Subject: [PATCH] openpic_hookup_cascade in linuxppc_2_5

From: Adrian Cox <[email-masked]>
Date: Tue, 16 Mar 2004 14:20:45 +0000

This patch ports the openpic_hookup_cascade() function from 2_4_devel,
as it is necessary for the Sandpoint X2. In doing this I have to change
almost every user of openpic_init.

pmac needs no changes.
chrp, lopec, mcpn765, pplus, prep, and sandpoint need simple changes.

But some of the platforms don't use the new, single argument, form of
openpic_init(). Thus, the following are already broken in 2.5: gemini,
mvme5100, powerpmc250, prmpm750, and prpmc800. I don't have any of these
platforms, so my patch doesn't touch them.

- Adrian Cox

diff -Nru a/arch/ppc/platforms/chrp_setup.c b/arch/ppc/platforms/chrp_setup.c
--- a/arch/ppc/platforms/chrp_setup.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/platforms/chrp_setup.c	Tue Mar 16 14:15:02 2004
@@ -407,6 +407,7 @@
 	OpenPIC_NumInitSenses = NR_IRQS - NUM_8259_INTERRUPTS;

 	openpic_init(NUM_8259_INTERRUPTS);
+        openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade", &i8259_irq);

 	for (i = 0; i < NUM_8259_INTERRUPTS; i++)
 		irq_desc[i].handler = &i8259_pic;
diff -Nru a/arch/ppc/platforms/lopec_setup.c b/arch/ppc/platforms/lopec_setup.c
--- a/arch/ppc/platforms/lopec_setup.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/platforms/lopec_setup.c	Tue Mar 16 14:15:02 2004
@@ -208,6 +208,7 @@
 	openpic_set_sources(19, 1, OpenPIC_Addr + 0x110C0);

 	openpic_init(NUM_8259_INTERRUPTS);
+        openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade", &i8259_irq);

 	/* Map i8259 interrupts */
 	for(i = 0; i < NUM_8259_INTERRUPTS; i++)
diff -Nru a/arch/ppc/platforms/mcpn765_setup.c b/arch/ppc/platforms/mcpn765_setup.c
--- a/arch/ppc/platforms/mcpn765_setup.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/platforms/mcpn765_setup.c	Tue Mar 16 14:15:02 2004
@@ -247,6 +247,7 @@
 		ppc_md.progress("init_irq: enter", 0);

 	openpic_init(NUM_8259_INTERRUPTS);
+        openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade", &i8259_irq);

 	for(i=0; i < NUM_8259_INTERRUPTS; i++)
 		irq_desc[i].handler = &i8259_pic;
diff -Nru a/arch/ppc/platforms/pplus.c b/arch/ppc/platforms/pplus.c
--- a/arch/ppc/platforms/pplus.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/platforms/pplus.c	Tue Mar 16 14:15:02 2004
@@ -672,6 +672,8 @@

 		openpic_set_sources(0, 16, OpenPIC_Addr + 0x10000);
 		openpic_init(NUM_8259_INTERRUPTS);
+                openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade",
+                                       &i8259_irq);
 		ppc_md.get_irq = openpic_get_irq;
 	}

diff -Nru a/arch/ppc/platforms/prep_setup.c b/arch/ppc/platforms/prep_setup.c
--- a/arch/ppc/platforms/prep_setup.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/platforms/prep_setup.c	Tue Mar 16 14:15:02 2004
@@ -854,8 +854,11 @@
 	int i;
 	unsigned int pci_viddid, pci_did;

-	if (OpenPIC_Addr != NULL)
+	if (OpenPIC_Addr != NULL) {
 		openpic_init(NUM_8259_INTERRUPTS);
+                openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade",
+                                       &i8259_irq);
+        }
 	for ( i = 0 ; i < NUM_8259_INTERRUPTS ; i++ )
 		irq_desc[i].handler = &i8259_pic;
 	/* If we have a Raven PCI bridge or a Hawk PCI bridge / Memory
diff -Nru a/arch/ppc/platforms/sandpoint.c b/arch/ppc/platforms/sandpoint.c
--- a/arch/ppc/platforms/sandpoint.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/platforms/sandpoint.c	Tue Mar 16 14:15:02 2004
@@ -444,6 +444,7 @@
 	openpic_set_sources(0, 16, OpenPIC_Addr + 0x10200);

 	openpic_init(NUM_8259_INTERRUPTS);
+        openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade", &i8259_irq);

