blob: bd93ac0eaf74a53a5c5bd84ee099d52efaf68c91 [file] [log] [blame]
From b71e843413947d8db7ba489e3143a9100672239a Mon Sep 17 00:00:00 2001
From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Date: Thu, 23 Jan 2020 11:19:25 +0000
Subject: [PATCH] powerpc/fsl_booke: Avoid creating duplicate tlb1 entry
commit aa4113340ae6c2811e046f08c2bc21011d20a072 upstream.
In the current implementation, the call to loadcam_multi() is wrapped
between switch_to_as1() and restore_to_as0() calls so, when it tries
to create its own temporary AS=1 TLB1 entry, it ends up duplicating
the existing one created by switch_to_as1(). Add a check to skip
creating the temporary entry if already running in AS=1.
Fixes: d9e1831a4202 ("powerpc/85xx: Load all early TLB entries at once")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200123111914.2565-1-laurentiu.tudor@nxp.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S
index 2ca407cedbe7..eaeee402f96e 100644
--- a/arch/powerpc/mm/nohash/tlb_low.S
+++ b/arch/powerpc/mm/nohash/tlb_low.S
@@ -397,7 +397,7 @@ _GLOBAL(set_context)
* extern void loadcam_entry(unsigned int index)
*
* Load TLBCAM[index] entry in to the L2 CAM MMU
- * Must preserve r7, r8, r9, and r10
+ * Must preserve r7, r8, r9, r10 and r11
*/
_GLOBAL(loadcam_entry)
mflr r5
@@ -433,6 +433,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_BIG_PHYS)
*/
_GLOBAL(loadcam_multi)
mflr r8
+ /* Don't switch to AS=1 if already there */
+ mfmsr r11
+ andi. r11,r11,MSR_IS
+ bne 10f
/*
* Set up temporary TLB entry that is the same as what we're
@@ -458,6 +462,7 @@ _GLOBAL(loadcam_multi)
mtmsr r6
isync
+10:
mr r9,r3
add r10,r3,r4
2: bl loadcam_entry
@@ -466,6 +471,10 @@ _GLOBAL(loadcam_multi)
mr r3,r9
blt 2b
+ /* Don't return to AS=0 if we were in AS=1 at function start */
+ andi. r11,r11,MSR_IS
+ bne 3f
+
/* Return to AS=0 and clear the temporary entry */
mfmsr r6
rlwinm. r6,r6,0,~(MSR_IS|MSR_DS)
@@ -481,6 +490,7 @@ _GLOBAL(loadcam_multi)
tlbwe
isync
+3:
mtlr r8
blr
#endif
--
2.7.4