From: Laurentiu Tudor laurentiu.tudor@nxp.com
[ Upstream commit aa4113340ae6c2811e046f08c2bc21011d20a072 ]
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: Sasha Levin sashal@kernel.org --- arch/powerpc/mm/tlb_nohash_low.S | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/tlb_nohash_low.S b/arch/powerpc/mm/tlb_nohash_low.S index e066a658acac6..56f58a362ea56 100644 --- a/arch/powerpc/mm/tlb_nohash_low.S +++ b/arch/powerpc/mm/tlb_nohash_low.S @@ -402,7 +402,7 @@ _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 @@ -438,6 +438,10 @@ 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 @@ -463,6 +467,7 @@ _GLOBAL(loadcam_multi) mtmsr r6 isync
+10: mr r9,r3 add r10,r3,r4 2: bl loadcam_entry @@ -471,6 +476,10 @@ _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) @@ -486,6 +495,7 @@ _GLOBAL(loadcam_multi) tlbwe isync
+3: mtlr r8 blr #endif