From 3e2c1e213ac2bfc9068a2686ef380ee0d8bef949 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Mon, 6 Apr 2026 16:23:00 -0700 Subject: driver core: Replace dev->dma_coherent with dev_dma_coherent() In C, bitfields are not necessarily safe to modify from multiple threads without locking. Switch "dma_coherent" over to the "flags" field so modifications are safe. Cc: Christoph Hellwig Reviewed-by: Rafael J. Wysocki (Intel) Reviewed-by: Danilo Krummrich Acked-by: Vinod Koul Acked-by: Greg Kroah-Hartman Acked-by: Marek Szyprowski Signed-off-by: Douglas Anderson Link: https://patch.msgid.link/20260406162231.v5.7.If839f6dde98979fce177f70c6c74689a1904ee76@changeid [ Since all DEV_FLAG_DMA_COHERENT accessors are exposed unconditionally, also drop the CONFIG guards around dev_assign_dma_coherent() in device_initialize() to ensure a correct default value. - Danilo ] Signed-off-by: Danilo Krummrich --- include/linux/device.h | 11 ++++------- include/linux/dma-map-ops.h | 2 +- 2 files changed, 5 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/device.h b/include/linux/device.h index fc4334ff3351..bab4315f4f61 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -527,6 +527,8 @@ struct device_physical_location { * @DEV_FLAG_STATE_SYNCED: The hardware state of this device has been synced to * match the software state of this device by calling the * driver/bus sync_state() callback. + * @DEV_FLAG_DMA_COHERENT: This particular device is dma coherent, even if the + * architecture supports non-coherent devices. * @DEV_FLAG_COUNT: Number of defined struct_device_flags. */ enum struct_device_flags { @@ -536,6 +538,7 @@ enum struct_device_flags { DEV_FLAG_DMA_SKIP_SYNC = 3, DEV_FLAG_DMA_OPS_BYPASS = 4, DEV_FLAG_STATE_SYNCED = 5, + DEV_FLAG_DMA_COHERENT = 6, DEV_FLAG_COUNT }; @@ -619,8 +622,6 @@ enum struct_device_flags { * @offline: Set after successful invocation of bus type's .offline(). * @of_node_reused: Set if the device-tree node is shared with an ancestor * device. - * @dma_coherent: this particular device is dma coherent, even if the - * architecture supports non-coherent devices. * @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 @@ -728,11 +729,6 @@ struct device { bool offline_disabled:1; bool offline:1; bool of_node_reused:1; -#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ - defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ - defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) - bool dma_coherent:1; -#endif DECLARE_BITMAP(flags, DEV_FLAG_COUNT); }; @@ -765,6 +761,7 @@ __create_dev_flag_accessors(dma_iommu, DEV_FLAG_DMA_IOMMU); __create_dev_flag_accessors(dma_skip_sync, DEV_FLAG_DMA_SKIP_SYNC); __create_dev_flag_accessors(dma_ops_bypass, DEV_FLAG_DMA_OPS_BYPASS); __create_dev_flag_accessors(state_synced, DEV_FLAG_STATE_SYNCED); +__create_dev_flag_accessors(dma_coherent, DEV_FLAG_DMA_COHERENT); #undef __create_dev_flag_accessors diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 9e677a79f3a8..bcb5b5428aea 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -225,7 +225,7 @@ int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start, extern bool dma_default_coherent; static inline bool dev_is_dma_coherent(struct device *dev) { - return dev->dma_coherent; + return dev_dma_coherent(dev); } #else #define dma_default_coherent true -- cgit v1.2.3