[PATCH 21/22] sparc: use generic dma_noncoherent_ops

Christoph Hellwig
2018-04-20T08:07:13Z

Switch to the generic noncoherent direct mapping implementation.

This removes the previous sync_single_for_device implementation, which
looks bogus given that no syncing is happening in the similar but more
important map_single case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/sparc/Kconfig | 2 +
arch/sparc/include/asm/dma-mapping.h | 5 +-
arch/sparc/kernel/ioport.c | 151 ++-------------------------
3 files changed, 14 insertions(+), 144 deletions(-)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index c1cfc17eb504..5680eece3014 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -49,6 +49,8 @@ config SPARC

config SPARC32
def_bool !64BIT
+ select ARCH_HAS_SYNC_DMA_FOR_CPU
+ select DMA_NONCOHERENT_OPS
select GENERIC_ATOMIC64
select CLZ_TAB
select HAVE_UID16
diff --git a/arch/sparc/include/asm/dma-mapping.h b/arch/sparc/include/asm/dma-mapping.h
index 12ae33daf52f..e17566376934 100644
--- a/arch/sparc/include/asm/dma-mapping.h
+++ b/arch/sparc/include/asm/dma-mapping.h
@@ -7,7 +7,6 @@
#include <linux/dma-debug.h>

extern const struct dma_map_ops *dma_ops;
-extern const struct dma_map_ops pci32_dma_ops;

extern struct bus_type pci_bus_type;

@@ -15,11 +14,11 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
#ifdef CONFIG_SPARC_LEON
if (sparc_cpu_model == sparc_leon)
- return &pci32_dma_ops;
+ return &dma_noncoherent_ops;
#endif
#if defined(CONFIG_SPARC32) && defined(CONFIG_PCI)
if (bus == &pci_bus_type)
- return &pci32_dma_ops;
+ return &dma_noncoherent_ops;
#endif
return dma_ops;
}
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index 3bcef9ce74df..7954512c42e7 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -38,6 +38,7 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/scatterlist.h>
+#include <linux/dma-noncoherent.h>
#include <linux/of_device.h>

#include <asm/io.h>
@@ -434,9 +435,8 @@ arch_initcall(sparc_register_ioport);
/* Allocate and map kernel buffer using consistent mode DMA for a device.
* hwdev should be valid struct pci_dev pointer for PCI devices.
*/
-static void *pci32_alloc_coherent(struct device *dev, size_t len,
- dma_addr_t *pba, gfp_t gfp,
- unsigned long attrs)
+void *arch_dma_alloc(struct device *dev, size_t len, dma_addr_t *pba, gfp_t gfp,
+ unsigned long attrs)
{
unsigned long len_total = PAGE_ALIGN(len);
void *va;
@@ -488,8 +488,8 @@ static void *pci32_alloc_coherent(struct device *dev, size_t len,
* References to the memory and mappings associated with cpu_addr/dma_addr
* past this call are illegal.
*/
-static void pci32_free_coherent(struct device *dev, size_t n, void *p,
- dma_addr_t ba, unsigned long attrs)
+void arch_dma_free(struct device *dev, size_t n, void *p, dma_addr_t ba,
+ unsigned long attrs)
{
struct resource *res;

@@ -519,146 +519,15 @@ static void pci32_free_coherent(struct device *dev, size_t n, void *p,
free_pages((unsigned long)phys_to_virt(ba), get_order(n));
}

