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linux/drivers/s390/scsi/zfcp_qdio.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2 
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

869 lines
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/*
* linux/drivers/s390/scsi/zfcp_qdio.c
*
* FCP adapter driver for IBM eServer zSeries
*
* QDIO related routines
*
* (C) Copyright IBM Corp. 2002, 2004
*
* Authors:
* Martin Peschke <mpeschke@de.ibm.com>
* Raimund Schroeder <raimund.schroeder@de.ibm.com>
* Wolfgang Taphorn
* Heiko Carstens <heiko.carstens@de.ibm.com>
* Andreas Herrmann <aherrman@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define ZFCP_QDIO_C_REVISION "$Revision: 1.20 $"
#include "zfcp_ext.h"
static inline void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
(struct zfcp_qdio_queue *, int, int);
static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
(struct zfcp_fsf_req *, int, int);
static inline volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
(struct zfcp_fsf_req *, unsigned long);
static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
(struct zfcp_fsf_req *, unsigned long);
static inline int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
static inline void zfcp_qdio_sbale_fill
(struct zfcp_fsf_req *, unsigned long, void *, int);
static inline int zfcp_qdio_sbals_from_segment
(struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
static inline int zfcp_qdio_sbals_from_buffer
(struct zfcp_fsf_req *, unsigned long, void *, unsigned long, int);
static qdio_handler_t zfcp_qdio_request_handler;
static qdio_handler_t zfcp_qdio_response_handler;
static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
unsigned int,
unsigned int, unsigned int);
#define ZFCP_LOG_AREA ZFCP_LOG_AREA_QDIO
/*
* Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
* array in the adapter struct.
* Cur_buf is the pointer array and count can be any number of required
* buffers, the page-fitting arithmetic is done entirely within this funciton.
*
* returns: number of buffers allocated
* locks: must only be called with zfcp_data.config_sema taken
*/
static int
zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
{
int buf_pos;
int qdio_buffers_per_page;
int page_pos = 0;
struct qdio_buffer *first_in_page = NULL;
qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
for (buf_pos = 0; buf_pos < count; buf_pos++) {
if (page_pos == 0) {
cur_buf[buf_pos] = (struct qdio_buffer *)
get_zeroed_page(GFP_KERNEL);
if (cur_buf[buf_pos] == NULL) {
ZFCP_LOG_INFO("error: allocation of "
"QDIO buffer failed \n");
goto out;
}
first_in_page = cur_buf[buf_pos];
} else {
cur_buf[buf_pos] = first_in_page + page_pos;
}
/* was initialised to zero */
page_pos++;
page_pos %= qdio_buffers_per_page;
}
out:
return buf_pos;
}
/*
* Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
* in the adapter struct cur_buf is the pointer array and count can be any
* number of buffers in the array that should be freed starting from buffer 0
*
* locks: must only be called with zfcp_data.config_sema taken
*/
static void
zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
{
int buf_pos;
int qdio_buffers_per_page;
qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
free_page((unsigned long) cur_buf[buf_pos]);
return;
}
/* locks: must only be called with zfcp_data.config_sema taken */
int
zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
{
int buffer_count;
int retval = 0;
buffer_count =
zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
QDIO_MAX_BUFFERS_PER_Q);
if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
"queue\n", buffer_count);
zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
buffer_count);
retval = -ENOMEM;
goto out;
}
buffer_count =
zfcp_qdio_buffers_enqueue(&(adapter->response_queue.buffer[0]),