 	/*
 	 * openpic_init() has set up irq_desc[16-31] to be openpic
diff -Nru a/arch/ppc/syslib/open_pic.c b/arch/ppc/syslib/open_pic.c
--- a/arch/ppc/syslib/open_pic.c	Tue Mar 16 14:15:02 2004
+++ b/arch/ppc/syslib/open_pic.c	Tue Mar 16 14:15:02 2004
@@ -48,6 +48,8 @@
 static u_int NumSources;
 static int open_pic_irq_offset;
 static volatile OpenPIC_Source *ISR[NR_IRQS];
+static int openpic_cascade_irq = -1;
+static int (*openpic_cascade_fn)(struct pt_regs *);

 /* Global Operations */
 static void openpic_disable_8259_pass_through(void);
@@ -417,12 +419,6 @@
 	if (ppc_md.progress) ppc_md.progress("openpic: spurious",0x3bd);
 	openpic_set_spurious(OPENPIC_VEC_SPURIOUS+offset);

-	/* Initialize the cascade */
-	if (offset) {
-		if (request_irq(offset, no_action, SA_INTERRUPT,
-				"82c59 cascade", NULL))
-			printk("Unable to get OpenPIC IRQ 0 for cascade\n");
-	}
 	openpic_disable_8259_pass_through();
 #ifdef CONFIG_EPIC_SERIAL_MODE
 	openpic_eicr_set_clk(7);	/* Slowest value until we know better */
@@ -682,6 +678,19 @@
  *
  */

+/*
+ * Hookup a cascade to the OpenPIC.
+ */
+void __init
+openpic_hookup_cascade(u_int irq, char *name,
+	int (*cascade_fn)(struct pt_regs *))
+{
+	openpic_cascade_irq = irq;
+	openpic_cascade_fn = cascade_fn;
+	if (request_irq(irq, no_action, SA_INTERRUPT, name, NULL))
+		printk("Unable to get OpenPIC IRQ %d for cascade\n",
+				irq - open_pic_irq_offset);
+}

 /*
  *  Enable/disable an external interrupt source
@@ -841,13 +850,18 @@
 	int irq = openpic_irq();

 	/*
-	 * This needs to be cleaned up.  We don't necessarily have
-	 * an i8259 cascaded or even a cascade.
+	 * Check for the cascade interrupt and call the cascaded
+	 * interrupt controller function (usually i8259_irq) if so.
+	 * This should move to irq.c eventually.  -- paulus
 	 */
-	if (open_pic_irq_offset && irq == open_pic_irq_offset) {
-		/* Get the IRQ from the cascade. */
-		irq = i8259_irq(regs);
-		openpic_eoi();
+	if (irq == openpic_cascade_irq && openpic_cascade_fn != NULL) {
+		int cirq = openpic_cascade_fn(regs);
+
+		/* Allow for the cascade being shared with other devices */
+		if (cirq != -1) {
+			irq = cirq;
+			openpic_eoi();
+		}
 	} else if (irq == OPENPIC_VEC_SPURIOUS + open_pic_irq_offset)
 		irq = -1;
 	return irq;
diff -Nru a/include/asm-ppc/open_pic.h b/include/asm-ppc/open_pic.h
--- a/include/asm-ppc/open_pic.h	Tue Mar 16 14:15:02 2004
+++ b/include/asm-ppc/open_pic.h	Tue Mar 16 14:15:02 2004
@@ -40,6 +40,8 @@
 /* Exported functions */
 extern void openpic_set_sources(int first_irq, int num_irqs, void *isr);
 extern void openpic_init(int linux_irq_offset);
+extern void openpic_hookup_cascade(u_int irq, char *name,
+                                   int (*cascade_fn)(struct pt_regs *));
 extern void openpic_init_nmi_irq(u_int irq);
 extern u_int openpic_irq(void);
 extern void openpic_eoi(void);

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