Jim Quinlan e97c5b6098 MIPS: Make irqflags.h functions preempt-safe for non-mipsr2 cpus ... For non MIPSr2 processors, such as the BMIPS 5000, calls to arch_local_irq_disable() and others may be preempted, and in doing so a stale value may be restored to c0_status. This fix disables preemption for such processors prior to the call and enables it after the call. Those functions that needed this fix have been "outlined" to mips-atomic.c, as they are no longer good candidates for inlining. This bug was observed in a BMIPS 5000, occuring once every few hours in a continuous reboot test. It was traced to the write_lock_irq() function which was being invoked in release_task() in exit.c. By placing a number of "nops" inbetween the mfc0/mtc0 pair in arch_local_irq_disable(), which is called by write_lock_irq(), we were able to greatly increase the occurance of this bug. Similarly, the application of this commit silenced the bug. Signed-off-by: Jim Quinlan <jim2101024@gmail.com> Cc: linux-mips@linux-mips.org Cc: David Daney <ddaney.cavm@gmail.com> Cc: Kevin Cernekee cernekee@gmail.com Cc: Jim Quinlan <jim2101024@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/4321/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>		2012-11-09 10:59:21 +01:00
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asm	MIPS: Make irqflags.h functions preempt-safe for non-mipsr2 cpus	2012-11-09 10:59:21 +01:00
uapi/asm	UAPI: (Scripted) Disintegrate arch/mips/include/asm	2012-10-09 09:47:14 +01:00