On Thu, Jan 21, 2021 at 05:24:19PM -0800, Moritz Fischer wrote: > Address issue observed on real world system with suboptimal IORT table > where DMA masks of PCI devices would get set to 0 as result. > > iort_dma_setup() would query the root complex'/named component IORT > entry for a DMA mask, and use that over the one the device has been > configured with earlier. > > Ideally we want to use the minimum mask of what the IORT contains for > the root complex and what the device was configured with. > > Fixes: 5ac65e8c8941 ("ACPI/IORT: Support address size limit for root complexes") > Signed-off-by: Moritz Fischer <mdf@xxxxxxxxxx> > --- > > Changes from v1: > - Changed warning to FW_BUG > - Warn for both Named Component or Root Complex > - Replaced min_not_zero() with min() > > --- > drivers/acpi/arm64/iort.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index d4eac6d7e9fb..2494138a6905 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -1107,6 +1107,11 @@ static int nc_dma_get_range(struct device *dev, u64 *size) > > ncomp = (struct acpi_iort_named_component *)node->node_data; > > + if (!ncomp->memory_address_limit) { > + pr_warn(FW_BUG "Named component missing memory address limit\n"); > + return -EINVAL; > + } > + > *size = ncomp->memory_address_limit >= 64 ? U64_MAX : > 1ULL<<ncomp->memory_address_limit; > > @@ -1126,6 +1131,11 @@ static int rc_dma_get_range(struct device *dev, u64 *size) > > rc = (struct acpi_iort_root_complex *)node->node_data; > > + if (!rc->memory_address_limit) { > + pr_warn(FW_BUG "Root complex missing memory address limit\n"); > + return -EINVAL; > + } > + > *size = rc->memory_address_limit >= 64 ? U64_MAX : > 1ULL<<rc->memory_address_limit; > > @@ -1173,8 +1183,8 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) > end = dmaaddr + size - 1; > mask = DMA_BIT_MASK(ilog2(end) + 1); > dev->bus_dma_limit = end; > - dev->coherent_dma_mask = mask; > - *dev->dma_mask = mask; > + dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask); > + *dev->dma_mask = min(*dev->dma_mask, mask); > } > > *dma_addr = dmaaddr; > -- > 2.30.0 >