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Use separate data-in and data-out buffers. 

Increase code simplicity at the expense of around 64 bytes.
This commit is contained in:
Michael Brown 2006-05-28 23:26:42 +00:00
parent 6d6252067f
commit 6f998cecb3
2 changed files with 72 additions and 74 deletions
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80
src/drivers/block/ata.c
View File

@ -50,39 +50,6 @@ ata_command ( struct ata_device *ata, struct ata_command *command ) {
return ata->command ( ata, command );
}
/**
* Read block from / write block to ATA device
*
* @v write Write flag (ATA_FL_WRITE or 0)
* @v blockdev Block device
* @v block LBA block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static __attribute__ (( regparm ( 1 ) )) int
ata_rw ( int write, struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct ata_device *ata = block_to_ata ( blockdev );
struct ata_command command;
int lba48 = ( ata->flags & ATA_FL_LBA48 );
memset ( &command, 0, sizeof ( command ) );
command.cb.lba.native = block;
command.cb.count.native = count;
command.cb.device = ( ata->flags | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
command.cb.flags = ( ata->flags | write );
command.cb.cmd_stat = ( write ? ATA_CMD_WRITE : ATA_CMD_READ );
if ( lba48 ) {
command.cb.cmd_stat |= ATA_CMD_EXT;
} else {
command.cb.device |= command.cb.lba.bytes.low_prev;
}
command.data = buffer;
command.data_len = ( count * blockdev->blksize );
return ata_command ( ata, &command );
}
/**
* Read block from ATA device
*
@ -94,10 +61,20 @@ ata_rw ( int write, struct block_device *blockdev, uint64_t block,
*/
static int ata_read ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
/* Pass through to ata_rw(). Since ata_rw is regparm(1), this
* is extremely efficient; just a mov and a jmp.
*/
return ata_rw ( 0, blockdev, block, count, buffer );
struct ata_device *ata = block_to_ata ( blockdev );
struct ata_command command;
memset ( &command, 0, sizeof ( command ) );
command.cb.lba.native = block;
command.cb.count.native = count;
command.cb.device = ( ata->device | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
command.cb.lba48 = ata->lba48;
if ( ! ata->lba48 )
command.cb.device |= command.cb.lba.bytes.low_prev;
command.cb.cmd_stat = ( ata->lba48 ? ATA_CMD_READ_EXT : ATA_CMD_READ );
command.data_in = buffer;
command.data_in_len = ( count * blockdev->blksize );
return ata_command ( ata, &command );
}
/**
@ -111,10 +88,21 @@ static int ata_read ( struct block_device *blockdev, uint64_t block,
*/
static int ata_write ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
/* Pass through to ata_rw(). Since ata_rw is regparm(1), this
* is extremely efficient; just a mov and a jmp.
*/
return ata_rw ( ATA_FL_WRITE, blockdev, block, count, buffer );
struct ata_device *ata = block_to_ata ( blockdev );
struct ata_command command;
memset ( &command, 0, sizeof ( command ) );
command.cb.lba.native = block;
command.cb.count.native = count;
command.cb.device = ( ata->device | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
command.cb.lba48 = ata->lba48;
if ( ! ata->lba48 )
command.cb.device |= command.cb.lba.bytes.low_prev;
command.cb.cmd_stat = ( ata->lba48 ?
ATA_CMD_WRITE_EXT : ATA_CMD_WRITE );
command.data_out = buffer;
command.data_out_len = ( count * blockdev->blksize );
return ata_command ( ata, &command );
}
/**
@ -131,17 +119,19 @@ static int ata_identify ( struct block_device *blockdev ) {
/* Issue IDENTIFY */
memset ( &command, 0, sizeof ( command ) );
command.cb.device = ( ata->flags | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
command.cb.count.native = 1; /* n/a according to spec, but at least
* AoE vblade devices require it. */
command.cb.device = ( ata->device | ATA_DEV_OBSOLETE | ATA_DEV_LBA );
command.cb.cmd_stat = ATA_CMD_IDENTIFY;
command.data = virt_to_user ( &identity );
command.data_len = sizeof ( identity );
command.data_in = virt_to_user ( &identity );
command.data_in_len = sizeof ( identity );
if ( ( rc = ata_command ( ata, &command ) ) != 0 )
return rc;
/* Fill in block device parameters */
blockdev->blksize = ATA_SECTOR_SIZE;
if ( identity.supports_lba48 & cpu_to_le16 ( ATA_SUPPORTS_LBA48 ) ) {
ata->flags |= ATA_FL_LBA48;
ata->lba48 = 1;
blockdev->blocks = le64_to_cpu ( identity.lba48_sectors );
} else {
blockdev->blocks = le32_to_cpu ( identity.lba_sectors );

66
src/include/gpxe/ata.h
View File

@ -56,9 +56,9 @@ union ata_lba {
uint8_t low_prev;
uint8_t mid_prev;
uint8_t high_prev;
uint8_t pad[2];
uint16_t pad;
#elif __BYTE_ORDER == __BIG_ENDIAN
uint8_t pad[2];
uint16_t pad;
uint8_t high_prev;
uint8_t mid_prev;
uint8_t low_prev;
@ -101,52 +101,55 @@ struct ata_cb {
uint8_t device;
/** Command/status register */
uint8_t cmd_stat;
/** Flags
*
* This field does not correspond to any ATA register.
*/
uint8_t flags;
/** LBA48 addressing flag */
int lba48;
};
/** LBA48 extended addressing */
#define ATA_FL_LBA48 0x40
/** Device 1 ("slave") */
#define ATA_FL_SLAVE 0x10
/** Write command */
#define ATA_FL_WRITE 0x01
/** Obsolete bits in the ATA device register */
#define ATA_DEV_OBSOLETE 0xa0
/** LBA flag in the ATA device register */
#define ATA_DEV_LBA 0x40
/** Slave ("device 1") flag in the ATA device register */
#define ATA_DEV_SLAVE 0x10
/** Master ("device 0") flag in the ATA device register */
#define ATA_DEV_MASTER 0x00
/** "Read sectors" command */
#define ATA_CMD_READ 0x20
/** "Read sectors (ext)" command */
#define ATA_CMD_READ_EXT 0x24
/** "Write sectors" command */
#define ATA_CMD_WRITE 0x30
/** "Write sectors (ext)" command */
#define ATA_CMD_WRITE_EXT 0x34
/** "Identify" command */
#define ATA_CMD_IDENTIFY 0xec
/** "Extended (LBA48)" command modifier
*
* This doesn't apply to all ATA commands, but it does for @c
* ATA_CMD_READ and @c ATA_CMD_WRITE.
*/
#define ATA_CMD_EXT 0x04
/** An ATA command */
struct ata_command {
/** ATA command block */
struct ata_cb cb;
/** Data buffer */
userptr_t data;
/** Data buffer length */
size_t data_len;
/** Data-out buffer (may be NULL) */
userptr_t data_out;
/** Data-out buffer length
*
* Must be zero if @c data_out is NULL
*/
size_t data_out_len;
/** Data-in buffer (may be NULL) */
userptr_t data_in;
/** Data-in buffer length
*
* Must be zero if @c data_in is NULL
*/
size_t data_in_len;
};
/**
@ -175,8 +178,13 @@ struct ata_identity {
struct ata_device {
/** Block device interface */
struct block_device blockdev;
/** Flags */
int flags;
/** Device number
*
* Must be ATA_DEV_MASTER or ATA_DEV_SLAVE.
*/
int device;
/** LBA48 extended addressing */
int lba48;
/**
* Issue ATA command
*