[PATCH v8 6/7] PCI: Update DMA configuration from DT

From: Murali Karicheri
Date: Tue Mar 03 2015 - 12:55:40 EST


If there is a DT node available for the root bridge's parent device, use
the DMA configuration from that device node. For example, Keystone PCI
devices would require dma_pfn_offset to be set correctly in the device
structure of the PCI device in order to have the correct DMA mask. The DT
node will have dma-ranges defined for this. Also support using the DT
property dma-coherent to allow coherent DMA operation by the PCI device.

Use the new helper function of_pci_dma_configure() to update the device DMA
configuration. This fixes DMA on systems where DMA addresses are a
constant offset from CPU physical addresses.

Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> (AMD Seattle)
Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
CC: Joerg Roedel <joro@xxxxxxxxxx>
CC: Grant Likely <grant.likely@xxxxxxxxxx>
CC: Rob Herring <robh+dt@xxxxxxxxxx>
CC: Russell King <linux@xxxxxxxxxxxxxxxx>
CC: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/pci/probe.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8d2f400..413c1dd 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -6,6 +6,7 @@
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
+#include <linux/of_pci.h>
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include <linux/module.h>
@@ -1520,6 +1521,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
dev->dev.dma_mask = &dev->dma_mask;
dev->dev.dma_parms = &dev->dma_parms;
dev->dev.coherent_dma_mask = 0xffffffffull;
+ of_pci_dma_configure(dev);

pci_set_dma_max_seg_size(dev, 65536);
pci_set_dma_seg_boundary(dev, 0xffffffff);
--
1.7.9.5

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