ irq_set_chip_and_handler(i, &cpu_interrupt_type,
+ handle_percpu_irq);
+ }
+
+ irq_set_handler(TIMER_IRQ, handle_percpu_irq);
+ if (request_irq(TIMER_IRQ, timer_interrupt, flags, "timer", NULL))
+ pr_err("Failed to register timer interrupt\n");
+#ifdef CONFIG_SMP
+ irq_set_handler(IPI_IRQ, handle_percpu_irq);
+ if (request_irq(IPI_IRQ, ipi_interrupt, IRQF_PERCPU, "IPI", NULL))
+ pr_err("Failed to register IPI interrupt\n");
+#endif
+}
+
+void init_IRQ(void)
+{
+ local_irq_disable(); /* PARANOID - should already be disabled */
+ mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
+#ifdef CONFIG_SMP
+ if (!cpu_eiem) {
+ claim_cpu_irqs();
+ cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
+ }
+#else
+ claim_cpu_irqs();
+ cpu_eiem = EIEM_MASK(TIMER_IRQ);
+#endif
+ set_eiem(cpu_eiem); /* EIEM : enable all external intr */
+}
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