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Commit b913efe7 authored by Sricharan R's avatar Sricharan R Committed by Joerg Roedel
Browse files

arm64: dma-mapping: Remove the notifier trick to handle early setting of dma_ops 



With arch_setup_dma_ops now being called late during device's probe after
the device's iommu is probed, the notifier trick required to handle the
early setup of dma_ops before the iommu group gets created is not
required. So removing the notifier's here.

Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarSricharan R <sricharan@codeaurora.org>
[rm: clean up even more]
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 5a1bb638

arch/arm64/mm/dma-mapping.c

+18 −124
Original line number Diff line number Diff line
@@ -813,34 +813,26 @@ static const struct dma_map_ops iommu_dma_ops = { 
	.mapping_error = iommu_dma_mapping_error,

};



/*

 * TODO: Right now __iommu_setup_dma_ops() gets called too early to do

 * everything it needs to - the device is only partially created and the

 * IOMMU driver hasn't seen it yet, so it can't have a group. Thus we

 * need this delayed attachment dance. Once IOMMU probe ordering is sorted

 * to move the arch_setup_dma_ops() call later, all the notifier bits below

 * become unnecessary, and will go away.

 */

struct iommu_dma_notifier_data {

	struct list_head list;

	struct device *dev;

	const struct iommu_ops *ops;

	u64 dma_base;

	u64 size;

};

static LIST_HEAD(iommu_dma_masters);

static DEFINE_MUTEX(iommu_dma_notifier_lock);

static int __init __iommu_dma_init(void)

{

	return iommu_dma_init();

}

arch_initcall(__iommu_dma_init);



static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,

			   u64 dma_base, u64 size)

static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

				  const struct iommu_ops *ops)

{

	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);

	struct iommu_domain *domain;



	if (!ops)

		return;



	/*

	 * If the IOMMU driver has the DMA domain support that we require,

	 * then the IOMMU core will have already configured a group for this

	 * device, and allocated the default domain for that group.

	 * The IOMMU core code allocates the default DMA domain, which the

	 * underlying IOMMU driver needs to support via the dma-iommu layer.

	 */

	domain = iommu_get_domain_for_dev(dev);



	if (!domain)

		goto out_err;
@@ -851,109 +843,11 @@ static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops, 
		dev->dma_ops = &iommu_dma_ops;

	}



	return true;

	return;



out_err:

	 pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",

		 dev_name(dev));

	return false;

}



static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,

			      u64 dma_base, u64 size)

{

	struct iommu_dma_notifier_data *iommudata;



	iommudata = kzalloc(sizeof(*iommudata), GFP_KERNEL);

	if (!iommudata)

		return;



	iommudata->dev = dev;

	iommudata->ops = ops;

	iommudata->dma_base = dma_base;

	iommudata->size = size;



	mutex_lock(&iommu_dma_notifier_lock);

	list_add(&iommudata->list, &iommu_dma_masters);

	mutex_unlock(&iommu_dma_notifier_lock);

}



static int __iommu_attach_notifier(struct notifier_block *nb,

				   unsigned long action, void *data)

{

	struct iommu_dma_notifier_data *master, *tmp;



	if (action != BUS_NOTIFY_BIND_DRIVER)

		return 0;



	mutex_lock(&iommu_dma_notifier_lock);

	list_for_each_entry_safe(master, tmp, &iommu_dma_masters, list) {

		if (data == master->dev && do_iommu_attach(master->dev,

				master->ops, master->dma_base, master->size)) {

			list_del(&master->list);

			kfree(master);

			break;

		}

	}

	mutex_unlock(&iommu_dma_notifier_lock);

	return 0;

}



static int __init register_iommu_dma_ops_notifier(struct bus_type *bus)

{

	struct notifier_block *nb = kzalloc(sizeof(*nb), GFP_KERNEL);

	int ret;



	if (!nb)

		return -ENOMEM;



	nb->notifier_call = __iommu_attach_notifier;



	ret = bus_register_notifier(bus, nb);

	if (ret) {

		pr_warn("Failed to register DMA domain notifier; IOMMU DMA ops unavailable on bus '%s'\n",

			bus->name);

		kfree(nb);

	}

	return ret;

}



static int __init __iommu_dma_init(void)

{

	int ret;



	ret = iommu_dma_init();

	if (!ret)

		ret = register_iommu_dma_ops_notifier(&platform_bus_type);

	if (!ret)

		ret = register_iommu_dma_ops_notifier(&amba_bustype);

#ifdef CONFIG_PCI

	if (!ret)

		ret = register_iommu_dma_ops_notifier(&pci_bus_type);

#endif

	return ret;

}

arch_initcall(__iommu_dma_init);



static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

				  const struct iommu_ops *ops)

{

	struct iommu_group *group;



	if (!ops)

		return;

	/*

	 * TODO: As a concession to the future, we're ready to handle being

	 * called both early and late (i.e. after bus_add_device). Once all

	 * the platform bus code is reworked to call us late and the notifier

	 * junk above goes away, move the body of do_iommu_attach here.

	 */

	group = iommu_group_get(dev);

	if (group) {

		do_iommu_attach(dev, ops, dma_base, size);

		iommu_group_put(group);

	} else {

		queue_iommu_attach(dev, ops, dma_base, size);

	}

}



void arch_teardown_dma_ops(struct device *dev)