[PATCH AUTOSEL 4.20 051/105] powerpc/8xx: fix setting of pagetable for Abatron BDI debug tool.

[Sasha Levin]

From: Christophe Leroy <christophe.leroy at c-s.fr>

[ Upstream commit fb0bdec51a4901b7dd088de0a1e365e1b9f5cd21 ]

Commit 8c8c10b90d88 ("powerpc/8xx: fix handling of early NULL pointer
dereference") moved the loading of r6 earlier in the code. As some
functions are called inbetween, r6 needs to be loaded again with the
address of swapper_pg_dir in order to set PTE pointers for
the Abatron BDI.

Fixes: 8c8c10b90d88 ("powerpc/8xx: fix handling of early NULL pointer dereference")
Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 arch/powerpc/kernel/head_8xx.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 3b67b9533c82..438512759e82 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -927,11 +927,12 @@ start_here:
 
 	/* set up the PTE pointers for the Abatron bdiGDB.
 	*/
-	tovirt(r6,r6)
 	lis	r5, abatron_pteptrs at h
 	ori	r5, r5, abatron_pteptrs at l
 	stw	r5, 0xf0(0)	/* Must match your Abatron config file */
 	tophys(r5,r5)
+	lis	r6, swapper_pg_dir at h
+	ori	r6, r6, swapper_pg_dir at l
 	stw	r6, 0(r5)
 
 /* Now turn on the MMU for real! */
-- 
2.19.1