linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Kumar Gala <galak@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH] powerpc/fsl-booke: Fixup 64-bite PTE reading for SMP support
Date: Wed, 16 Jul 2008 16:24:27 -0500 (CDT)	[thread overview]
Message-ID: <Pine.LNX.4.64.0807161624030.13167@blarg.am.freescale.net> (raw)

We need to create a false data dependency to ensure the loads of
the pte are done in the right order.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
 arch/powerpc/kernel/head_fsl_booke.S |   24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 3cb52fa..fa39cce 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -579,13 +579,19 @@ interrupt_base:

 	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
-	bne	2f			/* Bail if permission mismach */

 #ifdef CONFIG_PTE_64BIT
-	lwz	r13, 0(r12)
+#ifdef CONFIG_SMP
+	subf	r10, r11, r12		/* create false data dep */
+	lwzx	r13, r11, r10		/* Get upper pte bits */
+#else
+	lwz	r13, 0(r12)		/* Get upper pte bits */
 #endif
+#endif
+
+	bne	2f			/* Bail if permission/valid mismach */

-	 /* Jump to common tlb load */
+	/* Jump to common tlb load */
 	b	finish_tlb_load
 2:
 	/* The bailout.  Restore registers to pre-exception conditions
@@ -640,6 +646,16 @@ interrupt_base:

 	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
+
+#ifdef CONFIG_PTE_64BIT
+#ifdef CONFIG_SMP
+	subf	r10, r11, r12		/* create false data dep */
+	lwzx	r13, r11, r10		/* Get upper pte bits */
+#else
+	lwz	r13, 0(r12)		/* Get upper pte bits */
+#endif
+#endif
+
 	bne	2f			/* Bail if permission mismach */

 #ifdef CONFIG_PTE_64BIT
@@ -702,7 +718,7 @@ interrupt_base:
 /*
  * Both the instruction and data TLB miss get to this
  * point to load the TLB.
- *	r10 - EA of fault
+ *	r10 - available to use
  *	r11 - TLB (info from Linux PTE)
  *	r12 - available to use
  *	r13 - upper bits of PTE (if PTE_64BIT) or available to use
-- 
1.5.5.1

                 reply	other threads:[~2008-07-16 21:24 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=Pine.LNX.4.64.0807161624030.13167@blarg.am.freescale.net \
    --to=galak@kernel.crashing.org \
    --cc=linuxppc-dev@ozlabs.org \
    /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).