Commit 828d09de authored by Jeff Garzik's avatar Jeff Garzik

[libata ahci, qstor] fix miscount of scatter/gather entries

Don't directly reference qc->n_elem, as that might cause an off-by-one
error for misaligned (padded) ATAPI transfers.
parent cd52d1ee
......@@ -474,11 +474,12 @@ static void ahci_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
ata_tf_from_fis(d2h_fis, tf);
}
static void ahci_fill_sg(struct ata_queued_cmd *qc)
static unsigned int ahci_fill_sg(struct ata_queued_cmd *qc)
{
struct ahci_port_priv *pp = qc->ap->private_data;
struct scatterlist *sg;
struct ahci_sg *ahci_sg;
unsigned int n_sg = 0;
VPRINTK("ENTER\n");
......@@ -493,8 +494,12 @@ static void ahci_fill_sg(struct ata_queued_cmd *qc)
ahci_sg->addr = cpu_to_le32(addr & 0xffffffff);
ahci_sg->addr_hi = cpu_to_le32((addr >> 16) >> 16);
ahci_sg->flags_size = cpu_to_le32(sg_len - 1);
ahci_sg++;
n_sg++;
}
return n_sg;
}
static void ahci_qc_prep(struct ata_queued_cmd *qc)
......@@ -503,13 +508,14 @@ static void ahci_qc_prep(struct ata_queued_cmd *qc)
struct ahci_port_priv *pp = ap->private_data;
u32 opts;
const u32 cmd_fis_len = 5; /* five dwords */
unsigned int n_elem;
/*
* Fill in command slot information (currently only one slot,
* slot 0, is currently since we don't do queueing)
*/
opts = (qc->n_elem << 16) | cmd_fis_len;
opts = cmd_fis_len;
if (qc->tf.flags & ATA_TFLAG_WRITE)
opts |= AHCI_CMD_WRITE;
if (is_atapi_taskfile(&qc->tf))
......@@ -533,7 +539,9 @@ static void ahci_qc_prep(struct ata_queued_cmd *qc)
if (!(qc->flags & ATA_QCFLAG_DMAMAP))
return;
ahci_fill_sg(qc);
n_elem = ahci_fill_sg(qc);
pp->cmd_slot[0].opts |= cpu_to_le32(n_elem << 16);
}
static void ahci_intr_error(struct ata_port *ap, u32 irq_stat)
......
......@@ -268,7 +268,7 @@ static void qs_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
writel(val, (void __iomem *)(ap->ioaddr.scr_addr + (sc_reg * 8)));
}
static void qs_fill_sg(struct ata_queued_cmd *qc)
static unsigned int qs_fill_sg(struct ata_queued_cmd *qc)
{
struct scatterlist *sg;
struct ata_port *ap = qc->ap;
......@@ -296,6 +296,8 @@ static void qs_fill_sg(struct ata_queued_cmd *qc)
(unsigned long long)addr, len);
nelem++;
}
return nelem;
}
static void qs_qc_prep(struct ata_queued_cmd *qc)
......@@ -304,6 +306,7 @@ static void qs_qc_prep(struct ata_queued_cmd *qc)
u8 dflags = QS_DF_PORD, *buf = pp->pkt;
u8 hflags = QS_HF_DAT | QS_HF_IEN | QS_HF_VLD;
u64 addr;
unsigned int nelem;
VPRINTK("ENTER\n");
......@@ -313,7 +316,7 @@ static void qs_qc_prep(struct ata_queued_cmd *qc)
return;
}
qs_fill_sg(qc);
nelem = qs_fill_sg(qc);
if ((qc->tf.flags & ATA_TFLAG_WRITE))
hflags |= QS_HF_DIRO;
......@@ -324,7 +327,7 @@ static void qs_qc_prep(struct ata_queued_cmd *qc)
buf[ 0] = QS_HCB_HDR;
buf[ 1] = hflags;
*(__le32 *)(&buf[ 4]) = cpu_to_le32(qc->nsect * ATA_SECT_SIZE);
*(__le32 *)(&buf[ 8]) = cpu_to_le32(qc->n_elem);
*(__le32 *)(&buf[ 8]) = cpu_to_le32(nelem);
addr = ((u64)pp->pkt_dma) + QS_CPB_BYTES;
*(__le64 *)(&buf[16]) = cpu_to_le64(addr);
......
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