parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures
about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9."
Those opcodes evaluate to the ldcw() assembly instruction which requires
(on 32bit) an alignment of 16 bytes to ensure atomicity.
As it turns out, qemu is correct and in our assembly code in entry.S and
pacache.S we don't pay attention to the required alignment.
This patch fixes the problem by aligning the lock offset in assembly
code in the same manner as we do in our C-code.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.0+
diff --git a/arch/parisc/include/asm/ldcw.h b/arch/parisc/include/asm/ldcw.h
index dd5a08a..3eb4bfc 100644
--- a/arch/parisc/include/asm/ldcw.h
+++ b/arch/parisc/include/asm/ldcw.h
@@ -12,6 +12,7 @@
for the semaphore. */
#define __PA_LDCW_ALIGNMENT 16
+#define __PA_LDCW_ALIGN_ORDER 4
#define __ldcw_align(a) ({ \
unsigned long __ret = (unsigned long) &(a)->lock[0]; \
__ret = (__ret + __PA_LDCW_ALIGNMENT - 1) \
@@ -29,6 +30,7 @@
ldcd). */
#define __PA_LDCW_ALIGNMENT 4
+#define __PA_LDCW_ALIGN_ORDER 2
#define __ldcw_align(a) (&(a)->slock)
#define __LDCW "ldcw,co"
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index f3cecf5..e95207c 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -35,6 +35,7 @@
#include <asm/pgtable.h>
#include <asm/signal.h>
#include <asm/unistd.h>
+#include <asm/ldcw.h>
#include <asm/thread_info.h>
#include <linux/linkage.h>
@@ -46,6 +47,14 @@
#endif
.import pa_tlb_lock,data
+ .macro load_pa_tlb_lock reg
+#if __PA_LDCW_ALIGNMENT > 4
+ load32 PA(pa_tlb_lock) + __PA_LDCW_ALIGNMENT-1, \reg
+ depi 0,31,__PA_LDCW_ALIGN_ORDER, \reg
+#else
+ load32 PA(pa_tlb_lock), \reg
+#endif
+ .endm
/* space_to_prot macro creates a prot id from a space id */
@@ -457,7 +466,7 @@
.macro tlb_lock spc,ptp,pte,tmp,tmp1,fault
#ifdef CONFIG_SMP
cmpib,COND(=),n 0,\spc,2f
- load32 PA(pa_tlb_lock),\tmp
+ load_pa_tlb_lock \tmp
1: LDCW 0(\tmp),\tmp1
cmpib,COND(=) 0,\tmp1,1b
nop
@@ -480,7 +489,7 @@
/* Release pa_tlb_lock lock. */
.macro tlb_unlock1 spc,tmp
#ifdef CONFIG_SMP
- load32 PA(pa_tlb_lock),\tmp
+ load_pa_tlb_lock \tmp
tlb_unlock0 \spc,\tmp
#endif
.endm
diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S
index adf7187..2d40c4f 100644
--- a/arch/parisc/kernel/pacache.S
+++ b/arch/parisc/kernel/pacache.S
@@ -36,6 +36,7 @@
#include <asm/assembly.h>
#include <asm/pgtable.h>
#include <asm/cache.h>
+#include <asm/ldcw.h>
#include <linux/linkage.h>
.text
@@ -333,8 +334,12 @@
.macro tlb_lock la,flags,tmp
#ifdef CONFIG_SMP
- ldil L%pa_tlb_lock,%r1
- ldo R%pa_tlb_lock(%r1),\la
+#if __PA_LDCW_ALIGNMENT > 4
+ load32 pa_tlb_lock + __PA_LDCW_ALIGNMENT-1, \la
+ depi 0,31,__PA_LDCW_ALIGN_ORDER, \la
+#else
+ load32 pa_tlb_lock, \la
+#endif
rsm PSW_SM_I,\flags
1: LDCW 0(\la),\tmp
cmpib,<>,n 0,\tmp,3f