From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4AF943BD.3020808@domain.hid> Date: Tue, 10 Nov 2009 11:43:09 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <4AF8A72E.1060204@domain.hid> <4AF8B50E.4010900@domain.hid> <1257848915.2210.487.camel@domain.hid> In-Reply-To: <1257848915.2210.487.camel@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [Xenomai-core] [PATCH] hal: Ensure atomicity of rthal_local_irq_disabled List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: xenomai-core Philippe Gerum wrote: > On Tue, 2009-11-10 at 01:34 +0100, Gilles Chanteperdrix wrote: >> Jan Kiszka wrote: >>> [Patch is now also available in 'for-upstream'] >>> >>> ipipe_test_pipeline_from is not atomic /wrt reading the current cpu >>> number (or an offset for the per-cpu area) and actually reading the >>> virtualized interrupt state. Work around this by disabling hard IRQs >>> while accessing this service. >>> >>> This fixes false-positives of RTDM driver debug checks. >>> >>> Signed-off-by: Jan Kiszka >>> --- >>> include/asm-generic/hal.h | 9 ++++++++- >>> 1 files changed, 8 insertions(+), 1 deletions(-) >>> >>> diff --git a/include/asm-generic/hal.h b/include/asm-generic/hal.h >>> index 97c549e..3095b85 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(__flags); \ >>> + __ret = ipipe_test_pipeline_from(&rthal_domain); \ >>> + local_irq_restore_hw(__flags); \ >>> + __ret; \ >>> +}) >> Maybe we can avoid that on UP systems? >> > > Yes, we should rather use local_irq_save/restore_hw_smp(). > Oh, *_hw_smp is new, isn't it? Do we need to wrap it for older I-pipes? Jan