linux-kernel - [PATCH 18/52] provide __smp_call

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon,  3 Mar 2008 14:12:46 -0300
From:	Glauber Costa <gcosta@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	akpm@...ux-foundation.org, glommer@...il.com, mingo@...e.hu,
	tglx@...utronix.de, Glauber Costa <gcosta@...hat.com>
Subject: [PATCH 18/52] provide __smp_call_function

This function is used in smp_send_stop(). It's like
smp_call_function_mask, but always go to all online cpus,
and does not take any locks.

It is added to x86_64, but will soon be unified in a common file

Signed-off-by: Glauber Costa <gcosta@...hat.com>
---
 arch/x86/kernel/smp_64.c |   34 +++++++++++++++++++++++++++++++++-
 1 files changed, 33 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/smp_64.c b/arch/x86/kernel/smp_64.c
index 1d8b863..aa2edb7 100644
--- a/arch/x86/kernel/smp_64.c
+++ b/arch/x86/kernel/smp_64.c
@@ -322,6 +322,38 @@ void unlock_ipi_call_lock(void)
 	spin_unlock_irq(&call_lock);
 }
 
+static void __smp_call_function(void (*func) (void *info), void *info,
+				int nonatomic, int wait)
+{
+	struct call_data_struct data;
+	int cpus = num_online_cpus() - 1;
+
+	if (!cpus)
+		return;
+
+	data.func = func;
+	data.info = info;
+	atomic_set(&data.started, 0);
+	data.wait = wait;
+	if (wait)
+		atomic_set(&data.finished, 0);
+
+	call_data = &data;
+	mb();
+
+	/* Send a message to all other CPUs and wait for them to respond */
+	send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+
+	/* Wait for response */
+	while (atomic_read(&data.started) != cpus)
+		cpu_relax();
+
+	if (wait)
+		while (atomic_read(&data.finished) != cpus)
+			cpu_relax();
+}
+
+
 /*
  * this function sends a 'generic call function' IPI to all other CPU
  * of the system defined in the mask.
@@ -424,7 +456,7 @@ void smp_send_stop(void)
 	/* Don't deadlock on the call lock in panic */
 	nolock = !spin_trylock(&call_lock);
 	local_irq_save(flags);
-	__smp_call_function_mask(cpu_online_map, stop_this_cpu, NULL, 0);
+	__smp_call_function(stop_this_cpu, NULL, 0, 0);
 	if (!nolock)
 		spin_unlock(&call_lock);
 	disable_local_APIC();
-- 
1.5.0.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/