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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+
This commit is contained in:
Helge Deller 2018-01-02 20:36:44 +01:00
parent 28df2f83c3
commit 88776c0e70
3 changed files with 20 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/parisc/include/asm/ldcw.h
View File

@ -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"

13
arch/parisc/kernel/entry.S
View File

@ -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

9
arch/parisc/kernel/pacache.S
View File

@ -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 @@ ENDPROC_CFI(flush_data_cache_local)
.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