Skip to content

Commit

Permalink
libata: fix ATAPI DMA alignment issues
Browse files Browse the repository at this point in the history 
ATAPI needs to be padded to next 4 byte boundary, if misaligned.

Original work by me, many fixes from Tejun Heo.
  • Loading branch information
Jeff Garzik committed Oct 5, 2005
1 parent ed39f73 commit cedc9a4
Show file tree
Hide file tree
Showing 6 changed files with 174 additions and 41 deletions.
30 changes: 19 additions & 11 deletions drivers/scsi/ahci.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -314,8 +314,15 @@ static int ahci_port_start(struct ata_port *ap)
return -ENOMEM;
memset(pp, 0, sizeof(*pp));

ap->pad = dma_alloc_coherent(dev, ATA_DMA_PAD_BUF_SZ, &ap->pad_dma, GFP_KERNEL);
if (!ap->pad) {
kfree(pp);
return -ENOMEM;
}

mem = dma_alloc_coherent(dev, AHCI_PORT_PRIV_DMA_SZ, &mem_dma, GFP_KERNEL);
if (!mem) {
dma_free_coherent(dev, ATA_DMA_PAD_BUF_SZ, ap->pad, ap->pad_dma);
kfree(pp);
return -ENOMEM;
}
Expand Down Expand Up @@ -391,6 +398,7 @@ static void ahci_port_stop(struct ata_port *ap)
ap->private_data = NULL;
dma_free_coherent(dev, AHCI_PORT_PRIV_DMA_SZ,
pp->cmd_slot, pp->cmd_slot_dma);
dma_free_coherent(dev, ATA_DMA_PAD_BUF_SZ, ap->pad, ap->pad_dma);
kfree(pp);
}

Expand Down Expand Up @@ -476,23 +484,23 @@ static void ahci_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
static void ahci_fill_sg(struct ata_queued_cmd *qc)
{
struct ahci_port_priv *pp = qc->ap->private_data;
unsigned int i;
struct scatterlist *sg;
struct ahci_sg *ahci_sg;

VPRINTK("ENTER\n");

/*
* Next, the S/G list.
*/
for (i = 0; i < qc->n_elem; i++) {
u32 sg_len;
dma_addr_t addr;

addr = sg_dma_address(&qc->sg[i]);
sg_len = sg_dma_len(&qc->sg[i]);

pp->cmd_tbl_sg[i].addr = cpu_to_le32(addr & 0xffffffff);
pp->cmd_tbl_sg[i].addr_hi = cpu_to_le32((addr >> 16) >> 16);
pp->cmd_tbl_sg[i].flags_size = cpu_to_le32(sg_len - 1);
ahci_sg = pp->cmd_tbl_sg;
ata_for_each_sg(sg, qc) {
dma_addr_t addr = sg_dma_address(sg);
u32 sg_len = sg_dma_len(sg);

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++;
}
}

Expand Down
123 changes: 106 additions & 17 deletions drivers/scsi/libata-core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2156,8 +2156,9 @@ static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev)
static void ata_sg_clean(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct scatterlist *sg = qc->sg;
struct scatterlist *sg = qc->__sg;
int dir = qc->dma_dir;
void *pad_buf = NULL;

assert(qc->flags & ATA_QCFLAG_DMAMAP);
assert(sg != NULL);
Expand All @@ -2167,14 +2168,35 @@ static void ata_sg_clean(struct ata_queued_cmd *qc)

