From dde2020754aeb14e17052d61784dcb37f252aac2 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Tue, 19 Feb 2008 11:36:56 +0100 Subject: libata: eliminate the home grown dma padding in favour of that provided by the block layer ATA requires that all DMA transfers begin and end on word boundaries. Because of this, a large amount of machinery grew up in ide to adjust scatterlists on this basis. However, as of 2.5, the block layer has a dma_alignment variable which ensures both the beginning and length of a DMA transfer are aligned on the dma_alignment boundary. Although the block layer does adjust the beginning of the transfer to ensure this happens, it doesn't actually adjust the length, it merely makes sure that space is allocated for transfers beyond the declared length. The upshot of this is that scatterlists may be padded to any size between the actual length and the length adjusted to the dma_alignment safely knowing that memory is allocated in this region. Right at the moment, SCSI takes the default dma_aligment which is on a 512 byte boundary. Note that this aligment only applies to transfers coming in from user space. However, since all kernel allocations are automatically aligned on a minimum of 32 byte boundaries, it is safe to adjust them in this manner as well. tj: * Adjusting sg after padding is done in block layer. Make libata set queue alignment correctly for ATAPI devices and drop broken sg mangling from ata_sg_setup(). * Use request->raw_data_len for ATAPI transfer chunk size. * Killed qc->raw_nbytes. * Separated out killing qc->n_iter. Signed-off-by: James Bottomley Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/libata.h | 28 +--------------------------- 1 file changed, 1 insertion(+), 27 deletions(-) (limited to 'include/linux/libata.h') diff --git a/include/linux/libata.h b/include/linux/libata.h index bc5a8d0c709..2e098f940ce 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -278,7 +278,6 @@ enum { /* size of buffer to pad xfers ending on unaligned boundaries */ ATA_DMA_PAD_SZ = 4, - ATA_DMA_PAD_BUF_SZ = ATA_DMA_PAD_SZ * ATA_MAX_QUEUE, /* ering size */ ATA_ERING_SIZE = 32, @@ -457,24 +456,18 @@ struct ata_queued_cmd { unsigned long flags; /* ATA_QCFLAG_xxx */ unsigned int tag; unsigned int n_elem; - unsigned int mapped_n_elem; int dma_dir; - unsigned int pad_len; unsigned int sect_size; unsigned int nbytes; - unsigned int raw_nbytes; unsigned int curbytes; struct scatterlist *cursg; unsigned int cursg_ofs; - struct scatterlist *last_sg; - struct scatterlist saved_last_sg; struct scatterlist sgent; - struct scatterlist extra_sg[2]; struct scatterlist *sg; @@ -619,9 +612,6 @@ struct ata_port { struct ata_prd *prd; /* our SG list */ dma_addr_t prd_dma; /* and its DMA mapping */ - void *pad; /* array of DMA pad buffers */ - dma_addr_t pad_dma; - struct ata_ioports ioaddr; /* ATA cmd/ctl/dma register blocks */ u8 ctl; /* cache of ATA control register */ @@ -1363,12 +1353,9 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc) qc->flags = 0; qc->cursg = NULL; qc->cursg_ofs = 0; - qc->nbytes = qc->raw_nbytes = qc->curbytes = 0; + qc->nbytes = qc->curbytes = 0; qc->n_elem = 0; - qc->mapped_n_elem = 0; qc->err_mask = 0; - qc->pad_len = 0; - qc->last_sg = NULL; qc->sect_size = ATA_SECT_SIZE; ata_tf_init(qc->dev, &qc->tf); @@ -1423,19 +1410,6 @@ static inline unsigned int __ac_err_mask(u8 status) return mask; } -static inline int ata_pad_alloc(struct ata_port *ap, struct device *dev) -{ - ap->pad_dma = 0; - ap->pad = dmam_alloc_coherent(dev, ATA_DMA_PAD_BUF_SZ, - &ap->pad_dma, GFP_KERNEL); - return (ap->pad == NULL) ? -ENOMEM : 0; -} - -static inline void ata_pad_free(struct ata_port *ap, struct device *dev) -{ - dmam_free_coherent(dev, ATA_DMA_PAD_BUF_SZ, ap->pad, ap->pad_dma); -} - static inline struct ata_port *ata_shost_to_port(struct Scsi_Host *host) { return *(struct ata_port **)&host->hostdata[0]; -- cgit v1.2.3-70-g09d2 From 5d44b414daa8c1d8551aed6130d86d54175db43f Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Fri, 15 Feb 2008 13:41:32 -0800 Subject: ata: fix sparse warning in libata.h Avoids lots of these, also is more readable. include/linux/libata.h:1210:13: warning: potentially expensive pointer subtraction Change the subtraction to addition on the other side of the comparison. Thanks to Christer Weinigel for the suggestion. Signed-off-by: Harvey Harrison Acked-by: Tejun Heo Signed-off-by: Jeff Garzik --- include/linux/libata.