On 2016/12/5 20:26, Lorenzo Pieralisi wrote:

The introduction of acpi_dma_configure() allows to configure DMA
and related IOMMU for any device that is DMA capable. To achieve
that goal it ensures DMA masks are set-up to sane default values
before proceeding with IOMMU and DMA ops configuration.

On x86/ia64 systems, through acpi_bind_one(), acpi_dma_configure() is
called for every device that has an ACPI companion, in that every device
is considered DMA capable on x86/ia64 systems (ie acpi_get_dma_attr() API),
which has the side effect of initializing dma masks also for
pseudo-devices (eg CPUs and memory nodes) and potentially for devices
whose dma masks were not set-up before the acpi_dma_configure() API was
introduced, which may have noxious side effects.

Therefore, in preparation for IORT firmware specific DMA masks set-up,
wrap the default DMA masks set-up in acpi_dma_configure() inside an IORT
specific wrapper that reverts to a NOP on x86/ia64 systems, restoring the
default expected behaviour on x86/ia64 systems and keeping DMA default
masks set-up on IORT based (ie ARM) arch configurations.

Signed-off-by: Lorenzo Pieralisi <redacted>
Cc: Will Deacon <redacted>
Cc: Hanjun Guo <redacted>

Add this patch on top of your v9 acpi smmu patchset,
tested on Hisilicon D03 (ARM64), devices with SMMU
enabled work fine,

Tested-by: Hanjun Guo <redacted>
Reviewed-by: Hanjun Guo <redacted>

Thanks
Hanjun