From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932895AbbIUQlc (ORCPT ); Mon, 21 Sep 2015 12:41:32 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60935 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757187AbbIUQla (ORCPT ); Mon, 21 Sep 2015 12:41:30 -0400 Date: Mon, 21 Sep 2015 09:41:28 -0700 From: Greg KH To: KY Srinivasan Cc: "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , "olaf@aepfle.de" , "apw@canonical.com" , "vkuznets@redhat.com" , "jasowang@redhat.com" , Jake Oshins Subject: Re: [PATCH 2/3] drivers:hv: Export the API to invoke a hypercall on Hyper-V Message-ID: <20150921164128.GC26912@kroah.com> References: <1442366782-23929-1-git-send-email-kys@microsoft.com> <1442366809-23968-1-git-send-email-kys@microsoft.com> <1442366809-23968-2-git-send-email-kys@microsoft.com> <20150921052824.GC24350@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 21, 2015 at 04:22:01PM +0000, KY Srinivasan wrote: > > > > -----Original Message----- > > From: Greg KH [mailto:gregkh@linuxfoundation.org] > > Sent: Sunday, September 20, 2015 10:28 PM > > To: KY Srinivasan > > Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org; > > olaf@aepfle.de; apw@canonical.com; vkuznets@redhat.com; > > jasowang@redhat.com; Jake Oshins > > Subject: Re: [PATCH 2/3] drivers:hv: Export the API to invoke a hypercall on > > Hyper-V > > > > On Tue, Sep 15, 2015 at 06:26:48PM -0700, K. Y. Srinivasan wrote: > > > From: Jake Oshins > > > > > > This patch exposes the function that hv_vmbus.ko uses to make hypercalls. > > This > > > is necessary for retargeting an interrupt when it is given a new affinity. > > > > > > Since we are exporting this API, rename the API as it will be visible outside > > > the hv.c file. > > > > > > Signed-off-by: Jake Oshins > > > Signed-off-by: K. Y. Srinivasan > > > --- > > > drivers/hv/hv.c | 9 +++++---- > > > include/linux/hyperv.h | 1 + > > > 2 files changed, 6 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c > > > index 6341be8..a7b6c6a 100644 > > > --- a/drivers/hv/hv.c > > > +++ b/drivers/hv/hv.c > > > @@ -89,9 +89,9 @@ static int query_hypervisor_info(void) > > > } > > > > > > /* > > > - * do_hypercall- Invoke the specified hypercall > > > + * hv_do_hypercall- Invoke the specified hypercall > > > */ > > > -static u64 do_hypercall(u64 control, void *input, void *output) > > > +u64 hv_do_hypercall(u64 control, void *input, void *output) > > > { > > > u64 input_address = (input) ? virt_to_phys(input) : 0; > > > u64 output_address = (output) ? virt_to_phys(output) : 0; > > > @@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, > > void *output) > > > return hv_status_lo | ((u64)hv_status_hi << 32); > > > #endif /* !x86_64 */ > > > } > > > +EXPORT_SYMBOL_GPL(hv_do_hypercall); > > > > > > #ifdef CONFIG_X86_64 > > > static cycle_t read_hv_clock_tsc(struct clocksource *arg) > > > @@ -329,7 +330,7 @@ int hv_post_message(union hv_connection_id > > connection_id, > > > aligned_msg->payload_size = payload_size; > > > memcpy((void *)aligned_msg->payload, payload, payload_size); > > > > > > - status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL) > > > + status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, > > NULL) > > > & 0xFFFF; > > > > > > put_cpu(); > > > @@ -347,7 +348,7 @@ u16 hv_signal_event(void *con_id) > > > { > > > u16 status; > > > > > > - status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & > > 0xFFFF); > > > + status = (hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & > > 0xFFFF); > > > > What's with the crazy () around a function call? > > I will address this and resend. > > > > And why are you passing a 64bit return value into a 16bit status value? > > That seems like something is broken. > > The low order 16 bits have the valid status codes we are interested in. Then why even return a 64bit number if no one uses it? greg k-h