patch-2.2.18 linux/arch/ppc/kernel/open_pic.c

• Lines: 150
• Date: Wed Nov 8 23:00:34 2000
• Orig file: v2.2.17/arch/ppc/kernel/open_pic.c
• Orig date: Fri Apr 21 12:45:47 2000

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/arch/ppc/kernel/open_pic.c linux/arch/ppc/kernel/open_pic.c
@@ -1,48 +1,126 @@
+/*
+ * open_pic.c
+ *
+ * Common support routines for platforms with an OpenPIC interrupt controller
+ *
+ */
+
 #include <linux/stddef.h>
 #include <linux/init.h>
 #include <linux/sched.h>
 #include <linux/signal.h>
 #include <linux/openpic.h>
 #include <asm/irq.h>
+#include <asm/processor.h>
 #include "open_pic.h"
 #include "i8259.h"
 
-#ifdef __SMP__
-void openpic_ipi_action(int cpl, void *dev_id, struct pt_regs *regs)
-{
-	smp_message_recv(cpl-OPENPIC_VEC_IPI);
-}
-#endif /* __SMP__ */
+extern volatile unsigned char *chrp_int_ack_special;
 
-void chrp_mask_and_ack_irq(unsigned int irq_nr)
+void open_pic_do_IRQ(struct pt_regs *regs, int cpu, int isfake)
 {
-	if ((_machine != _MACH_gemini) && is_8259_irq(irq_nr))
-		i8259_pic.mask_and_ack(irq_nr);
-}
+	int irq;
+        int openpic_eoi_done = 0;
 
-static void chrp_mask_irq(unsigned int irq_nr)
-{
-	if ((_machine != _MACH_gemini) && is_8259_irq(irq_nr))
-		i8259_pic.disable(irq_nr);
+#ifdef __SMP__
+        {
+                unsigned int loops = 1000000;
+                while (test_bit(0, &global_irq_lock)) {
+                        if (smp_processor_id() == global_irq_holder) {
+                                printk("uh oh, interrupt while we hold global irq lock!\n");
+#ifdef CONFIG_XMON
+                                xmon(0);
+#endif
+                                break;
+                        }
+                        if (loops-- == 0) {
+                                printk("do_IRQ waiting for irq lock (holder=%d)\n", global_irq_holder);
+#ifdef CONFIG_XMON
+                                xmon(0);
+#endif
+                        }
+                }
+        }
+#endif /* __SMP__ */
+	
+        irq = openpic_irq(smp_processor_id());
+	/* make sure open_pic.irq_offset is set to something!
+	 * do we really need the _MACH_Pmac test??
+	 */
+        if (!(_machine == _MACH_Pmac) && (irq == open_pic.irq_offset))
+        {
+                /*
+                 * This magic address generates a PCI IACK cycle.
+                 *
+                 * This should go in the above mask/ack code soon. -- Cort
+                 */
+		if ( chrp_int_ack_special )
+			irq = *chrp_int_ack_special;
+#ifndef CONFIG_PMAC
+		else
+			irq = i8259_irq(0);
+#endif
+                /*
+                 * Acknowledge as soon as possible to allow i8259
+                 * interrupt nesting                         */
+                openpic_eoi(smp_processor_id());
+                openpic_eoi_done = 1;
+        }
+        if (irq == OPENPIC_VEC_SPURIOUS)
+        {
+                /*
+                 * Spurious interrupts should never be
+                 * acknowledged
+                 */
+                ppc_spurious_interrupts++;
+                openpic_eoi_done = 1;
+		goto out;
+        }
+
+        if (irq < 0)
+        {
+                printk(KERN_DEBUG "Bogus interrupt %d from PC = %lx\n",
+                       irq, regs->nip);
+                ppc_spurious_interrupts++;
+        }
 	else
-		openpic_disable_irq(irq_nr-open_pic.irq_offset);
+        {
+		ppc_irq_dispatch_handler( regs, irq );
+	}
+out:
+        if (!openpic_eoi_done)
+                openpic_eoi(smp_processor_id());
 }
 
-static void chrp_unmask_irq(unsigned int irq_nr)
+#ifdef __SMP__
+void openpic_ipi_action(int cpl, void *dev_id, struct pt_regs *regs)
 {
-	if ((_machine != _MACH_gemini) && is_8259_irq(irq_nr))
-		i8259_pic.enable(irq_nr);
-	else
-		openpic_enable_irq(irq_nr-open_pic.irq_offset);
+	smp_message_recv(cpl-OPENPIC_VEC_IPI);
 }
+#endif /* __SMP__ */
+
 
 struct hw_interrupt_type open_pic = {
 	" OpenPIC  ",
 	NULL,
 	NULL,
 	NULL,
-	chrp_unmask_irq,
-	chrp_mask_irq,
-	chrp_mask_and_ack_irq,
+	openpic_enable_irq,
+	openpic_disable_irq,
+	/* Theorically, the mask&ack should be NULL for OpenPIC. However, doing
+	 * so shows tons of bogus interrupts coming in.
+	 * This problem is apparently due to the common code always calling
+	 * unmask(). I apparently (need more test) fixed it in the 2.4 new IRQ
+	 * management by cleanly implementing the handler's end() function, so
+	 * neither mask nor unmask are needed. In the meantime, the fix below will
+	 * work for 2.2 -Benh
+	 *
+	 * Hopefully this will fix my bogus interrups on MTX
+	 * I merged everthing together so we don't have the same code in three
+	 * places. This might cause stability problems, but I'd rather
+	 * get it right once than three different times because someone forgot
+	 * to make the same change to PReP or something --Troy
+	 */
+	openpic_disable_irq,
 	0
 };