From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754347AbdEQO3y (ORCPT ); Wed, 17 May 2017 10:29:54 -0400 Received: from foss.arm.com ([217.140.101.70]:48148 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752548AbdEQO3u (ORCPT ); Wed, 17 May 2017 10:29:50 -0400 Subject: Re: [PATCH v8 06/08] iommu/ipmmu-vmsa: Use fwspec iommu_priv on ARM64 To: Magnus Damm , joro@8bytes.org References: <149501557669.21593.1017116915706613060.sendpatchset@little-apple> <149501564036.21593.16964345443958773870.sendpatchset@little-apple> Cc: laurent.pinchart+renesas@ideasonboard.com, geert+renesas@glider.be, sricharan@codeaurora.org, will.deacon@arm.com, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, iommu@lists.linux-foundation.org, horms+renesas@verge.net.au, m.szyprowski@samsung.com From: Robin Murphy Message-ID: <2c64bcfc-e93b-703a-0326-54b6eef73766@arm.com> Date: Wed, 17 May 2017 15:29:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <149501564036.21593.16964345443958773870.sendpatchset@little-apple> 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 Hi Magnus, On 17/05/17 11:07, Magnus Damm wrote: > From: Magnus Damm > > Convert from archdata to iommu_priv via iommu_fwspec on ARM64 but > let 32-bit ARM keep on using archdata for now. > > Once the 32-bit ARM code and the IPMMU driver is able to move over > to CONFIG_IOMMU_DMA=y then coverting to fwspec via ->of_xlate() will > be easy. > > For now fwspec ids and num_ids are not used to allow code sharing between > 32-bit and 64-bit ARM code inside the driver. That's not what I meant at all - this just looks like a crazy unmaintainable mess that's making things that much harder to unpick in future. Leaving the existing code fossilised and building up half of a second separate driver around it wrapped in ifdefs is not only hideous, it's more work in the end than simply pulling things into the right shape to begin with. What I meant was to start with the below (compile-tested only), and add the of_xlate support on top. AFAICS the arm/arm64 differences overall should only come down to a bit of special-casing in add_device(), and (optionally) whether you outright reject IOMMU_DOMAIN_DMA or not. Sorry, but I just can't agree with the two-drivers-in-one approach. Robin. ----->8----- From: Robin Murphy Subject: [PATCH] iommu/ipmmu-vmsa: Convert to iommu_fwspec The parent IPMMU pointer and set of uTLB IDs are, as intended, a perfect fit for the generic iommu_fwspec. Get rid of the architecture-specific archdata handling in favour of the common solution. Signed-off-by: Robin Murphy --- drivers/iommu/ipmmu-vmsa.c | 68 ++++++++++++++++++++-------------------------- 1 file changed, 29 insertions(+), 39 deletions(-) diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c index b7e14ee863f9..96479690269f 100644 --- a/drivers/iommu/ipmmu-vmsa.c +++ b/drivers/iommu/ipmmu-vmsa.c @@ -47,12 +47,6 @@ struct ipmmu_vmsa_domain { spinlock_t lock; /* Protects mappings */ }; -struct ipmmu_vmsa_archdata { - struct ipmmu_vmsa_device *mmu; - unsigned int *utlbs; - unsigned int num_utlbs; -}; - static DEFINE_SPINLOCK(ipmmu_devices_lock); static LIST_HEAD(ipmmu_devices); @@ -455,6 +449,8 @@ static irqreturn_t ipmmu_irq(int irq, void *dev) * IOMMU Operations */ +static const struct iommu_ops ipmmu_ops; + static struct iommu_domain *ipmmu_domain_alloc(unsigned type) { struct ipmmu_vmsa_domain *domain; @@ -487,18 +483,20 @@ static void ipmmu_domain_free(struct iommu_domain *io_domain) static int ipmmu_attach_device(struct iommu_domain *io_domain, struct device *dev) { - struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu; - struct