[ARM] make page_to_dma() highmem aware
If a machine class has a custom __virt_to_bus() implementation then it
must provide a __arch_page_to_dma() implementation as well which is
_not_ based on page_address() to support highmem.
This patch fixes existing __arch_page_to_dma() and provide a default
implementation otherwise. The default implementation for highmem is
based on __pfn_to_bus() which is defined only when no custom
__virt_to_bus() is provided by the machine class.
That leaves only ebsa110 and footbridge which cannot support highmem
until they provide their own __arch_page_to_dma() implementation.
But highmem support on those legacy platforms with limited memory is
certainly not a priority.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index f030f07..734ac91 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
+#include <linux/page-flags.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
@@ -349,6 +350,12 @@
BUG_ON(!valid_dma_direction(dir));
+ if (PageHighMem(page)) {
+ dev_err(dev, "DMA buffer bouncing of HIGHMEM pages "
+ "is not supported\n");
+ return ~0;
+ }
+
return map_single(dev, page_address(page) + offset, size, dir);
}
EXPORT_SYMBOL(dma_map_page);
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 59fa762..ff46dfa 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -15,10 +15,20 @@
* must not be used by drivers.
*/
#ifndef __arch_page_to_dma
+
+#if !defined(CONFIG_HIGHMEM)
static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
{
return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page));
}
+#elif defined(__pfn_to_bus)
+static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
+{
+ return (dma_addr_t)__pfn_to_bus(page_to_pfn(page));
+}
+#else
+#error "this machine class needs to define __arch_page_to_dma to use HIGHMEM"
+#endif
static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
{
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index ae472bc..85763db 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -188,6 +188,7 @@
#ifndef __virt_to_bus
#define __virt_to_bus __virt_to_phys
#define __bus_to_virt __phys_to_virt
+#define __pfn_to_bus(x) ((x) << PAGE_SHIFT)
#endif
static inline __deprecated unsigned long virt_to_bus(void *x)
diff --git a/arch/arm/mach-iop13xx/include/mach/memory.h b/arch/arm/mach-iop13xx/include/mach/memory.h
index e012bf1..42ae29b 100644
--- a/arch/arm/mach-iop13xx/include/mach/memory.h
+++ b/arch/arm/mach-iop13xx/include/mach/memory.h
@@ -59,7 +59,10 @@
})
#define __arch_page_to_dma(dev, page) \
- __arch_virt_to_dma(dev, page_address(page))
+ ({ \
+ /* __is_lbus_virt() can never be true for RAM pages */ \
+ (dma_addr_t)page_to_phys(page); \
+ })
#endif /* CONFIG_ARCH_IOP13XX */
#endif /* !ASSEMBLY */
diff --git a/arch/arm/mach-ks8695/include/mach/memory.h b/arch/arm/mach-ks8695/include/mach/memory.h
index 6d5887c..76e5308 100644
--- a/arch/arm/mach-ks8695/include/mach/memory.h
+++ b/arch/arm/mach-ks8695/include/mach/memory.h
@@ -35,7 +35,11 @@
__phys_to_virt(x) : __bus_to_virt(x)); })
#define __arch_virt_to_dma(dev, x) ({ is_lbus_device(dev) ? \
(dma_addr_t)__virt_to_phys(x) : (dma_addr_t)__virt_to_bus(x); })
-#define __arch_page_to_dma(dev, x) __arch_virt_to_dma(dev, page_address(x))
+#define __arch_page_to_dma(dev, x) \
+ ({ dma_addr_t __dma = page_to_phys(page); \
+ if (!is_lbus_device(dev)) \
+ __dma = __dma - PHYS_OFFSET + KS8695_PCIMEM_PA; \
+ __dma; })
#endif
diff --git a/arch/arm/plat-omap/include/mach/memory.h b/arch/arm/plat-omap/include/mach/memory.h
index d6b5ca6..99ed564 100644
--- a/arch/arm/plat-omap/include/mach/memory.h
+++ b/arch/arm/plat-omap/include/mach/memory.h
@@ -61,9 +61,11 @@
#define lbus_to_virt(x) ((x) - OMAP1510_LB_OFFSET + PAGE_OFFSET)
#define is_lbus_device(dev) (cpu_is_omap15xx() && dev && (strncmp(dev_name(dev), "ohci", 4) == 0))
-#define __arch_page_to_dma(dev, page) ({is_lbus_device(dev) ? \
- (dma_addr_t)virt_to_lbus(page_address(page)) : \
- (dma_addr_t)__virt_to_phys(page_address(page));})
+#define __arch_page_to_dma(dev, page) \
+ ({ dma_addr_t __dma = page_to_phys(page); \
+ if (is_lbus_device(dev)) \
+ __dma = __dma - PHYS_OFFSET + OMAP1510_LB_OFFSET; \
+ __dma; })
#define __arch_dma_to_virt(dev, addr) ({ (void *) (is_lbus_device(dev) ? \
lbus_to_virt(addr) : \