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 --- arch/xtensa/kernel/head.S | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S index 2f76118ecf62..9053a5622d2c 100644 --- 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: