From: Douglas Anderson Date: Mon, 6 Apr 2026 23:22:56 +0000 (-0700) Subject: driver core: Replace dev->dma_iommu with dev_dma_iommu() X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=7fa1e85cfe6844cd7b09cb8288e5fb68952c88f7;p=thirdparty%2Fkernel%2Flinux.git driver core: Replace dev->dma_iommu with dev_dma_iommu() In C, bitfields are not necessarily safe to modify from multiple threads without locking. Switch "dma_iommu" over to the "flags" field so modifications are safe. Cc: Leon Romanovsky Cc: Robin Murphy Cc: Christoph Hellwig Reviewed-by: Rafael J. Wysocki (Intel) Reviewed-by: Danilo Krummrich Acked-by: Greg Kroah-Hartman Acked-by: Marek Szyprowski Signed-off-by: Douglas Anderson Link: https://patch.msgid.link/20260406162231.v5.3.Id20d5973cbff542fea290e13177e9423f5d81342@changeid Signed-off-by: Danilo Krummrich --- diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 54d96e847f161..3fdcbbf273fa2 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -2142,18 +2142,21 @@ EXPORT_SYMBOL_GPL(dma_iova_destroy); void iommu_setup_dma_ops(struct device *dev, struct iommu_domain *domain) { + bool dma_iommu; + if (dev_is_pci(dev)) dev->iommu->pci_32bit_workaround = !iommu_dma_forcedac; - dev->dma_iommu = iommu_is_dma_domain(domain); - if (dev->dma_iommu && iommu_dma_init_domain(domain, dev)) + dma_iommu = iommu_is_dma_domain(domain); + dev_assign_dma_iommu(dev, dma_iommu); + if (dma_iommu && iommu_dma_init_domain(domain, dev)) goto out_err; return; out_err: pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n", dev_name(dev)); - dev->dma_iommu = false; + dev_clear_dma_iommu(dev); } static bool has_msi_cookie(const struct iommu_domain *domain) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 61c12ba782066..fccdbaf6dbd57 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -590,9 +590,8 @@ static void iommu_deinit_device(struct device *dev) dev->iommu_group = NULL; module_put(ops->owner); dev_iommu_free(dev); -#ifdef CONFIG_IOMMU_DMA - dev->dma_iommu = false; -#endif + if (IS_ENABLED(CONFIG_IOMMU_DMA)) + dev_clear_dma_iommu(dev); } static struct iommu_domain *pasid_array_entry_to_domain(void *entry) diff --git a/include/linux/device.h b/include/linux/device.h index 00113821ebe9b..bb02afb00f05e 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -515,11 +515,14 @@ struct device_physical_location { * @DEV_FLAG_CAN_MATCH: The device has matched with a driver at least once or it * is in a bus (like AMBA) which can't check for matching drivers * until other devices probe successfully. + * @DEV_FLAG_DMA_IOMMU: Device is using default IOMMU implementation for DMA and + * doesn't rely on dma_ops structure. * @DEV_FLAG_COUNT: Number of defined struct_device_flags. */ enum struct_device_flags { DEV_FLAG_READY_TO_PROBE = 0, DEV_FLAG_CAN_MATCH = 1, + DEV_FLAG_DMA_IOMMU = 2, DEV_FLAG_COUNT }; @@ -614,8 +617,6 @@ enum struct_device_flags { * for dma allocations. This flag is managed by the dma ops * instance from ->dma_supported. * @dma_skip_sync: DMA sync operations can be skipped for coherent buffers. - * @dma_iommu: Device is using default IOMMU implementation for DMA and - * doesn't rely on dma_ops structure. * @flags: DEV_FLAG_XXX flags. Use atomic bitfield operations to modify. * * At the lowest level, every device in a Linux system is represented by an @@ -735,9 +736,6 @@ struct device { #ifdef CONFIG_DMA_NEED_SYNC bool dma_skip_sync:1; #endif -#ifdef CONFIG_IOMMU_DMA - bool dma_iommu:1; -#endif DECLARE_BITMAP(flags, DEV_FLAG_COUNT); }; @@ -766,6 +764,7 @@ static inline bool dev_test_and_set_##accessor_name(struct device *dev) \ __create_dev_flag_accessors(ready_to_probe, DEV_FLAG_READY_TO_PROBE); __create_dev_flag_accessors(can_match, DEV_FLAG_CAN_MATCH); +__create_dev_flag_accessors(dma_iommu, DEV_FLAG_DMA_IOMMU); #undef __create_dev_flag_accessors diff --git a/include/linux/iommu-dma.h b/include/linux/iommu-dma.h index a92b3ff9b9343..060f6e23ab3c8 100644 --- a/include/linux/iommu-dma.h +++ b/include/linux/iommu-dma.h @@ -7,12 +7,13 @@ #ifndef _LINUX_IOMMU_DMA_H #define _LINUX_IOMMU_DMA_H +#include #include #ifdef CONFIG_IOMMU_DMA static inline bool use_dma_iommu(struct device *dev) { - return dev->dma_iommu; + return dev_dma_iommu(dev); } #else static inline bool use_dma_iommu(struct device *dev)