[PATCH 4.18 061/171] xtensa: fix boot parameters address translation
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2018-11-19 16:41:56
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4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Max Filippov <jcmvbkbc@gmail.com> 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> --- 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: