| Quellcodebibliothek Statistik Leitseite products/Sources/formale Sprachen/C/Linux/arch/xtensa/include/asm/ (Linux Kernel Version 6.17.9©) Datei vom 24.10.2025 mit Größe 1 kB |
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Quelle dma.h Sprache: C |
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/* * include/asm-xtensa/dma.h * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2003 - 2005 Tensilica Inc. */ #ifndef _XTENSA_DMA_H #define _XTENSA_DMA_H #include <asm/io.h> /* need byte IO */ /* * This is only to be defined if we have PC-like DMA. * By default this is not true on an Xtensa processor, * however on boards with a PCI bus, such functionality * might be emulated externally. * * NOTE: there still exists driver code that assumes * this is defined, eg. drivers/sound/soundcard.c (as of 2.4). */ #define MAX_DMA_CHANNELS 8 /* * The maximum virtual address to which DMA transfers * can be performed on this platform. * * NOTE: This is board (platform) specific, not processor-specific! * * NOTE: This assumes DMA transfers can only be performed on * the section of physical memory contiguously mapped in virtual * space for the kernel. For the Xtensa architecture, this * means the maximum possible size of this DMA area is * the size of the statically mapped kernel segment * (XCHAL_KSEG_{CACHED,BYPASS}_SIZE), ie. 128 MB. * * NOTE: When the entire KSEG area is DMA capable, we subtract * one from the max address so that the virt_to_phys() macro * works correctly on the address (otherwise the address * enters another area, and virt_to_phys() may not return * the value desired). */ #ifndef MAX_DMA_ADDRESS #define MAX_DMA_ADDRESS (PAGE_OFFSET + XCHAL_KIO_SIZE - 1) #endif /* Reserve and release a DMA channel */ extern int request_dma(unsigned int dmanr, const char * device_id); extern void free_dma(unsigned int dmanr); #endif
¤ Dauer der Verarbeitung: 0.9 Sekunden (vorverarbeitet am 2026-10-02) ¤*© Formatika GbR, Deutschland |
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2026-10-10