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| author | Michael Neuling <mikey@neuling.org> | 2013-08-09 17:29:30 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-08-09 18:07:08 +1000 |
| commit | c2d52644e2da8a07ecab5ca62dd0bc563089e8dc (patch) | |
| tree | a21b5652b82e1e0dee7e996c1c77c9d7ac5e9033 /arch/powerpc/kernel/process.c | |
| parent | 2517617e0de65f8f7cfe75cae745d06b1fa98586 (diff) | |
| download | linux-c2d52644e2da8a07ecab5ca62dd0bc563089e8dc.tar.bz2 | |
powerpc: Save the TAR register earlier
This moves us to save the Target Address Register (TAR) a earlier in
__switch_to. It introduces a new function save_tar() to do this.
We need to save the TAR earlier as we will overwrite it in the transactional
memory reclaim/recheckpoint path. We are going to do this in a subsequent
patch which will fix saving the TAR register when it's modified inside a
transaction.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index c517dbe705fd..8083be20fe5e 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -600,6 +600,16 @@ struct task_struct *__switch_to(struct task_struct *prev, struct ppc64_tlb_batch *batch; #endif + /* Back up the TAR across context switches. + * Note that the TAR is not available for use in the kernel. (To + * provide this, the TAR should be backed up/restored on exception + * entry/exit instead, and be in pt_regs. FIXME, this should be in + * pt_regs anyway (for debug).) + * Save the TAR here before we do treclaim/trecheckpoint as these + * will change the TAR. + */ + save_tar(&prev->thread); + __switch_to_tm(prev); #ifdef CONFIG_SMP |