qemu-e2k/include/hw/ppc/mac_dbdma.h
Alexander Graf 80fc95d8bd PPC: dbdma: Support unaligned DMA access
The DBDMA engine really just reads bytes from a producing device (IDE
in our case) and shoves these bytes into memory. It doesn't care whether
any alignment takes place or not.

Our code today however assumes that block accesses always happen on
sector (512 byte) boundaries. This is a fair assumption for most cases.

However, Mac OS X really likes to do unaligned, incomplete accesses
that it finishes with the next DMA request.

So we need to read / write the unaligned bits independent of the actual
asynchronous request, because that one can only handle 512-byte-aligned
data. We also need to cache these unaligned sectors until the next DMA
request, at which point the data might be successfully flushed from the
pipe.

Signed-off-by: Alexander Graf <agraf@suse.de>
2013-07-11 18:51:25 +02:00

173 lines
6.0 KiB
C

/*
* Copyright (c) 2009 Laurent Vivier
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef HW_MAC_DBDMA_H
#define HW_MAC_DBDMA_H 1
#include "exec/memory.h"
typedef struct DBDMA_io DBDMA_io;
typedef void (*DBDMA_flush)(DBDMA_io *io);
typedef void (*DBDMA_rw)(DBDMA_io *io);
typedef void (*DBDMA_end)(DBDMA_io *io);
struct DBDMA_io {
void *opaque;
void *channel;
hwaddr addr;
int len;
int is_last;
int is_dma_out;
DBDMA_end dma_end;
/* DMA is in progress, don't start another one */
bool processing;
/* unaligned last sector of a request */
uint8_t remainder[0x200];
int remainder_len;
};
/*
* DBDMA control/status registers. All little-endian.
*/
#define DBDMA_CONTROL 0x00
#define DBDMA_STATUS 0x01
#define DBDMA_CMDPTR_HI 0x02
#define DBDMA_CMDPTR_LO 0x03
#define DBDMA_INTR_SEL 0x04
#define DBDMA_BRANCH_SEL 0x05
#define DBDMA_WAIT_SEL 0x06
#define DBDMA_XFER_MODE 0x07
#define DBDMA_DATA2PTR_HI 0x08
#define DBDMA_DATA2PTR_LO 0x09
#define DBDMA_RES1 0x0A
#define DBDMA_ADDRESS_HI 0x0B
#define DBDMA_BRANCH_ADDR_HI 0x0C
#define DBDMA_RES2 0x0D
#define DBDMA_RES3 0x0E
#define DBDMA_RES4 0x0F
#define DBDMA_REGS 16
#define DBDMA_SIZE (DBDMA_REGS * sizeof(uint32_t))
#define DBDMA_CHANNEL_SHIFT 7
#define DBDMA_CHANNEL_SIZE (1 << DBDMA_CHANNEL_SHIFT)
#define DBDMA_CHANNELS (0x1000 >> DBDMA_CHANNEL_SHIFT)
/* Bits in control and status registers */
#define RUN 0x8000
#define PAUSE 0x4000
#define FLUSH 0x2000
#define WAKE 0x1000
#define DEAD 0x0800
#define ACTIVE 0x0400
#define BT 0x0100
#define DEVSTAT 0x00ff
/*
* DBDMA command structure. These fields are all little-endian!
*/
typedef struct dbdma_cmd {
uint16_t req_count; /* requested byte transfer count */
uint16_t command; /* command word (has bit-fields) */
uint32_t phy_addr; /* physical data address */
uint32_t cmd_dep; /* command-dependent field */
uint16_t res_count; /* residual count after completion */
uint16_t xfer_status; /* transfer status */
} dbdma_cmd;
/* DBDMA command values in command field */
#define COMMAND_MASK 0xf000
#define OUTPUT_MORE 0x0000 /* transfer memory data to stream */
#define OUTPUT_LAST 0x1000 /* ditto followed by end marker */
#define INPUT_MORE 0x2000 /* transfer stream data to memory */
#define INPUT_LAST 0x3000 /* ditto, expect end marker */
#define STORE_WORD 0x4000 /* write word (4 bytes) to device reg */
#define LOAD_WORD 0x5000 /* read word (4 bytes) from device reg */
#define DBDMA_NOP 0x6000 /* do nothing */
#define DBDMA_STOP 0x7000 /* suspend processing */
/* Key values in command field */
#define KEY_MASK 0x0700
#define KEY_STREAM0 0x0000 /* usual data stream */
#define KEY_STREAM1 0x0100 /* control/status stream */
#define KEY_STREAM2 0x0200 /* device-dependent stream */
#define KEY_STREAM3 0x0300 /* device-dependent stream */
#define KEY_STREAM4 0x0400 /* reserved */
#define KEY_REGS 0x0500 /* device register space */
#define KEY_SYSTEM 0x0600 /* system memory-mapped space */
#define KEY_DEVICE 0x0700 /* device memory-mapped space */
/* Interrupt control values in command field */
#define INTR_MASK 0x0030
#define INTR_NEVER 0x0000 /* don't interrupt */
#define INTR_IFSET 0x0010 /* intr if condition bit is 1 */
#define INTR_IFCLR 0x0020 /* intr if condition bit is 0 */
#define INTR_ALWAYS 0x0030 /* always interrupt */
/* Branch control values in command field */
#define BR_MASK 0x000c
#define BR_NEVER 0x0000 /* don't branch */
#define BR_IFSET 0x0004 /* branch if condition bit is 1 */
#define BR_IFCLR 0x0008 /* branch if condition bit is 0 */
#define BR_ALWAYS 0x000c /* always branch */
/* Wait control values in command field */
#define WAIT_MASK 0x0003
#define WAIT_NEVER 0x0000 /* don't wait */
#define WAIT_IFSET 0x0001 /* wait if condition bit is 1 */
#define WAIT_IFCLR 0x0002 /* wait if condition bit is 0 */
#define WAIT_ALWAYS 0x0003 /* always wait */
typedef struct DBDMA_channel {
int channel;
uint32_t regs[DBDMA_REGS];
qemu_irq irq;
DBDMA_io io;
DBDMA_rw rw;
DBDMA_flush flush;
dbdma_cmd current;
} DBDMA_channel;
typedef struct {
MemoryRegion mem;
DBDMA_channel channels[DBDMA_CHANNELS];
QEMUBH *bh;
} DBDMAState;
/* Externally callable functions */
void DBDMA_register_channel(void *dbdma, int nchan, qemu_irq irq,
DBDMA_rw rw, DBDMA_flush flush,
void *opaque);
void DBDMA_kick(DBDMAState *dbdma);
void* DBDMA_init (MemoryRegion **dbdma_mem);
#endif