ACPI: Make acpi_dma_configure() DMA regions aware

Current ACPI DMA configuration set-up device DMA capabilities through
kernel defaults that do not take into account platform specific DMA
configurations reported by firmware.

By leveraging the ACPI acpi_dev_get_dma_resources() API, add code
in acpi_dma_configure() to retrieve the DMA regions to correctly
set-up PCI devices DMA parameters.

Rework the ACPI IORT kernel API to make sure they can accommodate
the DMA set-up required by firmware. By making PCI devices DMA set-up
ACPI IORT specific, the kernel is shielded from unwanted regressions
that could be triggered by parsing DMA resources on arches that were
previously ignoring them (ie x86/ia64), leaving kernel behaviour
unchanged on those arches.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 4 insertions, 8 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 94500d99f2d6..0483d36433ac 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1446,20 +1446,16 @@ int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
 int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
 {
 	const struct iommu_ops *iommu;
-	u64 size;
+	u64 dma_addr = 0, size = 0;
 
-	iort_set_dma_mask(dev);
+	iort_dma_setup(dev, &dma_addr, &size);
 
 	iommu = iort_iommu_configure(dev);
 	if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
 
-	size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
-	/*
-	 * Assume dma valid range starts at 0 and covers the whole
-	 * coherent_dma_mask.
-	 */
-	arch_setup_dma_ops(dev, 0, size, iommu, attr == DEV_DMA_COHERENT);
+	arch_setup_dma_ops(dev, dma_addr, size,
+				iommu, attr == DEV_DMA_COHERENT);
 
 	return 0;
 }