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arm64: dma-mapping: Remove the notifier trick to handle early setting…
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… 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: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
[rm: clean up even more]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Sricharan R authored and Joerg Roedel committed Apr 20, 2017
1 parent 5a1bb63 commit b913efe
Showing 1 changed file with 18 additions and 124 deletions.
142 changes: 18 additions & 124 deletions arch/arm64/mm/dma-mapping.c
Original file line number Diff line number Diff line change
@@ -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",
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)

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