1 files changed, 601 insertions, 0 deletions

diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
new file mode 100644
index 000000000..2762e8540
--- /dev/null
+++ b/arch/parisc/kernel/irq.c
@@ -0,0 +1,601 @@
+// 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 <asm/io.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;
+
+	/* whatever mask they set, we just allow one CPU */
+	cpu_dest = cpumask_next_and(d->irq & (num_online_cpus()-1),
+					dest, cpu_online_mask);
+	if (cpu_dest >= nr_cpu_ids)
+		cpu_dest = cpumask_first_and(dest, cpu_online_mask);
+
+	return cpu_dest;
+}
+
+static int cpu_set_affinity_irq(struct irq_data *d, const struct cpumask *dest,
+				bool force)
+{
+	int cpu_dest;
+
+	cpu_dest = cpu_check_affinity(d, dest);
+	if (cpu_dest < 0)
+		return -1;
+
+	cpumask_copy(irq_data_get_affinity_mask(d), dest);
+
+	return 0;
+}
+#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,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= cpu_set_affinity_irq,
+#endif
+	/* 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);
+#ifdef CONFIG_SMP
+		for_each_online_cpu(j)
+			seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
+#else
+		seq_printf(p, "%10u ", kstat_irqs(i));
+#endif
+
+		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);
+	cpumask_copy(irq_data_get_affinity_mask(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)
+
+	/* Our stack starts directly behind the thread_info struct. */
+	unsigned long stack_start = (unsigned long) current_thread_info();
+	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),
+			 64); /* 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;
+}
+
+void do_softirq_own_stack(void)
+{
+	execute_on_irq_stack(__do_softirq, 0);
+}
+#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 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 */
+}