1 files changed, 194 insertions, 0 deletions

diff --git a/arch/mips/sni/irq.c b/arch/mips/sni/irq.c
new file mode 100644
index 000000000000..62c760f14674
--- /dev/null
+++ b/arch/mips/sni/irq.c
@@ -0,0 +1,194 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Copyright (C) 1994 - 2000 Ralf Baechle
+ */
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+
+#include <asm/i8259.h>
+#include <asm/io.h>
+#include <asm/sni.h>
+
+DEFINE_SPINLOCK(pciasic_lock);
+
+extern asmlinkage void sni_rm200_pci_handle_int(void);
+
+static void enable_pciasic_irq(unsigned int irq)
+{
+        unsigned int mask = 1 << (irq - PCIMT_IRQ_INT2);
+        unsigned long flags;
+
+        spin_lock_irqsave(&pciasic_lock, flags);
+        *(volatile u8 *) PCIMT_IRQSEL |= mask;
+        spin_unlock_irqrestore(&pciasic_lock, flags);
+}
+
+static unsigned int startup_pciasic_irq(unsigned int irq)
+{
+        enable_pciasic_irq(irq);
+        return 0; /* never anything pending */
+}
+
+#define shutdown_pciasic_irq    disable_pciasic_irq
+
+void disable_pciasic_irq(unsigned int irq)
+{
+        unsigned int mask = ~(1 << (irq - PCIMT_IRQ_INT2));
+        unsigned long flags;
+
+        spin_lock_irqsave(&pciasic_lock, flags);
+        *(volatile u8 *) PCIMT_IRQSEL &= mask;
+        spin_unlock_irqrestore(&pciasic_lock, flags);
+}
+
+#define mask_and_ack_pciasic_irq disable_pciasic_irq
+
+static void end_pciasic_irq(unsigned int irq)
+{
+        if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+                enable_pciasic_irq(irq);
+}
+
+static struct hw_interrupt_type pciasic_irq_type = {
+        "ASIC-PCI",
+        startup_pciasic_irq,
+        shutdown_pciasic_irq,
+        enable_pciasic_irq,
+        disable_pciasic_irq,
+        mask_and_ack_pciasic_irq,
+        end_pciasic_irq,
+        NULL
+};
+
+/*
+ * hwint0 should deal with MP agent, ASIC PCI, EISA NMI and debug
+ * button interrupts.  Later ...
+ */
+void pciasic_hwint0(struct pt_regs *regs)
+{
+        panic("Received int0 but no handler yet ...");
+}
+
+/* This interrupt was used for the com1 console on the first prototypes.  */
+void pciasic_hwint2(struct pt_regs *regs)
+{
+        /* I think this shouldn't happen on production machines.  */
+        panic("hwint2 and no handler yet");
+}
+
+/* hwint5 is the r4k count / compare interrupt  */
+void pciasic_hwint5(struct pt_regs *regs)
+{
+        panic("hwint5 and no handler yet");
+}
+
+static unsigned int ls1bit8(unsigned int x)
+{
+        int b = 7, s;
+
+        s = 4; if ((x & 0x0f) == 0) s = 0; b -= s; x <<= s;
+        s = 2; if ((x & 0x30) == 0) s = 0; b -= s; x <<= s;
+        s = 1; if ((x & 0x40) == 0) s = 0; b -= s;
+
+        return b;
+}
+
+/*
+ * hwint 1 deals with EISA and SCSI interrupts,
+ * 
+ * The EISA_INT bit in CSITPEND is high active, all others are low active.
+ */
+void pciasic_hwint1(struct pt_regs *regs)
+{
+        u8 pend = *(volatile char *)PCIMT_CSITPEND;
+        unsigned long flags;
+
+        if (pend & IT_EISA) {
+                int irq;
+                /*
+                 * Note: ASIC PCI's builtin interrupt achknowledge feature is
+                 * broken.  Using it may result in loss of some or all i8259
+                 * interupts, so don't use PCIMT_INT_ACKNOWLEDGE ...
+                 */
+                irq = i8259_irq();
+                if (unlikely(irq < 0))
+                        return;
+
+                do_IRQ(irq, regs);
+        }
+
+        if (!(pend & IT_SCSI)) {
+                flags = read_c0_status();
+                clear_c0_status(ST0_IM);
+                do_IRQ(PCIMT_IRQ_SCSI, regs);
+                write_c0_status(flags);
+        }
+}
+
+/*
+ * hwint 3 should deal with the PCI A - D interrupts,
+ */
+void pciasic_hwint3(struct pt_regs *regs)
+{
+        u8 pend = *(volatile char *)PCIMT_CSITPEND;
+        int irq;
+
+        pend &= (IT_INTA | IT_INTB | IT_INTC | IT_INTD);
+        clear_c0_status(IE_IRQ3);
+        irq = PCIMT_IRQ_INT2 + ls1bit8(pend);
+        do_IRQ(irq, regs);
+        set_c0_status(IE_IRQ3);
+}
+
+/*
+ * hwint 4 is used for only the onboard PCnet 32.
+ */
+void pciasic_hwint4(struct pt_regs *regs)
+{
+        clear_c0_status(IE_IRQ4);
+        do_IRQ(PCIMT_IRQ_ETHERNET, regs);
+        set_c0_status(IE_IRQ4);
+}
+
+void __init init_pciasic(void)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&pciasic_lock, flags);
+        * (volatile u8 *) PCIMT_IRQSEL =
+                IT_EISA | IT_INTA | IT_INTB | IT_INTC | IT_INTD;
+        spin_unlock_irqrestore(&pciasic_lock, flags);
+}
+
+/*
+ * On systems with i8259-style interrupt controllers we assume for
+ * driver compatibility reasons interrupts 0 - 15 to be the i8295
+ * interrupts even if the hardware uses a different interrupt numbering.
+ */
+void __init arch_init_irq(void)
+{
+        int i;
+
+        set_except_vector(0, sni_rm200_pci_handle_int);
+
+        init_i8259_irqs();                      /* Integrated i8259  */
+        init_pciasic();
+
+        /* Actually we've got more interrupts to handle ...  */
+        for (i = PCIMT_IRQ_INT2; i <= PCIMT_IRQ_ETHERNET; i++) {
+                irq_desc[i].status     = IRQ_DISABLED;
+                irq_desc[i].action     = 0;
+                irq_desc[i].depth      = 1;
+                irq_desc[i].handler    = &pciasic_irq_type;
+        }
+
+        change_c0_status(ST0_IM, IE_IRQ1|IE_IRQ2|IE_IRQ3|IE_IRQ4);
+}