diff options
author | Ralf Baechle <ralf@linux-mips.org> | 2007-10-17 10:29:42 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 19:42:57 +0400 |
commit | 622a9edd919de98ef59571ae6c40c7458244e3f2 (patch) | |
tree | c25684f90ed52c459c39d97d6ab641fe3bb6b09d | |
parent | bc154b1efb7f8430ea9faabd5953ebc411f8ead5 (diff) | |
download | linux-622a9edd919de98ef59571ae6c40c7458244e3f2.tar.xz |
Remove dma_cache_(wback|inv|wback_inv) functions
dma_cache_(wback|inv|wback_inv) were the earliest attempt on a generalized
cache managment API for I/O purposes. Originally it was basically the raw
MIPS low level cache API exported to the entire world. The API has
suffered from a lack of documentation, was not very widely used unlike it's
more modern brothers and can easily be replaced by dma_cache_sync. So
remove it rsp. turn the surviving bits back into an arch private API, as
discussed on linux-arch.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | arch/avr32/mm/dma-coherent.c | 6 | ||||
-rw-r--r-- | arch/mips/mm/cache.c | 2 | ||||
-rw-r--r-- | arch/sh/drivers/pci/dma-dreamcast.c | 2 | ||||
-rw-r--r-- | arch/sh/mm/consistent.c | 8 | ||||
-rw-r--r-- | arch/sh64/mm/consistent.c | 3 | ||||
-rw-r--r-- | include/asm-alpha/io.h | 6 | ||||
-rw-r--r-- | include/asm-avr32/io.h | 7 | ||||
-rw-r--r-- | include/asm-blackfin/io.h | 4 | ||||
-rw-r--r-- | include/asm-h8300/io.h | 6 | ||||
-rw-r--r-- | include/asm-ia64/io.h | 4 | ||||
-rw-r--r-- | include/asm-m68k/io.h | 6 | ||||
-rw-r--r-- | include/asm-m68knommu/io.h | 6 | ||||
-rw-r--r-- | include/asm-mips/io.h | 2 | ||||
-rw-r--r-- | include/asm-parisc/io.h | 5 | ||||
-rw-r--r-- | include/asm-powerpc/io.h | 17 | ||||
-rw-r--r-- | include/asm-ppc/io.h | 17 | ||||
-rw-r--r-- | include/asm-sh/floppy.h | 2 | ||||
-rw-r--r-- | include/asm-sh/io.h | 25 | ||||
-rw-r--r-- | include/asm-sh64/dma-mapping.h | 6 | ||||
-rw-r--r-- | include/asm-sh64/io.h | 48 | ||||
-rw-r--r-- | include/asm-sparc/io.h | 7 | ||||
-rw-r--r-- | include/asm-sparc64/io.h | 6 | ||||
-rw-r--r-- | include/asm-x86/io_32.h | 11 | ||||
-rw-r--r-- | include/asm-x86/io_64.h | 6 |
24 files changed, 19 insertions, 193 deletions
diff --git a/arch/avr32/mm/dma-coherent.c b/arch/avr32/mm/dma-coherent.c index 099212d4567c..177fea8f7b71 100644 --- a/arch/avr32/mm/dma-coherent.c +++ b/arch/avr32/mm/dma-coherent.c @@ -21,13 +21,13 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, int direction) switch (direction) { case DMA_FROM_DEVICE: /* invalidate only */ - dma_cache_inv(vaddr, size); + invalidate_dcache_region(vaddr, size); break; case DMA_TO_DEVICE: /* writeback only */ - dma_cache_wback(vaddr, size); + clean_dcache_region(vaddr, size); break; case DMA_BIDIRECTIONAL: /* writeback and invalidate */ - dma_cache_wback_inv(vaddr, size); + flush_dcache_region(vaddr, size); break; default: BUG(); diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c index 43dde874f414..81f30ac2bff9 100644 --- a/arch/mips/mm/cache.c +++ b/arch/mips/mm/cache.c @@ -47,8 +47,6 @@ void (*_dma_cache_wback)(unsigned long start, unsigned long size); void (*_dma_cache_inv)(unsigned long start, unsigned long size); EXPORT_SYMBOL(_dma_cache_wback_inv); -EXPORT_SYMBOL(_dma_cache_wback); -EXPORT_SYMBOL(_dma_cache_inv); #endif /* CONFIG_DMA_NONCOHERENT */ diff --git a/arch/sh/drivers/pci/dma-dreamcast.c b/arch/sh/drivers/pci/dma-dreamcast.c index 230d6ec0d239..888a34050599 100644 --- a/arch/sh/drivers/pci/dma-dreamcast.c +++ b/arch/sh/drivers/pci/dma-dreamcast.c @@ -51,7 +51,7 @@ void *dreamcast_consistent_alloc(struct device *dev, size_t size, buf = P2SEGADDR(buf); /* Flush the dcache before we hand off the buffer */ - dma_cache_wback_inv((void *)buf, size); + __flush_purge_region((void *)buf, size); return (void *)buf; } diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c index 38c82d890ffd..e220c29a3c00 100644 --- a/arch/sh/mm/consistent.c +++ b/arch/sh/mm/consistent.c @@ -34,7 +34,7 @@ void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle) /* * We must flush the cache before we pass it on to the device */ - dma_cache_wback_inv(ret, size); + __flush_purge_region(ret, size); page = virt_to_page(ret); free = page + (size >> PAGE_SHIFT); @@ -68,13 +68,13 @@ void consistent_sync(void *vaddr, size_t size, int direction) switch (direction) { case DMA_FROM_DEVICE: /* invalidate only */ - dma_cache_inv(p1addr, size); + __flush_invalidate_region(p1addr, size); break; case DMA_TO_DEVICE: /* writeback only */ - dma_cache_wback(p1addr, size); + __flush_wback_region(p1addr, size); break; case DMA_BIDIRECTIONAL: /* writeback and invalidate */ - dma_cache_wback_inv(p1addr, size); + __flush_purge_region(p1addr, size); break; default: BUG(); diff --git a/arch/sh64/mm/consistent.c b/arch/sh64/mm/consistent.c index 8875a2a40da7..c439620402cb 100644 --- a/arch/sh64/mm/consistent.c +++ b/arch/sh64/mm/consistent.c @@ -11,6 +11,7 @@ #include <linux/mm.h> #include <linux/string.h> #include <linux/pci.h> +#include <linux/dma-mapping.h> #include <linux/module.h> #include <asm/io.h> @@ -32,7 +33,7 @@ void *consistent_alloc(struct pci_dev *hwdev, size_t size, if (vp != NULL) { memset(vp, 0, size); *dma_handle = virt_to_phys(ret); - dma_cache_wback_inv((unsigned long)ret, size); + dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL); } return vp; diff --git a/include/asm-alpha/io.h b/include/asm-alpha/io.h index ab5b60dcef19..38f18cf18c9d 100644 --- a/include/asm-alpha/io.h +++ b/include/asm-alpha/io.h @@ -551,12 +551,6 @@ extern void outsl (unsigned long port, const void *src, unsigned long count); #endif #define RTC_ALWAYS_BCD 0 -/* Nothing to do */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - /* * Some mucking forons use if[n]def writeq to check if platform has it. * It's a bloody bad idea and we probably want ARCH_HAS_WRITEQ for them diff --git a/include/asm-avr32/io.h b/include/asm-avr32/io.h index 64bb92bb6773..8be7ea9c9047 100644 --- a/include/asm-avr32/io.h +++ b/include/asm-avr32/io.h @@ -298,13 +298,6 @@ extern void __iounmap(void __iomem *addr); #define ioport_map(port, nr) ioremap(port, nr) #define ioport_unmap(port) iounmap(port) -#define dma_cache_wback_inv(_start, _size) \ - flush_dcache_region(_start, _size) -#define dma_cache_inv(_start, _size) \ - invalidate_dcache_region(_start, _size) -#define dma_cache_wback(_start, _size) \ - clean_dcache_region(_start, _size) - /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access diff --git a/include/asm-blackfin/io.h b/include/asm-blackfin/io.h index 525179bf43d7..d1d2e6be3b59 100644 --- a/include/asm-blackfin/io.h +++ b/include/asm-blackfin/io.h @@ -183,10 +183,6 @@ extern void blkfin_inv_cache_all(void); #define ioport_map(port, nr) ((void __iomem*)(port)) #define ioport_unmap(addr) -#define dma_cache_inv(_start,_size) do { blkfin_inv_cache_all();} while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { blkfin_inv_cache_all();} while (0) - /* Pages to physical address... */ #define page_to_phys(page) ((page - mem_map) << PAGE_SHIFT) #define page_to_bus(page) ((page - mem_map) << PAGE_SHIFT) diff --git a/include/asm-h8300/io.h b/include/asm-h8300/io.h index 91b7487cb7ae..7543a57b4ea1 100644 --- a/include/asm-h8300/io.h +++ b/include/asm-h8300/io.h @@ -264,12 +264,6 @@ static inline void *ioremap_fullcache(unsigned long physaddr, unsigned long size extern void iounmap(void *addr); -/* Nothing to do */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - /* H8/300 internal I/O functions */ static __inline__ unsigned char ctrl_inb(unsigned long addr) { diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h