From c3ef1f4d379cbc79daf80ffb8d43c611da090b82 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Wed, 22 Jan 2014 09:16:37 +0400 Subject: [PATCH] xtensa: add double exception fixup handler for fast_unaligned fast_unaligned_fixup restores user registers and runs normal exception handler in the current stack frame. Unaligned load/store is retried after that. Signed-off-by: Max Filippov --- arch/xtensa/kernel/align.S | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/arch/xtensa/kernel/align.S b/arch/xtensa/kernel/align.S index 25a6593..904f32f 100644 --- a/arch/xtensa/kernel/align.S +++ b/arch/xtensa/kernel/align.S @@ -8,6 +8,7 @@ * this archive for more details. * * Copyright (C) 2001 - 2005 Tensilica, Inc. + * Copyright (C) 2014 Cadence Design Systems Inc. * * Rewritten by Chris Zankel * @@ -174,6 +175,10 @@ ENTRY(fast_unaligned) s32i a0, a2, PT_AREG2 s32i a3, a2, PT_AREG3 + rsr a3, excsave1 + movi a4, fast_unaligned_fixup + s32i a4, a3, EXC_TABLE_FIXUP + /* Keep value of SAR in a0 */ rsr a0, sar @@ -430,6 +435,10 @@ ENTRY(fast_unaligned) .Linvalid_instruction_store: .Linvalid_instruction: + movi a4, 0 + rsr a3, excsave1 + s32i a4, a3, EXC_TABLE_FIXUP + /* Restore a4...a8 and SAR, set SP, and jump to default exception. */ l32i a8, a2, PT_AREG8 @@ -451,4 +460,38 @@ ENTRY(fast_unaligned) ENDPROC(fast_unaligned) +ENTRY(fast_unaligned_fixup) + + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + wsr a3, excsave1 + + l32i a8, a2, PT_AREG8 + l32i a7, a2, PT_AREG7 + l32i a6, a2, PT_AREG6 + l32i a5, a2, PT_AREG5 + l32i a4, a2, PT_AREG4 + l32i a0, a2, PT_AREG2 + xsr a0, depc # restore depc and a0 + wsr a0, sar + + rsr a0, exccause + s32i a0, a2, PT_DEPC # mark as a regular exception + + rsr a0, ps + bbsi.l a0, PS_UM_BIT, 1f # jump if user mode + + rsr a0, exccause + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_KERNEL # load handler + l32i a3, a2, PT_AREG3 + jx a0 +1: + rsr a0, exccause + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_USER # load handler + l32i a3, a2, PT_AREG3 + jx a0 + +ENDPROC(fast_unaligned_fixup) + #endif /* XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION */ -- 2.7.4