From f97bb36f705da0a86b3ea77bfeee3415fee0b025 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 16 Jun 2009 16:42:49 +0000 Subject: powerpc/rtas: Turn rtas lock into a raw spinlock RTAS currently uses a normal spinlock. However it can be called from contexts where this is not necessarily a good idea. For example, it can be called while syncing timebases, with the core timebase being frozen. Unfortunately, that will deadlock in case of lock contention when spinlock debugging is enabled as the spin lock debugging code will try to use __delay() which ... relies on the timebase being enabled. Also RTAS can be used in some low level IRQ handling code path so it may as well be a raw spinlock for -rt sake. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/rtas.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/include/asm/rtas.h') diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h index 01c12339b304..0af42d20b692 100644 --- a/arch/powerpc/include/asm/rtas.h +++ b/arch/powerpc/include/asm/rtas.h @@ -58,7 +58,7 @@ struct rtas_t { unsigned long entry; /* physical address pointer */ unsigned long base; /* physical address pointer */ unsigned long size; - spinlock_t lock; + raw_spinlock_t lock; struct rtas_args args; struct device_node *dev; /* virtual address pointer */ }; -- cgit v1.2.1 From c4007a2fbf5f82b7e694c22b5929c87e38415a56 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 16 Jun 2009 16:42:50 +0000 Subject: powerpc: Use one common impl. of RTAS timebase sync and use raw spinlock Several platforms use their own copy of what is essentially the same code, using RTAS to synchronize the timebases when bringing up new CPUs. This moves it all into a single common implementation and additionally turns the spinlock into a raw spinlock since the former can rely on the timebase not being frozen when spinlock debugging is enabled, and finally masks interrupts while the timebase is disabled. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/rtas.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/include/asm/rtas.h') diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h index 0af42d20b692..168fce726201 100644 --- a/arch/powerpc/include/asm/rtas.h +++ b/arch/powerpc/include/asm/rtas.h @@ -245,5 +245,8 @@ static inline u32 rtas_config_addr(int busno, int devfn, int reg) (devfn << 8) | (reg & 0xff); } +extern void __cpuinit rtas_give_timebase(void); +extern void __cpuinit rtas_take_timebase(void); + #endif /* __KERNEL__ */ #endif /* _POWERPC_RTAS_H */ -- cgit v1.2.1