[PATCH 0/4] ACPI: DMA ranges management

[Lorenzo Pieralisi]

As reported in:

http://lkml.kernel.org/r/CAL85gmA_SSCwM80TKdkZqEe+S1beWzDEvdki1kpkmUTDRmSP7g@mail.gmail.com

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 at arm.com>
Cc: Hanjun Guo <hanjun.guo at linaro.org>
Cc: Feng Kan <fkan at apm.com>
Cc: Jon Masters <jcm at redhat.com>
Cc: Robert Moore <robert.moore at intel.com>
Cc: Robin Murphy <robin.murphy at arm.com>
Cc: Zhang Rui <rui.zhang at intel.com>
Cc: "Rafael J. Wysocki" <rjw at rjwysocki.net>

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