index eb17a8692967..4ebed77aa472 100644 --- a/include/asm-ia64/io.h +++ b/include/asm-ia64/io.h @@ -435,10 +435,6 @@ extern void memcpy_fromio(void *dst, const volatile void __iomem *src, long n); extern void memcpy_toio(volatile void __iomem *dst, const void *src, long n); extern void memset_io(volatile void __iomem *s, int c, long n); -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - # endif /* __KERNEL__ */ /* diff --git a/include/asm-m68k/io.h b/include/asm-m68k/io.h index 47bb9cf107b7..baf4f9b8acfc 100644 --- a/include/asm-m68k/io.h +++ b/include/asm-m68k/io.h @@ -384,12 +384,6 @@ static inline void __iomem *ioremap_fullcache(unsigned long physaddr, return __ioremap(physaddr, size, IOMAP_FULL_CACHING); } - -/* m68k caches aren't DMA coherent */ -extern void dma_cache_wback_inv(unsigned long start, unsigned long size); -extern void dma_cache_wback(unsigned long start, unsigned long size); -extern void dma_cache_inv(unsigned long start, unsigned long size); - static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count) { __builtin_memset((void __force *) addr, val, count); diff --git a/include/asm-m68knommu/io.h b/include/asm-m68knommu/io.h index 8df4cee2a0cd..653d9b2d7ddf 100644 --- a/include/asm-m68knommu/io.h +++ b/include/asm-m68knommu/io.h @@ -165,12 +165,6 @@ static inline void *ioremap_fullcache(unsigned long physaddr, unsigned long size extern void iounmap(void *addr); -/* Nothing to do */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - /* Pages to physical address... */ #define page_to_phys(page) ((page - mem_map) << PAGE_SHIFT) #define page_to_bus(page) ((page - mem_map) << PAGE_SHIFT) diff --git a/include/asm-mips/io.h b/include/asm-mips/io.h index 2cd8323c8586..e62058b0d28c 100644 --- a/include/asm-mips/io.h +++ b/include/asm-mips/io.h @@ -554,6 +554,8 @@ static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int * caches. Dirty lines of the caches may be written back or simply * be discarded. This operation is necessary before dma operations * to the memory. + * + * This API used to be exported; it now is for arch code internal use only. */ #ifdef CONFIG_DMA_NONCOHERENT diff --git a/include/asm-parisc/io.h b/include/asm-parisc/io.h index 4cc9bcec0564..95f00e11c7b4 100644 --- a/include/asm-parisc/io.h +++ b/include/asm-parisc/io.h @@ -270,11 +270,6 @@ extern void outsl (unsigned long port, const void *src, unsigned long count); /* IO Port space is : BBiiii where BB is HBA number. */ #define IO_SPACE_LIMIT 0x00ffffff - -#define dma_cache_inv(_start,_size) do { flush_kernel_dcache_range(_start,_size); } while (0) -#define dma_cache_wback(_start,_size) do { flush_kernel_dcache_range(_start,_size); } while (0) -#define dma_cache_wback_inv(_start,_size) do { flush_kernel_dcache_range(_start,_size); } while (0) - /* PA machines have an MM I/O space from 0xf0000000-0xffffffff in 32 * bit mode and from 0xfffffffff0000000-0xfffffffffffffff in 64 bit * mode (essentially just sign extending. This macro takes in a 32 diff --git a/include/asm-powerpc/io.h b/include/asm-powerpc/io.h index 0d0589ef8ea6..bf14ab4ef4c9 100644 --- a/include/asm-powerpc/io.h +++ b/include/asm-powerpc/io.h @@ -498,23 +498,6 @@ static inline void name at \ #define writeq writeq #endif -#ifdef CONFIG_NOT_COHERENT_CACHE - -#define dma_cache_inv(_start,_size) \ - invalidate_dcache_range(_start, (_start + _size)) -#define dma_cache_wback(_start,_size) \ - clean_dcache_range(_start, (_start + _size)) -#define dma_cache_wback_inv(_start,_size) \ - flush_dcache_range(_start, (_start + _size)) - -#else /* CONFIG_NOT_COHERENT_CACHE */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - -#endif /* !CONFIG_NOT_COHERENT_CACHE */ - /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access