Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932861AbcDTJ1u (ORCPT ); Wed, 20 Apr 2016 05:27:50 -0400 Received: from foss.arm.com ([217.140.101.70]:45614 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754149AbcDTJ1r (ORCPT ); Wed, 20 Apr 2016 05:27:47 -0400 Subject: Re: [PATCH v7 6/8] irqchip/gicv2m: implement msi_doorbell_info callback To: Eric Auger , eric.auger@st.com, robin.murphy@arm.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org References: <1461085990-2547-1-git-send-email-eric.auger@linaro.org> <1461085990-2547-7-git-send-email-eric.auger@linaro.org> Cc: patches@linaro.org, linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, pranav.sawargaonkar@gmail.com, p.fedin@samsung.com, iommu@lists.linux-foundation.org, Jean-Philippe.Brucker@arm.com, julien.grall@arm.com From: Marc Zyngier X-Enigmail-Draft-Status: N1110 Organization: ARM Ltd Message-ID: <57174B8E.9050803@arm.com> Date: Wed, 20 Apr 2016 10:27:42 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.7.0 MIME-Version: 1.0 In-Reply-To: <1461085990-2547-7-git-send-email-eric.auger@linaro.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4237 Lines: 135 On 19/04/16 18:13, Eric Auger wrote: > This patch implements the msi_doorbell_info callback in the > gicv2m driver. > > The driver now is able to return its doorbell characteristics > (base, size, prot). A single doorbell is exposed. > > This will allow the msi layer to iommu_map this doorbell when > requested. > > Signed-off-by: Eric Auger > > --- > > v7: creation > --- > drivers/irqchip/irq-gic-v2m.c | 32 +++++++++++++++++++++++++++++++- > 1 file changed, 31 insertions(+), 1 deletion(-) > > diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c > index 28f047c..54690b9 100644 > --- a/drivers/irqchip/irq-gic-v2m.c > +++ b/drivers/irqchip/irq-gic-v2m.c > @@ -24,6 +24,8 @@ > #include > #include > #include > +#include > +#include > > /* > * MSI_TYPER: > @@ -64,6 +66,7 @@ struct v2m_data { > u32 nr_spis; /* The number of SPIs for MSIs */ > unsigned long *bm; /* MSI vector bitmap */ > u32 flags; /* v2m flags for specific implementation */ > + struct irq_chip_msi_doorbell_info doorbell_info; > }; > > static void gicv2m_mask_msi_irq(struct irq_data *d) > @@ -105,6 +108,16 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) > msg->data -= v2m->spi_start; > } > > +static const struct irq_chip_msi_doorbell_info * > +gicv2m_msi_doorbell_info(struct irq_data *data) > +{ > + struct v2m_data *v2m = irq_data_get_irq_chip_data(data); > + > + if (!v2m) > + return NULL; How can this ever be NULL? I think you can drop that test. > + return (const struct irq_chip_msi_doorbell_info *)(&v2m->doorbell_info); Please don't do that. Use "const" in the functions that are using irq_chip_msi_doorbell_info, but do not make this "const" here. > +} > + > static struct irq_chip gicv2m_irq_chip = { > .name = "GICv2m", > .irq_mask = irq_chip_mask_parent, > @@ -112,6 +125,7 @@ static struct irq_chip gicv2m_irq_chip = { > .irq_eoi = irq_chip_eoi_parent, > .irq_set_affinity = irq_chip_set_affinity_parent, > .irq_compose_msi_msg = gicv2m_compose_msi_msg, > + .msi_doorbell_info = gicv2m_msi_doorbell_info, > }; > > static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain, > @@ -247,6 +261,7 @@ static void gicv2m_teardown(void) > > list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) { > list_del(&v2m->entry); > + free_percpu(v2m->doorbell_info.percpu_doorbells); > kfree(v2m->bm); > iounmap(v2m->base); > of_node_put(to_of_node(v2m->fwnode)); > @@ -299,6 +314,7 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, > { > int ret; > struct v2m_data *v2m; > + struct irq_chip_msi_doorbell __percpu *doorbell; > > v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL); > if (!v2m) { > @@ -311,11 +327,23 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, > > memcpy(&v2m->res, res, sizeof(struct resource)); > > + v2m->doorbell_info.percpu_doorbells = > + alloc_percpu(struct irq_chip_msi_doorbell); > + if (WARN_ON(!v2m->doorbell_info.percpu_doorbells)) { > + ret = -ENOMEM; > + goto err_free_v2m; > + } > + doorbell = per_cpu_ptr(v2m->doorbell_info.percpu_doorbells, 0); > + doorbell->base = v2m->res.start; > + doorbell->size = 4; > + doorbell->prot = IOMMU_WRITE; You probably need to also have something that says IOMMU_DEVICE or something similar, because I'm afraid you're getting a memory mapping here. I've had a quick look at the two other series, but couldn't find anything that would force the memory attributes. > + v2m->doorbell_info.nb_doorbells = 1; > + > v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res)); > if (!v2m->base) { > pr_err("Failed to map GICv2m resource\n"); > ret = -ENOMEM; > - goto err_free_v2m; > + goto err_free_v2m_doorbells; > } > > if (spi_start && nr_spis) { > @@ -359,6 +387,8 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, > > err_iounmap: > iounmap(v2m->base); > +err_free_v2m_doorbells: > + free_percpu(v2m->doorbell_info.percpu_doorbells); > err_free_v2m: > kfree(v2m); > return ret; > Thanks, M. -- Jazz is not dead. It just smells funny...