From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Wed, 10 Sep 2014 18:07:40 +0100 From: Will Deacon Subject: Re: [PATCH 04/13] arm64: Add new hcall HVC_CALL_FUNC Message-ID: <20140910170740.GE1710@arm.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Geoff Levand Cc: Marc Zyngier , Catalin Marinas , "kexec@lists.infradead.org" , "linux-arm-kernel@lists.infradead.org" , "christoffer.dall@linaro.org" On Tue, Sep 09, 2014 at 11:49:04PM +0100, Geoff Levand wrote: > Add the new hcall HVC_CALL_FUNC that allows execution of a function at EL2. > During CPU reset the CPU must be brought to the exception level it had on > entry to the kernel. The HVC_CALL_FUNC hcall will provide the mechanism > needed for this exception level switch. > > Signed-off-by: Geoff Levand > --- > arch/arm64/include/asm/virt.h | 11 +++++++++++ > arch/arm64/kernel/hyp-stub.S | 10 ++++++++++ > 2 files changed, 21 insertions(+) [...] > diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S > index 9ab5f70..a21cf51 100644 > --- a/arch/arm64/kernel/hyp-stub.S > +++ b/arch/arm64/kernel/hyp-stub.S > @@ -75,7 +75,17 @@ el1_sync: > 1: cmp x10, #HVC_SET_VECTORS > b.ne 1f > msr vbar_el2, x0 > + b 2f > > +1: cmp x10, #HVC_CALL_FUNC > + b.ne 1f > + mov x29, lr > + mov lr, x0 > + mov x0, x1 > + mov x1, x2 > + mov x2, x3 > + blr lr > + mov lr, x29 Why are you clobbering x29? Will _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec