[PATCH] mips: add support for Qemu system architecture
Add support for the virtual MIPS system that is emulated by Qemu. See
http://www.linux-mips.org/wiki/Qemu for a detailed current status.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/mips/qemu/q-irq.c b/arch/mips/qemu/q-irq.c
new file mode 100644
index 0000000..2c4e070
--- /dev/null
+++ b/arch/mips/qemu/q-irq.c
@@ -0,0 +1,37 @@
+#include <linux/init.h>
+#include <linux/linkage.h>
+
+#include <asm/i8259.h>
+#include <asm/mipsregs.h>
+#include <asm/qemu.h>
+#include <asm/system.h>
+#include <asm/time.h>
+
+extern asmlinkage void qemu_handle_int(void);
+
+asmlinkage void do_qemu_int(struct pt_regs *regs)
+{
+ unsigned int pending = read_c0_status() & read_c0_cause();
+
+ if (pending & 0x8000) {
+ ll_timer_interrupt(Q_COUNT_COMPARE_IRQ, regs);
+ return;
+ }
+ if (pending & 0x0400) {
+ int irq = i8259_irq();
+
+ if (likely(irq >= 0))
+ do_IRQ(irq, regs);
+
+ return;
+ }
+}
+
+void __init arch_init_irq(void)
+{
+ set_except_vector(0, qemu_handle_int);
+ mips_hpt_frequency = QEMU_C0_COUNTER_CLOCK; /* 100MHz */
+
+ init_i8259_irqs();
+ set_c0_status(0x8400);
+}