patch-2.4.20 linux-2.4.20/arch/x86_64/kernel/i8259.c

• Lines: 465
• Date: Thu Nov 28 15:53:12 2002
• Orig file: linux-2.4.19/arch/x86_64/kernel/i8259.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/x86_64/kernel/i8259.c linux-2.4.20/arch/x86_64/kernel/i8259.c
@@ -0,0 +1,464 @@
+#include <linux/linkage.h>
+#include <linux/config.h>
+#include <linux/ptrace.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/atomic.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/hw_irq.h>
+#include <asm/bitops.h>
+#include <asm/pgtable.h>
+#include <asm/delay.h>
+#include <asm/desc.h>
+#include <asm/apic.h>
+
+#include <linux/irq.h>
+
+/* When we have things working, we can switch to always use
+   IOAPIC. --pavel */
+
+/*
+ * Common place to define all x86 IRQ vectors
+ *
+ * This builds up the IRQ handler stubs using some ugly macros in irq.h
+ *
+ * These macros create the low-level assembly IRQ routines that save
+ * register context and call do_IRQ(). do_IRQ() then does all the
+ * operations that are needed to keep the AT (or SMP IOAPIC)
+ * interrupt-controller happy.
+ */
+
+BUILD_COMMON_IRQ()
+
+#define BI(x,y) \
+	BUILD_IRQ(x##y)
+
+#define BUILD_16_IRQS(x) \
+	BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
+	BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
+	BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
+	BI(x,c) BI(x,d) BI(x,e) BI(x,f)
+
+/*
+ * ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
+ * (these are usually mapped to vectors 0x20-0x2f)
+ */
+BUILD_16_IRQS(0x0)
+
+#ifdef CONFIG_X86_IO_APIC
+/*
+ * The IO-APIC gives us many more interrupt sources. Most of these
+ * are unused but an SMP system is supposed to have enough memory ...
+ * sometimes (mostly wrt. hw bugs) we get corrupted vectors all
+ * across the spectrum, so we really want to be prepared to get all
+ * of these. Plus, more powerful systems might have more than 64
+ * IO-APIC registers.
+ *
+ * (these are usually mapped into the 0x30-0xff vector range)
+ */
+		   BUILD_16_IRQS(0x1) BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
+BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
+BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
+BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd)
+#endif
+
+#undef BUILD_16_IRQS
+#undef BI
+
+
+/*
+ * The following vectors are part of the Linux architecture, there
+ * is no hardware IRQ pin equivalent for them, they are triggered
+ * through the ICC by us (IPIs)
+ */
+#ifdef CONFIG_SMP
+BUILD_SMP_INTERRUPT(reschedule_interrupt,RESCHEDULE_VECTOR);
+BUILD_SMP_INTERRUPT(invalidate_interrupt,INVALIDATE_TLB_VECTOR);
+BUILD_SMP_INTERRUPT(call_function_interrupt,CALL_FUNCTION_VECTOR);
+#endif
+
+#ifdef CONFIG_X86_LOCAL_APIC
+BUILD_SMP_INTERRUPT(apic_timer_interrupt,LOCAL_TIMER_VECTOR);
+BUILD_SMP_INTERRUPT(error_interrupt,ERROR_APIC_VECTOR);
+BUILD_SMP_INTERRUPT(spurious_interrupt,SPURIOUS_APIC_VECTOR);
+#endif
+
+#define IRQ(x,y) \
+	IRQ##x##y##_interrupt
+
+#define IRQLIST_16(x) \
+	IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
+	IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
+	IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
+	IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f)
+
+void (*interrupt[NR_IRQS])(void) = {
+	IRQLIST_16(0x0),
+
+#ifdef CONFIG_X86_IO_APIC
+			 IRQLIST_16(0x1), IRQLIST_16(0x2), IRQLIST_16(0x3),
+	IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7),
+	IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb),
+	IRQLIST_16(0xc), IRQLIST_16(0xd)
+#endif
+};
+
+#undef IRQ
+#undef IRQLIST_16
+
+/*
+ * This is the 'legacy' 8259A Programmable Interrupt Controller,
+ * present in the majority of PC/AT boxes.
+ * plus some generic x86 specific things if generic specifics makes
+ * any sense at all.
