On Thu, Aug 3, 2017 at 5:32 AM, Lorenzo Pieralisi
[off-list ref] wrote:

This patch series is v3 of a previous posting:

v2->v3:
        - Fixed DMA masks computation
        - Fixed size computation overflow in acpi_dma_get_range()

v1->v2:
        - Reworked acpi_dma_get_range() flow and logs
        - Added IORT named component address limits
        - Renamed acpi_dev_get_resources() helper function
        - Rebased against v4.13-rc3

v2: http://lkml.kernel.org/r/20170731152323.32488-1-lorenzo.pieralisi at arm.com
v1: http://lkml.kernel.org/r/20170720144517.32529-1-lorenzo.pieralisi at arm.com

-- Original cover letter --

As reported in:

http://lkml.kernel.org/r/CAL85gmA_SSCwM80TKdkZqEe+S1beWzDEvdki1kpkmUTDRmSP7g at 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 <redacted>
Cc: Hanjun Guo <redacted>
Cc: Feng Kan <redacted>
Cc: Jon Masters <redacted>
Cc: Robert Moore <redacted>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: "Rafael J. Wysocki" <redacted>

Lorenzo Pieralisi (5):
  ACPICA: resource_mgr: 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
  ACPI/IORT: Add IORT named component memory address limits

 drivers/acpi/acpica/rsxface.c |  7 ++--
 drivers/acpi/arm64/iort.c     | 57 ++++++++++++++++++++++++++-
 drivers/acpi/resource.c       | 82 +++++++++++++++++++++++++++++---------
 drivers/acpi/scan.c           | 91 +++++++++++++++++++++++++++++++++++++++----
 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, 219 insertions(+), 34 deletions(-)

--
2.10.0

Lorenzo:

A network driver can use pci_set_dma_mask or its like to override what
is done with this patch here.
Which would result in iova allocation greater than the original _DMA
aperture. Should we force
the dma_set_mask to not change if an existing mask is already set?