xtensa: fix boot parameters address translation

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@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 23ce62e604359d01fe8be9f41df9d1914ae90796..27c8e07ace43fcd0756eca17f2648dec7940d293 100644 (file)
--- 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
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