Hi Lorenzo, On 8/3/2017 8:32 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@xxxxxxx v1: http://lkml.kernel.org/r/20170720144517.32529-1-lorenzo.pieralisi@xxxxxxx -- Original cover letter -- 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 (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(-)
I tested with named components and with _DMA objects at a variety of sizes and verified the configured masks matched the expected values. Tested-by: Nate Watterson <nwatters@xxxxxxxxxxxxxx> One general question I had while testing the patch is whether it is possible to define a complete 64-bit range using the _DMA method. For instance, to get a 64-bit dma_mask I had to use a non-zero MIN value so that LEN would not overflow. QWORDMemory( ResourceConsumer, PosDecode, // _DEC MinFixed, // _MIF MaxFixed, // _MAF Prefetchable, // _MEM ReadWrite, // _RW 0, // _GRA 0x1000, // _MIN 0xffffffffffffffff, // _MAX 0x0, // _TRA 0xfffffffffffff000, // _LEN , , , ) -Nate -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- 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