[PATCH 4.19 065/115] libata: Fix retrieving of active qcs

Greg Kroah-Hartman
2020-01-07T21:06:25Z

From: Sascha Hauer <s.hauer@pengutronix.de>

commit 8385d756e114f2df8568e508902d5f9850817ffb upstream.

ata_qc_complete_multiple() is called with a mask of the still active
tags.

mv_sata doesn't have this information directly and instead calculates
the still active tags from the started tags (ap->qc_active) and the
finished tags as (ap->qc_active ^ done_mask)

Since 28361c40368 the hw_tag and tag are no longer the same and the
equation is no longer valid. In ata_exec_internal_sg() ap->qc_active is
initialized as 1ULL << ATA_TAG_INTERNAL, but in hardware tag 0 is
started and this will be in done_mask on completion. ap->qc_active ^
done_mask becomes 0x100000000 ^ 0x1 = 0x100000001 and thus tag 0 used as
the internal tag will never be reported as completed.

This is fixed by introducing ata_qc_get_active() which returns the
active hardware tags and calling it where appropriate.

This is tested on mv_sata, but sata_fsl and sata_nv suffer from the same
problem. There is another case in sata_nv that most likely needs fixing
as well, but this looks a little different, so I wasn't confident enough
to change that.

Fixes: 28361c403683 ("libata: add extra internal command")
Cc: stable@vger.kernel.org
Tested-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing export of ata_qc_get_active(), as per Pali.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

---
drivers/ata/libata-core.c | 24 ++++++++++++++++++++++++
drivers/ata/sata_fsl.c | 2 +-
drivers/ata/sata_mv.c | 2 +-
drivers/ata/sata_nv.c | 2 +-
include/linux/libata.h | 1 +
5 files changed, 28 insertions(+), 3 deletions(-)

--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5344,6 +5344,30 @@ void ata_qc_complete(struct ata_queued_c
}

/**
+ * ata_qc_get_active - get bitmask of active qcs
+ * @ap: port in question
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host lock)
+ *
+ * RETURNS:
+ * Bitmask of active qcs
+ */
+u64 ata_qc_get_active(struct ata_port *ap)
+{
+ u64 qc_active = ap->qc_active;
+
+ /* ATA_TAG_INTERNAL is sent to hw as tag 0 */
+ if (qc_active & (1ULL << ATA_TAG_INTERNAL)) {
+ qc_active |= (1 << 0);
+ qc_active &= ~(1ULL << ATA_TAG_INTERNAL);
+ }
+
+ return qc_active;
+}
+EXPORT_SYMBOL_GPL(ata_qc_get_active);
+
+/**
* ata_qc_complete_multiple - Complete multiple qcs successfully
* @ap: port in question
* @qc_active: new qc_active mask
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -1283,7 +1283,7 @@ static void sata_fsl_host_intr(struct at
i, ioread32(hcr_base + CC),
ioread32(hcr_base + CA));
}
- ata_qc_complete_multiple(ap, ap->qc_active ^ done_mask);
+ ata_qc_complete_multiple(ap, ata_qc_get_active(ap) ^ done_mask);
return;

} else if ((ap->qc_active & (1ULL << ATA_TAG_INTERNAL))) {
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -2840,7 +2840,7 @@ static void mv_process_crpb_entries(stru
}

if (work_done) {
- ata_qc_complete_multiple(ap, ap->qc_active ^ done_mask);
+ ata_qc_complete_multiple(ap, ata_qc_get_active(ap) ^ done_mask);

/* Update the software queue position index in hardware */
writelfl((pp->crpb_dma & EDMA_RSP_Q_BASE_LO_MASK) |
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -1000,7 +1000,7 @@ static irqreturn_t nv_adma_interrupt(int
check_commands = 0;
check_commands &= ~(1 << pos);
}
- ata_qc_complete_multiple(ap, ap->qc_active ^ done_mask);
+ ata_qc_complete_multiple(ap, ata_qc_get_active(ap) ^ done_mask);
}
}

--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1190,6 +1190,7 @@ extern unsigned int ata_do_dev_read_id(s
struct ata_taskfile *tf, u16 *id);
extern void ata_qc_complete(struct ata_queued_cmd *qc);
extern int ata_qc_complete_multiple(struct ata_port *ap, u64 qc_active);
+extern u64 ata_qc_get_active(struct ata_port *ap);
extern void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd);
extern int ata_std_bios_param(struct scsi_device *sdev,
struct block_device *bdev,