diff --git a/include/asm-ppc/io.h b/include/asm-ppc/io.h index 8f58231a8bc6..a0d409a5d80f 100644 --- a/include/asm-ppc/io.h +++ b/include/asm-ppc/io.h @@ -478,23 +478,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *); #include <asm/mpc8260_pci9.h> #endif -#ifdef CONFIG_NOT_COHERENT_CACHE - -#define dma_cache_inv(_start,_size) \ - invalidate_dcache_range(_start, (_start + _size)) -#define dma_cache_wback(_start,_size) \ - clean_dcache_range(_start, (_start + _size)) -#define dma_cache_wback_inv(_start,_size) \ - flush_dcache_range(_start, (_start + _size)) - -#else - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - -#endif - /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access diff --git a/include/asm-sh/floppy.h b/include/asm-sh/floppy.h index 942ade98757b..59fbfdc90dfb 100644 --- a/include/asm-sh/floppy.h +++ b/include/asm-sh/floppy.h @@ -213,7 +213,7 @@ static int hard_dma_setup(char *addr, unsigned long size, int mode, int io) } #endif - dma_cache_wback_inv(addr, size); + __flush_purge_region(addr, size); /* actual, physical DMA */ doing_pdma = 0; diff --git a/include/asm-sh/io.h b/include/asm-sh/io.h index 1a336cdc75fe..6ed34d8eac5f 100644 --- a/include/asm-sh/io.h +++ b/include/asm-sh/io.h @@ -327,31 +327,6 @@ __ioremap_mode(unsigned long offset, unsigned long size, unsigned long flags) __iounmap((addr)) /* - * The caches on some architectures aren't dma-coherent and have need to - * handle this in software. There are three types of operations that - * can be applied to dma buffers. - * - * - dma_cache_wback_inv(start, size) makes caches and RAM coherent by - * writing the content of the caches back to memory, if necessary. - * The function also invalidates the affected part of the caches as - * necessary before DMA transfers from outside to memory. - * - dma_cache_inv(start, size) invalidates the affected parts of the - * caches. Dirty lines of the caches may be written back or simply - * be discarded. This operation is necessary before dma operations - * to the memory. - * - dma_cache_wback(start, size) writes back any dirty lines but does - * not invalidate the cache. This can be used before DMA reads from - * memory, - */ - -#define dma_cache_wback_inv(_start,_size) \ - __flush_purge_region(_start,_size) -#define dma_cache_inv(_start,_size) \ - __flush_invalidate_region(_start,_size) -#define dma_cache_wback(_start,_size) \ - __flush_wback_region(_start,_size) - -/* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access */ diff --git a/include/asm-sh64/dma-mapping.h b/include/asm-sh64/dma-mapping.h index de4309960207..e661857f98dc 100644 --- a/include/asm-sh64/dma-mapping.h +++ b/include/asm-sh64/dma-mapping.h @@ -42,7 +42,11 @@ static inline void dma_free_coherent(struct device *dev, size_t size, static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size, enum dma_data_direction dir) { - dma_cache_wback_inv((unsigned long)vaddr, size); + unsigned long s = (unsigned long) vaddr & L1_CACHE_ALIGN_MASK; + unsigned long e = (vaddr + size) & L1_CACHE_ALIGN_MASK; + + for (; s <= e; s += L1_CACHE_BYTES) + asm volatile ("ocbp %0, 0" : : "r" (s)); } static inline dma_addr_t dma_map_single(struct device *dev, diff --git a/include/asm-sh64/io.h b/include/asm-sh64/io.h index 3de3ad99f457..7bd7314d38c2 100644 --- a/include/asm-sh64/io.h +++ b/include/asm-sh64/io.h @@ -182,54 +182,6 @@ unsigned long onchip_remap(unsigned long addr, unsigned long size, const char* n extern void onchip_unmap(unsigned long vaddr); /* - * The caches on some architectures aren't dma-coherent and have need to - * handle this in software. There are three types of operations that - * can be applied to dma buffers. - * - * - dma_cache_wback_inv(start, size) makes caches and RAM coherent by - * writing