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-rw-r--r--arch/x86/kernel/pci-dma.c2
-rw-r--r--include/linux/device.h6
-rw-r--r--kernel/dma/direct.c6
3 files changed, 7 insertions, 7 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index ab5d9dd668d2..80f9fe8d27d0 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -175,7 +175,7 @@ rootfs_initcall(pci_iommu_init);
static int via_no_dac_cb(struct pci_dev *pdev, void *data)
{
- pdev->dev.dma_32bit_limit = true;
+ pdev->dev.bus_dma_mask = DMA_BIT_MASK(32);
return 0;
}
diff --git a/include/linux/device.h b/include/linux/device.h
index 055a69dbcd18..6d3b000be57e 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -886,6 +886,8 @@ struct dev_links_info {
* @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
* hardware supports 64-bit addresses for consistent allocations
* such descriptors.
+ * @bus_dma_mask: Mask of an upstream bridge or bus which imposes a smaller DMA
+ * limit than the device itself supports.
* @dma_pfn_offset: offset of DMA memory range relatively of RAM
* @dma_parms: A low level driver may set these to teach IOMMU code about
* segment limitations.
@@ -912,8 +914,6 @@ struct dev_links_info {
* @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_32bit_limit: bridge limited to 32bit DMA even if the device itself
- * indicates support for a higher limit in the dma_mask field.
*
* At the lowest level, every device in a Linux system is represented by an
* instance of struct device. The device structure contains the information
@@ -967,6 +967,7 @@ struct device {
not all hardware supports
64 bit addresses for consistent
allocations such descriptors. */
+ u64 bus_dma_mask; /* upstream dma_mask constraint */
unsigned long dma_pfn_offset;
struct device_dma_parameters *dma_parms;
@@ -1002,7 +1003,6 @@ struct device {
bool offline_disabled:1;
bool offline:1;
bool of_node_reused:1;
- bool dma_32bit_limit:1;
};
static inline struct device *kobj_to_dev(struct kobject *kobj)
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 8be8106270c2..c2860c5a9e96 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -180,10 +180,10 @@ int dma_direct_supported(struct device *dev, u64 mask)
return 0;
#endif
/*
- * Various PCI/PCIe bridges have broken support for > 32bit DMA even
- * if the device itself might support it.
+ * Upstream PCI/PCIe bridges or SoC interconnects may not carry
+ * as many DMA address bits as the device itself supports.
*/
- if (dev->dma_32bit_limit && mask > DMA_BIT_MASK(32))
+ if (dev->bus_dma_mask && mask > dev->bus_dma_mask)
return 0;
return 1;
}
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