Resurrect Cobalt support for 2.6.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 73 insertions, 38 deletions

diff --git a/arch/mips/cobalt/irq.c b/arch/mips/cobalt/irq.c
index 6d2a81581397..0d90851f925e 100644
--- a/arch/mips/cobalt/irq.c
+++ b/arch/mips/cobalt/irq.c
@@ -10,6 +10,8 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
 
 #include <asm/i8259.h>
 #include <asm/irq_cpu.h>
@@ -25,8 +27,8 @@ extern void cobalt_handle_int(void);
  * the CPU interrupt lines, and ones that come in on the via chip. The CPU
  * mappings are:
  *
- *    16,  - Software interrupt 0 (unused)      IE_SW0
- *    17   - Software interrupt 1 (unused)      IE_SW0
+ *    16   - Software interrupt 0 (unused)      IE_SW0
+ *    17   - Software interrupt 1 (unused)      IE_SW1
  *    18   - Galileo chip (timer)               IE_IRQ0
  *    19   - Tulip 0 + NCR SCSI                 IE_IRQ1
  *    20   - Tulip 1                            IE_IRQ2
@@ -42,61 +44,94 @@ extern void cobalt_handle_int(void);
  *    15  - IDE1
  */
 
-asmlinkage void cobalt_irq(struct pt_regs *regs)
+static inline void galileo_irq(struct pt_regs *regs)
 {
-        unsigned int pending = read_c0_status() & read_c0_cause();
-
-        if (pending & CAUSEF_IP2) {                     /* int 18 */
-                unsigned long irq_src = GALILEO_INL(GT_INTRCAUSE_OFS);
-
-                /* Check for timer irq ... */
-                if (irq_src & GALILEO_T0EXP) {
-                        /* Clear the int line */
-                        GALILEO_OUTL(0, GT_INTRCAUSE_OFS);
-                        do_IRQ(COBALT_TIMER_IRQ, regs);
-                }
-                return;
-        }
+        unsigned int mask, pending, devfn;
 
-        if (pending & CAUSEF_IP6) {                     /* int 22 */
-                int irq = i8259_irq();
+        mask = GALILEO_INL(GT_INTRMASK_OFS);
+        pending = GALILEO_INL(GT_INTRCAUSE_OFS) & mask;
 
-                if (irq >= 0)
-                        do_IRQ(irq, regs);
-                return;
-        }
+        if (pending & GALILEO_INTR_T0EXP) {
 
-        if (pending & CAUSEF_IP3) {                     /* int 19 */
-                do_IRQ(COBALT_ETH0_IRQ, regs);
-                return;
-        }
+                GALILEO_OUTL(~GALILEO_INTR_T0EXP, GT_INTRCAUSE_OFS);
+                do_IRQ(COBALT_GALILEO_IRQ, regs);
 
-        if (pending & CAUSEF_IP4) {                     /* int 20 */
-                do_IRQ(COBALT_ETH1_IRQ, regs);
-                return;
-        }
+        } else if (pending & GALILEO_INTR_RETRY_CTR) {
 
-        if (pending & CAUSEF_IP5) {                     /* int 21 */
-                do_IRQ(COBALT_SERIAL_IRQ, regs);
-                return;
-        }
+                devfn = GALILEO_INL(GT_PCI0_CFGADDR_OFS) >> 8;
+                GALILEO_OUTL(~GALILEO_INTR_RETRY_CTR, GT_INTRCAUSE_OFS);
+                printk(KERN_WARNING "Galileo: PCI retry count exceeded (%02x.%u)\n",
+                        PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+        } else {
 
-        if (pending & CAUSEF_IP7) {                     /* int 23 */
-                do_IRQ(COBALT_QUBE_SLOT_IRQ, regs);
-                return;
+                GALILEO_OUTL(mask & ~pending, GT_INTRMASK_OFS);
+                printk(KERN_WARNING "Galileo: masking unexpected interrupt %08x\n", pending);
         }
 }
 
+static inline void via_pic_irq(struct pt_regs *regs)
+{
+        int irq;
+
+        irq = i8259_irq();
+        if (irq >= 0)
+                do_IRQ(irq, regs);
+}
+
+asmlinkage void cobalt_irq(struct pt_regs *regs)
+{
+        unsigned pending;
+
+        pending = read_c0_status() & read_c0_cause();
+
+        if (pending & CAUSEF_IP2)                       /* COBALT_GALILEO_IRQ (18) */
+
+                galileo_irq(regs);
+
+        else if (pending & CAUSEF_IP6)                  /* COBALT_VIA_IRQ (22) */
+
+                via_pic_irq(regs);
+
+        else if (pending & CAUSEF_IP3)                  /* COBALT_ETH0_IRQ (19) */
+
+                do_IRQ(COBALT_CPU_IRQ + 3, regs);
+
+        else if (pending & CAUSEF_IP4)                  /* COBALT_ETH1_IRQ (20) */
+
+                do_IRQ(COBALT_CPU_IRQ + 4, regs);
+
+        else if (pending & CAUSEF_IP5)                  /* COBALT_SERIAL_IRQ (21) */
+
+                do_IRQ(COBALT_CPU_IRQ + 5, regs);
+
+        else if (pending & CAUSEF_IP7)                  /* IRQ 23 */
+
+                do_IRQ(COBALT_CPU_IRQ + 7, regs);
+}
+
+static struct irqaction irq_via = {
+        no_action, 0, { { 0, } }, "cascade", NULL, NULL
+};
+
 void __init arch_init_irq(void)
 {
+        /*
+         * Mask all Galileo interrupts. The Galileo
+         * handler is set in cobalt_timer_setup()
+         */
+        GALILEO_OUTL(0, GT_INTRMASK_OFS);
+
         set_except_vector(0, cobalt_handle_int);
 
         init_i8259_irqs();                              /*  0 ... 15 */
-        mips_cpu_irq_init(16);                          /* 16 ... 23 */
+        mips_cpu_irq_init(COBALT_CPU_IRQ);              /* 16 ... 23 */
 
         /*
          * Mask all cpu interrupts
          *  (except IE4, we already masked those at VIA level)
          */
         change_c0_status(ST0_IM, IE_IRQ4);
+
+        setup_irq(COBALT_VIA_IRQ, &irq_via);
 }