the content of the caches back to memory, if necessary. - * The function also invalidates the affected part of the caches as - * necessary before DMA transfers from outside to memory. - * - dma_cache_inv(start, size) invalidates the affected parts of the - * caches. Dirty lines of the caches may be written back or simply - * be discarded. This operation is necessary before dma operations - * to the memory. - * - dma_cache_wback(start, size) writes back any dirty lines but does - * not invalidate the cache. This can be used before DMA reads from - * memory, - */ - -static __inline__ void dma_cache_wback_inv (unsigned long start, unsigned long size) -{ - unsigned long s = start & L1_CACHE_ALIGN_MASK; - unsigned long e = (start + size) & L1_CACHE_ALIGN_MASK; - - for (; s <= e; s += L1_CACHE_BYTES) - asm volatile ("ocbp %0, 0" : : "r" (s)); -} - -static __inline__ void dma_cache_inv (unsigned long start, unsigned long size) -{ - // Note that caller has to be careful with overzealous - // invalidation should there be partial cache lines at the extremities - // of the specified range - unsigned long s = start & L1_CACHE_ALIGN_MASK; - unsigned long e = (start + size) & L1_CACHE_ALIGN_MASK; - - for (; s <= e; s += L1_CACHE_BYTES) - asm volatile ("ocbi %0, 0" : : "r" (s)); -} - -static __inline__ void dma_cache_wback (unsigned long start, unsigned long size) -{ - unsigned long s = start & L1_CACHE_ALIGN_MASK; - unsigned long e = (start + size) & L1_CACHE_ALIGN_MASK; - - for (; s <= e; s += L1_CACHE_BYTES) - asm volatile ("ocbwb %0, 0" : : "r" (s)); -} - -/* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access */ diff --git a/include/asm-sparc/io.h b/include/asm-sparc/io.h index c23e74a0eaa8..243bf8e9a058 100644 --- a/include/asm-sparc/io.h +++ b/include/asm-sparc/io.h @@ -310,13 +310,6 @@ extern void sbus_iounmap(volatile void __iomem *vaddr, unsigned long size); #define RTC_PORT(x) (rtc_port + (x)) #define RTC_ALWAYS_BCD 0 -/* Nothing to do */ -/* P3: Only IDE DMA may need these. XXX Verify that it still does... */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - #endif #define __ARCH_HAS_NO_PAGE_ZERO_MAPPED 1 diff --git a/include/asm-sparc64/io.h b/include/asm-sparc64/io.h index 9565a892801e..cd7ef3097ac2 100644 --- a/include/asm-sparc64/io.h +++ b/include/asm-sparc64/io.h @@ -474,12 +474,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *); #define sbus_iounmap(__addr, __size) \ release_region((unsigned long)(__addr), (__size)) -/* Nothing to do */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access diff --git a/include/asm-x86/io_32.h b/include/asm-x86/io_32.h index e8e0bd641120..4ea7b1ad3c1d 100644 --- a/include/asm-x86/io_32.h +++ b/include/asm-x86/io_32.h @@ -237,18 +237,9 @@ static inline void flush_write_buffers(void) __asm__ __volatile__ ("lock; addl $0,0(%%esp)": : :"memory"); } -#define dma_cache_inv(_start,_size) flush_write_buffers() -#define dma_cache_wback(_start,_size) flush_write_buffers() -#define dma_cache_wback_inv(_start,_size) flush_write_buffers() - #else -/* Nothing to do */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) -#define flush_write_buffers() +#define flush_write_buffers() do { } while (0) #endif diff --git a/include/asm-x86/io_64.h b/include/asm-x86/io_64.h index 7475095c5061..a037b0794332 100644 --- a/include/asm-x86/io_64.h +++ b/include/asm-x86/io_64.h @@ -249,12 +249,6 @@ void memset_io(volatile void __iomem *a, int b, size_t c); */ #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET)) -/* Nothing to do */ - -#define dma_cache_inv(_start,_size) do { } while (0) -#define dma_cache_wback(_start,_size) do { } while (0) -#define dma_cache_wback_inv(_start,_size) do { } while (0) - #define flush_write_buffers() extern int iommu_bio_merge; |