-/*
- * Same as pci_map_single, but with pages.
- */
-static dma_addr_t pci32_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction dir,
- unsigned long attrs)
-{
- /* IIep is write-through, not flushing. */
- return page_to_phys(page) + offset;
-}
-
-static void pci32_unmap_page(struct device *dev, dma_addr_t ba, size_t size,
- enum dma_data_direction dir, unsigned long attrs)
-{
- if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
- dma_make_coherent(ba, PAGE_ALIGN(size));
-}
-
-/* Map a set of buffers described by scatterlist in streaming
- * mode for DMA. This is the scatter-gather version of the
- * above pci_map_single interface. Here the scatter gather list
- * elements are each tagged with the appropriate dma address
- * and length. They are obtained via sg_dma_{address,length}(SG).
- *
- * NOTE: An implementation may be able to use a smaller number of
- * DMA address/length pairs than there are SG table elements.
- * (for example via virtual mapping capabilities)
- * The routine returns the number of addr/length pairs actually
- * used, at most nents.
- *
- * Device ownership issues as mentioned above for pci_map_single are
- * the same here.
- */
-static int pci32_map_sg(struct device *device, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir,
- unsigned long attrs)
-{
- struct scatterlist *sg;
- int n;
-
- /* IIep is write-through, not flushing. */
- for_each_sg(sgl, sg, nents, n) {
- sg->dma_address = sg_phys(sg);
- sg->dma_length = sg->length;
- }
- return nents;
-}
-
-/* Unmap a set of streaming mode DMA translations.
- * Again, cpu read rules concerning calls here are the same as for
- * pci_unmap_single() above.
- */
-static void pci32_unmap_sg(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir,
- unsigned long attrs)
-{
- struct scatterlist *sg;
- int n;
-
- if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
- for_each_sg(sgl, sg, nents, n) {
- dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
- }
- }
-}
+/* IIep is write-through, not flushing on cpu to device transfer. */

-/* Make physical memory consistent for a single
- * streaming mode DMA translation before or after a transfer.
- *
- * If you perform a pci_map_single() but wish to interrogate the
- * buffer using the cpu, yet do not wish to teardown the PCI dma
- * mapping, you must call this function before doing so. At the
- * next point you give the PCI dma address back to the card, you
- * must first perform a pci_dma_sync_for_device, and then the
- * device again owns the buffer.
- */
-static void pci32_sync_single_for_cpu(struct device *dev, dma_addr_t ba,
- size_t size, enum dma_data_direction dir)
+void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
{
- if (dir != PCI_DMA_TODEVICE) {
- dma_make_coherent(ba, PAGE_ALIGN(size));
- }
-}
-
-static void pci32_sync_single_for_device(struct device *dev, dma_addr_t ba,
- size_t size, enum dma_data_direction dir)
-{
- if (dir != PCI_DMA_TODEVICE) {
- dma_make_coherent(ba, PAGE_ALIGN(size));
- }
+ if (dir != PCI_DMA_TODEVICE)
+ dma_make_coherent(paddr, PAGE_ALIGN(size));
}

-/* Make physical memory consistent for a set of streaming
- * mode DMA translations after a transfer.
- *
- * The same as pci_dma_sync_single_* but for a scatter-gather list,
- * same rules and usage.
- */
-static void pci32_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir)
-{
- struct scatterlist *sg;
- int n;
-
- if (dir != PCI_DMA_TODEVICE) {
- for_each_sg(sgl, sg, nents, n) {
- dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
- }
- }
-}
-
-static void pci32_sync_sg_for_device(struct device *device, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir)
-{
- struct scatterlist *sg;
- int n;
-
- if (dir != PCI_DMA_TODEVICE) {
- for_each_sg(sgl, sg, nents, n) {
- dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
- }
- }
-}
-
-/* note: leon re-uses pci32_dma_ops */
-const struct dma_map_ops pci32_dma_ops = {
- .alloc = pci32_alloc_coherent,
- .free = pci32_free_coherent,
- .map_page = pci32_map_page,
- .unmap_page = pci32_unmap_page,
- .map_sg = pci32_map_sg,
- .unmap_sg = pci32_unmap_sg,
- .sync_single_for_cpu = pci32_sync_single_for_cpu,
- .sync_single_for_device = pci32_sync_single_for_device,
- .sync_sg_for_cpu = pci32_sync_sg_for_cpu,
- .sync_sg_for_device = pci32_sync_sg_for_device,
-};
-EXPORT_SYMBOL(pci32_dma_ops);
-
const struct dma_map_ops *dma_ops = &sbus_dma_ops;
EXPORT_SYMBOL(dma_ops);

--
2.17.0