QDIO_MAX_BUFFERS_PER_Q);
if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for response "
"queue", buffer_count);
zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
buffer_count);
ZFCP_LOG_TRACE("freeing request_queue buffers\n");
zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
QDIO_MAX_BUFFERS_PER_Q);
retval = -ENOMEM;
goto out;
}
out:
return retval;
}
/* locks: must only be called with zfcp_data.config_sema taken */
void
zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
{
ZFCP_LOG_TRACE("freeing request_queue buffers\n");
zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
QDIO_MAX_BUFFERS_PER_Q);
ZFCP_LOG_TRACE("freeing response_queue buffers\n");
zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
QDIO_MAX_BUFFERS_PER_Q);
}
int
zfcp_qdio_allocate(struct zfcp_adapter *adapter)
{
struct qdio_initialize *init_data;
init_data = &adapter->qdio_init_data;
init_data->cdev = adapter->ccw_device;
init_data->q_format = QDIO_SCSI_QFMT;
memcpy(init_data->adapter_name, &adapter->name, 8);
init_data->qib_param_field_format = 0;
init_data->qib_param_field = NULL;
init_data->input_slib_elements = NULL;
init_data->output_slib_elements = NULL;
init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
init_data->no_input_qs = 1;
init_data->no_output_qs = 1;
init_data->input_handler = zfcp_qdio_response_handler;
init_data->output_handler = zfcp_qdio_request_handler;
init_data->int_parm = (unsigned long) adapter;
init_data->flags = QDIO_INBOUND_0COPY_SBALS |
QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
init_data->input_sbal_addr_array =
(void **) (adapter->response_queue.buffer);
init_data->output_sbal_addr_array =
(void **) (adapter->request_queue.buffer);
return qdio_allocate(init_data);
}
/*
* function: zfcp_qdio_handler_error_check
*
* purpose: called by the response handler to determine error condition
*
* returns: error flag
*
*/
static inline int
zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter,
unsigned int status,
unsigned int qdio_error, unsigned int siga_error)
{
int retval = 0;
if (ZFCP_LOG_CHECK(ZFCP_LOG_LEVEL_TRACE)) {
if (status & QDIO_STATUS_INBOUND_INT) {
ZFCP_LOG_TRACE("status is"
" QDIO_STATUS_INBOUND_INT \n");
}
if (status & QDIO_STATUS_OUTBOUND_INT) {
ZFCP_LOG_TRACE("status is"
" QDIO_STATUS_OUTBOUND_INT \n");
}
} // if (ZFCP_LOG_CHECK(ZFCP_LOG_LEVEL_TRACE))
if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
retval = -EIO;
ZFCP_LOG_FLAGS(1, "QDIO_STATUS_LOOK_FOR_ERROR \n");
ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
"qdio_error=0x%x, siga_error=0x%x)\n",
status, qdio_error, siga_error);
if (status & QDIO_STATUS_ACTIVATE_CHECK_CONDITION) {
ZFCP_LOG_FLAGS(2,
"QDIO_STATUS_ACTIVATE_CHECK_CONDITION\n");
}
if (status & QDIO_STATUS_MORE_THAN_ONE_QDIO_ERROR) {
ZFCP_LOG_FLAGS(2,
"QDIO_STATUS_MORE_THAN_ONE_QDIO_ERROR\n");
}
if (status & QDIO_STATUS_MORE_THAN_ONE_SIGA_ERROR) {
ZFCP_LOG_FLAGS(2,
"QDIO_STATUS_MORE_THAN_ONE_SIGA_ERROR\n");
}
if (siga_error & QDIO_SIGA_ERROR_ACCESS_EXCEPTION) {
ZFCP_LOG_FLAGS(2, "QDIO_SIGA_ERROR_ACCESS_EXCEPTION\n");
}
if (siga_error & QDIO_SIGA_ERROR_B_BIT_SET) {
ZFCP_LOG_FLAGS(2, "QDIO_SIGA_ERROR_B_BIT_SET\n");
}
switch (qdio_error) {
case 0:
ZFCP_LOG_FLAGS(3, "QDIO_OK");
break;
case SLSB_P_INPUT_ERROR:
ZFCP_LOG_FLAGS(1, "SLSB_P_INPUT_ERROR\n");
break;
case SLSB_P_OUTPUT_ERROR:
ZFCP_LOG_FLAGS(1, "SLSB_P_OUTPUT_ERROR\n");
break;
default:
ZFCP_LOG_NORMAL("bug: unknown QDIO error 0x%x\n",
qdio_error);
break;
}
/* Restarting IO on the failed adapter from scratch */
debug_text_event(adapter->erp_dbf, 1, "qdio_err");
/*
* Since we have been using this adapter, it is save to assume
* that it is not failed but recoverable. The card seems to
* report link-up events by self-initiated queue shutdown.
