[PATCH 3.16 263/306] parisc: Also flush data TLB in flush_icache_page_asm

Ben Hutchings
2017-02-16T00:25:23Z

From: John David Anglin <dave.anglin@bell.net>

commit 5035b230e7b67ac12691ed3b5495bbb617027b68 upstream.

This is the second issue I noticed in reviewing the parisc TLB code.

The fic instruction may use either the instruction or data TLB in
flushing the instruction cache. Thus, on machines with a split TLB, we
should also flush the data TLB after setting up the temporary alias
registers.

Although this has no functional impact, I changed the pdtlb and pitlb
instructions to consistently use the index register %r0. These
instructions do not support integer displacements.

Tested on rp3440 and c8000.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/parisc/kernel/pacache.S | 37 ++++++++++++++++++++++---------------
1 file changed, 22 insertions(+), 15 deletions(-)

--- a/arch/parisc/kernel/pacache.S
+++ b/arch/parisc/kernel/pacache.S
@@ -96,7 +96,7 @@ fitmanyloop: /* Loop if LOOP >= 2 */

fitmanymiddle: /* Loop if LOOP >= 2 */
addib,COND(>) -1, %r31, fitmanymiddle /* Adjusted inner loop decr */
- pitlbe 0(%sr1, %r28)
+ pitlbe %r0(%sr1, %r28)
pitlbe,m %arg1(%sr1, %r28) /* Last pitlbe and addr adjust */
addib,COND(>) -1, %r29, fitmanymiddle /* Middle loop decr */
copy %arg3, %r31 /* Re-init inner loop count */
@@ -139,7 +139,7 @@ fdtmanyloop: /* Loop if LOOP >= 2 */

fdtmanymiddle: /* Loop if LOOP >= 2 */
addib,COND(>) -1, %r31, fdtmanymiddle /* Adjusted inner loop decr */
- pdtlbe 0(%sr1, %r28)
+ pdtlbe %r0(%sr1, %r28)
pdtlbe,m %arg1(%sr1, %r28) /* Last pdtlbe and addr adjust */
addib,COND(>) -1, %r29, fdtmanymiddle /* Middle loop decr */
copy %arg3, %r31 /* Re-init inner loop count */
@@ -620,12 +620,12 @@ ENTRY(copy_user_page_asm)
/* Purge any old translations */

#ifdef CONFIG_PA20
- pdtlb,l 0(%r28)
- pdtlb,l 0(%r29)
+ pdtlb,l %r0(%r28)
+ pdtlb,l %r0(%r29)
#else
tlb_lock %r20,%r21,%r22
- pdtlb 0(%r28)
- pdtlb 0(%r29)
+ pdtlb %r0(%r28)
+ pdtlb %r0(%r29)
tlb_unlock %r20,%r21,%r22
#endif

@@ -768,10 +768,10 @@ ENTRY(clear_user_page_asm)
/* Purge any old translation */

#ifdef CONFIG_PA20
- pdtlb,l 0(%r28)
+ pdtlb,l %r0(%r28)
#else
tlb_lock %r20,%r21,%r22
- pdtlb 0(%r28)
+ pdtlb %r0(%r28)
tlb_unlock %r20,%r21,%r22
#endif

@@ -852,10 +852,10 @@ ENTRY(flush_dcache_page_asm)
/* Purge any old translation */

#ifdef CONFIG_PA20
- pdtlb,l 0(%r28)
+ pdtlb,l %r0(%r28)
#else
tlb_lock %r20,%r21,%r22
- pdtlb 0(%r28)
+ pdtlb %r0(%r28)
tlb_unlock %r20,%r21,%r22
#endif

@@ -892,10 +892,10 @@ ENTRY(flush_dcache_page_asm)
sync

#ifdef CONFIG_PA20
- pdtlb,l 0(%r25)
+ pdtlb,l %r0(%r25)
#else
tlb_lock %r20,%r21,%r22
- pdtlb 0(%r25)
+ pdtlb %r0(%r25)
tlb_unlock %r20,%r21,%r22
#endif

@@ -925,13 +925,18 @@ ENTRY(flush_icache_page_asm)
depwi 0, 31,PAGE_SHIFT, %r28 /* Clear any offset bits */
#endif

- /* Purge any old translation */
+ /* Purge any old translation. Note that the FIC instruction
+ * may use either the instruction or data TLB. Given that we
+ * have a flat address space, it's not clear which TLB will be
+ * used. So, we purge both entries. */

#ifdef CONFIG_PA20
+ pdtlb,l %r0(%r28)
pitlb,l %r0(%sr4,%r28)
#else
tlb_lock %r20,%r21,%r22
- pitlb (%sr4,%r28)
+ pdtlb %r0(%r28)
+ pitlb %r0(%sr4,%r28)
tlb_unlock %r20,%r21,%r22
#endif

@@ -970,10 +975,12 @@ ENTRY(flush_icache_page_asm)
sync

#ifdef CONFIG_PA20
+ pdtlb,l %r0(%r28)
pitlb,l %r0(%sr4,%r25)
#else
tlb_lock %r20,%r21,%r22
- pitlb (%sr4,%r25)
+ pdtlb %r0(%r28)
+ pitlb %r0(%sr4,%r25)
tlb_unlock %r20,%r21,%r22
#endif