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Message-ID: <20070928011219.GO30013@sgi.com>
Date: Thu, 27 Sep 2007 18:12:19 -0700
From: akepner@....com
To: Grant Grundler <grundler@...isc-linux.org>,
Jesse Barnes <jbarnes@...tuousgeek.org>,
Jes Sorensen <jes@....com>,
Randy Dunlap <randy.dunlap@...cle.com>,
RolandDreier <rdreier@...co.com>,
James Bottomley <James.Bottomley@...eleye.com>
Cc: linux-kernel@...r.kernel.org
Subject: [2/4] dma: redefine dma_flags_set_dmabarrier() for sn-ia64
define dma_flags_set_dmabarrier() for sn-ia64 - it "borrows"
bits from the direction argument (renamed "flags") to the
dma_map_* routines to pass an additional "dmabarrier" attribute.
Also define routines to retrieve the original direction and
attribute from "flags".
Signed-off-by: Arthur Kepner <akepner@....com>
---
arch/ia64/sn/pci/pci_dma.c | 35 ++++++++++++++++++++++++++---------
include/asm-ia64/sn/io.h | 24 ++++++++++++++++++++++++
2 files changed, 50 insertions(+), 9 deletions(-)
diff --git a/arch/ia64/sn/pci/pci_dma.c b/arch/ia64/sn/pci/pci_dma.c
index d79ddac..6c0a498 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 dmabarrier = dma_flags_get_dmabarrier(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 (dmabarrier)
+ 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 dmabarrier = dma_flags_get_dmabarrier(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 (dmabarrier) {
+ 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..301bc47 100644
--- a/include/asm-ia64/sn/io.h
+++ b/include/asm-ia64/sn/io.h
@@ -271,4 +271,28 @@ 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_BARRIER_ATTR 0x1
+/* Setting DMA_BARRIER_ATTR on a DMA-mapped memory region causes all in-
+ * flight DMA to be flushed when the memory region is written to. So
+ * DMA_BARRIER_ATTR is a mechanism to enforce ordering of DMA. */
+#define DMA_DIR_MASK ((1 << DMA_ATTR_SHIFT) - 1)
+#define DMA_ATTR_MASK ~DMA_DIR_MASK
+
+static inline int dma_flags_set_dmabarrier(int dir) {
+ return (dir | (DMA_BARRIER_ATTR<< DMA_ATTR_SHIFT));
+}
+
+static inline int dma_flags_get_direction(int dir) {
+ return (dir & DMA_DIR_MASK);
+}
+
+static inline int dma_flags_get_dmabarrier(int dir) {
+ return (((dir & DMA_ATTR_MASK) >> DMA_ATTR_SHIFT) & DMA_BARRIER_ATTR);
+}
+
#endif /* _ASM_SN_IO_H */
-
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