[PATCH 4.19 078/205] xtensa: fix boot parameters address translation

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Max Filippov <jcmvbkbc@xxxxxxxxx>

commit 40dc948f234b73497c3278875eb08a01d5854d3f upstream.

The bootloader may pass physical address of the boot parameters structure
to the MMUv3 kernel in the register a2. Code in the _SetupMMU block in
the arch/xtensa/kernel/head.S is supposed to map that physical address to
the virtual address in the configured virtual memory layout.

This code haven't been updated when additional 256+256 and 512+512
memory layouts were introduced and it may produce wrong addresses when
used with these layouts.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/xtensa/kernel/head.S |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -88,9 +88,12 @@ _SetupMMU:
 	initialize_mmu
 #if defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
 	rsr	a2, excsave1
-	movi	a3, 0x08000000
+	movi	a3, XCHAL_KSEG_PADDR
+	bltu	a2, a3, 1f
+	sub	a2, a2, a3
+	movi	a3, XCHAL_KSEG_SIZE
 	bgeu	a2, a3, 1f
-	movi	a3, 0xd0000000
+	movi	a3, XCHAL_KSEG_CACHED_VADDR
 	add	a2, a2, a3
 	wsr	a2, excsave1
 1: