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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 6/7] xen/arm: SMMU: Support generic IOMMU bindings
On Fri, 30 Jun 2017, Wei Chen wrote:
> The SMMU MasterIDs are placed at the master devices' DT node while
> using the generic bindings. In this case, it's very hard for us to
> register SMMU masters while probing SMMU as we had done for legacy
> bindings. Because we have to go through whole device tree for all
> SMMU devices to find their master devices.
>
> It's better to register SMMU master for generic bindings in add_device
> callback. This callback will only be called while constructing Dom0.
>
> Signed-off-by: Wei Chen <Wei.Chen@xxxxxxx>
> ---
> xen/drivers/passthrough/arm/smmu.c | 144
> ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 143 insertions(+), 1 deletion(-)
>
> diff --git a/xen/drivers/passthrough/arm/smmu.c
> b/xen/drivers/passthrough/arm/smmu.c
> index 895024c..25f2207 100644
> --- a/xen/drivers/passthrough/arm/smmu.c
> +++ b/xen/drivers/passthrough/arm/smmu.c
> @@ -2621,8 +2621,150 @@ static void arm_smmu_destroy_iommu_domain(struct
> iommu_domain *domain)
> xfree(domain);
> }
>
> +static int arm_smmu_add_generic_master_id(struct arm_smmu_device *smmu,
> + struct device *master_dev, u16 fwid)
> +{
> + struct arm_smmu_master *master;
> + struct device_node *master_np = master_dev->of_node;
> +
> + master = find_smmu_master(smmu, master_np);
> + if (!master) {
> + dev_notice(smmu->dev,
> + "This smmu master [%s] hasn't been registered, creating
> now!\n",
> + master_np->full_name);
> + master = devm_kzalloc(smmu->dev, sizeof(*master), GFP_KERNEL);
> + if (!master)
> + return -ENOMEM;
> +
> + master->of_node = master_np;
> + master->cfg.num_streamids = 0;
> +
> + /*
> + * Xen: Let Xen know that the device is protected by a SMMU.
> + * Only do while registering the master.
> + */
> + dt_device_set_protected(master_np);
> + }
> +
> + /*
> + * If the smmu is using the stream index mode, check whether
> + * the streamid exceeds the max allowed id,
> + */
> + if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) &&
> + (fwid >= smmu->num_mapping_groups)) {
> + dev_err(smmu->dev,
> + "Stream ID for master device %s greater than maximum
> allowed (%d)\n",
> + master_np->name, smmu->num_mapping_groups);
> + return -ERANGE;
> + }
> +
> + if (master->cfg.num_streamids >= MAX_MASTER_STREAMIDS) {
> + dev_err(smmu->dev,
> + "Reached maximum number (%d) of stream IDs for master
> device %s\n",
> + MAX_MASTER_STREAMIDS, master_np->name);
> + return -ENOSPC;
> + }
> +
> + /*
> + * If this is the first time we add id to this master,
> + * we have to register this master to rb tree.
> + */
> + if (!master->cfg.num_streamids) {
> + int ret;
> + ret = insert_smmu_master(smmu, master);
> + if ( ret && ret != -EEXIST ) {
> + dev_err(smmu->dev,
> + "Insert %s to smmu's master rb tree failed\n",
> master_np->name);
> + return ret;
> + }
> + }
> +
> + master->cfg.streamids[master->cfg.num_streamids] = fwid;
> + master->cfg.num_streamids++;
> + dev_dbg(smmu->dev,
> + "Add new streamid [%d] to smmu [%s] for master [%s]!\n",
> + fwid, smmu->dev->of_node->name, master_np->name);
> +
> + return 0;
> +}
> +
> +static struct arm_smmu_device *find_smmu(const struct device *dev);
> +
> +static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args
> *args)
> +{
> + struct arm_smmu_device *smmu;
> + u32 mask = 0, fwid = 0;
> +
> + smmu = find_smmu(dt_to_dev(args->np));
> + if (!smmu) {
> + dev_err(dev, "Could not find smmu device!\n");
> + return -ENODEV;
> + }
> +
> + if (args->args_count > 0)
> + fwid |= (u16)args->args[0];
> +
> + if (args->args_count > 1)
> + fwid |= (u16)args->args[1] << SMR_MASK_SHIFT;
> + else if (!of_property_read_u32(args->np, "stream-match-mask", &mask))
> + fwid |= (u16)mask << SMR_MASK_SHIFT;
> + dev_dbg(dev, "%s fwid:%08x mask:%08x args_count:%d\n",
> + args->np->full_name, fwid,
> + mask, args->args_count);
I don't understand why fwid is declared as u32 but used as a u16 below.
Shouldn't it be declared as u16 in the first place?
> + return arm_smmu_add_generic_master_id(smmu, dev, (u16)fwid);
> +}
> +
> +/*
> + * Parse "iommus" information from generic bindings of platfomr master
> + * device, and then xlate to master IDs and register to SMMU device.
> + */
> +static int arm_smmu_platform_iommu_init(struct device *dev)
> +{
> + struct of_phandle_args iommu_spec;
> + int idx = 0, ret;
> +
> + /*
> + * We don't currently walk up the tree looking for a parent IOMMU.
> + * See the `Notes:' section of
> + * Documentation/devicetree/bindings/iommu/iommu.txt
> + */
> + while (!of_parse_phandle_with_args(dev->of_node, "iommus",
> + "#iommu-cells",
> + idx, &iommu_spec)) {
> + ret = arm_smmu_of_xlate(dev, &iommu_spec);
> + if (ret) {
> + dev_err(dev,
> + "Do of_xlate for platform device failed,
> err=%d\n", ret);
^ remove Do
> + return ret;
> + }
> +
> + idx++;
> + }
> +
> + /*
> + * Return 0 if the device is not protected to follow the behavior
> + * of PCI add device.
> + */
> + return 0;
> +}
> +
> static int arm_smmu_xen_add_device(u8 devfn, struct device*dev)
> {
> + int ret;
> +
> + /*
> + * iommu_add_dt_device() is only called for the hardware domain.
> + * If the SMMU is using generic bindings, we should parse and
> + * register Master IDs while this function had been invoked.
> + */
> + if (using_generic_binding) {
> + ret = arm_smmu_platform_iommu_init(dev);
> + if (ret)
> + return ret;
> + }
> +
> if (dt_device_is_protected(dev->of_node)) {
> if (!dev->archdata.iommu) {
> dev->archdata.iommu = xzalloc(struct
> arm_smmu_xen_device);
> @@ -2832,7 +2974,7 @@ static const struct iommu_ops arm_smmu_iommu_ops = {
> .unmap_page = arm_smmu_unmap_page,
> };
>
> -static __init const struct arm_smmu_device *find_smmu(const struct device
> *dev)
> +static struct arm_smmu_device *find_smmu(const struct device *dev)
> {
> struct arm_smmu_device *smmu;
> bool found = false;
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