DPRINTK("unmapping %u sg elements\n", qc->n_elem);

if (qc->flags & ATA_QCFLAG_SG)
/* if we padded the buffer out to 32-bit bound, and data
* xfer direction is from-device, we must copy from the
* pad buffer back into the supplied buffer
*/
if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);

if (qc->flags & ATA_QCFLAG_SG) {
dma_unmap_sg(ap->host_set->dev, sg, qc->n_elem, dir);
else
/* restore last sg */
sg[qc->orig_n_elem - 1].length += qc->pad_len;
if (pad_buf) {
struct scatterlist *psg = &qc->pad_sgent;
void *addr = kmap_atomic(psg->page, KM_IRQ0);
memcpy(addr + psg->offset, pad_buf, qc->pad_len);
kunmap_atomic(psg->page, KM_IRQ0);
}
} else {
dma_unmap_single(ap->host_set->dev, sg_dma_address(&sg[0]),
sg_dma_len(&sg[0]), dir);
/* restore sg */
sg->length += qc->pad_len;
if (pad_buf)
memcpy(qc->buf_virt + sg->length - qc->pad_len,
pad_buf, qc->pad_len);
}

qc->flags &= ~ATA_QCFLAG_DMAMAP;
qc->sg = NULL;
qc->__sg = NULL;
}

/**
Expand All @@ -2190,15 +2212,15 @@ static void ata_sg_clean(struct ata_queued_cmd *qc)
*/
static void ata_fill_sg(struct ata_queued_cmd *qc)
{
struct scatterlist *sg = qc->sg;
struct ata_port *ap = qc->ap;
unsigned int idx, nelem;
struct scatterlist *sg;
unsigned int idx;

assert(sg != NULL);
assert(qc->__sg != NULL);
assert(qc->n_elem > 0);

idx = 0;
for (nelem = qc->n_elem; nelem; nelem--,sg++) {
ata_for_each_sg(sg, qc) {
u32 addr, offset;
u32 sg_len, len;

Expand Down Expand Up @@ -2289,11 +2311,12 @@ void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
qc->flags |= ATA_QCFLAG_SINGLE;

memset(&qc->sgent, 0, sizeof(qc->sgent));
qc->sg = &qc->sgent;
qc->__sg = &qc->sgent;
qc->n_elem = 1;
qc->orig_n_elem = 1;
qc->buf_virt = buf;

sg = qc->sg;
sg = qc->__sg;
sg->page = virt_to_page(buf);
sg->offset = (unsigned long) buf & ~PAGE_MASK;
sg->length = buflen;
Expand All @@ -2317,8 +2340,9 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
unsigned int n_elem)
{
qc->flags |= ATA_QCFLAG_SG;
qc->sg = sg;
qc->__sg = sg;
qc->n_elem = n_elem;
qc->orig_n_elem = n_elem;
}

/**
Expand All @@ -2338,9 +2362,32 @@ static int ata_sg_setup_one(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
int dir = qc->dma_dir;
struct scatterlist *sg = qc->sg;
struct scatterlist *sg = qc->__sg;
dma_addr_t dma_address;

/* we must lengthen transfers to end on a 32-bit boundary */
qc->pad_len = sg->length & 3;
if (qc->pad_len) {
void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
struct scatterlist *psg = &qc->pad_sgent;

assert(qc->dev->class == ATA_DEV_ATAPI);

memset(pad_buf, 0, ATA_DMA_PAD_SZ);

if (qc->tf.flags & ATA_TFLAG_WRITE)
memcpy(pad_buf, qc->buf_virt + sg->length - qc->pad_len,
qc->pad_len);

sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
sg_dma_len(psg) = ATA_DMA_PAD_SZ;
/* trim sg */
sg->length -= qc->pad_len;

DPRINTK("padding done, sg->length=%u pad_len=%u\n",
sg->length, qc->pad_len);
}

dma_address = dma_map_single(ap->host_set->dev, qc->buf_virt,
sg->length, dir);
if (dma_mapping_error(dma_address))
Expand Down Expand Up @@ -2372,12 +2419,47 @@ static int ata_sg_setup_one(struct ata_queued_cmd *qc)
static int ata_sg_setup(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct scatterlist *sg = qc->sg;
struct scatterlist *sg = qc->__sg;
struct scatterlist *lsg = &sg[qc->n_elem - 1];
int n_elem, dir;