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/libata.h') diff --git a/include/linux/libata.h b/include/linux/libata.h index 2e098f940ce..ce7603a7315 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1197,7 +1197,7 @@ static inline struct ata_link *ata_port_next_link(struct ata_link *link) return ap->pmp_link; } - if (++link - ap->pmp_link < ap->nr_pmp_links) + if (++link < ap->nr_pmp_links + ap->pmp_link) return link; return NULL; } -- cgit v1.2.3-70-g09d2 From 9116300634c5c76cfcd0d2af689846e04d172256 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 21 Feb 2008 13:25:50 +0900 Subject: libata: automatically use DMADIR if drive/bridge requires it Back in 2.6.17-rc2, a libata module parameter was added for atapi_dmadir. That's nice, but most SATA devices which need it will tell us about it in their IDENTIFY PACKET response, as bit-15 of word-62 of the returned data (as per ATA7, ATA8 specifications). So for those which specify it, we should automatically use the DMADIR bit. Otherwise, disc writing will fail by default on many SATA-ATAPI drives. This patch adds ATA_DFLAG_DMADIR and make ata_dev_configure() set it if atapi_dmadir is set or identify data indicates DMADIR is necessary. atapi_xlat() is converted to check ATA_DFLAG_DMADIR before setting DMADIR. Original patch is from Mark Lord. Signed-off-by: Tejun Heo Cc: Mark Lord Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 11 +++++++++-- drivers/ata/libata-scsi.c | 3 ++- include/linux/ata.h | 5 +++++ include/linux/libata.h | 1 + 4 files changed, 17 insertions(+), 3 deletions(-) (limited to 'include/linux/libata.h') diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 9812bbf05e6..1845119cc7f 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2396,6 +2396,7 @@ int ata_dev_configure(struct ata_device *dev) else if (dev->class == ATA_DEV_ATAPI) { const char *cdb_intr_string = ""; const char *atapi_an_string = ""; + const char *dma_dir_string = ""; u32 sntf; rc = atapi_cdb_len(id); @@ -2436,13 +2437,19 @@ int ata_dev_configure(struct ata_device *dev) cdb_intr_string = ", CDB intr"; } + if (atapi_dmadir || atapi_id_dmadir(dev->id)) { + dev->flags |= ATA_DFLAG_DMADIR; + dma_dir_string = ", DMADIR"; + } + /* print device info to dmesg */ if (ata_msg_drv(ap) && print_info) ata_dev_printk(dev, KERN_INFO, - "ATAPI: %s, %s, max %s%s%s\n", + "ATAPI: %s, %s, max %s%s%s%s\n", modelbuf, fwrevbuf, ata_mode_string(xfer_mask), - cdb_intr_string, atapi_an_string); + cdb_intr_string, atapi_an_string, + dma_dir_string); } /* determine max_sectors */ diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index f888babc828..0562b0a49f3 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2582,7 +2582,8 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) qc->tf.protocol = ATAPI_PROT_DMA; qc->tf.feature |= ATAPI_PKT_DMA; - if (atapi_dmadir && (scmd->sc_data_direction != DMA_TO_DEVICE)) + if ((dev->flags & ATA_DFLAG_DMADIR) && + (scmd->sc_data_direction != DMA_TO_DEVICE)) /* some SATA bridges need us to indicate data xfer direction */ qc->tf.feature |= ATAPI_DMADIR; } diff --git a/include/linux/ata.h b/include/linux/ata.h index 78bbacaed8c..1c622e2b050 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -659,6 +659,11 @@ static inline int atapi_command_packet_set(const u16 *dev_id) return (dev_id[0] >> 8) & 0x1f; } +static inline int atapi_id_dmadir(const u16 *dev_id) +{ + return ata_id_major_version(dev_id) >= 7 && (dev_id[62] & 0x8000); +} + static inline int is_multi_taskfile(struct ata_taskfile *tf) { return (tf->command == ATA_CMD_READ_MULTI) || diff --git a/include/linux/libata.h b/include/linux/libata.h index ce7603a7315..a05f6001364 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -138,6 +138,7 @@ enum { ATA_DFLAG_AN = (1 << 7), /* AN configured */ ATA_DFLAG_HIPM = (1 << 8), /* device supports HIPM */ ATA_DFLAG_DIPM = (1 << 9), /* device supports DIPM */ + ATA_DFLAG_DMADIR = (1 << 10), /* device requires DMADIR */ ATA_DFLAG_CFG_MASK = (1 << 12) - 1, ATA_DFLAG_PIO = (1 << 12), /* device limited to PIO mode */ -- cgit v1.2.3-70-g09d2