From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Fleming Subject: Re: [PATCH v2 7/7] efi: runtime-wrappers: run UEFI Runtime Services with interrupts enabled Date: Tue, 8 Dec 2015 13:53:44 +0000 Message-ID: <20151208135344.GE2518@codeblueprint.co.uk> References: <1448967020-20190-1-git-send-email-ard.biesheuvel@linaro.org> <1448967020-20190-8-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1448967020-20190-8-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ard Biesheuvel Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On Tue, 01 Dec, at 11:50:20AM, Ard Biesheuvel wrote: > The UEFI spec allows Runtime Services to be invoked with interrupts > enabled. The only reason we were disabling interrupts was to prevent > recursive calls into the services on the same CPU, which will lead to > deadlock. However, the only context where such invocations may occur > legally is from efi-pstore via efivars, and that code has been updated > to call a non-blocking alternative when invoked from a non-interruptible > context. > > So instead, update the ordinary, blocking UEFI Runtime Services wrappers > to execute with interrupts enabled. This aims to prevent excessive interrupt > latencies on uniprocessor platforms with slow variable stores. > > Signed-off-by: Ard Biesheuvel > --- > drivers/firmware/efi/runtime-wrappers.c | 73 ++++++++------------ > 1 file changed, 30 insertions(+), 43 deletions(-) Thanks Ard, this and all the other patches in this series look good to me, apart from the comments I had for patch 4. Once that is resolved I'd like to get this queued up for v4.5.