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From: Hari Bathini <hbathini@linux.vnet.ibm.com>
To: linuxppc-dev <linuxppc-dev@ozlabs.org>
Cc: Michael Neuling <mikey@neuling.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
	Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: [PATCH v4 3/3] ppc64/book3s: remove __end_handlers marker
Date: Fri, 08 Apr 2016 03:30:34 +0530	[thread overview]
Message-ID: <20160407215914.8404.10459.stgit@hbathini.in.ibm.com> (raw)
In-Reply-To: <20160407215541.8404.15022.stgit@hbathini.in.ibm.com>

__end_handlers marker was intended to mark down upto code that gets
called from exception prologs. But that hasn't kept pace with code
changes. Case in point, slb_miss_realmode being called from exception
prolog code but isn't below __end_handlers marker. So, __end_handlers
marker is as good as a comment but could be misleading at times if
it isn't in sync with the code, as is the case now. So, let us avoid
this confusion by having a better comment and removing __end_handlers
marker altogether.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/exceptions-64s.S |   13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index c193ebd..80f9fc4 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -764,11 +764,10 @@ kvmppc_skip_Hinterrupt:
 #endif
 
 /*
- * Code from here down to __end_handlers is invoked from the
- * exception prologs above.  Because the prologs assemble the
- * addresses of these handlers using the LOAD_HANDLER macro,
- * which uses an ori instruction, these handlers must be in
- * the first 64k of the kernel image.
+ * Ensure that any handlers that get invoked from the exception prologs
+ * above are below the first 64KB (0x10000) of the kernel image because
+ * the prologs assemble the addresses of these handlers using the
+ * LOAD_HANDLER macro, which uses an ori instruction.
  */
 
 /*** Common interrupt handlers ***/
@@ -1243,10 +1242,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	bl	vsx_unavailable_exception
 	b	ret_from_except
 
-	.align	7
-	.globl	__end_handlers
-__end_handlers:
-
 #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
 /*
  * Data area reserved for FWNMI option.

  parent reply	other threads:[~2016-04-07 22:01 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-07 21:57 [PATCH v4 1/3] ppc64/book3s: fix branching to out of line handlers in relocation kernel Hari Bathini
2016-04-07 21:58 ` [PATCH v4 2/3] ppc64/book3s: make some room for common interrupt vector code Hari Bathini
2016-04-15 11:06   ` [v4, " Michael Ellerman
2016-04-15 12:59     ` Michael Ellerman
2016-04-18  3:44       ` Hari Bathini
2016-04-07 22:00 ` Hari Bathini [this message]
2016-04-21 13:39   ` [v4,3/3] ppc64/book3s: remove __end_handlers marker Michael Ellerman

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