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[SCSI] mpt2sas: Added multisegment mode support for Linux BSG Driver
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Added support for Block IO requests with multiple segments (vectors) in
the SMP handler of the SAS Transport Class. This is required by the
BSG driver. Multisegment support added for both, Request and Response.

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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nagalakshmi.nandigama@lsi.com authored and James Bottomley committed Apr 23, 2012
1 parent 913809f commit 77a6edf
Showing 1 changed file with 104 additions and 29 deletions.
133 changes: 104 additions & 29 deletions drivers/scsi/mpt2sas/mpt2sas_transport.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1828,7 +1828,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
struct MPT2SAS_ADAPTER *ioc = shost_priv(shost);
Mpi2SmpPassthroughRequest_t *mpi_request;
Mpi2SmpPassthroughReply_t *mpi_reply;
int rc;
int rc, i;
u16 smid;
u32 ioc_state;
unsigned long timeleft;
Expand All @@ -1837,24 +1837,20 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
u8 issue_reset = 0;
dma_addr_t dma_addr_in = 0;
dma_addr_t dma_addr_out = 0;
dma_addr_t pci_dma_in = 0;
dma_addr_t pci_dma_out = 0;
void *pci_addr_in = NULL;
void *pci_addr_out = NULL;
u16 wait_state_count;
struct request *rsp = req->next_rq;
struct bio_vec *bvec = NULL;

if (!rsp) {
printk(MPT2SAS_ERR_FMT "%s: the smp response space is "
"missing\n", ioc->name, __func__);
return -EINVAL;
}

/* do we need to support multiple segments? */
if (req->bio->bi_vcnt > 1 || rsp->bio->bi_vcnt > 1) {
printk(MPT2SAS_ERR_FMT "%s: multiple segments req %u %u, "
"rsp %u %u\n", ioc->name, __func__, req->bio->bi_vcnt,
blk_rq_bytes(req), rsp->bio->bi_vcnt, blk_rq_bytes(rsp));
return -EINVAL;
}

if (ioc->shost_recovery) {
if (ioc->shost_recovery || ioc->pci_error_recovery) {
printk(MPT2SAS_INFO_FMT "%s: host reset in progress!\n",
__func__, ioc->name);
return -EFAULT;
Expand All @@ -1872,6 +1868,59 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
}
ioc->transport_cmds.status = MPT2_CMD_PENDING;

/* Check if the request is split across multiple segments */
if (req->bio->bi_vcnt > 1) {
u32 offset = 0;

/* Allocate memory and copy the request */
pci_addr_out = pci_alloc_consistent(ioc->pdev,
blk_rq_bytes(req), &pci_dma_out);
if (!pci_addr_out) {
printk(MPT2SAS_INFO_FMT "%s(): PCI Addr out = NULL\n",
ioc->name, __func__);
rc = -ENOMEM;
goto out;
}

bio_for_each_segment(bvec, req->bio, i) {
memcpy(pci_addr_out + offset,
page_address(bvec->bv_page) + bvec->bv_offset,
bvec->bv_len);
offset += bvec->bv_len;
}
} else {
dma_addr_out = pci_map_single(ioc->pdev, bio_data(req->bio),
blk_rq_bytes(req), PCI_DMA_BIDIRECTIONAL);
if (!dma_addr_out) {
printk(MPT2SAS_INFO_FMT "%s(): DMA Addr out = NULL\n",
ioc->name, __func__);
rc = -ENOMEM;
goto free_pci;
}
}

/* Check if the response needs to be populated across
* multiple segments */
if (rsp->bio->bi_vcnt > 1) {
pci_addr_in = pci_alloc_consistent(ioc->pdev, blk_rq_bytes(rsp),
&pci_dma_in);
if (!pci_addr_in) {
printk(MPT2SAS_INFO_FMT "%s(): PCI Addr in = NULL\n",
ioc->name, __func__);
rc = -ENOMEM;
goto unmap;
}
} else {
dma_addr_in = pci_map_single(ioc->pdev, bio_data(rsp->bio),
blk_rq_bytes(rsp), PCI_DMA_BIDIRECTIONAL);
if (!dma_addr_in) {
printk(MPT2SAS_INFO_FMT "%s(): DMA Addr in = NULL\n",
ioc->name, __func__);
rc = -ENOMEM;
goto unmap;
}
}

