[PATCH 2/2] sh: Add unaligned memory access for PC relative intructions

[PATCH 2/2] sh: Add unaligned memory access for PC relative intructions

[Phil Edworthy]

This add unaligned memory access support for the following instructions:
  mov.w @(disp,PC),Rn
  mov.l @(disp,PC),Rn

These instructions are often used on SH2A toolchains.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
---
 arch/sh/kernel/traps_32.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index 61fa4a5..957c506 100644
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -316,6 +316,37 @@ static int handle_unaligned_ins(insn_size_t instruction, struct pt_regs *regs,
 			break;
 		}
 		break;
+
+	case 9: /* mov.w @(disp,PC),Rn */
+		srcu = (unsigned char __user *)regs->pc;
+		srcu += (instruction & 0x00FF) << 1;
+		dst = (unsigned char *)rn;
+		*(unsigned long *)dst = 0;
+
+#if !defined(__LITTLE_ENDIAN__)
+		dst += 2;
+#endif
+
+		if (ma->from(dst, srcu, 2))
+			goto fetch_fault;
+		sign_extend(2, dst);
+		ret = 0;
+		break;
+
+	case 0xd: /* mov.l @(disp,PC),Rn */
+		srcu = (unsigned char __user *)regs->pc;
+		srcu += (instruction & 0x00FF) << 2;
+		dst = (unsigned char *)rn;
+		*(unsigned long *)dst = 0;
+
+#if !defined(__LITTLE_ENDIAN__)
+		dst += 2;
+#endif
+
+		if (ma->from(dst, srcu, 4))
+			goto fetch_fault;
+		ret = 0;
+		break;
 	}
 	return ret;
 
@@ -496,6 +527,9 @@ int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
 		}
 		break;
 
+	case 0x9000: /* mov.w @(disp,Rm),Rn */
+		goto simple;
+
 	case 0xA000: /* bra label */
 		ret = handle_delayslot(regs, instruction, ma);
 		if (ret=0)
@@ -509,6 +543,9 @@ int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
 			regs->pc += SH_PC_12BIT_OFFSET(instruction);
 		}
 		break;
+
+	case 0xD000: /* mov.l @(disp,Rm),Rn */
+		goto simple;
 	}
 	return ret;
 
-- 
1.7.0.4

Re: [PATCH 2/2] sh: Add unaligned memory access for PC relative intructions

[Paul Mundt]

On Mon, Aug 22, 2011 at 04:56:37PM +0100, Phil Edworthy wrote:
> This add unaligned memory access support for the following instructions:
>   mov.w @(disp,PC),Rn
>   mov.l @(disp,PC),Rn
> 
> These instructions are often used on SH2A toolchains.
> 
Looks good! Are there any other instruction pairs you've stumbled in to
on the SH-2A side? The 32-bit instructions are still a largely unresolved
issue, too.

Re: [PATCH 2/2] sh: Add unaligned memory access for PC relative

[phil.edworthy]

> > This add unaligned memory access support for the following 
instructions:
> >   mov.w @(disp,PC),Rn
> >   mov.l @(disp,PC),Rn
> > 
> > These instructions are often used on SH2A toolchains.
> > 
> Looks good! Are there any other instruction pairs you've stumbled in to
> on the SH-2A side? The 32-bit instructions are still a largely 
unresolved
> issue, too.

Not so far, though I haven't run much yet. I'm still having some issues 
with the loader so it's difficult to be sure that these emulated 
instructions are correct...
Phil