On 22 August 2016 at 12:23, Shaun Tancheff <shaun@xxxxxxxxxxxx> wrote: > Safely overwriting the attached page to ATA format from the SCSI formatted > variant. > > Signed-off-by: Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx> > --- > v6: > - Fix bisect bug reported by Tom Yan <tom.ty89@xxxxxxxxx> > - Change to use sg_copy_from_buffer as per Christoph Hellwig <hch@xxxxxx> > v5: > - Added prep patch to work with non-page aligned scatterlist pages > and use kmap_atomic() to lock page during modification. > > drivers/ata/libata-scsi.c | 56 ++++++++++++++++++++++++++++++++++++++++++----- > include/linux/ata.h | 26 ---------------------- > 2 files changed, 51 insertions(+), 31 deletions(-) > > diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c > index e207b33..7990cb2 100644 > --- a/drivers/ata/libata-scsi.c > +++ b/drivers/ata/libata-scsi.c > @@ -3282,6 +3282,54 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc) > return 1; > } > > +/** > + * ata_format_dsm_trim_descr() - SATL Write Same to DSM Trim > + * @cmd: SCSI command being translated > + * @num: Maximum number of entries (nominally 64). > + * @sector: Starting sector > + * @count: Total Range of request > + * > + * Rewrite the WRITE SAME descriptor to be a DSM TRIM little-endian formatted > + * descriptor. > + * > + * Upto 64 entries of the format: > + * 63:48 Range Length > + * 47:0 LBA > + * > + * Range Length of 0 is ignored. > + * LBA's should be sorted order and not overlap. > + * > + * NOTE: this is the same format as ADD LBA(S) TO NV CACHE PINNED SET > + */ > +static unsigned int ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 num, > + u64 sector, u32 count) > +{ > + __le64 *buffer; > + u32 i = 0, used_bytes; > + unsigned long flags; > + > + BUILD_BUG_ON(512 > ATA_SCSI_RBUF_SIZE); > + > + spin_lock_irqsave(&ata_scsi_rbuf_lock, flags); > + buffer = ((void *)ata_scsi_rbuf); > + while (i < num) { > + u64 entry = sector | > + ((u64)(count > 0xffff ? 0xffff : count) << 48); > + buffer[i++] = __cpu_to_le64(entry); > + if (count <= 0xffff) > + break; > + count -= 0xffff; > + sector += 0xffff; > + } > + > + used_bytes = ALIGN(i * 8, 512); > + memset(buffer + i, 0, used_bytes - i * 8); > + sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buffer, 512); > + spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags); > + > + return used_bytes; > +} > + > static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) > { > struct ata_taskfile *tf = &qc->tf; > @@ -3290,8 +3338,8 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) > const u8 *cdb = scmd->cmnd; > u64 block; > u32 n_block; > + const u32 trmax = ATA_MAX_TRIM_RNUM; This does not seem like a good idea. > u32 size; > - void *buf; > u16 fp; > u8 bp = 0xff; > > @@ -3319,10 +3367,8 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) > if (!scsi_sg_count(scmd)) > goto invalid_param_len; > > - buf = page_address(sg_page(scsi_sglist(scmd))); > - > - if (n_block <= 65535 * ATA_MAX_TRIM_RNUM) { > - size = ata_set_lba_range_entries(buf, ATA_MAX_TRIM_RNUM, block, n_block); > + if (n_block <= 0xffff * trmax) { Note that the limit here would always be the advertised Maximum Write Same Length (ata_scsiop_inq_b0). It would be best for them to look the same. Besides, it doesn't seem necessary to create this trmax anyway. > + size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block); > } else { > fp = 2; > goto invalid_fld; > diff --git a/include/linux/ata.h b/include/linux/ata.h > index adbc812..45a1d71 100644 > --- a/include/linux/ata.h > +++ b/include/linux/ata.h > @@ -1071,32 +1071,6 @@ static inline void ata_id_to_hd_driveid(u16 *id) > #endif > } > > -/* > - * Write LBA Range Entries to the buffer that will cover the extent from > - * sector to sector + count. This is used for TRIM and for ADD LBA(S) > - * TO NV CACHE PINNED SET. > - */ > -static inline unsigned ata_set_lba_range_entries(void *_buffer, > - unsigned num, u64 sector, unsigned long count) > -{ > - __le64 *buffer = _buffer; > - unsigned i = 0, used_bytes; > - > - while (i < num) { > - u64 entry = sector | > - ((u64)(count > 0xffff ? 0xffff : count) << 48); > - buffer[i++] = __cpu_to_le64(entry); > - if (count <= 0xffff) > - break; > - count -= 0xffff; > - sector += 0xffff; > - } > - > - used_bytes = ALIGN(i * 8, 512); > - memset(buffer + i, 0, used_bytes - i * 8); > - return used_bytes; > -} > - > static inline bool ata_ok(u8 status) > { > return ((status & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ | ATA_ERR)) > -- > 2.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html