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| author | Max Filippov <jcmvbkbc@gmail.com> | 2014-01-22 06:16:37 +0100 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2014-08-14 09:59:27 +0200 |
| commit | c3ef1f4d379cbc79daf80ffb8d43c611da090b82 (patch) | |
| tree | 69e296cac620848d60c94867597d551e8872dbd5 /arch | |
| parent | xtensa: fix kernel/user jump out of fast_unaligned (diff) | |
| download | linux-c3ef1f4d379cbc79daf80ffb8d43c611da090b82.tar.xz linux-c3ef1f4d379cbc79daf80ffb8d43c611da090b82.zip | |
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 <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/xtensa/kernel/align.S | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/align.S b/arch/xtensa/kernel/align.S index 25a65938dda8..904f32f05c09 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 <chris@zankel.net> * @@ -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 */ |