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

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"