ipmmu_vmsa_device *mmu = archdata->mmu; + struct iommu_fwspec *fwspec = dev->iommu_fwspec; + struct ipmmu_vmsa_device *mmu; struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain); unsigned long flags; unsigned int i; int ret = 0; - if (!mmu) { + if (!fwspec || fwspec->ops != &ipmmu_ops) { dev_err(dev, "Cannot attach to IPMMU\n"); return -ENXIO; } + mmu = fwspec->iommu_priv; + spin_lock_irqsave(&domain->lock, flags); if (!domain->mmu) { @@ -520,8 +518,8 @@ static int ipmmu_attach_device(struct iommu_domain *io_domain, if (ret < 0) return ret; - for (i = 0; i < archdata->num_utlbs; ++i) - ipmmu_utlb_enable(domain, archdata->utlbs[i]); + for (i = 0; i < fwspec->num_ids; ++i) + ipmmu_utlb_enable(domain, fwspec->ids[i]); return 0; } @@ -529,12 +527,15 @@ static int ipmmu_attach_device(struct iommu_domain *io_domain, static void ipmmu_detach_device(struct iommu_domain *io_domain, struct device *dev) { - struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu; + struct iommu_fwspec *fwspec = dev->iommu_fwspec; struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain); unsigned int i; - for (i = 0; i < archdata->num_utlbs; ++i) - ipmmu_utlb_disable(domain, archdata->utlbs[i]); + if (!fwspec || fwspec->ops != &ipmmu_ops) + return; + + for (i = 0; i < fwspec->num_ids; ++i) + ipmmu_utlb_disable(domain, fwspec->ids[i]); /* * TODO: Optimize by disabling the context when no device is attached. @@ -597,7 +598,6 @@ static int ipmmu_find_utlbs(struct ipmmu_vmsa_device *mmu, struct device *dev, static int ipmmu_add_device(struct device *dev) { - struct ipmmu_vmsa_archdata *archdata; struct ipmmu_vmsa_device *mmu; struct iommu_group *group = NULL; unsigned int *utlbs; @@ -605,7 +605,7 @@ static int ipmmu_add_device(struct device *dev) int num_utlbs; int ret = -ENODEV; - if (dev->archdata.iommu) { + if (dev->iommu_fwspec) { dev_warn(dev, "IOMMU driver already assigned to device %s\n", dev_name(dev)); return -EINVAL; @@ -638,13 +638,20 @@ static int ipmmu_add_device(struct device *dev) spin_unlock(&ipmmu_devices_lock); if (ret < 0) - goto error; + return ret; + + ret = iommu_fwspec_init(dev, mmu->dev->fwnode, &ipmmu_ops); + if (ret) + return ret; + + dev->iommu_fwspec->iommu_priv = mmu; for (i = 0; i < num_utlbs; ++i) { if (utlbs[i] >= mmu->num_utlbs) { ret = -EINVAL; goto error; } + iommu_fwspec_add_ids(dev, &utlbs[i], 1); } /* Create a device group and add the device to it. */ @@ -664,17 +671,6 @@ static int ipmmu_add_device(struct device *dev) goto error; } - archdata = kzalloc(sizeof(*archdata), GFP_KERNEL); - if (!archdata) { - ret = -ENOMEM; - goto error; - } - - archdata->mmu = mmu; - archdata->utlbs = utlbs; - archdata->num_utlbs = num_utlbs; - dev->archdata.iommu = archdata; - /* * Create the ARM mapping, used by the ARM DMA mapping core to allocate * VAs. This will allocate a corresponding IOMMU domain. @@ -710,28 +706,22 @@ static int ipmmu_add_device(struct device *dev) error: arm_iommu_release_mapping(mmu->mapping); - kfree(dev->archdata.iommu); - kfree(utlbs); - - dev->archdata.iommu = NULL; - if (!IS_ERR_OR_NULL(group)) iommu_group_remove_device(dev); + iommu_fwspec_free(dev); + return ret; } static void ipmmu_remove_device(struct device *dev) { - struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu; + if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &ipmmu_ops) + return; arm_iommu_detach_device(dev); iommu_group_remove_device(dev); - - kfree(archdata->utlbs); - kfree(archdata); - - dev->archdata.iommu = NULL; + iommu_fwspec_free(dev); } static const struct iommu_ops ipmmu_ops = {