system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()

The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().

The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.

The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)

There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Acked-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/target/openrisc/sys_helper.c b/target/openrisc/sys_helper.c
index 782a575..77567af 100644
--- a/target/openrisc/sys_helper.c
+++ b/target/openrisc/sys_helper.c
@@ -160,20 +160,20 @@ void HELPER(mtspr)(CPUOpenRISCState *env, target_ulong spr, target_ulong rb)
         break;
     case TO_SPR(9, 0):  /* PICMR */
         env->picmr = rb;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         if (env->picsr & env->picmr) {
             cpu_interrupt(cs, CPU_INTERRUPT_HARD);
         } else {
             cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     case TO_SPR(9, 2):  /* PICSR */
         env->picsr &= ~rb;
         break;
     case TO_SPR(10, 0): /* TTMR */
         {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             if ((env->ttmr & TTMR_M) ^ (rb & TTMR_M)) {
                 switch (rb & TTMR_M) {
                 case TIMER_NONE:
@@ -198,15 +198,15 @@ void HELPER(mtspr)(CPUOpenRISCState *env, target_ulong spr, target_ulong rb)
                 cs->interrupt_request &= ~CPU_INTERRUPT_TIMER;
             }
             cpu_openrisc_timer_update(cpu);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
         break;
 
     case TO_SPR(10, 1): /* TTCR */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_openrisc_count_set(cpu, rb);
         cpu_openrisc_timer_update(cpu);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     }
 #endif
@@ -347,9 +347,9 @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env, target_ulong rd,
         return env->ttmr;
 
     case TO_SPR(10, 1): /* TTCR */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_openrisc_count_update(cpu);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return cpu_openrisc_count_get(cpu);
     }
 #endif