As reported in: http://lkml.kernel.org/r/CAL85gmA_SSCwM80TKdkZqEe+S1beWzDEvdki1kpkmUTDRmSP7g@xxxxxxxxxxxxxx the bus connecting devices to an IOMMU bus can be smaller in size than the IOMMU input address bits which results in devices DMA HW bugs in particular related to IOVA allocation (ie chopping of higher address bits owing to system bus HW capabilities mismatch with the IOMMU). Fortunately this problem can be solved through an already present but never used ACPI 6.2 firmware bindings (ie _DMA object) allowing to define the DMA window for a specific bus in ACPI and therefore all upstream devices connected to it. This small patch series enables _DMA parsing in ACPI core code and use it in ACPI IORT code in order to detect DMA ranges for devices and update their data structures to make them work with their related DMA addressing restrictions. Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx> Cc: Feng Kan <fkan@xxxxxxx> Cc: Jon Masters <jcm@xxxxxxxxxx> Cc: Robert Moore <robert.moore@xxxxxxxxx> Cc: Robin Murphy <robin.murphy@xxxxxxx> Cc: Zhang Rui <rui.zhang@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Lorenzo Pieralisi (4): ACPI: Allow _DMA method in walk resources ACPI: Make acpi_dev_get_resources() method agnostic ACPI: Introduce DMA ranges parsing ACPI: Make acpi_dma_configure() DMA regions aware drivers/acpi/acpica/rsxface.c | 7 ++-- drivers/acpi/arm64/iort.c | 27 +++++++++++- drivers/acpi/resource.c | 83 ++++++++++++++++++++++++++++--------- drivers/acpi/scan.c | 95 +++++++++++++++++++++++++++++++++++++++---- include/acpi/acnames.h | 1 + include/acpi/acpi_bus.h | 2 + include/linux/acpi.h | 8 ++++ include/linux/acpi_iort.h | 5 ++- 8 files changed, 194 insertions(+), 34 deletions(-) -- 2.10.0 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
