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author | Albert Lee <albertcc@tw.ibm.com> | 2005-08-12 14:15:34 +0800 |
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committer | Jeff Garzik <jgarzik@pobox.com> | 2005-08-12 02:44:20 -0400 |
commit | 6ae4cfb5711b6f2878c9e384617971d98c34a7f5 (patch) | |
tree | d5e4f3ab6381c0c5429429eb9f4159e321af8431 /drivers/scsi/libata-core.c | |
parent | bc68552faad0e134eb22281343d5ae5a4873fa80 (diff) | |
download | op-kernel-dev-6ae4cfb5711b6f2878c9e384617971d98c34a7f5.zip op-kernel-dev-6ae4cfb5711b6f2878c9e384617971d98c34a7f5.tar.gz |
[PATCH] libata ata_data_xfer() fix
PATCH 1/2: ata_data_xfer() fix
Changes:
- Modify ata_mmio_data_xfer() and ata_pio_data_xfer() to handle odd-lengthed buffer.
- Add some function comments
This patch does not reuse ap->pad as alignment buffer since
using local variable seems good enough.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Diffstat (limited to 'drivers/scsi/libata-core.c')
-rw-r--r-- | drivers/scsi/libata-core.c | 111 |
1 files changed, 108 insertions, 3 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 73b1f72..8f6e536 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -2519,6 +2519,20 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words) #endif /* __BIG_ENDIAN */ } +/** + * ata_mmio_data_xfer - Transfer data by MMIO + * @ap: port to read/write + * @buf: data buffer + * @buflen: buffer length + * @do_write: read/write + * + * Transfer data from/to the device data register by MMIO. + * + * LOCKING: + * Inherited from caller. + * + */ + static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf, unsigned int buflen, int write_data) { @@ -2527,6 +2541,7 @@ static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf, u16 *buf16 = (u16 *) buf; void __iomem *mmio = (void __iomem *)ap->ioaddr.data_addr; + /* Transfer multiple of 2 bytes */ if (write_data) { for (i = 0; i < words; i++) writew(le16_to_cpu(buf16[i]), mmio); @@ -2534,19 +2549,76 @@ static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf, for (i = 0; i < words; i++) buf16[i] = cpu_to_le16(readw(mmio)); } + + /* Transfer trailing 1 byte, if any. */ + if (unlikely(buflen & 0x01)) { + u16 align_buf[1] = { 0 }; + unsigned char *trailing_buf = buf + buflen - 1; + + if (write_data) { + memcpy(align_buf, trailing_buf, 1); + writew(le16_to_cpu(align_buf[0]), mmio); + } else { + align_buf[0] = cpu_to_le16(readw(mmio)); + memcpy(trailing_buf, align_buf, 1); + } + } } +/** + * ata_pio_data_xfer - Transfer data by PIO + * @ap: port to read/write + * @buf: data buffer + * @buflen: buffer length + * @do_write: read/write + * + * Transfer data from/to the device data register by PIO. + * + * LOCKING: + * Inherited from caller. + * + */ + static void ata_pio_data_xfer(struct ata_port *ap, unsigned char *buf, unsigned int buflen, int write_data) { - unsigned int dwords = buflen >> 1; + unsigned int words = buflen >> 1; + /* Transfer multiple of 2 bytes */ if (write_data) - outsw(ap->ioaddr.data_addr, buf, dwords); + outsw(ap->ioaddr.data_addr, buf, words); else - insw(ap->ioaddr.data_addr, buf, dwords); + insw(ap->ioaddr.data_addr, buf, words); + + /* Transfer trailing 1 byte, if any. */ + if (unlikely(buflen & 0x01)) { + u16 align_buf[1] = { 0 }; + unsigned char *trailing_buf = buf + buflen - 1; + + if (write_data) { + memcpy(align_buf, trailing_buf, 1); + outw(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr); + } else { + align_buf[0] = cpu_to_le16(inw(ap->ioaddr.data_addr)); + memcpy(trailing_buf, align_buf, 1); + } + } } +/** + * ata_data_xfer - Transfer data from/to the data register. + * @ap: port to read/write + * @buf: data buffer + * @buflen: buffer length + * @do_write: read/write + * + * Transfer data from/to the device data register. + * + * LOCKING: + * Inherited from caller. + * + */ + static void ata_data_xfer(struct ata_port *ap, unsigned char *buf, unsigned int buflen, int do_write) { @@ -2556,6 +2628,16 @@ static void ata_data_xfer(struct ata_port *ap, unsigned char *buf, ata_pio_data_xfer(ap, buf, buflen, do_write); } +/** + * ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data. + * @qc: Command on going + * + * Transfer ATA_SECT_SIZE of data from/to the ATA device. + * + * LOCKING: + * Inherited from caller. + */ + static void ata_pio_sector(struct ata_queued_cmd *qc) { int do_write = (qc->tf.flags & ATA_TFLAG_WRITE); @@ -2594,6 +2676,18 @@ static void ata_pio_sector(struct ata_queued_cmd *qc) kunmap(page); } +/** + * __atapi_pio_bytes - Transfer data from/to the ATAPI device. + * @qc: Command on going + * @bytes: number of bytes + * + * Transfer Transfer data from/to the ATAPI device. + * + * LOCKING: + * Inherited from caller. + * + */ + static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes) { int do_write = (qc->tf.flags & ATA_TFLAG_WRITE); @@ -2645,6 +2739,17 @@ next_sg: } } +/** + * atapi_pio_bytes - Transfer data from/to the ATAPI device. + * @qc: Command on going + * + * Transfer Transfer data from/to the ATAPI device. + * + * LOCKING: + * Inherited from caller. + * + */ + static void atapi_pio_bytes(struct ata_queued_cmd *qc) { struct ata_port *ap = qc->ap; |