[PATCH 2/4] dma: redefine dma_flags_set_dmaflush() for sn-ia64

akepner
2007-09-26T00:03:30Z

define dma_flags_set_dmaflush() for sn-ia64 - it "borrows"
bits from the direction argument (renamed "flags") to the
dma_map_* routines to pass an additional "dmaflush" attribute.
Also define routines to retrieve the original direction and
attribute from "flags".

Signed-off-by: Arthur Kepner <akepner@sgi.com>
--
arch/ia64/sn/pci/pci_dma.c | 35 ++++++++++++++++++++++++++---------
include/asm-ia64/sn/io.h | 26 ++++++++++++++++++++++++++
2 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/arch/ia64/sn/pci/pci_dma.c b/arch/ia64/sn/pci/pci_dma.c
index d79ddac..754240b 100644
--- a/arch/ia64/sn/pci/pci_dma.c
+++ b/arch/ia64/sn/pci/pci_dma.c
@@ -153,7 +153,7 @@ EXPORT_SYMBOL(sn_dma_free_coherent);
* @dev: device to map for
* @cpu_addr: kernel virtual address of the region to map
* @size: size of the region
- * @direction: DMA direction
+ * @flags: DMA direction, and arch-specific attributes
*
* Map the region pointed to by @cpu_addr for DMA and return the
* DMA address.
@@ -167,17 +167,23 @@ EXPORT_SYMBOL(sn_dma_free_coherent);
* figure out how to save dmamap handle so can use two step.
*/
dma_addr_t sn_dma_map_single(struct device *dev, void *cpu_addr, size_t size,
- int direction)
+ int flags)
{
dma_addr_t dma_addr;
unsigned long phys_addr;
struct pci_dev *pdev = to_pci_dev(dev);
struct sn_pcibus_provider *provider = SN_PCIDEV_BUSPROVIDER(pdev);
+ int dmaflush = dma_flags_get_dmaflush(flags);

BUG_ON(dev->bus != &pci_bus_type);

phys_addr = __pa(cpu_addr);
- dma_addr = provider->dma_map(pdev, phys_addr, size, SN_DMA_ADDR_PHYS);
+ if (dmaflush)
+ dma_addr = provider->dma_map_consistent(pdev, phys_addr, size,
+ SN_DMA_ADDR_PHYS);
+ else
+ dma_addr = provider->dma_map(pdev, phys_addr, size,
+ SN_DMA_ADDR_PHYS);
if (!dma_addr) {
printk(KERN_ERR "%s: out of ATEs\n", __FUNCTION__);
return 0;
@@ -240,18 +246,20 @@ EXPORT_SYMBOL(sn_dma_unmap_sg);
* @dev: device to map for
* @sg: scatterlist to map
* @nhwentries: number of entries
- * @direction: direction of the DMA transaction
+ * @flags: direction of the DMA transaction, and arch-specific attributes
*
* Maps each entry of @sg for DMA.
*/
int sn_dma_map_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
- int direction)
+ int flags)
{
unsigned long phys_addr;
struct scatterlist *saved_sg = sg;
struct pci_dev *pdev = to_pci_dev(dev);
struct sn_pcibus_provider *provider = SN_PCIDEV_BUSPROVIDER(pdev);
int i;
+ int dmaflush = dma_flags_get_dmaflush(flags);
+ int direction = dma_flags_get_direction(flags);

BUG_ON(dev->bus != &pci_bus_type);

@@ -259,12 +267,21 @@ int sn_dma_map_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
* Setup a DMA address for each entry in the scatterlist.
*/
for (i = 0; i < nhwentries; i++, sg++) {
+ dma_addr_t dma_addr;
phys_addr = SG_ENT_PHYS_ADDRESS(sg);
- sg->dma_address = provider->dma_map(pdev,
- phys_addr, sg->length,
- SN_DMA_ADDR_PHYS);

- if (!sg->dma_address) {
+ if (dmaflush) {
+ dma_addr = provider->dma_map_consistent(pdev,
+ phys_addr,
+ sg->length,
+ SN_DMA_ADDR_PHYS);
+ } else {
+ dma_addr = provider->dma_map(pdev,
+ phys_addr, sg->length,
+ SN_DMA_ADDR_PHYS);
+ }
+
+ if (!(sg->dma_address = dma_addr)) {
printk(KERN_ERR "%s: out of ATEs\n", __FUNCTION__);

/*
diff --git a/include/asm-ia64/sn/io.h b/include/asm-ia64/sn/io.h
index 41c73a7..71f88ee 100644
--- a/include/asm-ia64/sn/io.h
+++ b/include/asm-ia64/sn/io.h
@@ -271,4 +271,30 @@ sn_pci_set_vchan(struct pci_dev *pci_dev, unsigned long *addr, int vchan)
return 0;
}

+#define ARCH_CAN_REORDER_DMA
+/* here we steal some upper bits from the "direction" argument to the
+ * dma_map_* routines */
+#define DMA_ATTR_SHIFT 8
+/* bottom 8 bits for direction, remaining bits for additional "attributes" */
+#define DMA_FLUSH_ATTR 0x1
+/* For now the only attribute is "flush in-flight dma when writing to
+ * this DMA mapped memory" */
+#define DMA_DIR_MASK ((1 << DMA_ATTR_SHIFT) - 1)
+#define DMA_ATTR_MASK ~DMA_DIR_MASK
+
+static inline int
+dma_flags_set_dmaflush(int dir) {
+ return (dir | (DMA_FLUSH_ATTR<< DMA_ATTR_SHIFT));
+}
+
+static inline int
+dma_flags_get_direction(int dir) {
+ return (dir & DMA_DIR_MASK);
+}
+
+static inline int
+dma_flags_get_dmaflush(int dir) {
+ return (((dir & DMA_ATTR_MASK) >> DMA_ATTR_SHIFT) & DMA_FLUSH_ATTR);
+}
+
#endif /* _ASM_SN_IO_H */