commit 102cedc32a6e3cd537374a3678d407591d5a6fab
author Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Mon Mar 25 12:09:02 2013 -0500
committer Ralf Baechle <ralf@linux-mips.org> Thu May 09 17:55:18 2013 +0200
tree 7a91493a82e65c0da845afb12020e1534d83ee5d
parent cf6d905828c2c75ebe8c818901e71e09ffe6f629

MIPS: microMIPS: Floating point support.

Add logic needed to do floating point emulation in microMIPS mode.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Steven J. Hill <Steven. Hill@imgtec.com>

arch/mips/math-emu/dsemul.c

diff --git a/arch/mips/math-emu/dsemul.c b/arch/mips/math-emu/dsemul.c
index 384a3b0..7ea622a 100644
--- a/arch/mips/math-emu/dsemul.c
+++ b/arch/mips/math-emu/dsemul.c
@@ -55,7 +55,9 @@
 	struct emuframe __user *fr;
 	int err;
 
-	if (ir == 0) {		/* a nop is easy */
+	if ((get_isa16_mode(regs->cp0_epc) && ((ir >> 16) == MM_NOP16)) ||
+		(ir == 0)) {
+		/* NOP is easy */
 		regs->cp0_epc = cpc;
 		regs->cp0_cause &= ~CAUSEF_BD;
 		return 0;
@@ -91,8 +93,16 @@
 	if (unlikely(!access_ok(VERIFY_WRITE, fr, sizeof(struct emuframe))))
 		return SIGBUS;
 
-	err = __put_user(ir, &fr->emul);
-	err |= __put_user((mips_instruction)BREAK_MATH, &fr->badinst);
+	if (get_isa16_mode(regs->cp0_epc)) {
+		err = __put_user(ir >> 16, (u16 __user *)(&fr->emul));
+		err |= __put_user(ir & 0xffff, (u16 __user *)((long)(&fr->emul) + 2));
+		err |= __put_user(BREAK_MATH >> 16, (u16 __user *)(&fr->badinst));
+		err |= __put_user(BREAK_MATH & 0xffff, (u16 __user *)((long)(&fr->badinst) + 2));
+	} else {
+		err = __put_user(ir, &fr->emul);
+		err |= __put_user((mips_instruction)BREAK_MATH, &fr->badinst);
+	}
+
 	err |= __put_user((mips_instruction)BD_COOKIE, &fr->cookie);
 	err |= __put_user(cpc, &fr->epc);
 
@@ -101,7 +111,8 @@
 		return SIGBUS;
 	}
 
-	regs->cp0_epc = (unsigned long) &fr->emul;
+	regs->cp0_epc = ((unsigned long) &fr->emul) |
+		get_isa16_mode(regs->cp0_epc);
 
 	flush_cache_sigtramp((unsigned long)&fr->badinst);
 
@@ -114,9 +125,10 @@
 	unsigned long epc;
 	u32 insn, cookie;
 	int err = 0;
+	u16 instr[2];
 
 	fr = (struct emuframe __user *)
-		(xcp->cp0_epc - sizeof(mips_instruction));
+		(msk_isa16_mode(xcp->cp0_epc) - sizeof(mips_instruction));
 
 	/*
 	 * If we can't even access the area, something is very wrong, but we'll
@@ -131,7 +143,13 @@
 	 *  - Is the instruction pointed to by the EPC an BREAK_MATH?
 	 *  - Is the following memory word the BD_COOKIE?
 	 */
-	err = __get_user(insn, &fr->badinst);
+	if (get_isa16_mode(xcp->cp0_epc)) {
+		err = __get_user(instr[0], (u16 __user *)(&fr->badinst));
+		err |= __get_user(instr[1], (u16 __user *)((long)(&fr->badinst) + 2));
+		insn = (instr[0] << 16) | instr[1];
+	} else {
+		err = __get_user(insn, &fr->badinst);
+	}
 	err |= __get_user(cookie, &fr->cookie);
 
 	if (unlikely(err || (insn != BREAK_MATH) || (cookie != BD_COOKIE))) {