Subject: [PATCH] arm64: iort: take _DMA methods into account for named components

From: Ard Biesheuvel <[email-masked]>
Date: Sat, 4 Apr 2020 09:30:47 +0200

Where IORT nodes for named components can describe simple DMA limits
expressed as the number of address bits a device can driver, _DMA methods
in AML can express more complex topologies, involving DMA translation in
particular.

Currently, we only take this _DMA method into account if it appears on a
ACPI device node describing a PCIe root complex, but it is perfectly
acceptable to attach them to named components as well, so let's ensure
we take them into account in those cases too.

Reported-by: Andrei Warkentin <[email-masked]>
Fixes: 7ad4263980826e8b ("ACPI: Make acpi_dma_configure() DMA regions aware")
Cc: <[email-masked]> # v4.14+
Signed-off-by: Ard Biesheuvel <[email-masked]>
---
 drivers/acpi/arm64/iort.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index ed3d2d1a7ae9..07eb78baf198 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1146,13 +1146,10 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
 	else
 		size = 1ULL << 32;
 
-	if (dev_is_pci(dev)) {
-		ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size);
-		if (ret == -ENODEV)
-			ret = rc_dma_get_range(dev, &size);
-	} else {
-		ret = nc_dma_get_range(dev, &size);
-	}
+	ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size);
+	if (ret == -ENODEV)
+		ret = dev_is_pci(dev) ? rc_dma_get_range(dev, &size)
+				      : nc_dma_get_range(dev, &size);
 
 	if (!ret) {
 		/*
-- 
2.17.1

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