IORT revision D allows PCI root complex nodes to specify a memory
address size limit equivalently to named components, to help describe
straightforward integrations which don't really warrant a full-blown
_DMA method. Now that our headers are up-to-date, plumb it in.
If both _DMA and an address size limit are present, we would always
expect the former to be a more specific subset of the latter (since it
makes little sense for a _DMA range to involve bits which IORT says
aren't wired up), thus we can save calculating an explicit intersection
of the two effective masks and simply use short-circuit logic instead.
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
drivers/acpi/arm64/iort.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 7a3a541046ed..4a66896e2aa3 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -947,6 +947,24 @@ static int nc_dma_get_range(struct device *dev, u64 *size)
return 0;
}
+static int rc_dma_get_range(struct device *dev, u64 *size)
+{
+ struct acpi_iort_node *node;
+ struct acpi_iort_root_complex *rc;
+
+ node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+ iort_match_node_callback, dev);
+ if (!node || node->revision < 1)
+ return -ENODEV;
+
+ rc = (struct acpi_iort_root_complex *)node->node_data;
+
+ *size = rc->memory_address_limit >= 64 ? U64_MAX :
+ 1ULL<<rc->memory_address_limit;
+
+ return 0;
+}
+
/**
* iort_dma_setup() - Set-up device DMA parameters.
*
@@ -975,10 +993,13 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
- if (dev_is_pci(dev))
+ if (dev_is_pci(dev)) {
ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size);
- else
+ if (ret == -ENODEV)
+ ret = rc_dma_get_range(dev, &size);
+ } else {
ret = nc_dma_get_range(dev, &size);
+ }
if (!ret) {
msb = fls64(dmaaddr + size - 1);
--
2.17.1.dirty
--
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