[PATCH v5 03/11] target/riscv: Disable the MMU correctly

Alistair Francis posted 11 patches 5 years, 8 months ago
Maintainers: Palmer Dabbelt <palmer@dabbelt.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Alistair Francis <Alistair.Francis@wdc.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Sagar Karandikar <sagark@eecs.berkeley.edu>
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[PATCH v5 03/11] target/riscv: Disable the MMU correctly
Posted by Alistair Francis 5 years, 8 months ago
Previously if we didn't enable the MMU it would be enabled in the
realize() function anyway. Let's ensure that if we don't want the MMU we
disable it. We also don't need to enable the MMU as it will be enalbed
in realize() by default.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 5eb3c02735..8deba3d16d 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -142,7 +142,6 @@ static void rv32gcsu_priv1_09_1_cpu_init(Object *obj)
     set_misa(env, RV32 | RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
     set_priv_version(env, PRIV_VERSION_1_09_1);
     set_resetvec(env, DEFAULT_RSTVEC);
-    set_feature(env, RISCV_FEATURE_MMU);
     set_feature(env, RISCV_FEATURE_PMP);
 }
 
@@ -152,7 +151,6 @@ static void rv32gcsu_priv1_10_0_cpu_init(Object *obj)
     set_misa(env, RV32 | RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
     set_priv_version(env, PRIV_VERSION_1_10_0);
     set_resetvec(env, DEFAULT_RSTVEC);
-    set_feature(env, RISCV_FEATURE_MMU);
     set_feature(env, RISCV_FEATURE_PMP);
 }
 
@@ -163,6 +161,7 @@ static void rv32imacu_nommu_cpu_init(Object *obj)
     set_priv_version(env, PRIV_VERSION_1_10_0);
     set_resetvec(env, DEFAULT_RSTVEC);
     set_feature(env, RISCV_FEATURE_PMP);
+    qdev_prop_set_bit(DEVICE(obj), "mmu", false);
 }
 
 static void rv32imafcu_nommu_cpu_init(Object *obj)
@@ -172,6 +171,7 @@ static void rv32imafcu_nommu_cpu_init(Object *obj)
     set_priv_version(env, PRIV_VERSION_1_10_0);
     set_resetvec(env, DEFAULT_RSTVEC);
     set_feature(env, RISCV_FEATURE_PMP);
+    qdev_prop_set_bit(DEVICE(obj), "mmu", false);
 }
 
 #elif defined(TARGET_RISCV64)
@@ -190,7 +190,6 @@ static void rv64gcsu_priv1_09_1_cpu_init(Object *obj)
     set_misa(env, RV64 | RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
     set_priv_version(env, PRIV_VERSION_1_09_1);
     set_resetvec(env, DEFAULT_RSTVEC);
-    set_feature(env, RISCV_FEATURE_MMU);
     set_feature(env, RISCV_FEATURE_PMP);
 }
 
@@ -200,7 +199,6 @@ static void rv64gcsu_priv1_10_0_cpu_init(Object *obj)
     set_misa(env, RV64 | RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
     set_priv_version(env, PRIV_VERSION_1_10_0);
     set_resetvec(env, DEFAULT_RSTVEC);
-    set_feature(env, RISCV_FEATURE_MMU);
     set_feature(env, RISCV_FEATURE_PMP);
 }
 
@@ -211,6 +209,7 @@ static void rv64imacu_nommu_cpu_init(Object *obj)
     set_priv_version(env, PRIV_VERSION_1_10_0);
     set_resetvec(env, DEFAULT_RSTVEC);
     set_feature(env, RISCV_FEATURE_PMP);
+    qdev_prop_set_bit(DEVICE(obj), "mmu", false);
 }
 
 #endif
-- 
2.26.2


Re: [PATCH v5 03/11] target/riscv: Disable the MMU correctly
Posted by Bin Meng 5 years, 8 months ago
On Fri, May 29, 2020 at 6:22 AM Alistair Francis
<alistair.francis@wdc.com> wrote:
>
> Previously if we didn't enable the MMU it would be enabled in the
> realize() function anyway. Let's ensure that if we don't want the MMU we
> disable it. We also don't need to enable the MMU as it will be enalbed

typo: enabled

> in realize() by default.
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>

Reviewed-by: Bin Meng <bin.meng@windriver.com>