[PATCH 01/18] PCI: endpoint: pci-epc-core: Use of_dma_configure() to set initial dma mask

Kishon Vijay Abraham I
2017-08-18T14:57:53Z

Use of_dma_configure() to set the initial dma mask of epf device. This
helps to get rid of "Coherent DMA mask 0x0 (pfn 0x0-0x1) covers a smaller
range of system memory than the DMA zone pfn" warning in certain platforms
like TI's K2G resulting in coherent dma mask not being set.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/pci/endpoint/pci-epc-core.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index caa7be10e473..42c2a1156325 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -21,6 +21,7 @@
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/of_device.h>

#include <linux/pci-epc.h>
#include <linux/pci-epf.h>
@@ -370,6 +371,7 @@ EXPORT_SYMBOL_GPL(pci_epc_write_header);
int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)
{
unsigned long flags;
+ struct device *dev = epc->dev.parent;

if (epf->epc)
return -EBUSY;
@@ -381,8 +383,12 @@ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)
return -EINVAL;

epf->epc = epc;
- dma_set_coherent_mask(&epf->dev, epc->dev.coherent_dma_mask);
- epf->dev.dma_mask = epc->dev.dma_mask;
+ if (dev->of_node) {
+ of_dma_configure(&epf->dev, dev->of_node);
+ } else {
+ dma_set_coherent_mask(&epf->dev, epc->dev.coherent_dma_mask);
+ epf->dev.dma_mask = epc->dev.dma_mask;
+ }

spin_lock_irqsave(&epc->lock, flags);
list_add_tail(&epf->list, &epc->pci_epf);
@@ -500,6 +506,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
dma_set_coherent_mask(&epc->dev, dev->coherent_dma_mask);
epc->dev.class = pci_epc_class;
epc->dev.dma_mask = dev->dma_mask;
+ epc->dev.parent = dev;
epc->ops = ops;

ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
--
2.11.0