1 files changed, 86 insertions, 0 deletions
diff --git a/arch/mips/kernel/r2300_scall.S b/arch/mips/kernel/r2300_scall.S
new file mode 100644
index 000000000..358f46664
--- /dev/null
+++ b/arch/mips/kernel/r2300_scall.S
@@ -0,0 +1,86 @@
+/* $Id: r2300_scall.S,v 1.3 1996/06/29 12:41:08 dm Exp $
+ * r2300_scall.S: R2000/R3000 specific code to handle system calls.
+ *
+ * Copyright (C) 1994, 1995, 1996 by Ralf Baechle and Andreas Busse
+ *
+ * Multi-arch abstraction and beautification:
+ * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
+ */
+#include <asm/asm.h>
+#include <asm/bootinfo.h>
+#include <asm/cachectl.h>
+#include <asm/fpregdef.h>
+#include <asm/mipsconfig.h>
+#include <asm/mipsregs.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/regdef.h>
+#include <asm/segment.h>
+#include <asm/stackframe.h>
+
+/*
+ * do_syscall calls the function in a1 with upto 7 arguments.  If over
+ * four arguments are being requested, the additional arguments will
+ * be copied from the user stack pointed to by a0->reg29.
+ *
+ * a0 (struct pt_regs *)  pointer to user registers
+ * a1 (syscall_t)         pointer to syscall to do
+ * a2 (int)               number of arguments to syscall
+ */
+	.set	noreorder
+	.text
+NESTED(r2300_do_syscalls, 32, sp)
+	subu	sp,32
+	sw	ra,28(sp)
+	sll	a2,a2,PTRLOG
+	lw	t0,dst(a2)
+	move	t2,a1
+	jalr	t0
+	 lw	t0,PT_R29(a0)		# get old user stack pointer
+
+7:
+	lw	t1,24(t0)		# parameter #7 from usp
+	nop				# delay slot
+	sw	t1,24(sp)
+6:
+	lw	t1,20(t0)		# parameter #6 from usp
+	nop				# delay slot
+	sw	t1,20(sp)
+5:
+	lw	t1,16(t0)		# parameter #5 from usp
+	nop				# delay slot
+	sw	t1,16(sp)
+4:
+	lw	a3,PT_R7(a0)		# 4 args
+3:
+	lw	a2,PT_R6(a0)		# 3 args
+2:
+	lw	a1,PT_R5(a0)		# 2 args
+1:
+	jalr	t2			# 1 args
+	 lw	a0,PT_R4(a0)
+
+	lw	ra,28(sp)
+	addiu	sp,32
+	jr	ra
+	 nop
+
+0:
+	jalr	t2			# 0 args, just pass a0
+	 lw	ra,28(sp)
+	addiu	sp,32
+
+	jr	ra
+	 nop				# delay slot
+	END(r2300_do_syscalls)
+
+		.rdata
+		.align	PTRLOG
+dst:		PTR	0b, 1b, 2b, 3b, 4b, 5b, 6b, 7b
+
+		.section	__ex_table,"a"
+		PTR	7b,bad_stack
+		PTR	6b,bad_stack
+		PTR	5b,bad_stack
+		.text