+ * this file should become arch/i386/kernel/irq.c when the old irq.c
+ * moves to arch independent land
+ */
+
+spinlock_t i8259A_lock = SPIN_LOCK_UNLOCKED;
+
+static void end_8259A_irq (unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+		enable_8259A_irq(irq);
+}
+
+#define shutdown_8259A_irq	disable_8259A_irq
+
+ void mask_and_ack_8259A(unsigned int);
+
+static unsigned int startup_8259A_irq(unsigned int irq)
+{
+	enable_8259A_irq(irq);
+	return 0; /* never anything pending */
+}
+
+static struct hw_interrupt_type i8259A_irq_type = {
+	"XT-PIC",
+	startup_8259A_irq,
+	shutdown_8259A_irq,
+	enable_8259A_irq,
+	disable_8259A_irq,
+	mask_and_ack_8259A,
+	end_8259A_irq,
+	NULL
+};
+
+/*
+ * 8259A PIC functions to handle ISA devices:
+ */
+
+/*
+ * This contains the irq mask for both 8259A irq controllers,
+ */
+static unsigned int cached_irq_mask = 0xffff;
+
+#define __byte(x,y)	(((unsigned char *)&(y))[x])
+#define cached_21	(__byte(0,cached_irq_mask))
+#define cached_A1	(__byte(1,cached_irq_mask))
+
+/*
+ * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
+ * boards the timer interrupt is not really connected to any IO-APIC pin,
+ * it's fed to the master 8259A's IR0 line only.
+ *
+ * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
+ * this 'mixed mode' IRQ handling costs nothing because it's only used
+ * at IRQ setup time.
+ */
+unsigned long io_apic_irqs;
+
+void disable_8259A_irq(unsigned int irq)
+{
+	unsigned int mask = 1 << irq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+	cached_irq_mask |= mask;
+	if (irq & 8)
+		outb(cached_A1,0xA1);
+	else
+		outb(cached_21,0x21);
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+void enable_8259A_irq(unsigned int irq)
+{
+	unsigned int mask = ~(1 << irq);
+	unsigned long flags;
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+	cached_irq_mask &= mask;
+	if (irq & 8)
+		outb(cached_A1,0xA1);
+	else
+		outb(cached_21,0x21);
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+int i8259A_irq_pending(unsigned int irq)
+{
+	unsigned int mask = 1<<irq;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+	if (irq < 8)
+		ret = inb(0x20) & mask;
+	else
+		ret = inb(0xA0) & (mask >> 8);
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+
+	return ret;
+}
+
+void make_8259A_irq(unsigned int irq)
+{
+	disable_irq_nosync(irq);
+	io_apic_irqs &= ~(1<<irq);
+	irq_desc[irq].handler = &i8259A_irq_type;
+	enable_irq(irq);
+}
+
+/*
+ * This function assumes to be called rarely. Switching between
+ * 8259A registers is slow.
+ * This has to be protected by the irq controller spinlock
+ * before being called.
+ */
+static inline int i8259A_irq_real(unsigned int irq)
+{
+	int value;
+	int irqmask = 1<<irq;
+
+	if (irq < 8) {
+		outb(0x0B,0x20);		/* ISR register */
+		value = inb(0x20) & irqmask;
+		outb(0x0A,0x20);		/* back to the IRR register */
+		return value;
+	}
+	outb(0x0B,0xA0);		/* ISR register */
+	value = inb(0xA0) & (irqmask >> 8);
+	outb(0x0A,0xA0);		/* back to the IRR register */
+	return value;
+}
+
+/*
+ * Careful! The 8259A is a fragile beast, it pretty
+ * much _has_ to be done exactly like this (mask it
+ * first, _then_ send the EOI, and the order of EOI
+ * to the two 8259s is important!
+ */
+void mask_and_ack_8259A(unsigned int irq)
+{
+	unsigned int irqmask = 1 << irq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+	/*
+	 * Lightweight spurious IRQ detection. We do not want
+	 * to overdo spurious IRQ handling - it's usually a sign
+	 * of hardware problems, so we only do the checks we can
+	 * do without slowing down good hardware unnecesserily.
+	 *
+	 * Note that IRQ7 and IRQ15 (the two spurious IRQs
+	 * usually resulting from the 8259A-1|2 PICs) occur
+	 * even if the IRQ is masked in the 8259A. Thus we
+	 * can check spurious 8259A IRQs without doing the
+	 * quite slow i8259A_irq_real() call for every IRQ.
+	 * This does not cover 100% of spurious interrupts,
+	 * but should be enough to warn the user that there
+	 * is something bad going on ...
+	 */
+	if (cached_irq_mask & irqmask)
+		goto spurious_8259A_irq;
+	cached_irq_mask |= irqmask;
+
+handle_real_irq:
+	if (irq & 8) {
+		inb(0xA1);		/* DUMMY - (do we need this?) */
+		outb(cached_A1,0xA1);
+		outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */
+		outb(0x62,0x20);	/* 'Specific EOI' to master-IRQ2 */
+	} else {
+		inb(0x21);		/* DUMMY - (do we need this?) */
+		outb(cached_21,0x21);
+		outb(0x60+irq,0x20);	/* 'Specific EOI' to master */
+	}
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+	return;
+
+spurious_8259A_irq:
+	/*
+	 * this is the slow path - should happen rarely.
+	 */
+	if (i8259A_irq_real(irq))
+		/*
+		 * oops, the IRQ _is_ in service according to the
+		 * 8259A - not spurious, go handle it.
