linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@lists.ozlabs.org
Cc: Scott Wood <scottwood@freescale.com>,
	Mihai Caraman <mihai.caraman@freescale.com>,
	kvm-ppc@vger.kernel.org, Tiejun Chen <tiejun.chen@windriver.com>
Subject: [PATCH] powerpc: Make hard_irq_disable() do the right thing vs. irq tracing
Date: Tue, 07 May 2013 17:04:02 +1000	[thread overview]
Message-ID: <1367910242.5769.11.camel@pasglop> (raw)

If hard_irq_disable() is called while interrupts are already soft-disabled
(which is the most common case) all is already well.

However you can (and in some cases want) to call it while everything is
enabled (to make sure you don't get a lazy even, for example before entry
into KVM guests) and in this case we need to inform the irq tracer that
the irqs are going off.

We have to change the inline into a macro to avoid an include circular
dependency hell hole.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

Tested on pseries, Scott, I don't expect a problem with that patch especially
since most callers already are soft disabled, so I'll merge it now along with
my other pending stuff and you can simplify your KVM one.

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index e45c494..d615b28 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -95,15 +95,13 @@ static inline bool arch_irqs_disabled(void)
 #define __hard_irq_disable()	__mtmsrd(local_paca->kernel_msr, 1)
 #endif
 
-static inline void hard_irq_disable(void)
-{
-	__hard_irq_disable();
-	get_paca()->soft_enabled = 0;
-	get_paca()->irq_happened |= PACA_IRQ_HARD_DIS;
-}
-
-/* include/linux/interrupt.h needs hard_irq_disable to be a macro */
-#define hard_irq_disable	hard_irq_disable
+#define hard_irq_disable()	do {			\
+	__hard_irq_disable();				\
+	if (local_paca->soft_enabled)			\
+		trace_hardirqs_off();			\
+	get_paca()->soft_enabled = 0;			\
+	get_paca()->irq_happened |= PACA_IRQ_HARD_DIS;	\
+} while(0)
 
 static inline bool lazy_irq_pending(void)
 {

             reply	other threads:[~2013-05-07  7:04 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-07  7:04 Benjamin Herrenschmidt [this message]
2013-05-07  7:15 ` [PATCH] powerpc: Make hard_irq_disable() do the right thing vs. irq tracing tiejun.chen
2013-05-07  7:25   ` Benjamin Herrenschmidt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1367910242.5769.11.camel@pasglop \
    --to=benh@kernel.crashing.org \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mihai.caraman@freescale.com \
    --cc=scottwood@freescale.com \
    --cc=tiejun.chen@windriver.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).