Re: [Xenomai-core] [PATCH] hal: Ensure atomicity of rthal_local_irq_disabled

[Jan Kiszka <jan.kiszka@domain.hid>]

Philippe Gerum wrote:
> On Tue, 2009-11-10 at 11:43 +0100, Jan Kiszka wrote:
[...]
>> Oh, *_hw_smp is new, isn't it? Do we need to wrap it for older I-pipes?
> 
> Yes, it was introduced to solve the SMP migration issue actually, so we
> need a wrapper. The advantage of having that wrapper instead of going
> for inlined #ifdef CONFIG_SMP is that I could simply get rid of that
> wrapper in 3.x, since all legacy pipeline patches would be deprecated
> there anyway.

Something like this, or where to put the wrapper?

Jan

---

diff --git a/include/asm-generic/hal.h b/include/asm-generic/hal.h
index 97c549e..a8bc5ec 100644
--- a/include/asm-generic/hal.h
+++ b/include/asm-generic/hal.h
@@ -117,7 +117,14 @@ typedef spinlock_t rthal_spinlock_t;
 #endif /* !CONFIG_XENO_OPT_PIPELINE_HEAD */
 #define rthal_local_irq_flags(x)	((x) = ipipe_test_pipeline_from(&rthal_domain) & 1)
 #define rthal_local_irq_test()		ipipe_test_pipeline_from(&rthal_domain)
-#define rthal_local_irq_disabled()	ipipe_test_pipeline_from(&rthal_domain)
+#define rthal_local_irq_disabled()				\
+({								\
+	unsigned long __flags, __ret;				\
+	local_irq_save_hw_smp(__flags);				\
+	__ret = ipipe_test_pipeline_from(&rthal_domain);	\
+	local_irq_restore_hw_smp(__flags);			\
+	__ret;							\
+})
 #define rthal_stage_irq_enable(dom)	ipipe_unstall_pipeline_from(dom)
 #define rthal_local_irq_save_hw(x)	local_irq_save_hw(x)
 #define rthal_local_irq_restore_hw(x)	local_irq_restore_hw(x)
diff --git a/include/asm-generic/wrappers.h b/include/asm-generic/wrappers.h
index 1cfd60c..c175ea4 100644
--- a/include/asm-generic/wrappers.h
+++ b/include/asm-generic/wrappers.h
@@ -555,4 +555,16 @@ static inline void wrap_proc_dir_entry_owner(struct proc_dir_entry *entry)
 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,6,30) */
 #endif /* CONFIG_PROC_FS */
 
+#include <linux/ipipe.h>
+
+#ifndef local_irq_save_hw_smp
+#ifdef CONFIG_SMP
+#define local_irq_save_hw_smp(flags)	local_irq_save_hw(flags)
+#define local_irq_restore_hw_smp(flags)	local_irq_restore_hw(flags)
+#else /* !CONFIG_SMP */
+#define local_irq_save_hw_smp(flags)	do { (void)(flags); } while (0)
+#define local_irq_restore_hw_smp(flags)	do { } while (0)
+#endif /* !CONFIG_SMP */
+#endif /* !local_irq_save_hw_smp */
+
 #endif /* _XENO_ASM_GENERIC_WRAPPERS_H */