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-rw-r--r--arch/parisc/kernel/irq.c343
1 files changed, 343 insertions, 0 deletions
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
new file mode 100644
index 000000000000..006385dbee66
--- /dev/null
+++ b/arch/parisc/kernel/irq.c
@@ -0,0 +1,343 @@
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/bitops.h>
+#include <linux/config.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/spinlock.h>
+#include <linux/types.h>
+
+#undef PARISC_IRQ_CR16_COUNTS
+
+extern irqreturn_t timer_interrupt(int, void *, struct pt_regs *);
+extern irqreturn_t ipi_interrupt(int, void *, struct pt_regs *);
+
+#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;
+
+static void cpu_set_eiem(void *info)
+{
+ set_eiem((unsigned long) info);
+}
+
+static inline void cpu_disable_irq(unsigned int irq)
+{
+ unsigned long eirr_bit = EIEM_MASK(irq);
+
+ cpu_eiem &= ~eirr_bit;
+ on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
+}
+
+static void cpu_enable_irq(unsigned int irq)
+{
+ unsigned long eirr_bit = EIEM_MASK(irq);
+
+ mtctl(eirr_bit, 23); /* clear EIRR bit before unmasking */
+ cpu_eiem |= eirr_bit;
+ on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
+}
+
+static unsigned int cpu_startup_irq(unsigned int irq)
+{
+ cpu_enable_irq(irq);
+ return 0;
+}
+
+void no_ack_irq(unsigned int irq) { }
+void no_end_irq(unsigned int irq) { }
+
+static struct hw_interrupt_type cpu_interrupt_type = {
+ .typename = "CPU",
+ .startup = cpu_startup_irq,
+ .shutdown = cpu_disable_irq,
+ .enable = cpu_enable_irq,
+ .disable = cpu_disable_irq,
+ .ack = no_ack_irq,
+ .end = no_end_irq,
+// .set_affinity = cpu_set_affinity_irq,
+};
+
+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 irqaction *action;
+
+ spin_lock_irqsave(&irq_desc[i].lock, flags);
+ action = irq_desc[i].action;
+ if (!action)
+ goto skip;
+ seq_printf(p, "%3d: ", i);
+#ifdef CONFIG_SMP
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
+#else
+ seq_printf(p, "%10u ", kstat_irqs(i));
+#endif
+
+ seq_printf(p, " %14s", irq_desc[i].handler->typename);
+#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:
+ spin_unlock_irqrestore(&irq_desc[i].lock, flags);
+ }
+
+ 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 hw_interrupt_type *type, void *data)
+{
+ if (irq_desc[irq].action)
+ return -EBUSY;
+ if (irq_desc[irq].handler != &cpu_interrupt_type)
+ return -EBUSY;
+
+ if (type) {
+ irq_desc[irq].handler = type;
+ irq_desc[irq].handler_data = data;
+ cpu_interrupt_type.enable(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_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_CPUS) && (!cpu_data[next_cpu].txn_addr ||
+ !cpu_online(next_cpu)))
+ next_cpu++;
+
+ if (next_cpu >= NR_CPUS)
+ next_cpu = 0; /* nothing else, assign monarch */
+
+ return cpu_data[next_cpu].txn_addr;
+}
+
+
+unsigned int txn_alloc_data(unsigned int virt_irq)
+{
+ return virt_irq - CPU_IRQ_BASE;
+}
+
+/* ONLY called from entry.S:intr_extint() */
+void do_cpu_irq_mask(struct pt_regs *regs)
+{
+ unsigned long eirr_val;
+
+ irq_enter();
+
+ /*
+ * Only allow interrupt processing to be interrupted by the
+ * timer tick
+ */
+ set_eiem(EIEM_MASK(TIMER_IRQ));
+
+ /* 1) only process IRQs that are enabled/unmasked (cpu_eiem)
+ * 2) We loop here on EIRR contents in order to avoid
+ * nested interrupts or having to take another interrupt
+ * when we could have just handled it right away.
+ */
+ for (;;) {
+ unsigned long bit = (1UL << (BITS_PER_LONG - 1));
+ unsigned int irq;
+ eirr_val = mfctl(23) & cpu_eiem;
+ if (!eirr_val)
+ break;
+
+ if (eirr_val & EIEM_MASK(TIMER_IRQ))
+ set_eiem(0);
+
+ mtctl(eirr_val, 23); /* reset bits we are going to process */
+
+ /* Work our way from MSb to LSb...same order we alloc EIRs */
+ for (irq = TIMER_IRQ; eirr_val && bit; bit>>=1, irq++) {
+ if (!(bit & eirr_val))
+ continue;
+
+ /* clear bit in mask - can exit loop sooner */
+ eirr_val &= ~bit;
+
+ __do_IRQ(irq, regs);
+ }
+ }
+ set_eiem(cpu_eiem);
+ irq_exit();
+}
+
+
+static struct irqaction timer_action = {
+ .handler = timer_interrupt,
+ .name = "timer",
+};
+
+#ifdef CONFIG_SMP
+static struct irqaction ipi_action = {
+ .handler = ipi_interrupt,
+ .name = "IPI",
+};
+#endif
+
+static void claim_cpu_irqs(void)
+{
+ int i;
+ for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
+ irq_desc[i].handler = &cpu_interrupt_type;
+ }
+
+ irq_desc[TIMER_IRQ].action = &timer_action;
+ irq_desc[TIMER_IRQ].status |= IRQ_PER_CPU;
+#ifdef CONFIG_SMP
+ irq_desc[IPI_IRQ].action = &ipi_action;
+ irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
+#endif
+}
+
+void __init init_IRQ(void)
+{
+ local_irq_disable(); /* PARANOID - should already be disabled */
+ mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
+ claim_cpu_irqs();
+#ifdef CONFIG_SMP
+ if (!cpu_eiem)
+ cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
+#else
+ cpu_eiem = EIEM_MASK(TIMER_IRQ);
+#endif
+ set_eiem(cpu_eiem); /* EIEM : enable all external intr */
+
+}
+
+void hw_resend_irq(struct hw_interrupt_type *type, unsigned int irq)
+{
+ /* XXX: Needs to be written. We managed without it so far, but
+ * we really ought to write it.
+ */
+}
+
+void ack_bad_irq(unsigned int irq)
+{
+ printk("unexpected IRQ %d\n", irq);
+}
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