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 <lorenzo.pieralisi@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx> 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 <hanjun.guo@xxxxxxxxxx> Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
