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Commit ef2d7392 authored by Shaun Tancheff's avatar Shaun Tancheff Committed by Tejun Heo
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libata: SCT Write Same / DSM Trim 



Correct handling of devices with sector_size other that 512 bytes.

In the case of a 4Kn device sector_size it is possible to describe a much
larger DSM Trim than the current fixed default of 512 bytes.

This patch assumes the minimum descriptor is sector_size and fills out
the descriptor accordingly.

The ACS-2 specification is quite clear that the DSM command payload is
sized as number of 512 byte transfers so a 4Kn device will operate
correctly without this patch.

Signed-off-by: default avatarShaun Tancheff <shaun.tancheff@seagate.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
parent 7b203094

drivers/ata/libata-scsi.c

+57 −28
Original line number Diff line number Diff line
@@ -3283,7 +3283,7 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc) 
/**

 * ata_format_dsm_trim_descr() - SATL Write Same to DSM Trim

 * @cmd: SCSI command being translated

 * @num: Maximum number of entries (nominally 64).

 * @trmax: Maximum number of entries that will fit in sector_size bytes.

 * @sector: Starting sector

 * @count: Total Range of request in logical sectors

 *
@@ -3298,63 +3298,80 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc) 
 *  LBA's should be sorted order and not overlap.

 *

 * NOTE: this is the same format as ADD LBA(S) TO NV CACHE PINNED SET

 *

 * Return: Number of bytes copied into sglist.

 */

static unsigned int ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 num,

static size_t ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 trmax,

					u64 sector, u32 count)

{

	__le64 *buffer;

	u32 i = 0, used_bytes;

	struct scsi_device *sdp = cmd->device;

	size_t len = sdp->sector_size;

	size_t r;

	__le64 *buf;

	u32 i = 0;

	unsigned long flags;



	BUILD_BUG_ON(512 > ATA_SCSI_RBUF_SIZE);

	WARN_ON(len > ATA_SCSI_RBUF_SIZE);



	if (len > ATA_SCSI_RBUF_SIZE)

		len = ATA_SCSI_RBUF_SIZE;



	spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);

	buffer = ((void *)ata_scsi_rbuf);

	while (i < num) {

	buf = ((void *)ata_scsi_rbuf);

	memset(buf, 0, len);

	while (i < trmax) {

		u64 entry = sector |

			((u64)(count > 0xffff ? 0xffff : count) << 48);

		buffer[i++] = __cpu_to_le64(entry);

		buf[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);

	r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, len);

	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);



	return used_bytes;

	return r;

}



/**

 * ata_format_dsm_trim_descr() - SATL Write Same to ATA SCT Write Same

 * @cmd: SCSI command being translated

 * @lba: Starting sector

 * @num: Number of logical sectors to be zero'd.

 * @num: Number of sectors to be zero'd.

 *

 * Rewrite the WRITE SAME descriptor to be an SCT Write Same formatted

 * Rewrite the WRITE SAME payload to be an SCT Write Same formatted

 * descriptor.

 * NOTE: Writes a pattern (0's) in the foreground.

 *       Large write-same requents can timeout.

 *

 * Return: Number of bytes copied into sglist.

 */

static void ata_format_sct_write_same(struct scsi_cmnd *cmd, u64 lba, u64 num)

static size_t ata_format_sct_write_same(struct scsi_cmnd *cmd, u64 lba, u64 num)

{

	u16 *sctpg;

	struct scsi_device *sdp = cmd->device;

	size_t len = sdp->sector_size;

	size_t r;

	u16 *buf;

	unsigned long flags;



	spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);

	sctpg = ((void *)ata_scsi_rbuf);

	buf = ((void *)ata_scsi_rbuf);



	put_unaligned_le16(0x0002,  &buf[0]); /* SCT_ACT_WRITE_SAME */

	put_unaligned_le16(0x0101,  &buf[1]); /* WRITE PTRN FG */

	put_unaligned_le64(lba,     &buf[2]);

	put_unaligned_le64(num,     &buf[6]);

	put_unaligned_le32(0u,      &buf[10]); /* pattern */



	WARN_ON(len > ATA_SCSI_RBUF_SIZE);



	put_unaligned_le16(0x0002,  &sctpg[0]); /* SCT_ACT_WRITE_SAME */

	put_unaligned_le16(0x0101,  &sctpg[1]); /* WRITE PTRN FG */

	put_unaligned_le64(lba,     &sctpg[2]);

	put_unaligned_le64(num,     &sctpg[6]);

	put_unaligned_le32(0u,      &sctpg[10]);

	if (len > ATA_SCSI_RBUF_SIZE)

		len = ATA_SCSI_RBUF_SIZE;



	sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), sctpg, 512);

	r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, len);

	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);



	return r;

}



/**
@@ -3371,11 +3388,13 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) 
{

	struct ata_taskfile *tf = &qc->tf;

	struct scsi_cmnd *scmd = qc->scsicmd;

	struct scsi_device *sdp = scmd->device;

	size_t len = sdp->sector_size;

	struct ata_device *dev = qc->dev;

	const u8 *cdb = scmd->cmnd;

	u64 block;

	u32 n_block;

	const u32 trmax = ATA_MAX_TRIM_RNUM;

	const u32 trmax = len >> 3;

	u32 size;

	u16 fp;

	u8 bp = 0xff;
@@ -3420,8 +3439,16 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) 
	if (!scsi_sg_count(scmd))

		goto invalid_param_len;



	/*

	 * size must match sector size in bytes

	 * For DATA SET MANAGEMENT TRIM in ACS-2 nsect (aka count)

	 * is defined as number of 512 byte blocks to be transferred.

	 */

	if (unmap) {

		size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);

		if (size != len)

			goto invalid_param_len;



		if (ata_ncq_enabled(dev) && ata_fpdma_dsm_supported(dev)) {

			/* Newer devices support queued TRIM commands */

			tf->protocol = ATA_PROT_NCQ;
@@ -3441,7 +3468,9 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) 
			tf->command = ATA_CMD_DSM;

		}

	} else {

		ata_format_sct_write_same(scmd, block, n_block);

		size = ata_format_sct_write_same(scmd, block, n_block);

		if (size != len)

			goto invalid_param_len;



		tf->hob_feature = 0;

		tf->feature = 0;