VPRINTK("ENTER, ata%u\n", ap->id);
assert(qc->flags & ATA_QCFLAG_SG);

/* we must lengthen transfers to end on a 32-bit boundary */
qc->pad_len = lsg->length & 3;
if (qc->pad_len) {
void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
struct scatterlist *psg = &qc->pad_sgent;
unsigned int offset;

assert(qc->dev->class == ATA_DEV_ATAPI);

memset(pad_buf, 0, ATA_DMA_PAD_SZ);

/*
* psg->page/offset are used to copy to-be-written
* data in this function or read data in ata_sg_clean.
*/
offset = lsg->offset + lsg->length - qc->pad_len;
psg->page = nth_page(lsg->page, offset >> PAGE_SHIFT);
psg->offset = offset_in_page(offset);

if (qc->tf.flags & ATA_TFLAG_WRITE) {
void *addr = kmap_atomic(psg->page, KM_IRQ0);
memcpy(pad_buf, addr + psg->offset, qc->pad_len);
kunmap_atomic(psg->page, KM_IRQ0);
}

sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
sg_dma_len(psg) = ATA_DMA_PAD_SZ;
/* trim last sg */
lsg->length -= qc->pad_len;

DPRINTK("padding done, sg[%d].length=%u pad_len=%u\n",
qc->n_elem - 1, lsg->length, qc->pad_len);
}

dir = qc->dma_dir;
n_elem = dma_map_sg(ap->host_set->dev, sg, qc->n_elem, dir);
if (n_elem < 1)
Expand Down Expand Up @@ -2655,7 +2737,7 @@ static void ata_data_xfer(struct ata_port *ap, unsigned char *buf,
static void ata_pio_sector(struct ata_queued_cmd *qc)
{
int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
struct scatterlist *sg = qc->sg;
struct scatterlist *sg = qc->__sg;
struct ata_port *ap = qc->ap;
struct page *page;
unsigned int offset;
Expand Down Expand Up @@ -2705,7 +2787,7 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
{
int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
struct scatterlist *sg = qc->sg;
struct scatterlist *sg = qc->__sg;
struct ata_port *ap = qc->ap;
struct page *page;
unsigned char *buf;
Expand Down Expand Up @@ -2738,7 +2820,7 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
return;
}

sg = &qc->sg[qc->cursg];
sg = &qc->__sg[qc->cursg];

page = sg->page;
offset = sg->offset + qc->cursg_ofs;
Expand Down Expand Up @@ -3145,7 +3227,7 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,

qc = ata_qc_new(ap);
if (qc) {
qc->sg = NULL;
qc->__sg = NULL;
qc->flags = 0;
qc->scsicmd = NULL;
qc->ap = ap;
Expand Down Expand Up @@ -3837,6 +3919,12 @@ int ata_port_start (struct ata_port *ap)
if (!ap->prd)
return -ENOMEM;

ap->pad = dma_alloc_coherent(dev, ATA_DMA_PAD_BUF_SZ, &ap->pad_dma, GFP_KERNEL);
if (!ap->pad) {
dma_free_coherent(dev, ATA_PRD_TBL_SZ, ap->prd, ap->prd_dma);
return -ENOMEM;
}

DPRINTK("prd alloc, virt %p, dma %llx\n", ap->prd, (unsigned long long) ap->prd_dma);

return 0;
Expand All @@ -3859,6 +3947,7 @@ void ata_port_stop (struct ata_port *ap)
struct device *dev = ap->host_set->dev;

dma_free_coherent(dev, ATA_PRD_TBL_SZ, ap->prd, ap->prd_dma);
dma_free_coherent(dev, ATA_DMA_PAD_BUF_SZ, ap->pad, ap->pad_dma);
}

void ata_host_stop (struct ata_host_set *host_set)
Expand Down
14 changes: 12 additions & 2 deletions drivers/scsi/libata-scsi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -150,10 +150,10 @@ struct ata_queued_cmd *ata_scsi_qc_new(struct ata_port *ap,
qc->scsidone = done;

if (cmd->use_sg) {
qc->sg = (struct scatterlist *) cmd->request_buffer;
qc->__sg = (struct scatterlist *) cmd->request_buffer;
qc->n_elem = cmd->use_sg;
} else {
qc->sg = &qc->sgent;
qc->__sg = &qc->sgent;
qc->n_elem = 1;
}
} else {
Expand Down Expand Up @@ -364,6 +364,16 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
*/
blk_queue_max_sectors(sdev->request_queue, 2048);
}

