Messages in this thread | | | Subject | Re: [PATCH v3 0/5] ACPI: DMA ranges management | From | Jeremy Linton <> | Date | Wed, 9 Aug 2017 16:14:43 -0500 |
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Hi,
Better late than never I guess..
On 08/03/2017 07:32 AM, Lorenzo Pieralisi 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@arm.com > v1: http://lkml.kernel.org/r/20170720144517.32529-1-lorenzo.pieralisi@arm.com > > -- Original cover letter -- > > 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@arm.com> > Cc: Hanjun Guo <hanjun.guo@linaro.org> > Cc: Feng Kan <fkan@apm.com> > Cc: Jon Masters <jcm@redhat.com> > Cc: Robert Moore <robert.moore@intel.com> > Cc: Robin Murphy <robin.murphy@arm.com> > Cc: Zhang Rui <rui.zhang@intel.com> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > > 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(-)
Ok, despite being merged already I think its worthwhile to say that I've been testing this with:
Method(_DMA, 0, Serialized) { Return (ResourceTemplate() { QWORDMemory( ResourceConsumer, PosDecode, // _DEC MinFixed, // _MIF MaxFixed, // _MAF Prefetchable, // _MEM ReadWrite, // _RW 0, // _GRA 0x10000000, // _MIN 0x1fffffff, // _MAX 0x000000000, // _TRA 0x10000000, // _LEN , , , ) }) } // Method(_DMA)
(and a couple minor variations)
and a fair number of debug statements sprinkled around to verify that the IOVAs are appropriately limited. So I don't see anything wrong with the code and it appears to work and the devices behind a bridge limited like this continue to work as long as sane values are placed in the min/max/len fields.
Thanks,
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
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