1. Patchew
  2. QEMU
  3. [Qemu-devel] [PATCH 0/7] target-mips: support MTTCG feature
  4. View patch

[Qemu-devel] [PATCH 3/7] Revert "target/mips: hold BQL for timer interrupts"

Aleksandar Markovic posted 7 patches 8 years ago
There is a newer version of this series
[Qemu-devel] [PATCH 3/7] Revert "target/mips: hold BQL for timer interrupts"
Posted by Aleksandar Markovic 8 years ago 
From: Aleksandar Markovic <aleksandar.markovic@mips.com>

This reverts commit d394698d73836d1c50545bdb32dc58d09708fcfb.

Ther revert is needed in order not to cause overlap with subsequent
patches related to handling synchronization of interrupt code paths.

Signed-off-by: Miodrag Dinic <miodrag.dinic@mips.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
---
 target/mips/op_helper.c | 21 +++------------------
 1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
index a429987..3830ee8 100644
--- a/target/mips/op_helper.c
+++ b/target/mips/op_helper.c
@@ -17,7 +17,6 @@
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "qemu/osdep.h"
-#include "qemu/main-loop.h"
 #include "cpu.h"
 #include "internal.h"
 #include "qemu/host-utils.h"
@@ -809,11 +808,7 @@ target_ulong helper_mftc0_tcschefback(CPUMIPSState *env)
 
 target_ulong helper_mfc0_count(CPUMIPSState *env)
 {
-    int32_t count;
-    qemu_mutex_lock_iothread();
-    count = (int32_t) cpu_mips_get_count(env);
-    qemu_mutex_unlock_iothread();
-    return count;
+    return (int32_t)cpu_mips_get_count(env);
 }
 
 target_ulong helper_mftc0_entryhi(CPUMIPSState *env)
@@ -1388,9 +1383,7 @@ void helper_mtc0_hwrena(CPUMIPSState *env, target_ulong arg1)
 
 void helper_mtc0_count(CPUMIPSState *env, target_ulong arg1)
 {
-    qemu_mutex_lock_iothread();
     cpu_mips_store_count(env, arg1);
-    qemu_mutex_unlock_iothread();
 }
 
 void helper_mtc0_entryhi(CPUMIPSState *env, target_ulong arg1)
@@ -1439,9 +1432,7 @@ void helper_mttc0_entryhi(CPUMIPSState *env, target_ulong arg1)
 
 void helper_mtc0_compare(CPUMIPSState *env, target_ulong arg1)
 {
-    qemu_mutex_lock_iothread();
     cpu_mips_store_compare(env, arg1);
-    qemu_mutex_unlock_iothread();
 }
 
 void helper_mtc0_status(CPUMIPSState *env, target_ulong arg1)
@@ -1495,9 +1486,7 @@ void helper_mtc0_srsctl(CPUMIPSState *env, target_ulong arg1)
 
 void helper_mtc0_cause(CPUMIPSState *env, target_ulong arg1)
 {
-    qemu_mutex_lock_iothread();
     cpu_mips_store_cause(env, arg1);
-    qemu_mutex_unlock_iothread();
 }
 
 void helper_mttc0_cause(CPUMIPSState *env, target_ulong arg1)
@@ -2339,16 +2328,12 @@ target_ulong helper_rdhwr_synci_step(CPUMIPSState *env)
 
 target_ulong helper_rdhwr_cc(CPUMIPSState *env)
 {
-    int32_t count;
     check_hwrena(env, 2, GETPC());
 #ifdef CONFIG_USER_ONLY
-    count = env->CP0_Count;
+    return env->CP0_Count;
 #else
-    qemu_mutex_lock_iothread();
-    count = (int32_t)cpu_mips_get_count(env);
-    qemu_mutex_unlock_iothread();
+    return (int32_t)cpu_mips_get_count(env);
 #endif
-    return count;
 }
 
 target_ulong helper_rdhwr_ccres(CPUMIPSState *env)
-- 
2.7.4
Re: [Qemu-devel] [PATCH 3/7] Revert "target/mips: hold BQL for timer interrupts"
Posted by Alex Bennée 8 years ago 
Aleksandar Markovic <aleksandar.markovic@rt-rk.com> writes:

> From: Aleksandar Markovic <aleksandar.markovic@mips.com>
>
> This reverts commit d394698d73836d1c50545bdb32dc58d09708fcfb.
>
> Ther revert is needed in order not to cause overlap with subsequent
> patches related to handling synchronization of interrupt code paths.

