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Release 4.14 arch/parisc/include/asm/dma.h

/* SPDX-License-Identifier: GPL-2.0 */
/* asm/dma.h: Defines for using and allocating dma channels.
 * Written by Hennus Bergman, 1992.
 * High DMA channel support & info by Hannu Savolainen
 * and John Boyd, Nov. 1992.
 * (c) Copyright 2000, Grant Grundler
 */

#ifndef _ASM_DMA_H

#define _ASM_DMA_H

#include <asm/io.h>		/* need byte IO */


#define dma_outb	outb

#define dma_inb		inb

/*
** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up
** (or rather not merge) DMAs into manageable chunks.
** On parisc, this is more of the software/tuning constraint
** rather than the HW. I/O MMU allocation algorithms can be
** faster with smaller sizes (to some degree).
*/

#define DMA_CHUNK_SIZE	(BITS_PER_LONG*PAGE_SIZE)

/* The maximum address that we can perform a DMA transfer to on this platform
** New dynamic DMA interfaces should obsolete this....
*/

#define MAX_DMA_ADDRESS (~0UL)

/*
** We don't have DMA channels... well V-class does but the
** Dynamic DMA Mapping interface will support them... right? :^)
** Note: this is not relevant right now for PA-RISC, but we cannot 
** leave this as undefined because some things (e.g. sound)
** won't compile :-(
*/

#define MAX_DMA_CHANNELS 8

#define DMA_MODE_READ	0x44	
/* I/O to memory, no autoinit, increment, single mode */

#define DMA_MODE_WRITE	0x48	
/* memory to I/O, no autoinit, increment, single mode */

#define DMA_MODE_CASCADE 0xC0	
/* pass thru DREQ->HRQ, DACK<-HLDA only */


#define DMA_AUTOINIT	0x10

/* 8237 DMA controllers */

#define IO_DMA1_BASE	0x00	
/* 8 bit slave DMA, channels 0..3 */

#define IO_DMA2_BASE	0xC0	
/* 16 bit master DMA, ch 4(=slave input)..7 */

/* DMA controller registers */

#define DMA1_CMD_REG		0x08	
/* command register (w) */

#define DMA1_STAT_REG		0x08	
/* status register (r) */

#define DMA1_REQ_REG            0x09    
/* request register (w) */

#define DMA1_MASK_REG		0x0A	
/* single-channel mask (w) */

#define DMA1_MODE_REG		0x0B	
/* mode register (w) */

#define DMA1_CLEAR_FF_REG	0x0C	
/* clear pointer flip-flop (w) */

#define DMA1_TEMP_REG           0x0D    
/* Temporary Register (r) */

#define DMA1_RESET_REG		0x0D	
/* Master Clear (w) */

#define DMA1_CLR_MASK_REG       0x0E    
/* Clear Mask */

#define DMA1_MASK_ALL_REG       0x0F    
/* all-channels mask (w) */

#define DMA1_EXT_MODE_REG	(0x400 | DMA1_MODE_REG)


#define DMA2_CMD_REG		0xD0	
/* command register (w) */

#define DMA2_STAT_REG		0xD0	
/* status register (r) */

#define DMA2_REQ_REG            0xD2    
/* request register (w) */

#define DMA2_MASK_REG		0xD4	
/* single-channel mask (w) */

#define DMA2_MODE_REG		0xD6	
/* mode register (w) */

#define DMA2_CLEAR_FF_REG	0xD8	
/* clear pointer flip-flop (w) */

#define DMA2_TEMP_REG           0xDA    
/* Temporary Register (r) */

#define DMA2_RESET_REG		0xDA	
/* Master Clear (w) */

#define DMA2_CLR_MASK_REG       0xDC    
/* Clear Mask */

#define DMA2_MASK_ALL_REG       0xDE    
/* all-channels mask (w) */

#define DMA2_EXT_MODE_REG	(0x400 | DMA2_MODE_REG)


static __inline__ unsigned long claim_dma_lock(void) { return 0; }

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static __inline__ void release_dma_lock(unsigned long flags) { }

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/* Get DMA residue count. After a DMA transfer, this * should return zero. Reading this while a DMA transfer is * still in progress will return unpredictable results. * If called before the channel has been used, it may return 1. * Otherwise, it returns the number of _bytes_ left to transfer. * * Assumes DMA flip-flop is clear. */
static __inline__ int get_dma_residue(unsigned int dmanr) { unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE; /* using short to get 16-bit wrap around */ unsigned short count; count = 1 + dma_inb(io_port); count += dma_inb(io_port) << 8; return (dmanr<=3)? count : (count<<1); }

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/* enable/disable a specific DMA channel */
static __inline__ void enable_dma(unsigned int dmanr) { #ifdef CONFIG_SUPERIO if (dmanr<=3) dma_outb(dmanr, DMA1_MASK_REG); else dma_outb(dmanr & 3, DMA2_MASK_REG); #endif }

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static __inline__ void disable_dma(unsigned int dmanr) { #ifdef CONFIG_SUPERIO if (dmanr<=3) dma_outb(dmanr | 4, DMA1_MASK_REG); else dma_outb((dmanr & 3) | 4, DMA2_MASK_REG); #endif }

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/* reserve a DMA channel */ #define request_dma(dmanr, device_id) (0) /* Clear the 'DMA Pointer Flip Flop'. * Write 0 for LSB/MSB, 1 for MSB/LSB access. * Use this once to initialize the FF to a known state. * After that, keep track of it. :-) * --- In order to do that, the DMA routines below should --- * --- only be used while holding the DMA lock ! --- */
static __inline__ void clear_dma_ff(unsigned int dmanr) { }

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/* set mode (above) for a specific DMA channel */
static __inline__ void set_dma_mode(unsigned int dmanr, char mode) { }

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/* Set only the page register bits of the transfer address. * This is used for successive transfers when we know the contents of * the lower 16 bits of the DMA current address register, but a 64k boundary * may have been crossed. */
static __inline__ void set_dma_page(unsigned int dmanr, char pagenr) { }

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/* Set transfer address & page bits for specific DMA channel. * Assumes dma flipflop is clear. */
static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a) { }

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/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for * a specific DMA channel. * You must ensure the parameters are valid. * NOTE: from a manual: "the number of transfers is one more * than the initial word count"! This is taken into account. * Assumes dma flip-flop is clear. * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7. */
static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count) { }

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#define free_dma(dmanr) #ifdef CONFIG_PCI extern int isa_dma_bridge_buggy; #else #define isa_dma_bridge_buggy (0) #endif #endif /* _ASM_DMA_H */

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Total473100.00%8100.00%
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