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sbp2: split sbp2_create_command_orb() for better readability
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sbp2_create_command_orb() code cleanup:
 - add two helper functions to reduce nesting depth
 - omit the return value which was always ignored
 - remove unnecessary declaration from sb2.h

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>
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Stefan Richter authored and Jody McIntyre committed Dec 13, 2005
1 parent 209171a commit cf8d2c0
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Showing 2 changed files with 178 additions and 184 deletions.
355 changes: 178 additions & 177 deletions drivers/ieee1394/sbp2.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1707,26 +1707,184 @@ static int sbp2_agent_reset(struct scsi_id_instance_data *scsi_id, int wait)
return 0;
}

static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
struct sbp2scsi_host_info *hi,
struct sbp2_command_info *command,
unsigned int scsi_use_sg,
struct scatterlist *sgpnt,
u32 orb_direction,
enum dma_data_direction dma_dir)
{
command->dma_dir = dma_dir;
orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
orb->misc |= ORB_SET_DIRECTION(orb_direction);

/* Special case if only one element (and less than 64KB in size) */
if ((scsi_use_sg == 1) &&
(sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) {

SBP2_DEBUG("Only one s/g element");
command->dma_size = sgpnt[0].length;
command->dma_type = CMD_DMA_PAGE;
command->cmd_dma = pci_map_page(hi->host->pdev,
sgpnt[0].page,
sgpnt[0].offset,
command->dma_size,
command->dma_dir);
SBP2_DMA_ALLOC("single page scatter element");

orb->data_descriptor_lo = command->cmd_dma;
orb->misc |= ORB_SET_DATA_SIZE(command->dma_size);

} else {
struct sbp2_unrestricted_page_table *sg_element =
&command->scatter_gather_element[0];
u32 sg_count, sg_len;
dma_addr_t sg_addr;
int i, count = pci_map_sg(hi->host->pdev, sgpnt, scsi_use_sg,
dma_dir);

SBP2_DMA_ALLOC("scatter list");

command->dma_size = scsi_use_sg;
command->sge_buffer = sgpnt;

/* use page tables (s/g) */
orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
orb->data_descriptor_lo = command->sge_dma;

/*
* Loop through and fill out our sbp-2 page tables
* (and split up anything too large)
*/
for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) {
sg_len = sg_dma_len(sgpnt);
sg_addr = sg_dma_address(sgpnt);
while (sg_len) {
sg_element[sg_count].segment_base_lo = sg_addr;
if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
sg_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
} else {
sg_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
sg_len = 0;
}
sg_count++;
}
}

/* Number of page table (s/g) elements */
orb->misc |= ORB_SET_DATA_SIZE(sg_count);

sbp2util_packet_dump(sg_element,
(sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
"sbp2 s/g list", command->sge_dma);

/* Byte swap page tables if necessary */
sbp2util_cpu_to_be32_buffer(sg_element,
(sizeof(struct sbp2_unrestricted_page_table)) *
sg_count);
}
}

static void sbp2_prep_command_orb_no_sg(struct sbp2_command_orb *orb,
struct sbp2scsi_host_info *hi,
struct sbp2_command_info *command,
struct scatterlist *sgpnt,
u32 orb_direction,
unsigned int scsi_request_bufflen,
void *scsi_request_buffer,
enum dma_data_direction dma_dir)
{
command->dma_dir = dma_dir;
command->dma_size = scsi_request_bufflen;
command->dma_type = CMD_DMA_SINGLE;
command->cmd_dma = pci_map_single(hi->host->pdev, scsi_request_buffer,
command->dma_size, command->dma_dir);
orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
orb->misc |= ORB_SET_DIRECTION(orb_direction);

SBP2_DMA_ALLOC("single bulk");

/*
* Handle case where we get a command w/o s/g enabled (but
* check for transfers larger than 64K)
*/
if (scsi_request_bufflen <= SBP2_MAX_SG_ELEMENT_LENGTH) {

orb->data_descriptor_lo = command->cmd_dma;
orb->misc |= ORB_SET_DATA_SIZE(scsi_request_bufflen);