Hmm I'm fairly sure you should merge this with the follow-up patch to
add BQL locking to the appropriate place. Otherwise you break
bi-section.

>
> Signed-off-by: Miodrag Dinic <miodrag.dinic@mips.com>
> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
> ---
>  target/mips/op_helper.c | 21 +++------------------
>  1 file changed, 3 insertions(+), 18 deletions(-)
>
> diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
> index a429987..3830ee8 100644
> --- a/target/mips/op_helper.c
> +++ b/target/mips/op_helper.c
> @@ -17,7 +17,6 @@
>   * License along with this library; if not, see <http://www.gnu.org/licenses/>.
>   */
>  #include "qemu/osdep.h"
> -#include "qemu/main-loop.h"
>  #include "cpu.h"
>  #include "internal.h"
>  #include "qemu/host-utils.h"
> @@ -809,11 +808,7 @@ target_ulong helper_mftc0_tcschefback(CPUMIPSState *env)
>
>  target_ulong helper_mfc0_count(CPUMIPSState *env)
>  {
> -    int32_t count;
> -    qemu_mutex_lock_iothread();
> -    count = (int32_t) cpu_mips_get_count(env);
> -    qemu_mutex_unlock_iothread();
> -    return count;
> +    return (int32_t)cpu_mips_get_count(env);
>  }
>
>  target_ulong helper_mftc0_entryhi(CPUMIPSState *env)
> @@ -1388,9 +1383,7 @@ void helper_mtc0_hwrena(CPUMIPSState *env, target_ulong arg1)
>
>  void helper_mtc0_count(CPUMIPSState *env, target_ulong arg1)
>  {
> -    qemu_mutex_lock_iothread();
>      cpu_mips_store_count(env, arg1);
> -    qemu_mutex_unlock_iothread();
>  }
>
>  void helper_mtc0_entryhi(CPUMIPSState *env, target_ulong arg1)
> @@ -1439,9 +1432,7 @@ void helper_mttc0_entryhi(CPUMIPSState *env, target_ulong arg1)
>
>  void helper_mtc0_compare(CPUMIPSState *env, target_ulong arg1)
>  {
> -    qemu_mutex_lock_iothread();
>      cpu_mips_store_compare(env, arg1);
> -    qemu_mutex_unlock_iothread();
>  }
>
>  void helper_mtc0_status(CPUMIPSState *env, target_ulong arg1)
> @@ -1495,9 +1486,7 @@ void helper_mtc0_srsctl(CPUMIPSState *env, target_ulong arg1)
>
>  void helper_mtc0_cause(CPUMIPSState *env, target_ulong arg1)
>  {
> -    qemu_mutex_lock_iothread();
>      cpu_mips_store_cause(env, arg1);
> -    qemu_mutex_unlock_iothread();
>  }
>
>  void helper_mttc0_cause(CPUMIPSState *env, target_ulong arg1)
> @@ -2339,16 +2328,12 @@ target_ulong helper_rdhwr_synci_step(CPUMIPSState *env)
>
>  target_ulong helper_rdhwr_cc(CPUMIPSState *env)
>  {
> -    int32_t count;
>      check_hwrena(env, 2, GETPC());
>  #ifdef CONFIG_USER_ONLY
> -    count = env->CP0_Count;
> +    return env->CP0_Count;
>  #else
> -    qemu_mutex_lock_iothread();
> -    count = (int32_t)cpu_mips_get_count(env);
> -    qemu_mutex_unlock_iothread();
> +    return (int32_t)cpu_mips_get_count(env);
>  #endif
> -    return count;
>  }
>
>  target_ulong helper_rdhwr_ccres(CPUMIPSState *env)


--
Alex Bennée
Re: [Qemu-devel] [PATCH 3/7] Revert "target/mips: hold BQL for timer interrupts"
Posted by Aleksandar Markovic 8 years ago 
> From: Alex Bennée [alex.bennee@linaro.org]
> 
> > From: Aleksandar Markovic <aleksandar.markovic@mips.com>
> >
> > This reverts commit d394698d73836d1c50545bdb32dc58d09708fcfb.
> >
> > Ther revert is needed in order not to cause overlap with subsequent
> > patches related to handling synchronization of interrupt code paths.
> 
> Hmm I'm fairly sure you should merge this with the follow-up patch to
> add BQL locking to the appropriate place. Otherwise you break
> bi-section.

Thanks for the review, Alex!

You are right, the bisect would have been broken. I am going to merge this and
subsequent patch in v2.

I am going to address all your other concerns in v2 as well.

Regards,
Aleksandar

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.