[PATCH 77/77] target/microblaze: Reduce linux-user address space to 32-bit

[Richard Henderson]

User-space programs cannot use the 64-bit lwea/swea instructions.
We can improve code generation and runtime by restricting the
user-only address space to 32-bit.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/microblaze/cpu-param.h | 15 +++++++++++++++
 target/microblaze/cpu.h       |  2 +-
 target/microblaze/helper.c    |  4 ++--
 target/microblaze/translate.c | 28 +++++++++++++++++++++++++++-
 4 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/target/microblaze/cpu-param.h b/target/microblaze/cpu-param.h
index 4abbc62d50..4d8297fa94 100644
--- a/target/microblaze/cpu-param.h
+++ b/target/microblaze/cpu-param.h
@@ -8,9 +8,24 @@
 #ifndef MICROBLAZE_CPU_PARAM_H
 #define MICROBLAZE_CPU_PARAM_H 1
 
+/*
+ * While system mode can address up to 64 bits of address space,
+ * this is done via the lea/sea instructions, which are system-only
+ * (as they also bypass the mmu).
+ *
+ * We can improve the user-only experience by only exposing 32 bits
+ * of address space.
+ */
+#ifdef CONFIG_USER_ONLY
+#define TARGET_LONG_BITS 32
+#define TARGET_PHYS_ADDR_SPACE_BITS 32
+#define TARGET_VIRT_ADDR_SPACE_BITS 32
+#else
 #define TARGET_LONG_BITS 64
 #define TARGET_PHYS_ADDR_SPACE_BITS 64
 #define TARGET_VIRT_ADDR_SPACE_BITS 64
+#endif
+
 /* FIXME: MB uses variable pages down to 1K but linux only uses 4k.  */
 #define TARGET_PAGE_BITS 12
 #define NB_MMU_MODES 3
diff --git a/target/microblaze/cpu.h b/target/microblaze/cpu.h
index 4298f242a6..d11b6fa995 100644
--- a/target/microblaze/cpu.h
+++ b/target/microblaze/cpu.h
@@ -242,7 +242,7 @@ struct CPUMBState {
     uint32_t pc;
     uint32_t msr;    /* All bits of MSR except MSR[C] and MSR[CC] */
     uint32_t msr_c;  /* MSR[C], in low bit; other bits must be 0 */
-    uint64_t ear;
+    target_ulong ear;
     uint32_t esr;
     uint32_t fsr;
     uint32_t btr;
diff --git a/target/microblaze/helper.c b/target/microblaze/helper.c
index 1667822fb7..48547385b0 100644
--- a/target/microblaze/helper.c
+++ b/target/microblaze/helper.c
@@ -303,8 +303,8 @@ void mb_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
     iflags = cpu->env.iflags;
 
     qemu_log_mask(CPU_LOG_INT,
-                  "Unaligned access addr=" TARGET_FMT_lx
-                  " pc=%x iflags=%x\n", addr, cpu->env.pc, iflags);
+                  "Unaligned access addr=" TARGET_FMT_lx " pc=%x iflags=%x\n",
+                  (target_ulong)addr, cpu->env.pc, iflags);
 
     esr = ESR_EC_UNALIGNED_DATA;
     if (likely(iflags & ESR_ESS_FLAG)) {
diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index c8eb68ce4b..f6e16b7f5a 100644
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -729,6 +729,7 @@ static TCGv compute_ldst_addr_typeb(DisasContext *dc, int 
ra, int imm)
     return ret;
 }
 