} else {
struct sbp2_unrestricted_page_table *sg_element =
&command->scatter_gather_element[0];
u32 sg_count, sg_len;
dma_addr_t sg_addr;

/*
* Need to turn this into page tables, since the
* buffer is too large.
*/
orb->data_descriptor_lo = command->sge_dma;

/* Use page tables (s/g) */
orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);

/*
* fill out our sbp-2 page tables (and split up
* the large buffer)
*/
sg_count = 0;
sg_len = scsi_request_bufflen;
sg_addr = command->cmd_dma;
while (sg_len) {
sg_element[sg_count].segment_base_lo = sg_addr;
if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
sg_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
} else {
sg_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
sg_len = 0;
}
sg_count++;
}

/* Number of page table (s/g) elements */
orb->misc |= ORB_SET_DATA_SIZE(sg_count);

sbp2util_packet_dump(sg_element,
(sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
"sbp2 s/g list", command->sge_dma);

/* Byte swap page tables if necessary */
sbp2util_cpu_to_be32_buffer(sg_element,
(sizeof(struct sbp2_unrestricted_page_table)) *
sg_count);
}
}

/*
* This function is called to create the actual command orb and s/g list
* out of the scsi command itself.
*/
static int sbp2_create_command_orb(struct scsi_id_instance_data *scsi_id,
struct sbp2_command_info *command,
unchar *scsi_cmd,
unsigned int scsi_use_sg,
unsigned int scsi_request_bufflen,
void *scsi_request_buffer,
enum dma_data_direction dma_dir)
static void sbp2_create_command_orb(struct scsi_id_instance_data *scsi_id,
struct sbp2_command_info *command,
unchar *scsi_cmd,
unsigned int scsi_use_sg,
unsigned int scsi_request_bufflen,
void *scsi_request_buffer,
enum dma_data_direction dma_dir)
{
struct sbp2scsi_host_info *hi = scsi_id->hi;
struct scatterlist *sgpnt = (struct scatterlist *)scsi_request_buffer;
struct sbp2_command_orb *command_orb = &command->command_orb;
struct sbp2_unrestricted_page_table *scatter_gather_element =
&command->scatter_gather_element[0];
u32 sg_count, sg_len, orb_direction;
dma_addr_t sg_addr;
int i;
u32 orb_direction;

/*
* Set-up our command ORB..
Expand All @@ -1753,186 +1911,29 @@ static int sbp2_create_command_orb(struct scsi_id_instance_data *scsi_id,
orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
}

/*
* Set-up our pagetable stuff... unfortunately, this has become
* messier than I'd like. Need to clean this up a bit. ;-)
*/
/* Set-up our pagetable stuff */
if (orb_direction == ORB_DIRECTION_NO_DATA_TRANSFER) {

SBP2_DEBUG("No data transfer");

/*
* Handle no data transfer
*/
command_orb->data_descriptor_hi = 0x0;
command_orb->data_descriptor_lo = 0x0;
command_orb->misc |= ORB_SET_DIRECTION(1);

} else if (scsi_use_sg) {

SBP2_DEBUG("Use scatter/gather");

/*
* Special case if only one element (and less than 64KB in size)
*/
if ((scsi_use_sg == 1) && (sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) {

SBP2_DEBUG("Only one s/g element");
command->dma_dir = dma_dir;
command->dma_size = sgpnt[0].length;
command->dma_type = CMD_DMA_PAGE;
command->cmd_dma = pci_map_page(hi->host->pdev,
sgpnt[0].page,
sgpnt[0].offset,
command->dma_size,
command->dma_dir);
SBP2_DMA_ALLOC("single page scatter element");

command_orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
command_orb->data_descriptor_lo = command->cmd_dma;
command_orb->misc |= ORB_SET_DATA_SIZE(command->dma_size);
command_orb->misc |= ORB_SET_DIRECTION(orb_direction);

