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Diffstat (limited to 'kernel/arch/mips/sgi-ip27/ip27-irq.c')
-rw-r--r--kernel/arch/mips/sgi-ip27/ip27-irq.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/kernel/arch/mips/sgi-ip27/ip27-irq.c b/kernel/arch/mips/sgi-ip27/ip27-irq.c
new file mode 100644
index 000000000..3fbaef97a
--- /dev/null
+++ b/kernel/arch/mips/sgi-ip27/ip27-irq.c
@@ -0,0 +1,208 @@
+/*
+ * ip27-irq.c: Highlevel interrupt handling for IP27 architecture.
+ *
+ * Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 1999 - 2001 Kanoj Sarcar
+ */
+
+#undef DEBUG
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/timex.h>
+#include <linux/smp.h>
+#include <linux/random.h>
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+
+#include <asm/bootinfo.h>
+#include <asm/io.h>
+#include <asm/mipsregs.h>
+
+#include <asm/processor.h>
+#include <asm/sn/addrs.h>
+#include <asm/sn/agent.h>
+#include <asm/sn/arch.h>
+#include <asm/sn/hub.h>
+#include <asm/sn/intr.h>
+
+/*
+ * Linux has a controller-independent x86 interrupt architecture.
+ * every controller has a 'controller-template', that is used
+ * by the main code to do the right thing. Each driver-visible
+ * interrupt source is transparently wired to the appropriate
+ * controller. Thus drivers need not be aware of the
+ * interrupt-controller.
+ *
+ * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
+ * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
+ * (IO-APICs assumed to be messaging to Pentium local-APICs)
+ *
+ * the code is designed to be easily extended with new/different
+ * interrupt controllers, without having to do assembly magic.
+ */
+
+extern asmlinkage void ip27_irq(void);
+
+/*
+ * Find first bit set
+ */
+static int ms1bit(unsigned long x)
+{
+ int b = 0, s;
+
+ s = 16; if (x >> 16 == 0) s = 0; b += s; x >>= s;
+ s = 8; if (x >> 8 == 0) s = 0; b += s; x >>= s;
+ s = 4; if (x >> 4 == 0) s = 0; b += s; x >>= s;
+ s = 2; if (x >> 2 == 0) s = 0; b += s; x >>= s;
+ s = 1; if (x >> 1 == 0) s = 0; b += s;
+
+ return b;
+}
+
+/*
+ * This code is unnecessarily complex, because we do
+ * intr enabling. Basically, once we grab the set of intrs we need
+ * to service, we must mask _all_ these interrupts; firstly, to make
+ * sure the same intr does not intr again, causing recursion that
+ * can lead to stack overflow. Secondly, we can not just mask the
+ * one intr we are do_IRQing, because the non-masked intrs in the
+ * first set might intr again, causing multiple servicings of the
+ * same intr. This effect is mostly seen for intercpu intrs.
+ * Kanoj 05.13.00
+ */
+
+static void ip27_do_irq_mask0(void)
+{
+ int irq, swlevel;
+ hubreg_t pend0, mask0;
+ cpuid_t cpu = smp_processor_id();
+ int pi_int_mask0 =
+ (cputoslice(cpu) == 0) ? PI_INT_MASK0_A : PI_INT_MASK0_B;
+
+ /* copied from Irix intpend0() */
+ pend0 = LOCAL_HUB_L(PI_INT_PEND0);
+ mask0 = LOCAL_HUB_L(pi_int_mask0);
+
+ pend0 &= mask0; /* Pick intrs we should look at */
+ if (!pend0)
+ return;
+
+ swlevel = ms1bit(pend0);
+#ifdef CONFIG_SMP
+ if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
+ LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
+ scheduler_ipi();
+ } else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) {
+ LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ);
+ scheduler_ipi();
+ } else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
+ LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
+ smp_call_function_interrupt();
+ } else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
+ LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
+ smp_call_function_interrupt();
+ } else
+#endif
+ {
+ /* "map" swlevel to irq */
+ struct slice_data *si = cpu_data[cpu].data;
+
+ irq = si->level_to_irq[swlevel];
+ do_IRQ(irq);
+ }
+
+ LOCAL_HUB_L(PI_INT_PEND0);
+}
+
+static void ip27_do_irq_mask1(void)
+{
+ int irq, swlevel;
+ hubreg_t pend1, mask1;
+ cpuid_t cpu = smp_processor_id();
+ int pi_int_mask1 = (cputoslice(cpu) == 0) ? PI_INT_MASK1_A : PI_INT_MASK1_B;
+ struct slice_data *si = cpu_data[cpu].data;
+
+ /* copied from Irix intpend0() */
+ pend1 = LOCAL_HUB_L(PI_INT_PEND1);
+ mask1 = LOCAL_HUB_L(pi_int_mask1);
+
+ pend1 &= mask1; /* Pick intrs we should look at */
+ if (!pend1)
+ return;
+
+ swlevel = ms1bit(pend1);
+ /* "map" swlevel to irq */
+ irq = si->level_to_irq[swlevel];
+ LOCAL_HUB_CLR_INTR(swlevel);
+ do_IRQ(irq);
+
+ LOCAL_HUB_L(PI_INT_PEND1);
+}
+
+static void ip27_prof_timer(void)
+{
+ panic("CPU %d got a profiling interrupt", smp_processor_id());
+}
+
+static void ip27_hub_error(void)
+{
+ panic("CPU %d got a hub error interrupt", smp_processor_id());
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+ unsigned long pending = read_c0_cause() & read_c0_status();
+ extern unsigned int rt_timer_irq;
+
+ if (pending & CAUSEF_IP4)
+ do_IRQ(rt_timer_irq);
+ else if (pending & CAUSEF_IP2) /* PI_INT_PEND_0 or CC_PEND_{A|B} */
+ ip27_do_irq_mask0();
+ else if (pending & CAUSEF_IP3) /* PI_INT_PEND_1 */
+ ip27_do_irq_mask1();
+ else if (pending & CAUSEF_IP5)
+ ip27_prof_timer();
+ else if (pending & CAUSEF_IP6)
+ ip27_hub_error();
+}
+
+void __init arch_init_irq(void)
+{
+}
+
+void install_ipi(void)
+{
+ int slice = LOCAL_HUB_L(PI_CPU_NUM);
+ int cpu = smp_processor_id();
+ struct slice_data *si = cpu_data[cpu].data;
+ struct hub_data *hub = hub_data(cpu_to_node(cpu));
+ int resched, call;
+
+ resched = CPU_RESCHED_A_IRQ + slice;
+ __set_bit(resched, hub->irq_alloc_mask);
+ __set_bit(resched, si->irq_enable_mask);
+ LOCAL_HUB_CLR_INTR(resched);
+
+ call = CPU_CALL_A_IRQ + slice;
+ __set_bit(call, hub->irq_alloc_mask);
+ __set_bit(call, si->irq_enable_mask);
+ LOCAL_HUB_CLR_INTR(call);
+
+ if (slice == 0) {
+ LOCAL_HUB_S(PI_INT_MASK0_A, si->irq_enable_mask[0]);
+ LOCAL_HUB_S(PI_INT_MASK1_A, si->irq_enable_mask[1]);
+ } else {
+ LOCAL_HUB_S(PI_INT_MASK0_B, si->irq_enable_mask[0]);
+ LOCAL_HUB_S(PI_INT_MASK1_B, si->irq_enable_mask[1]);
+ }
+}