On 2020-09-10 06:40, Christoph Hellwig wrote:
Move the helpers to translate to and from direct mapping DMA addresses
to dma-direct.h. This not only is the most logical place, but the new
placement also avoids dependency loops with pending commits.
For the straightforward move as it should be,
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
However I do wonder how much of this could be cleaned up further...
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/arm/common/dmabounce.c | 2 +-
arch/arm/include/asm/dma-direct.h | 70 ++++++++++++++++++++++++++++++
arch/arm/include/asm/dma-mapping.h | 70 ------------------------------
3 files changed, 71 insertions(+), 71 deletions(-)
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index f4b719bde76367..d3e00ea9208834 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -24,7 +24,7 @@
#include <linux/slab.h>
#include <linux/page-flags.h>
#include <linux/device.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
#include <linux/dmapool.h>
#include <linux/list.h>
#include <linux/scatterlist.h>
diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
index 7c3001a6a775bf..de0f4ff9279615 100644
--- a/arch/arm/include/asm/dma-direct.h
+++ b/arch/arm/include/asm/dma-direct.h
@@ -2,6 +2,76 @@
#ifndef ASM_ARM_DMA_DIRECT_H
#define ASM_ARM_DMA_DIRECT_H 1
+#include <asm/memory.h>
+
+#ifdef __arch_page_to_dma
+#error Please update to __arch_pfn_to_dma
+#endif
This must be long, long dead by now.
+
+/*
+ * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
+ * functions used internally by the DMA-mapping API to provide DMA
+ * addresses. They must not be used by drivers.
+ */
+#ifndef __arch_pfn_to_dma
+static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
+{
+ if (dev)
+ pfn -= dev->dma_pfn_offset;
+ return (dma_addr_t)__pfn_to_bus(pfn);
+}
+
+static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
+{
+ unsigned long pfn = __bus_to_pfn(addr);
+
+ if (dev)
+ pfn += dev->dma_pfn_offset;
+
+ return pfn;
+}
These are only overridden for OMAP1510, and it looks like it wouldn't
take much for the platform code or ohci-omap driver to set up a generic
DMA offset for the relevant device.
+
+static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
+{
+ if (dev) {
+ unsigned long pfn = dma_to_pfn(dev, addr);
+
+ return phys_to_virt(__pfn_to_phys(pfn));
+ }
+
+ return (void *)__bus_to_virt((unsigned long)addr);
+}
This appears entirely unused.
+
+static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
+{
+ if (dev)
+ return pfn_to_dma(dev, virt_to_pfn(addr));
+
+ return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
+}
And this is only used for some debug prints in dmabounce.
Similarly the __bus_to_*()/__*_to_bus() calls themselves only appear
significant to mach-footbridge any more, and could probably also be
evolved into regular DMA offsets now that all API calls must have a
non-NULL device. I think I might come back and take a closer look at all
this at some point in future... :)
Robin.
+
+#else
+static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
+{
+ return __arch_pfn_to_dma(dev, pfn);
+}
+
+static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
+{
+ return __arch_dma_to_pfn(dev, addr);
+}
+
+static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
+{
+ return __arch_dma_to_virt(dev, addr);
+}
+
+static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
+{
+ return __arch_virt_to_dma(dev, addr);
+}
+#endif
+
static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
unsigned int offset = paddr & ~PAGE_MASK;
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index bdd80ddbca3451..0a1a536368c3a4 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -8,8 +8,6 @@
#include <linux/scatterlist.h>
#include <linux/dma-debug.h>
-#include <asm/memory.h>
-
#include <xen/xen.h>
#include <asm/xen/hypervisor.h>
@@ -23,74 +21,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
return NULL;
}
-#ifdef __arch_page_to_dma
-#error Please update to __arch_pfn_to_dma
-#endif
-
-/*
- * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
- * functions used internally by the DMA-mapping API to provide DMA
- * addresses. They must not be used by drivers.
- */
-#ifndef __arch_pfn_to_dma
-static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
-{
- if (dev)
- pfn -= dev->dma_pfn_offset;
- return (dma_addr_t)__pfn_to_bus(pfn);
-}
-
-static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
-{
- unsigned long pfn = __bus_to_pfn(addr);
-
- if (dev)
- pfn += dev->dma_pfn_offset;
-
- return pfn;
-}
-
-static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
-{
- if (dev) {
- unsigned long pfn = dma_to_pfn(dev, addr);
-
- return phys_to_virt(__pfn_to_phys(pfn));
- }
-
- return (void *)__bus_to_virt((unsigned long)addr);
-}
-
-static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
-{
- if (dev)
- return pfn_to_dma(dev, virt_to_pfn(addr));
-
- return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
-}
-
-#else
-static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
-{
- return __arch_pfn_to_dma(dev, pfn);
-}
-
-static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
-{
- return __arch_dma_to_pfn(dev, addr);
-}
-
-static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
-{
- return __arch_dma_to_virt(dev, addr);
-}
-
-static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
-{
- return __arch_virt_to_dma(dev, addr);
-}
-#endif
-
/**
* arm_dma_alloc - allocate consistent memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
