From: Michael Neuling <mikey@neuling•org>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>,
Kumar Gala <galak@kernel•crashing.org>
Cc: linuxppc-dev@lists•ozlabs.org
Subject: [RFC/PATCH 4/7] powerpc: Change fast_exception_return to restore r0, r7. r8, and CTR
Date: Tue, 07 Dec 2010 10:40:47 +1100 [thread overview]
Message-ID: <20101206234050.385929597@neuling.org> (raw)
In-Reply-To: 20101206234043.083045003@neuling.org
Currently we don't restore r0, r7, r8 and CTR in
fast_exception_return. This changes fast_exception_return to restore
these, which were saved anyway on exception entry.
This seems like a bug waiting to happen, plus we do it in hash_page
for 32bit anyway.
Signed-off-by: Michael Neuling <mikey@neuling•org>
---
arch/powerpc/kernel/entry_32.S | 4 ++++
arch/powerpc/mm/hash_low_32.S | 7 -------
2 files changed, 4 insertions(+), 7 deletions(-)
Index: linux-lazy/arch/powerpc/kernel/entry_32.S
===================================================================
--- linux-lazy.orig/arch/powerpc/kernel/entry_32.S
+++ linux-lazy/arch/powerpc/kernel/entry_32.S
@@ -720,6 +720,10 @@
#endif
2: REST_4GPRS(3, r11)
+ REST_2GPRS(7, r11)
+ REST_GPR(0, r11)
+ lwz r10,_CTR(r11)
+ mtctr r10
lwz r10,_CCR(r11)
REST_GPR(1, r11)
mtcr r10
Index: linux-lazy/arch/powerpc/mm/hash_low_32.S
===================================================================
--- linux-lazy.orig/arch/powerpc/mm/hash_low_32.S
+++ linux-lazy/arch/powerpc/mm/hash_low_32.S
@@ -146,13 +146,6 @@
li r0,0
stw r0,mmu_hash_lock@l(r8)
#endif
-
- /* Return from the exception */
- lwz r5,_CTR(r11)
- mtctr r5
- lwz r0,GPR0(r11)
- lwz r7,GPR7(r11)
- lwz r8,GPR8(r11)
b fast_exception_return
#ifdef CONFIG_SMP
next prev parent reply other threads:[~2010-12-06 23:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-06 23:40 [RFC/PATCH 0/7] powerpc: Implement lazy save of FP, VMX and VSX state in SMP Michael Neuling
2010-12-06 23:40 ` [RFC/PATCH 1/7] Add csd_locked function Michael Neuling
2010-12-06 23:40 ` [RFC/PATCH 2/7] Rearrange include files to make struct call_single_data usable in more places Michael Neuling
2010-12-06 23:40 ` [RFC/PATCH 3/7] powerpc: Reorganise powerpc include files to make call_single_data Michael Neuling
2010-12-06 23:40 ` Michael Neuling [this message]
2010-12-06 23:40 ` [RFC/PATCH 5/7] powerpc: Enable lazy save VMX registers for SMP Michael Neuling
2010-12-06 23:40 ` [RFC/PATCH 6/7] powerpc: Enable lazy save FP " Michael Neuling
2010-12-06 23:40 ` [RFC/PATCH 7/7] powerpc: Enable lazy save VSX " Michael Neuling
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