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>
This commit is contained in:
Stefan Hajnoczi 2024-01-02 10:35:25 -05:00
parent 897a06c6d7
commit 195801d700
95 changed files with 529 additions and 529 deletions

View file

@ -238,7 +238,7 @@ target_ulong helper_load_dpdes(CPUPPCState *env)
return dpdes;
}
qemu_mutex_lock_iothread();
bql_lock();
THREAD_SIBLING_FOREACH(cs, ccs) {
PowerPCCPU *ccpu = POWERPC_CPU(ccs);
CPUPPCState *cenv = &ccpu->env;
@ -248,7 +248,7 @@ target_ulong helper_load_dpdes(CPUPPCState *env)
dpdes |= (0x1 << thread_id);
}
}
qemu_mutex_unlock_iothread();
bql_unlock();
return dpdes;
}
@ -278,14 +278,14 @@ void helper_store_dpdes(CPUPPCState *env, target_ulong val)
}
/* Does iothread need to be locked for walking CPU list? */
qemu_mutex_lock_iothread();
bql_lock();
THREAD_SIBLING_FOREACH(cs, ccs) {
PowerPCCPU *ccpu = POWERPC_CPU(ccs);
uint32_t thread_id = ppc_cpu_tir(ccpu);
ppc_set_irq(cpu, PPC_INTERRUPT_DOORBELL, val & (0x1 << thread_id));
}
qemu_mutex_unlock_iothread();
bql_unlock();
}
#endif /* defined(TARGET_PPC64) */