From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v2 2/2] linux/xen: support pirq_eoi_map Date: Thu, 26 Jan 2012 13:51:56 -0500 Message-ID: <20120126185155.GA24768@phenom.dumpdata.com> References: <1327600839-23469-2-git-send-email-stefano.stabellini@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1327600839-23469-2-git-send-email-stefano.stabellini@eu.citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Stefano Stabellini Cc: xen-devel@lists.xensource.com, keir@xen.org, Ian.Campbell@citrix.com, JBeulich@suse.com List-Id: xen-devel@lists.xenproject.org On Thu, Jan 26, 2012 at 06:00:39PM +0000, Stefano Stabellini wrote: > The pirq_eoi_map is a bitmap offered by Xen to check which pirqs need to > be EOI'd without having to issue an hypercall every time. > We use PHYSDEVOP_pirq_eoi_gmfn (v2) to map the bitmap, then, if we > succeed, we use pirq_eoi_map to check whether pirqs need eoi. > > Signed-off-by: Stefano Stabellini > --- > drivers/xen/events.c | 17 ++++++++++++++++- > include/xen/interface/physdev.h | 12 ++++++++++++ > 2 files changed, 28 insertions(+), 1 deletions(-) > > diff --git a/drivers/xen/events.c b/drivers/xen/events.c > index 6e075cd..7fdc738 100644 > --- a/drivers/xen/events.c > +++ b/drivers/xen/events.c > @@ -37,6 +37,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -108,6 +109,7 @@ struct irq_info { > #define PIRQ_SHAREABLE (1 << 1) > > static int *evtchn_to_irq; > +static unsigned long *pirq_eoi_map; > > static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG], > cpu_evtchn_mask); > @@ -274,6 +276,9 @@ static bool pirq_needs_eoi(unsigned irq) > > BUG_ON(info->type != IRQT_PIRQ); > > + if (pirq_eoi_map != NULL) > + return test_bit(irq, pirq_eoi_map); > + How about just having a different function called pirq_needs_eoi_v2 which will just do return test_bit(irq, pirq_eoi_map)? And then set the pirq_needs_eoi_v2 in the function table? > return info->u.pirq.flags & PIRQ_NEEDS_EOI; > } > > @@ -1693,7 +1698,7 @@ void xen_callback_vector(void) {} > > void __init xen_init_IRQ(void) > { > - int i; > + int i, rc; > > evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq), > GFP_KERNEL); > @@ -1714,8 +1719,18 @@ void __init xen_init_IRQ(void) > * __acpi_register_gsi can point at the right function */ > pci_xen_hvm_init(); > } else { > + struct physdev_pirq_eoi_gmfn eoi_gmfn; > + > irq_ctx_init(smp_processor_id()); > if (xen_initial_domain()) > pci_xen_initial_domain(); > + > + pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO); > + eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map); > + rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn, &eoi_gmfn); Don't we want the v2 version? > + if (rc != 0) { > + free_page((unsigned long) pirq_eoi_map); > + pirq_eoi_map = NULL; > + } > } > } > diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h > index c1080d9..132c61f 100644 > --- a/include/xen/interface/physdev.h > +++ b/include/xen/interface/physdev.h > @@ -39,6 +39,18 @@ struct physdev_eoi { > }; > > /* > + * Register a shared page for the hypervisor to indicate whether the > + * guest must issue PHYSDEVOP_eoi. The page registered is used as a bit > + * array indexed by Xen's PIRQ value. > + */ > +#define PHYSDEVOP_pirq_eoi_gmfn 28 Ah, the number is right, but the name is the generic one. We should really mention that this is different from v1 or just #define PHYSDEVOP_pirq_eoi_gmfn_v2 28 and use that in the code? > +struct physdev_pirq_eoi_gmfn { > + /* IN */ > + unsigned long gmfn; > +}; > + > + > +/* > * Query the status of an IRQ line. > * @arg == pointer to physdev_irq_status_query structure. > */ > -- > 1.7.2.5