target/microblaze: Do not set MO_ALIGN for user-only

The kernel will fix up unaligned accesses, so emulate that
by allowing unaligned accesses to succeed.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index 437bbed6d68668f67dc4b5bd6c3095bbf446bb31..2561b904b9c25e60dba440bec2930387f1460c24 100644 (file)
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -722,6 +722,7 @@ static TCGv compute_ldst_addr_ea(DisasContext *dc, int ra, int rb)
 }
 #endif
 
+#ifndef CONFIG_USER_ONLY
 static void record_unaligned_ess(DisasContext *dc, int rd,
                                  MemOp size, bool store)
 {
@@ -734,6 +735,7 @@ static void record_unaligned_ess(DisasContext *dc, int rd,
 
     tcg_set_insn_start_param(dc->insn_start, 1, iflags);
 }
+#endif
 
 static bool do_load(DisasContext *dc, int rd, TCGv addr, MemOp mop,
                     int mem_index, bool rev)
@@ -755,12 +757,19 @@ static bool do_load(DisasContext *dc, int rd, TCGv addr, MemOp mop,
         }
     }
 
+    /*
+     * For system mode, enforce alignment if the cpu configuration
+     * requires it.  For user-mode, the Linux kernel will have fixed up
+     * any unaligned access, so emulate that by *not* setting MO_ALIGN.
+     */
+#ifndef CONFIG_USER_ONLY
     if (size > MO_8 &&
         (dc->tb_flags & MSR_EE) &&
         dc->cfg->unaligned_exceptions) {
         record_unaligned_ess(dc, rd, size, false);
         mop |= MO_ALIGN;
     }
+#endif
 
     tcg_gen_qemu_ld_i32(reg_for_write(dc, rd), addr, mem_index, mop);
 
@@ -901,12 +910,19 @@ static bool do_store(DisasContext *dc, int rd, TCGv addr, MemOp mop,
         }
     }
 
+    /*
+     * For system mode, enforce alignment if the cpu configuration
+     * requires it.  For user-mode, the Linux kernel will have fixed up
+     * any unaligned access, so emulate that by *not* setting MO_ALIGN.
+     */
+#ifndef CONFIG_USER_ONLY
     if (size > MO_8 &&
         (dc->tb_flags & MSR_EE) &&
         dc->cfg->unaligned_exceptions) {
         record_unaligned_ess(dc, rd, size, true);
         mop |= MO_ALIGN;
     }
+#endif
 
     tcg_gen_qemu_st_i32(reg_for_read(dc, rd), addr, mem_index, mop);