xtensa: fix boot parameters address translation

BugLink: https://bugs.launchpad.net/bugs/1810947

commit 40dc948f 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@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

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
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