summaryrefslogtreecommitdiffstats
path: root/arch/mips/fw/lib/call_o32.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/fw/lib/call_o32.S')
-rw-r--r--arch/mips/fw/lib/call_o32.S57
1 files changed, 35 insertions, 22 deletions
diff --git a/arch/mips/fw/lib/call_o32.S b/arch/mips/fw/lib/call_o32.S
index b308b2a0613e..4703fe4dbd9a 100644
--- a/arch/mips/fw/lib/call_o32.S
+++ b/arch/mips/fw/lib/call_o32.S
@@ -1,7 +1,7 @@
/*
* O32 interface for the 64 (or N32) ABI.
*
- * Copyright (C) 2002 Maciej W. Rozycki
+ * Copyright (C) 2002, 2014 Maciej W. Rozycki
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -12,28 +12,37 @@
#include <asm/asm.h>
#include <asm/regdef.h>
+/* O32 register size. */
+#define O32_SZREG 4
/* Maximum number of arguments supported. Must be even! */
#define O32_ARGC 32
-/* Number of static registers we save. */
+/* Number of static registers we save. */
#define O32_STATC 11
-/* Frame size for static register */
-#define O32_FRAMESZ (SZREG * O32_STATC)
-/* Frame size on new stack */
-#define O32_FRAMESZ_NEW (SZREG + 4 * O32_ARGC)
+/* Argument area frame size. */
+#define O32_ARGSZ (O32_SZREG * O32_ARGC)
+/* Static register save area frame size. */
+#define O32_STATSZ (SZREG * O32_STATC)
+/* Stack pointer register save area frame size. */
+#define O32_SPSZ SZREG
+/* Combined area frame size. */
+#define O32_FRAMESZ (O32_ARGSZ + O32_SPSZ + O32_STATSZ)
+/* Switched stack frame size. */
+#define O32_NFRAMESZ (O32_ARGSZ + O32_SPSZ)
.text
/*
* O32 function call dispatcher, for interfacing 32-bit ROM routines.
*
- * The standard 64 (N32) calling sequence is supported, with a0
- * holding a function pointer, a1 a new stack pointer, a2-a7 -- its
- * first six arguments and the stack -- remaining ones (up to O32_ARGC,
- * including a2-a7). Static registers, gp and fp are preserved, v0 holds
- * a result. This code relies on the called o32 function for sp and ra
- * restoration and this dispatcher has to be placed in a KSEGx (or KUSEG)
- * address space. Any pointers passed have to point to addresses within
- * one of these spaces as well.
+ * The standard 64 (N32) calling sequence is supported, with a0 holding
+ * a function pointer, a1 a pointer to the new stack to call the
+ * function with or 0 if no stack switching is requested, a2-a7 -- the
+ * function call's first six arguments, and the stack -- the remaining
+ * arguments (up to O32_ARGC, including a2-a7). Static registers, gp
+ * and fp are preserved, v0 holds the result. This code relies on the
+ * called o32 function for sp and ra restoration and this dispatcher has
+ * to be placed in a KSEGx (or KUSEG) address space. Any pointers
+ * passed have to point to addresses within one of these spaces as well.
*/
NESTED(call_o32, O32_FRAMESZ, ra)
REG_SUBU sp,O32_FRAMESZ
@@ -51,32 +60,36 @@ NESTED(call_o32, O32_FRAMESZ, ra)
REG_S s0,O32_FRAMESZ-11*SZREG(sp)
move jp,a0
- REG_SUBU s0,a1,O32_FRAMESZ_NEW
- REG_S sp,O32_FRAMESZ_NEW-1*SZREG(s0)
+
+ move fp,sp
+ beqz a1,0f
+ REG_SUBU fp,a1,O32_NFRAMESZ
+0:
+ REG_S sp,O32_NFRAMESZ-1*SZREG(fp)
sll a0,a2,zero
sll a1,a3,zero
sll a2,a4,zero
sll a3,a5,zero
- sw a6,0x10(s0)
- sw a7,0x14(s0)
+ sw a6,4*O32_SZREG(fp)
+ sw a7,5*O32_SZREG(fp)
PTR_LA t0,O32_FRAMESZ(sp)
- PTR_LA t1,0x18(s0)
+ PTR_LA t1,6*O32_SZREG(fp)
li t2,O32_ARGC-6
1:
lw t3,(t0)
REG_ADDU t0,SZREG
sw t3,(t1)
REG_SUBU t2,1
- REG_ADDU t1,4
+ REG_ADDU t1,O32_SZREG
bnez t2,1b
- move sp,s0
+ move sp,fp
jalr jp
- REG_L sp,O32_FRAMESZ_NEW-1*SZREG(sp)
+ REG_L sp,O32_NFRAMESZ-1*SZREG(sp)
REG_L s0,O32_FRAMESZ-11*SZREG(sp)
REG_L s1,O32_FRAMESZ-10*SZREG(sp)