* That is why we need to clear the the link-down flag
* which is set again in case we have missed by a mile.
*/
zfcp_erp_adapter_reopen(
adapter,
ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
ZFCP_STATUS_COMMON_ERP_FAILED);
}
return retval;
}
/*
* function: zfcp_qdio_request_handler
*
* purpose: is called by QDIO layer for completed SBALs in request queue
*
* returns: (void)
*/
static void
zfcp_qdio_request_handler(struct ccw_device *ccw_device,
unsigned int status,
unsigned int qdio_error,
unsigned int siga_error,
unsigned int queue_number,
int first_element,
int elements_processed,
unsigned long int_parm)
{
struct zfcp_adapter *adapter;
struct zfcp_qdio_queue *queue;
adapter = (struct zfcp_adapter *) int_parm;
queue = &adapter->request_queue;
ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
zfcp_get_busid_by_adapter(adapter),
first_element, elements_processed);
if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
siga_error)))
goto out;
/*
* we stored address of struct zfcp_adapter data structure
* associated with irq in int_parm
*/
/* cleanup all SBALs being program-owned now */
zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
/* increase free space in outbound queue */
atomic_add(elements_processed, &queue->free_count);
ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
wake_up(&adapter->request_wq);
ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
elements_processed, atomic_read(&queue->free_count));
out:
return;
}
/*
* function: zfcp_qdio_response_handler
*
* purpose: is called by QDIO layer for completed SBALs in response queue
*
* returns: (void)
*/
static void
zfcp_qdio_response_handler(struct ccw_device *ccw_device,
unsigned int status,
unsigned int qdio_error,
unsigned int siga_error,
unsigned int queue_number,
int first_element,
int elements_processed,
unsigned long int_parm)
{
struct zfcp_adapter *adapter;
struct zfcp_qdio_queue *queue;
int buffer_index;
int i;
struct qdio_buffer *buffer;
int retval = 0;
u8 count;
u8 start;
volatile struct qdio_buffer_element *buffere = NULL;
int buffere_index;
adapter = (struct zfcp_adapter *) int_parm;
queue = &adapter->response_queue;
if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
siga_error)))
goto out;
/*
* we stored address of struct zfcp_adapter data structure
* associated with irq in int_parm
*/
buffere = &(queue->buffer[first_element]->element[0]);
ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
/*
* go through all SBALs from input queue currently
* returned by QDIO layer
*/
for (i = 0; i < elements_processed; i++) {
buffer_index = first_element + i;
buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
buffer = queue->buffer[buffer_index];
/* go through all SBALEs of SBAL */
for (buffere_index = 0;
buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
buffere_index++) {
/* look for QDIO request identifiers in SB */
buffere = &buffer->element[buffere_index];
retval = zfcp_qdio_reqid_check(adapter,
(void *) buffere->addr);
if (retval) {
ZFCP_LOG_NORMAL("bug: unexpected inbound "
"packet on adapter %s "
"(reqid=0x%lx, "
"first_element=%d, "
"elements_processed=%d)\n",
zfcp_get_busid_by_adapter(adapter),
(unsigned long) buffere->addr,
first_element,
elements_processed);
ZFCP_LOG_NORMAL("hex dump of inbound buffer "
"at address %p "
"(buffer_index=%d, "
"buffere_index=%d)\n", buffer,
buffer_index, buffere_index);
ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
(char *) buffer, SBAL_SIZE);
}
/*
* A single used SBALE per inbound SBALE has been
* implemented by QDIO so far. Hope they will
* do some optimisation. Will need to change to
* unlikely() then.