/*
* SATA DMA transfers must be multiples of 4 byte, so
* we need to pad ATAPI transfers using an extra sg.
* Decrement max hw segments accordingly.
*/
if (dev->class == ATA_DEV_ATAPI) {
request_queue_t *q = sdev->request_queue;
blk_queue_max_hw_segments(q, q->max_hw_segments - 1);
}
}

return 0; /* scsi layer doesn't check return value, sigh */
Expand Down
8 changes: 5 additions & 3 deletions drivers/scsi/sata_qstor.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -268,16 +268,17 @@ static void qs_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)

static void qs_fill_sg(struct ata_queued_cmd *qc)
{
struct scatterlist *sg = qc->sg;
struct scatterlist *sg;
struct ata_port *ap = qc->ap;
struct qs_port_priv *pp = ap->private_data;
unsigned int nelem;
u8 *prd = pp->pkt + QS_CPB_BYTES;

assert(sg != NULL);
assert(qc->__sg != NULL);
assert(qc->n_elem > 0);

for (nelem = 0; nelem < qc->n_elem; nelem++,sg++) {
nelem = 0;
ata_for_each_sg(sg, qc) {
u64 addr;
u32 len;

Expand All @@ -291,6 +292,7 @@ static void qs_fill_sg(struct ata_queued_cmd *qc)

VPRINTK("PRD[%u] = (0x%llX, 0x%X)\n", nelem,
(unsigned long long)addr, len);
nelem++;
}
}

Expand Down
13 changes: 6 additions & 7 deletions drivers/scsi/sata_sx4.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -449,14 +449,14 @@ static inline void pdc20621_host_pkt(struct ata_taskfile *tf, u8 *buf,

static void pdc20621_dma_prep(struct ata_queued_cmd *qc)
{
struct scatterlist *sg = qc->sg;
struct scatterlist *sg;
struct ata_port *ap = qc->ap;
struct pdc_port_priv *pp = ap->private_data;
void __iomem *mmio = ap->host_set->mmio_base;
struct pdc_host_priv *hpriv = ap->host_set->private_data;
void __iomem *dimm_mmio = hpriv->dimm_mmio;
unsigned int portno = ap->port_no;
unsigned int i, last, idx, total_len = 0, sgt_len;
unsigned int i, idx, total_len = 0, sgt_len;
u32 *buf = (u32 *) &pp->dimm_buf[PDC_DIMM_HEADER_SZ];

assert(qc->flags & ATA_QCFLAG_DMAMAP);
Expand All @@ -469,12 +469,11 @@ static void pdc20621_dma_prep(struct ata_queued_cmd *qc)
/*
* Build S/G table
*/
last = qc->n_elem;
idx = 0;
for (i = 0; i < last; i++) {
buf[idx++] = cpu_to_le32(sg_dma_address(&sg[i]));
buf[idx++] = cpu_to_le32(sg_dma_len(&sg[i]));
total_len += sg_dma_len(&sg[i]);
ata_for_each_sg(sg, qc) {
buf[idx++] = cpu_to_le32(sg_dma_address(sg));
buf[idx++] = cpu_to_le32(sg_dma_len(sg));
total_len += sg_dma_len(sg);
}
buf[idx - 1] |= cpu_to_le32(ATA_PRD_EOT);
sgt_len = idx * 4;
Expand Down
Loading

0 comments on commit cedc9a4

Please sign in to comment.