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*参照元 [#r366bf96] #backlinks *説明 [#zc8145c8] -パス: [[linux-2.6.33/include/asm-generic/dma-coherent.h]] -FIXME: これは何？ --確保した領域は 0 データで埋められる --確保した領域は 0 データで埋められる。 --コンフィグにより、マクロの場合と関数の場合の 2通りある。 **引数 [#d5af6009] -struct device *dev --デバイス --[[linux-2.6.33/device]] -ssize_t size --確保する領域のサイズ -dma_addr_t *dma_handle --確保した領域の DMA アドレスを返すためのポインタ --失敗したときは不定値が返る --[[linux-2.6.33/dma_addr_t]] -void **ret --確保した領域の仮想アドレスを返すためのポインタ --失敗したときは不定値が返る **返り値 [#f8c12ac4] -int --成功なら 0以外、失敗なら 0 **参考 [#h5efe1a3] 汎用の関数を利用するようにコンフィグを定義しているアーキテクチャは、 arm, mips, sh, x86 の一部に存在する。 arch/arm/configs/acs5k_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/acs5k_tiny_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/afeb9260_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/am3517_evm_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/bcmring_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/cm_t35_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/cm_x2xx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/cm_x300_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/colibri_pxa270_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/colibri_pxa300_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/corgi_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/cpu9260_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/cpu9g20_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/cpuat91_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/da8xx_omapl_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/davinci_all_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/dove_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/em_x270_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/ep93xx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/eseries_pxa_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/ezx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/h3600_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/h5000_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/htcherald_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/igep0020_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/iop33x_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/jornada720_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/kb9202_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/kirkwood_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/ks8695_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/magician_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mini2440_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mv78xx0_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mx1_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mx21_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mx27_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mx31pdk_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/mx3_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/n8x0_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/neocore926_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/nhk8815_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/nuc910_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/nuc950_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/nuc960_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap3_beagle_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap3_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap3_evm_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap3_pandora_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap3_touchbook_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap_3430sdp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap_3630sdp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap_4430sdp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap_ldp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap_zoom2_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/omap_zoom3_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/orion5x_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/overo_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/palmz72_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/pxa168_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/pxa3xx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/pxa910_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/realview-smp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/realview_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/rx51_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/s3c2410_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/s3c6400_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/s5pc100_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/shark_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/spitz_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/stmp378x_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/stmp37xx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/u300_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/u8500_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/viper_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/xcep_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/arm/configs/zeus_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/mips/configs/fuloong2e_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/mips/configs/ip27_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/mips/configs/lemote2f_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/mips/configs/rbtx49xx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/ap325rxa_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/cayman_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/dreamcast_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/ecovec24-romimage_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/ecovec24_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/edosk7705_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/edosk7760_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/espt_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/hp6xx_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/kfr2r09-romimage_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/kfr2r09_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/landisk_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/lboxre2_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/magicpanelr2_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/microdev_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/migor_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/polaris_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/r7780mp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/r7785rp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/rsk7201_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/rsk7203_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/rts7751r2d1_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/rts7751r2dplus_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sdk7780_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7206_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7343_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7619_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7705_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7712_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7721_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7722_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7724_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7750_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7751_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/se7780_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh03_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh7710voipgw_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh7724_generic_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh7763rdp_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh7770_generic_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh7785lcr_32bit_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/sh7785lcr_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/shmin_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/shx3_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/snapgear_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/systemh_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/titan_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/ul2_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/sh/configs/urquell_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y arch/x86/configs/i386_defconfig:CONFIG_HAVE_GENERIC_DMA_COHERENT=y *実装 [#fd489f93] ** ヘッダ [#raa13539] #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT - --[[linux-2.6.33/CONFIG_HAVE_GENERIC_DMA_COHERENT]] /* * These two functions are only for dma allocator. * Don't use them in device drivers. */ int dma_alloc_from_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle, void **ret); (...中略...) #else #define dma_alloc_from_coherent(dev, size, handle, ret) (0) -何もせず、失敗を返す。 (...中略...) #endif ** drivers/base/dma-coherent.c: CONFIG_HAVE_GENERIC_DMA_COHERENT が定義される場合 [#s873c4a8] /** * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area * * @dev: device from which we allocate memory * @size: size of requested memory area * @dma_handle: This will be filled with the correct dma handle * @ret: This pointer will be filled with the virtual address * to allocated area. * * This function should be only called from per-arch dma_alloc_coherent() * to support allocation from per-device coherent memory pools. * * Returns 0 if dma_alloc_coherent should continue with allocating from * generic memory areas, or !0 if dma_alloc_coherent should return @ret. */ int dma_alloc_from_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle, void **ret) { struct dma_coherent_mem *mem; int order = get_order(size); int pageno; - --[[linux-2.6.33/dma_coherent_mem]] - --[[linux-2.6.33/get_order()]] if (!dev) return 0; mem = dev->dma_mem; if (!mem) return 0; *ret = NULL; if (unlikely(size > (mem->size << PAGE_SHIFT))) goto err; - --[[linux-2.6.33/PAGE_SHIFT]] pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); if (unlikely(pageno < 0)) goto err; - --[[linux-2.6.33/bitmap_find_free_region()]] - --[[linux-2.6.33/unlikely()]] /* * Memory was found in the per-device area. */ *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); *ret = mem->virt_base + (pageno << PAGE_SHIFT); memset(*ret, 0, size); return 1; err: /* * In the case where the allocation can not be satisfied from the * per-device area, try to fall back to generic memory if the * constraints allow it. */ return mem->flags & DMA_MEMORY_EXCLUSIVE; - --[[linux-2.6.33/DMA_MEMORY_EXCLUSIVE]] } EXPORT_SYMBOL(dma_alloc_from_coherent); -ライセンスに関係なくシンボルを公開する。 --[[linux-2.6.33/EXPORT_SYMBOL()]] ** include/asm-generic/dma-coherent.h: CONFIG_HAVE_GENERIC_DMA_COHERENT が定義されない場合 [#v329bf7d] #define dma_alloc_from_coherent(dev, size, handle, ret) (0) -何もせず、失敗を返す。 *コメント [#v7a5513c]
