From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhaoshenglong@huawei.com (Shannon Zhao) Date: Tue, 24 Nov 2015 11:49:37 +0800 Subject: [PATCH 12/13] arm/xen: Get event-channel irq through HVM_PARAM when booting with ACPI In-Reply-To: References: <1447754231-7772-1-git-send-email-shannon.zhao@linaro.org> <1447754231-7772-13-git-send-email-shannon.zhao@linaro.org> Message-ID: <5653DE51.9030104@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2015/11/21 1:11, Stefano Stabellini wrote: > On Tue, 17 Nov 2015, shannon.zhao at linaro.org wrote: >> From: Shannon Zhao >> >> When booting with ACPI, it could get the event-channel irq through >> HVM_PARAM_CALLBACK_IRQ. >> >> Signed-off-by: Shannon Zhao >> --- >> arch/arm/xen/enlighten.c | 23 +++++++++++++++++++---- >> 1 file changed, 19 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c >> index 1373d6d..b8e9db8 100644 >> --- a/arch/arm/xen/enlighten.c >> +++ b/arch/arm/xen/enlighten.c >> @@ -25,6 +25,7 @@ >> #include >> #include >> #include >> +#include >> >> #include >> >> @@ -190,10 +191,24 @@ static int __init xen_guest_init(void) >> if (!xen_domain()) >> return 0; >> >> - xen_events_irq = irq_of_parse_and_map(xen_node, 0); >> - if (!xen_events_irq) { >> - pr_err("Xen event channel interrupt not found\n"); >> - return -ENODEV; >> + if (!acpi_disabled) { >> + struct xen_hvm_param a; >> + >> + a.domid = DOMID_SELF; >> + a.index = HVM_PARAM_CALLBACK_IRQ; >> + if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)) { > > If HYPERVISOR_hvm_op returns an error (ret != 0), I wouldn't bother > checking for the returned value and simply return error. > > On the other hand, if HYPERVISOR_hvm_op is successful (ret == 0), then > it might make sense to check for (a.value >> 56) == 3. > Ok. > >> + if ((a.value >> 56) != 3) { >> + pr_err("Can't get Xen event-channel irq\n"); >> + return -ENODEV; >> + } >> + } >> + xen_events_irq = a.value & 0xff; >> + } else { >> + xen_events_irq = irq_of_parse_and_map(xen_node, 0); >> + if (!xen_events_irq) { >> + pr_err("Xen event channel interrupt not found\n"); >> + return -ENODEV; > > Please make the error message common and move it out of the if/else. > Sure. Thanks. > >> + } >> } >> >> shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL); >> -- >> 2.1.0 >> > > . > -- Shannon