+#ifndef CONFIG_USER_ONLY
 static TCGv compute_ldst_addr_ea(DisasContext *dc, int ra, int rb)
 {
     int addr_size = dc->cpu->cfg.addr_size;
@@ -754,6 +755,7 @@ static TCGv compute_ldst_addr_ea(DisasContext *dc, int ra, 
int rb)
     }
     return ret;
 }
+#endif
 
 static void record_unaligned_ess(DisasContext *dc, int rd,
                                  MemOp size, bool store)
@@ -818,8 +820,12 @@ static bool trans_lbuea(DisasContext *dc, arg_typea *arg)
     if (trap_userspace(dc, true)) {
         return true;
     }
+#ifdef CONFIG_USER_ONLY
+    return true;
+#else
     TCGv addr = compute_ldst_addr_ea(dc, arg->ra, arg->rb);
     return do_load(dc, arg->rd, addr, MO_UB, MMU_NOMMU_IDX, false);
+#endif
 }
 
 static bool trans_lbui(DisasContext *dc, arg_typeb *arg)
@@ -845,8 +851,12 @@ static bool trans_lhuea(DisasContext *dc, arg_typea *arg)
     if (trap_userspace(dc, true)) {
         return true;
     }
+#ifdef CONFIG_USER_ONLY
+    return true;
+#else
     TCGv addr = compute_ldst_addr_ea(dc, arg->ra, arg->rb);
     return do_load(dc, arg->rd, addr, MO_TEUW, MMU_NOMMU_IDX, false);
+#endif
 }
 
 static bool trans_lhui(DisasContext *dc, arg_typeb *arg)
@@ -872,8 +882,12 @@ static bool trans_lwea(DisasContext *dc, arg_typea *arg)
     if (trap_userspace(dc, true)) {
         return true;
     }
+#ifdef CONFIG_USER_ONLY
+    return true;
+#else
     TCGv addr = compute_ldst_addr_ea(dc, arg->ra, arg->rb);
     return do_load(dc, arg->rd, addr, MO_TEUL, MMU_NOMMU_IDX, false);
+#endif
 }
 
 static bool trans_lwi(DisasContext *dc, arg_typeb *arg)
@@ -952,8 +966,12 @@ static bool trans_sbea(DisasContext *dc, arg_typea *arg)
     if (trap_userspace(dc, true)) {
         return true;
     }
+#ifdef CONFIG_USER_ONLY
+    return true;
+#else
     TCGv addr = compute_ldst_addr_ea(dc, arg->ra, arg->rb);
     return do_store(dc, arg->rd, addr, MO_UB, MMU_NOMMU_IDX, false);
+#endif
 }
 
 static bool trans_sbi(DisasContext *dc, arg_typeb *arg)
@@ -979,8 +997,12 @@ static bool trans_shea(DisasContext *dc, arg_typea *arg)
     if (trap_userspace(dc, true)) {
         return true;
     }
+#ifdef CONFIG_USER_ONLY
+    return true;
+#else
     TCGv addr = compute_ldst_addr_ea(dc, arg->ra, arg->rb);
     return do_store(dc, arg->rd, addr, MO_TEUW, MMU_NOMMU_IDX, false);
+#endif
 }
 
 static bool trans_shi(DisasContext *dc, arg_typeb *arg)
@@ -1006,8 +1028,12 @@ static bool trans_swea(DisasContext *dc, arg_typea *arg)
     if (trap_userspace(dc, true)) {
         return true;
     }
+#ifdef CONFIG_USER_ONLY
+    return true;
+#else
     TCGv addr = compute_ldst_addr_ea(dc, arg->ra, arg->rb);
     return do_store(dc, arg->rd, addr, MO_TEUL, MMU_NOMMU_IDX, false);
+#endif
 }
 
 static bool trans_swi(DisasContext *dc, arg_typeb *arg)
@@ -1851,7 +1877,7 @@ void mb_cpu_dump_state(CPUState *cs, FILE *f, int flags)
     }
 
     qemu_fprintf(f, "\nesr=0x%04x fsr=0x%02x btr=0x%08x edr=0x%x\n"
-                 "ear=0x%016" PRIx64 " slr=0x%x shr=0x%x\n",
+                 "ear=0x" TARGET_FMT_lx " slr=0x%x shr=0x%x\n",
                  env->esr, env->fsr, env->btr, env->edr,
                  env->ear, env->slr, env->shr);
 
-- 
2.25.1