From d73cd42893f4cdc06e6829fea2347bb92cb789d1 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 15 Sep 2008 16:44:55 -0400 Subject: [ARM] kmap support The kmap virtual area borrows a 2MB range at the top of the 16MB area below PAGE_OFFSET currently reserved for kernel modules and/or the XIP kernel. This 2MB corresponds to the range covered by 2 consecutive second-level page tables, or a single pmd entry as seen by the Linux page table abstraction. Because XIP kernels are unlikely to be seen on systems needing highmem support, there shouldn't be any shortage of VM space for modules (14 MB for modules is still way more than twice the typical usage). Because the virtual mapping of highmem pages can go away at any moment after kunmap() is called on them, we need to bypass the delayed cache flushing provided by flush_dcache_page() in that case. The atomic kmap versions are based on fixmaps, and __cpuc_flush_dcache_page() is used directly in that case. Signed-off-by: Nicolas Pitre --- arch/arm/include/asm/memory.h | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'arch/arm/include/asm/memory.h') diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 0202a7c20e62..ae472bc376d3 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -44,13 +44,20 @@ * The module space lives between the addresses given by TASK_SIZE * and PAGE_OFFSET - it must be within 32MB of the kernel text. */ -#define MODULES_END (PAGE_OFFSET) -#define MODULES_VADDR (MODULES_END - 16*1048576) - +#define MODULES_VADDR (PAGE_OFFSET - 16*1024*1024) #if TASK_SIZE > MODULES_VADDR #error Top of user space clashes with start of module space #endif +/* + * The highmem pkmap virtual space shares the end of the module area. + */ +#ifdef CONFIG_HIGHMEM +#define MODULES_END (PAGE_OFFSET - PMD_SIZE) +#else +#define MODULES_END (PAGE_OFFSET) +#endif + /* * The XIP kernel gets mapped at the bottom of the module vm area. * Since we use sections to map it, this macro replaces the physical address -- cgit v1.2.3 From 58edb515724f9e63e569536d01ac8d8f8ddb367a Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 9 Sep 2008 15:54:13 -0400 Subject: [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 --- arch/arm/common/dmabounce.c | 7 +++++++ arch/arm/include/asm/dma-mapping.h | 10 ++++++++++ arch/arm/include/asm/memory.h | 1 + arch/arm/mach-iop13xx/include/mach/memory.h | 5 ++++- arch/arm/mach-ks8695/include/mach/memory.h | 6 +++++- arch/arm/plat-omap/include/mach/memory.h | 8 +++++--- 6 files changed, 32 insertions(+), 5 deletions(-) (limited to 'arch/arm/include/asm/memory.h') diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c index f030f0775be7..734ac9135998 100644 --- a/arch/arm/common/dmabounce.c +++ b/arch/arm/common/dmabounce.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -349,6 +350,12 @@ dma_addr_t dma_map_page(struct device *dev, struct page *page, 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 59fa762e9c66..ff46dfa68a97 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 ae472bc376d3..85763db87449 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -188,6 +188,7 @@ static inline void *phys_to_virt(unsigned long x) #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 e012bf13c955..42ae29b288a1 100644 --- a/arch/arm/mach-iop13xx/include/mach/memory.h +++ b/arch/arm/mach-iop13xx/include/mach/memory.h @@ -59,7 +59,10 @@ static inline unsigned long __lbus_to_virt(dma_addr_t x) }) #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 6d5887cf5742..76e5308685a4 100644 --- a/arch/arm/mach-ks8695/include/mach/memory.h +++ b/arch/arm/mach-ks8695/include/mach/memory.h @@ -35,7 +35,11 @@ extern struct bus_type platform_bus_type; __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 d6b5ca6c7da2..99ed564d9277 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) : \ -- cgit v1.2.3