1 files changed, 24 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 5ddb801bc154..cb71cf29edea 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -909,6 +909,26 @@ static int emulate_instruction(struct pt_regs *regs)
                 return emulate_isel(regs, instword);
         }
 
+#ifdef CONFIG_PPC64
+        /* Emulate the mfspr rD, DSCR. */
+        if (((instword & PPC_INST_MFSPR_DSCR_MASK) == PPC_INST_MFSPR_DSCR) &&
+                        cpu_has_feature(CPU_FTR_DSCR)) {
+                PPC_WARN_EMULATED(mfdscr, regs);
+                rd = (instword >> 21) & 0x1f;
+                regs->gpr[rd] = mfspr(SPRN_DSCR);
+                return 0;
+        }
+        /* Emulate the mtspr DSCR, rD. */
+        if (((instword & PPC_INST_MTSPR_DSCR_MASK) == PPC_INST_MTSPR_DSCR) &&
+                        cpu_has_feature(CPU_FTR_DSCR)) {
+                PPC_WARN_EMULATED(mtdscr, regs);
+                rd = (instword >> 21) & 0x1f;
+                mtspr(SPRN_DSCR, regs->gpr[rd]);
+                current->thread.dscr_inherit = 1;
+                return 0;
+        }
+#endif
+
         return -EINVAL;
 }
 
@@ -1506,6 +1526,10 @@ struct ppc_emulated ppc_emulated = {
 #ifdef CONFIG_VSX
         WARN_EMULATED_SETUP(vsx),
 #endif
+#ifdef CONFIG_PPC64
+        WARN_EMULATED_SETUP(mfdscr),
+        WARN_EMULATED_SETUP(mtdscr),
+#endif
 };
 
 u32 ppc_warn_emulated;