powerpc: Emulate sync instruction variants

Reserved fields of the sync instruction have been used for other
instructions (e.g. lwsync).  On processors that do not support variants
of the sync instruction, emulate it by executing a sync to subsume the
effect of the intended instruction.

Signed-off-by: James Yang <James.Yang@freescale.com>
[scottwood@freescale.com: whitespace and subject line fix]
Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index ad5fcf51b25225c7827f45347ce94d8f7c2584b6..442edee4b6aa5cba5306fddf2c84e82c890844d9 100644 (file)
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -143,6 +143,8 @@
 #define PPC_INST_LSWX                  0x7c00042a
 #define PPC_INST_LWARX                 0x7c000028
 #define PPC_INST_LWSYNC                        0x7c2004ac
+#define PPC_INST_SYNC                  0x7c0004ac
+#define PPC_INST_SYNC_MASK             0xfc0007fe
 #define PPC_INST_LXVD2X                        0x7c000698
 #define PPC_INST_MCRXR                 0x7c000400
 #define PPC_INST_MCRXR_MASK            0xfc0007fe

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index f0a6814007a521649be57a7b08de14f19493ceb0..36a1f95a2a363aa3622421fb4655a33cc135e794 100644 (file)
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1018,6 +1018,13 @@ static int emulate_instruction(struct pt_regs *regs)
                return emulate_isel(regs, instword);
        }
 
+       /* Emulate sync instruction variants */
+       if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) {
+               PPC_WARN_EMULATED(sync, regs);
+               asm volatile("sync");
+               return 0;
+       }
+
 #ifdef CONFIG_PPC64
        /* Emulate the mfspr rD, DSCR. */
        if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) ==