+		 */
+		goto handle_real_irq;
+
+	{
+		static int spurious_irq_mask;
+		/*
+		 * At this point we can be sure the IRQ is spurious,
+		 * lets ACK and report it. [once per IRQ]
+		 */
+		if (!(spurious_irq_mask & irqmask)) {
+			printk("spurious 8259A interrupt: IRQ%d.\n", irq);
+			spurious_irq_mask |= irqmask;
+		}
+		atomic_inc(&irq_err_count);
+		/*
+		 * Theoretically we do not have to handle this IRQ,
+		 * but in Linux this does not cause problems and is
+		 * simpler for us.
+		 */
+		goto handle_real_irq;
+	}
+}
+
+void __init init_8259A(int auto_eoi)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+
+	outb(0xff, 0x21);	/* mask all of 8259A-1 */
+	outb(0xff, 0xA1);	/* mask all of 8259A-2 */
+
+	/*
+	 * outb_p - this has to work on a wide range of PC hardware.
+	 */
+	outb_p(0x11, 0x20);	/* ICW1: select 8259A-1 init */
+	outb_p(0x20 + 0, 0x21);	/* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
+	outb_p(0x04, 0x21);	/* 8259A-1 (the master) has a slave on IR2 */
+	if (auto_eoi)
+		outb_p(0x03, 0x21);	/* master does Auto EOI */
+	else
+		outb_p(0x01, 0x21);	/* master expects normal EOI */
+
+	outb_p(0x11, 0xA0);	/* ICW1: select 8259A-2 init */
+	outb_p(0x20 + 8, 0xA1);	/* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
+	outb_p(0x02, 0xA1);	/* 8259A-2 is a slave on master's IR2 */
+	outb_p(0x01, 0xA1);	/* (slave's support for AEOI in flat mode
+				    is to be investigated) */
+
+	if (auto_eoi)
+		/*
+		 * in AEOI mode we just have to mask the interrupt
+		 * when acking.
+		 */
+		i8259A_irq_type.ack = disable_8259A_irq;
+	else
+		i8259A_irq_type.ack = mask_and_ack_8259A;
+
+	udelay(100);		/* wait for 8259A to initialize */
+
+	outb(cached_21, 0x21);	/* restore master IRQ mask */
+	outb(cached_A1, 0xA1);	/* restore slave IRQ mask */
+
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+/*
+ * IRQ2 is cascade interrupt to second interrupt controller
+ */
+
+static struct irqaction irq2 = { no_action, 0, 0, "cascade", NULL, NULL};
+
+void __init init_ISA_irqs (void)
+{
+	int i;
+
+#ifdef CONFIG_X86_LOCAL_APIC
+	init_bsp_APIC();
+#endif
+	init_8259A(0);
+
+	for (i = 0; i < NR_IRQS; i++) {
+		irq_desc[i].status = IRQ_DISABLED;
+		irq_desc[i].action = 0;
+		irq_desc[i].depth = 1;
+
+		if (i < 16) {
+			/*
+			 * 16 old-style INTA-cycle interrupts:
+			 */
+			irq_desc[i].handler = &i8259A_irq_type;
+		} else {
+			/*
+			 * 'high' PCI IRQs filled in on demand
+			 */
+			irq_desc[i].handler = &no_irq_type;
+		}
+	}
+}
+
+void __init init_IRQ(void)
+{
+	int i;
+
+#ifndef CONFIG_X86_VISWS_APIC
+	init_ISA_irqs();
+#else
+	init_VISWS_APIC_irqs();
+#endif
+	/*
+	 * Cover the whole vector space, no vector can escape
+	 * us. (some of these will be overridden and become
+	 * 'special' SMP interrupts)
+	 */
+	for (i = 0; i < NR_IRQS; i++) {
+		int vector = FIRST_EXTERNAL_VECTOR + i;
+		if (vector != IA32_SYSCALL_VECTOR && vector != KDBENTER_VECTOR) {
+			set_intr_gate(vector, interrupt[i]);
+		}
+	}
+
+#ifdef CONFIG_SMP
+	/*
+	 * IRQ0 must be given a fixed assignment and initialized,
+	 * because it's used before the IO-APIC is set up.
+	 */
+	set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
+
+	/*
+	 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
+	 * IPI, driven by wakeup.
+	 */
+	set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
+
+	/* IPI for invalidation */
+	set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
+
+	/* IPI for generic function call */
+	set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
+#endif
+
+#ifdef CONFIG_X86_LOCAL_APIC
+	/* self generated IPI for local APIC timer */
+	set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
+
+	/* IPI vectors for APIC spurious and error interrupts */
+	set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
+	set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
+#endif
+
+#ifndef CONFIG_VISWS
+	setup_irq(2, &irq2);
+#endif
+}