On Wed, 2020-07-01 at 18:16 +1000, Alexey Kardashevskiy wrote:

On 24/06/2020 16:24, Leonardo Bras wrote:

quoted

As of today, if a DDW is created and can't map the whole partition, it's
removed and the default DMA window "ibm,dma-window" is used instead.

Usually this DDW is bigger than the default DMA window, so it would be
better to make use of it instead.

Signed-off-by: Leonardo Bras <redacted>
---
 arch/powerpc/platforms/pseries/iommu.c | 28 +++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 4fcf00016fb1..2d217cda4075 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c

@@ -685,7 +685,7 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
 	struct iommu_table *tbl;
 	struct device_node *dn, *pdn;
 	struct pci_dn *ppci;
-	const __be32 *dma_window = NULL;
+	const __be32 *dma_window = NULL, *alt_dma_window = NULL;
 
 	dn = pci_bus_to_OF_node(bus);
 

@@ -699,8 +699,13 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
 			break;
 	}
 
+	/* If there is a DDW available, use it instead */
+	alt_dma_window = of_get_property(pdn, DIRECT64_PROPNAME, NULL);

It is not necessarily "direct" anymore as the name suggests, you may
want to change that. DMA64_PROPNAME, may be. Thanks,

Yeah, you are right.
I will change this for next version, also changing the string name to
reflect this.

-#define DIRECT64_PROPNAME "linux,direct64-ddr-window-info"
+#define DMA64_PROPNAME "linux,dma64-ddr-window-info"

Is that ok?

Thank you for helping!