} else {
int count = pci_map_sg(hi->host->pdev, sgpnt, scsi_use_sg, dma_dir);
SBP2_DMA_ALLOC("scatter list");

command->dma_size = scsi_use_sg;
command->dma_dir = dma_dir;
command->sge_buffer = sgpnt;

/* use page tables (s/g) */
command_orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
command_orb->misc |= ORB_SET_DIRECTION(orb_direction);
command_orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
command_orb->data_descriptor_lo = command->sge_dma;

/*
* Loop through and fill out our sbp-2 page tables
* (and split up anything too large)
*/
for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) {
sg_len = sg_dma_len(sgpnt);
sg_addr = sg_dma_address(sgpnt);
while (sg_len) {
scatter_gather_element[sg_count].segment_base_lo = sg_addr;
if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
scatter_gather_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
} else {
scatter_gather_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
sg_len = 0;
}
sg_count++;
}
}

/* Number of page table (s/g) elements */
command_orb->misc |= ORB_SET_DATA_SIZE(sg_count);

sbp2util_packet_dump(scatter_gather_element,
(sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
"sbp2 s/g list", command->sge_dma);

/*
* Byte swap page tables if necessary
*/
sbp2util_cpu_to_be32_buffer(scatter_gather_element,
(sizeof(struct sbp2_unrestricted_page_table)) *
sg_count);

}

sbp2_prep_command_orb_sg(command_orb, hi, command, scsi_use_sg,
sgpnt, orb_direction, dma_dir);
} else {

SBP2_DEBUG("No scatter/gather");

command->dma_dir = dma_dir;
command->dma_size = scsi_request_bufflen;
command->dma_type = CMD_DMA_SINGLE;
command->cmd_dma =
pci_map_single(hi->host->pdev, scsi_request_buffer,
command->dma_size, command->dma_dir);
SBP2_DMA_ALLOC("single bulk");

/*
* Handle case where we get a command w/o s/g enabled (but
* check for transfers larger than 64K)
*/
if (scsi_request_bufflen <= SBP2_MAX_SG_ELEMENT_LENGTH) {

command_orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
command_orb->data_descriptor_lo = command->cmd_dma;
command_orb->misc |= ORB_SET_DATA_SIZE(scsi_request_bufflen);
command_orb->misc |= ORB_SET_DIRECTION(orb_direction);

} else {
/*
* Need to turn this into page tables, since the
* buffer is too large.
*/
command_orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
command_orb->data_descriptor_lo = command->sge_dma;

/* Use page tables (s/g) */
command_orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
command_orb->misc |= ORB_SET_DIRECTION(orb_direction);

/*
* fill out our sbp-2 page tables (and split up
* the large buffer)
*/
sg_count = 0;
sg_len = scsi_request_bufflen;
sg_addr = command->cmd_dma;
while (sg_len) {
scatter_gather_element[sg_count].segment_base_lo = sg_addr;
if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
scatter_gather_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
} else {
scatter_gather_element[sg_count].length_segment_base_hi =
PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
sg_len = 0;
}
sg_count++;
}

/* Number of page table (s/g) elements */
command_orb->misc |= ORB_SET_DATA_SIZE(sg_count);

sbp2util_packet_dump(scatter_gather_element,
(sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
"sbp2 s/g list", command->sge_dma);

/*
* Byte swap page tables if necessary
*/
sbp2util_cpu_to_be32_buffer(scatter_gather_element,
(sizeof(struct sbp2_unrestricted_page_table)) *
sg_count);

}

sbp2_prep_command_orb_no_sg(command_orb, hi, command, sgpnt,
orb_direction, scsi_request_bufflen,
scsi_request_buffer, dma_dir);
}

/*
* Byte swap command ORB if necessary
*/
/* Byte swap command ORB if necessary */
sbp2util_cpu_to_be32_buffer(command_orb, sizeof(struct sbp2_command_orb));

/*
* Put our scsi command in the command ORB
*/
/* Put our scsi command in the command ORB */
memset(command_orb->cdb, 0, 12);
memcpy(command_orb->cdb, scsi_cmd, COMMAND_SIZE(*scsi_cmd));

return 0;
}

/*
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