From mboxrd@z Thu Jan 1 00:00:00 1970 From: robin.murphy@arm.com (Robin Murphy) Date: Tue, 30 Jun 2015 12:26:36 +0100 Subject: [PATCH 6/8] iommu/arm-smmu: add support for non-pci devices In-Reply-To: <1435307584-9812-7-git-send-email-thunder.leizhen@huawei.com> References: <1435307584-9812-1-git-send-email-thunder.leizhen@huawei.com> <1435307584-9812-7-git-send-email-thunder.leizhen@huawei.com> Message-ID: <55927CEC.4090900@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 26/06/15 09:33, Zhen Lei wrote: > Now, we only support a master with only one stream id. It will cover most > hardware platforms and coding so easy. > > Please refer Documentation\devicetree\bindings\iommu\iommu.txt on how to > bind device tree. > > Signed-off-by: Zhen Lei > --- > arch/arm64/include/asm/device.h | 2 + > drivers/iommu/arm-smmu-v3.c | 88 +++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 87 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/device.h b/arch/arm64/include/asm/device.h > index 243ef25..225e4f9 100644 > --- a/arch/arm64/include/asm/device.h > +++ b/arch/arm64/include/asm/device.h > @@ -20,6 +20,8 @@ struct dev_archdata { > struct dma_map_ops *dma_ops; > #ifdef CONFIG_IOMMU_API > void *iommu; /* private IOMMU data */ There's already a perfectly good place to store driver-private data right here. > + struct device_node *of_smmu; > + u32 sid; This looks far too specific to be in core code. It doesn't seem extensible for e.g. ACPI platform devices; it doesn't seem extensible for platform devices with multiple stream IDs e.g. PL330; it also doesn't seem (sensibly) extensible for IOMMUs with #iommu-cells > 1. Just allocate an SMMU-private struct for this and stash it in archdata.iommu - that way we can change things as much as we like in the driver with zero churn in core code. > #endif > bool dma_coherent; > }; > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 483c918..87c3d9b 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -30,9 +30,14 @@ > #include > #include > #include > +#include > +#include > > #include "io-pgtable.h" > > +/* Maximum number of stream IDs assigned to a single device */ > +#define MAX_MASTER_STREAMIDS 1 > + > /* MMIO registers */ > #define ARM_SMMU_IDR0 0x0 > #define IDR0_ST_LVL_SHIFT 27 > @@ -608,6 +613,22 @@ static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > return container_of(dom, struct arm_smmu_domain, domain); > } > > +static struct arm_smmu_device *find_smmu_for_device(struct device *dev) > +{ > + struct arm_smmu_device *smmu; > + > + spin_lock(&arm_smmu_devices_lock); > + list_for_each_entry(smmu, &arm_smmu_devices, list) { > + if (smmu->dev->of_node == dev->archdata.of_smmu) { > + spin_unlock(&arm_smmu_devices_lock); > + return smmu; > + } > + } > + spin_unlock(&arm_smmu_devices_lock); > + > + return NULL; > +} > + This should be unnecessary with the right probe order, see below... > /* Low-level queue manipulation functions */ > static bool queue_full(struct arm_smmu_queue *q) > { > @@ -1760,9 +1781,36 @@ static int arm_smmu_add_device(struct device *dev) > struct arm_smmu_group *smmu_group; > struct arm_smmu_device *smmu; > > - /* We only support PCI, for now */ > - if (!dev_is_pci(dev)) > - return -ENODEV; > + if (!dev_is_pci(dev)) { > + smmu = find_smmu_for_device(dev); > + if (!smmu) > + return -ENODEV; > + > + group = iommu_group_alloc(); > + if (IS_ERR(group)) { > + dev_err(dev, "Failed to allocate IOMMU group\n"); > + return PTR_ERR(group); > + } > + > + ret = iommu_group_add_device(group, dev); > + if (ret) > + goto out_put_group; > + > + smmu_group = kzalloc(sizeof(*smmu_group), GFP_KERNEL); > + if (!smmu_group) { > + ret = -ENOMEM; > + goto out_put_group; > + } > + > + smmu_group->ste.valid = true; > + smmu_group->smmu = smmu; > + iommu_group_set_iommudata(group, smmu_group, > + __arm_smmu_release_iommudata); > + > + sid = dev->archdata.sid; > + > + goto handle_stream_id; > + } > > pdev = to_pci_dev(dev); > group = iommu_group_get_for_dev(dev); > @@ -1793,6 +1841,8 @@ static int arm_smmu_add_device(struct device *dev) > > /* Assume SID == RID until firmware tells us otherwise */ > pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid, &sid); > + > +handle_stream_id: This is going to get messy quickly - how about breaking out the "platform device" and "PCI device" specifics above into their own functions that return the group and sid data to the common code here? > for (i = 0; i < smmu_group->num_sids; ++i) { > /* If we already know about this SID, then we're done */ > if (smmu_group->sids[i] == sid) > @@ -1881,7 +1931,23 @@ out_unlock: > return ret; > } > > +static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args) > +{ > + if (args->args_count > MAX_MASTER_STREAMIDS) { > + dev_err(dev, > + "reached maximum number (%d) of stream IDs for master device %s\n", > + MAX_MASTER_STREAMIDS, dev->of_node->name); > + return -ENOSPC; > + } > + > + dev->archdata.of_smmu = args->np; > + dev->archdata.sid = args->args[0]; > + > + return 0; > +} This isn't going to work the way you expect: the way the binding is defined, a master with multiple stream IDs should look like so: iommus = <&smmu 0>, <&smmu 1>,... so you'd get multiple calls, never hit the warning, and just end up with whichever ID came last. Secondly, as mentioned above, it would be nicer to just associate the arm_smmu_device directly here and obviate the indirect lookup. That would depend on having correct probe ordering, but you need to enforce that anyway, since any add_device callbacks before the SMMU itself has been probed will break. Laurent's probe deferral series that Will pointed to is the ultimate goal, but for a stop-gap solution which works with the current code I'd suggest taking a look at patches 16 and 17 of Marek's Exynos SysMMU series[1] Robin. [1]:http://thread.gmane.org/gmane.linux.kernel.samsung-soc/45416 > + > static struct iommu_ops arm_smmu_ops = { > + .of_xlate = arm_smmu_of_xlate, > .capable = arm_smmu_capable, > .domain_alloc = arm_smmu_domain_alloc, > .domain_free = arm_smmu_domain_free, > @@ -2655,6 +2721,14 @@ static int __init arm_smmu_init(void) > if (ret) > return ret; > > + if (!iommu_present(&platform_bus_type)) > + bus_set_iommu(&platform_bus_type, &arm_smmu_ops); > + > +#ifdef CONFIG_ARM_AMBA > + if (!iommu_present(&amba_bustype)) > + bus_set_iommu(&amba_bustype, &arm_smmu_ops); > +#endif > + > return bus_set_iommu(&pci_bus_type, &arm_smmu_ops); > } > > @@ -2666,6 +2740,14 @@ static void __exit arm_smmu_exit(void) > subsys_initcall(arm_smmu_init); > module_exit(arm_smmu_exit); > > +static int arm_smmu_of_iommu_init(struct device_node *np) > +{ > + of_iommu_set_ops(np, &arm_smmu_ops); > + > + return 0; > +} > +IOMMU_OF_DECLARE(arm_smmu_v3, "arm,smmu-v3", arm_smmu_of_iommu_init); > + > MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations"); > MODULE_AUTHOR("Will Deacon "); > MODULE_LICENSE("GPL v2"); > -- > 1.8.0 > > > _______________________________________________ > iommu mailing list > iommu at lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu >