From: Milton Miller <miltonm@bga.com>
To: linuxppc-dev@ozlabs.org,
Ben Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>
Subject: [PATCH 12/16] powerpc: reduce and comment xics ipi memory barrier
Date: Fri, 10 Oct 2008 06:56:44 -0500 (CDT) [thread overview]
Message-ID: <patch-xics-12@bga.com> (raw)
In-Reply-To: <patch-xics-0@bga.com>
A single full sync (mb()) is requrired to order the mmio to the qirr reg
with the set or clear of the message word. However, test_and_clear_bit
has the effect of smp_mb() and we are not doing any other io from here,
so we don't need a mb per bit processed.
Signed-off-by: Milton Miller <miltonm@bga.com>
Index: next.git/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- next.git.orig/arch/powerpc/platforms/pseries/xics.c 2008-10-04 23:56:15.000000000 -0500
+++ next.git/arch/powerpc/platforms/pseries/xics.c 2008-10-05 00:01:26.000000000 -0500
@@ -498,26 +498,23 @@ static irqreturn_t xics_ipi_dispatch(int
{
WARN_ON(cpu_is_offline(cpu));
+ mb(); /* order mmio clearing qirr */
while (xics_ipi_message[cpu].value) {
if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION,
&xics_ipi_message[cpu].value)) {
- mb();
smp_message_recv(PPC_MSG_CALL_FUNCTION);
}
if (test_and_clear_bit(PPC_MSG_RESCHEDULE,
&xics_ipi_message[cpu].value)) {
- mb();
smp_message_recv(PPC_MSG_RESCHEDULE);
}
if (test_and_clear_bit(PPC_MSG_CALL_FUNC_SINGLE,
&xics_ipi_message[cpu].value)) {
- mb();
smp_message_recv(PPC_MSG_CALL_FUNC_SINGLE);
}
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
&xics_ipi_message[cpu].value)) {
- mb();
smp_message_recv(PPC_MSG_DEBUGGER_BREAK);
}
#endif
next prev parent reply other threads:[~2008-10-10 11:56 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-10 11:56 [PATCH 00/16] xics and ipi cleanups for 2.6.28 Milton Miller
2008-10-10 11:56 ` [PATCH 1/16] powerpc pseries: eoi unmapped xics irqs after disable Milton Miller
2008-10-10 11:56 ` [PATCH 2/16] xics: update default_server during migrate_irqs_away Milton Miller
2008-10-13 20:04 ` Nathan Fontenot
2008-10-10 11:56 ` [PATCH 3/16] xics: consolidate ipi message encode and decode Milton Miller
2008-10-10 11:56 ` [PATCH 4/16] xics: rearrange file to group code by function Milton Miller
2008-10-10 11:56 ` [PATCH 5/16] xics: change arg type to remove casts Milton Miller
2008-10-10 11:56 ` [PATCH 6/16] xics: trim includes Milton Miller
2008-10-10 11:56 ` [PATCH 7/16] xics: initialization cleanups Milton Miller
2008-10-13 0:55 ` Benjamin Herrenschmidt
2008-10-10 11:56 ` [PATCH 8/16] xics: factor out giq set and unset Milton Miller
2008-10-10 11:56 ` [PATCH 9/16] powerpc: eoi xics ipi by hand in kexec Milton Miller
2008-10-10 11:56 ` [PATCH 10/16] xics: make printk formats fit on one line Milton Miller
2008-10-10 11:56 ` [PATCH 11/16] powerpc: mark xics ipi percpu Milton Miller
2008-10-10 11:56 ` Milton Miller [this message]
2008-10-10 11:56 ` [PATCH 13/16] powerpc smp: no need to set_need_resched in resched ipi Milton Miller
2008-10-10 11:56 ` [PATCH 14/16] powerpc: expand vs demux ipi actions per message Milton Miller
2008-10-10 11:56 ` [PATCH 15/16] powerpc cell: use smp_request_message_ipi Milton Miller
2008-10-10 11:56 ` [PATCH 14/16] powerpc mpic: " Milton Miller
2008-10-10 11:56 ` [PATCH 16/16] powerpc ps3: " Milton Miller
2008-10-10 12:55 ` [PATCH 14/16] powerpc: expand vs demux ipi actions per message Geert Uytterhoeven
2008-10-21 1:37 ` [PATCH 14/16 v2] " Milton Miller
2008-11-06 4:42 ` Paul Mackerras
2008-11-11 16:12 ` Milton Miller
2008-10-13 5:28 ` [PATCH 00/16] xics and ipi cleanups for 2.6.28 Benjamin Herrenschmidt
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