wait_state_count = 0;
ioc_state = mpt2sas_base_get_iocstate(ioc, 1);
while (ioc_state != MPI2_IOC_STATE_OPERATIONAL) {
Expand All @@ -1880,7 +1929,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
"%s: failed due to ioc not operational\n",
ioc->name, __func__);
rc = -EFAULT;
goto out;
goto unmap;
}
ssleep(1);
ioc_state = mpt2sas_base_get_iocstate(ioc, 1);
Expand All @@ -1897,7 +1946,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
printk(MPT2SAS_ERR_FMT "%s: failed obtaining a smid\n",
ioc->name, __func__);
rc = -EAGAIN;
goto out;
goto unmap;
}

rc = 0;
Expand All @@ -1919,16 +1968,14 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
sgl_flags = (MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
MPI2_SGE_FLAGS_END_OF_BUFFER | MPI2_SGE_FLAGS_HOST_TO_IOC);
sgl_flags = sgl_flags << MPI2_SGE_FLAGS_SHIFT;
dma_addr_out = pci_map_single(ioc->pdev, bio_data(req->bio),
blk_rq_bytes(req), PCI_DMA_BIDIRECTIONAL);
if (!dma_addr_out) {
mpt2sas_base_free_smid(ioc, smid);
goto unmap;
if (req->bio->bi_vcnt > 1) {
ioc->base_add_sg_single(psge, sgl_flags |
(blk_rq_bytes(req) - 4), pci_dma_out);
} else {
ioc->base_add_sg_single(psge, sgl_flags |
(blk_rq_bytes(req) - 4), dma_addr_out);
}

ioc->base_add_sg_single(psge, sgl_flags | (blk_rq_bytes(req) - 4),
dma_addr_out);

/* incr sgel */
psge += ioc->sge_size;

Expand All @@ -1937,16 +1984,14 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
MPI2_SGE_FLAGS_LAST_ELEMENT | MPI2_SGE_FLAGS_END_OF_BUFFER |
MPI2_SGE_FLAGS_END_OF_LIST);
sgl_flags = sgl_flags << MPI2_SGE_FLAGS_SHIFT;
dma_addr_in = pci_map_single(ioc->pdev, bio_data(rsp->bio),
blk_rq_bytes(rsp), PCI_DMA_BIDIRECTIONAL);
if (!dma_addr_in) {
mpt2sas_base_free_smid(ioc, smid);
goto unmap;
if (rsp->bio->bi_vcnt > 1) {
ioc->base_add_sg_single(psge, sgl_flags |
(blk_rq_bytes(rsp) + 4), pci_dma_in);
} else {
ioc->base_add_sg_single(psge, sgl_flags |
(blk_rq_bytes(rsp) + 4), dma_addr_in);
}

ioc->base_add_sg_single(psge, sgl_flags | (blk_rq_bytes(rsp) + 4),
dma_addr_in);

dtransportprintk(ioc, printk(MPT2SAS_INFO_FMT "%s - "
"sending smp request\n", ioc->name, __func__));

Expand Down Expand Up @@ -1982,6 +2027,27 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
req->resid_len = 0;
rsp->resid_len -=
le16_to_cpu(mpi_reply->ResponseDataLength);
/* check if the resp needs to be copied from the allocated
* pci mem */
if (rsp->bio->bi_vcnt > 1) {
u32 offset = 0;
u32 bytes_to_copy =
le16_to_cpu(mpi_reply->ResponseDataLength);
bio_for_each_segment(bvec, rsp->bio, i) {
if (bytes_to_copy <= bvec->bv_len) {
memcpy(page_address(bvec->bv_page) +
bvec->bv_offset, pci_addr_in +
offset, bytes_to_copy);
break;
} else {
memcpy(page_address(bvec->bv_page) +
bvec->bv_offset, pci_addr_in +
offset, bvec->bv_len);
bytes_to_copy -= bvec->bv_len;
}
offset += bvec->bv_len;
}
}
} else {
dtransportprintk(ioc, printk(MPT2SAS_INFO_FMT
"%s - no reply\n", ioc->name, __func__));
Expand All @@ -2003,6 +2069,15 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
pci_unmap_single(ioc->pdev, dma_addr_in, blk_rq_bytes(rsp),
PCI_DMA_BIDIRECTIONAL);

free_pci:
if (pci_addr_out)
pci_free_consistent(ioc->pdev, blk_rq_bytes(req), pci_addr_out,
pci_dma_out);

if (pci_addr_in)
pci_free_consistent(ioc->pdev, blk_rq_bytes(rsp), pci_addr_in,
pci_dma_in);

out:
ioc->transport_cmds.status = MPT2_CMD_NOT_USED;
mutex_unlock(&ioc->transport_cmds.mutex);
Expand Down

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