On Tue, Aug 26, 2014 at 05:04:43PM +0100, Catalin Marinas wrote:

On Fri, Aug 22, 2014 at 08:49:16PM +0100, Geoff Levand wrote:

quoted

Add the new arm64 routine local_disable() to allow the masking of several DAIF
flags in one operation.  Currently, we only have routines to mask individual
flags, and to mask several flags multiple calls to daifset are required.

Signed-off-by: Geoff Levand <geoff@infradead.org>
---
 arch/arm64/include/asm/irqflags.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
index 11cc941..28521d4 100644
--- a/arch/arm64/include/asm/irqflags.h
+++ b/arch/arm64/include/asm/irqflags.h

@@ -113,5 +113,18 @@ static inline int arch_irqs_disabled_flags(unsigned long flags)
 #define local_dbg_enable()	asm("msr	daifclr, #8" : : : "memory")
 #define local_dbg_disable()	asm("msr	daifset, #8" : : : "memory")
 
+enum daif_flag {
+	DAIF_FIQ   = (1UL << 6),
+	DAIF_IRQ   = (1UL << 7),
+	DAIF_ASYNC = (1UL << 8),
+	DAIF_DBG   = (1UL << 9),
+	DAIF_ALL   = (0xffUL << 6),
+};
+
+static inline void local_disable(unsigned long daif_flags)
+{
+	arch_local_irq_restore(daif_flags | arch_local_save_flags());
+}

Who's using this function? I don't see any patch in this series calling
it.

This was for implementing the spin-table cpu-return-addr idea. Before
returning to the spin-table we need to mask everything, and not doing
that as four back-to-back context-synchronizing writes would be nice.

It should probably be introduced by the cpu-return-addr series unless
this is useful elsewhere. If we don't actually have another use, we
could just have a msr daifset, #0xf (arch_local_disable_all?).

Thanks,
Mark.