From b913efe78a7ce1b2e64af7e5dc3a03748b997c61 Mon Sep 17 00:00:00 2001 From: Sricharan R Date: Mon, 10 Apr 2017 16:51:04 +0530 Subject: [PATCH] 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: Marek Szyprowski Tested-by: Hanjun Guo Acked-by: Will Deacon Signed-off-by: Sricharan R [rm: clean up even more] Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel --- arch/arm64/mm/dma-mapping.c | 142 +++++------------------------------- 1 file changed, 18 insertions(+), 124 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 81cdb2e844ed..b46575954032 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -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) -- 2.20.1