*/
if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
break;
};
if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
ZFCP_LOG_NORMAL("bug: End of inbound data "
"not marked!\n");
}
}
/*
* put range of SBALs back to response queue
* (including SBALs which have already been free before)
*/
count = atomic_read(&queue->free_count) + elements_processed;
start = queue->free_index;
ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
"queue_no=%i, index_in_queue=%i, count=%i, "
"buffers=0x%lx\n",
zfcp_get_busid_by_adapter(adapter),
QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
0, start, count, (unsigned long) &queue->buffer[start]);
retval = do_QDIO(ccw_device,
QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
0, start, count, NULL);
if (unlikely(retval)) {
atomic_set(&queue->free_count, count);
ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
"queues may be down "
"(count=%d, start=%d, retval=%d)\n",
count, start, retval);
} else {
queue->free_index += count;
queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
atomic_set(&queue->free_count, 0);
ZFCP_LOG_TRACE("%i buffers enqueued to response "
"queue at position %i\n", count, start);
}
out:
return;
}
/*
* function: zfcp_qdio_reqid_check
*
* purpose: checks for valid reqids or unsolicited status
*
* returns: 0 - valid request id or unsolicited status
* !0 - otherwise
*/
int
zfcp_qdio_reqid_check(struct zfcp_adapter *adapter, void *sbale_addr)
{
struct zfcp_fsf_req *fsf_req;
int retval = 0;
/* invalid (per convention used in this driver) */
if (unlikely(!sbale_addr)) {
ZFCP_LOG_NORMAL("bug: invalid reqid\n");
retval = -EINVAL;
goto out;
}
/* valid request id and thus (hopefully :) valid fsf_req address */
fsf_req = (struct zfcp_fsf_req *) sbale_addr;
if (unlikely(adapter != fsf_req->adapter)) {
ZFCP_LOG_NORMAL("bug: invalid reqid (fsf_req=%p, "
"fsf_req->adapter=%p, adapter=%p)\n",
fsf_req, fsf_req->adapter, adapter);
retval = -EINVAL;
goto out;
}
ZFCP_LOG_TRACE("fsf_req at %p, QTCB at %p\n", fsf_req, fsf_req->qtcb);
if (likely(fsf_req->qtcb)) {
ZFCP_LOG_TRACE("hex dump of QTCB:\n");
ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_TRACE, (char *) fsf_req->qtcb,
sizeof(struct fsf_qtcb));
}
/* finish the FSF request */
zfcp_fsf_req_complete(fsf_req);
out:
return retval;
}
/**
* zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
* @queue: queue from which SBALE should be returned
* @sbal: specifies number of SBAL in queue
* @sbale: specifes number of SBALE in SBAL
*/
static inline volatile struct qdio_buffer_element *
zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
{
return &queue->buffer[sbal]->element[sbale];
}
/**
* zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
* a struct zfcp_fsf_req
*/
inline volatile struct qdio_buffer_element *
zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
{
return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
sbal, sbale);
}
/**
* zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
* a struct zfcp_fsf_req
*/
static inline volatile struct qdio_buffer_element *
zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
{
return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
sbal, sbale);
}
/**
* zfcp_qdio_sbale_curr - return current SBALE on request_queue for
* a struct zfcp_fsf_req
*/
inline volatile struct qdio_buffer_element *
zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
{
return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
fsf_req->sbale_curr);
}
/**
* zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
* on the request_queue for a struct zfcp_fsf_req
* @fsf_req: the number of the last SBAL that can be used is stored herein
* @max_sbals: used to pass an upper limit for the number of SBALs
*
* Note: We can assume at least one free SBAL in the request_queue when called.
*/
static inline void
zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
{
int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
count = min(count, max_sbals);
fsf_req->sbal_last = fsf_req->sbal_first;
fsf_req->sbal_last += (count - 1);
fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
}
/**
* zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
* request
* @fsf_req: zfcp_fsf_req to be processed
* @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
*
* This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
*/
static inline volatile struct qdio_buffer_element *
zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
volatile struct qdio_buffer_element *sbale;
/* set last entry flag in current SBALE of current SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
/* don't exceed last allowed SBAL */
if (fsf_req->sbal_curr == fsf_req->sbal_last)
return NULL;
/* set chaining flag in first SBALE of current SBAL */
sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
/* calculate index of next SBAL */
fsf_req->sbal_curr++;
fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
/* keep this requests number of SBALs up-to-date */
fsf_req->sbal_number++;
/* start at first SBALE of new SBAL */
fsf_req->sbale_curr = 0;
/* set storage-block type for new SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= sbtype;
return sbale;
}
/**
* zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
*/
static inline volatile struct qdio_buffer_element *
zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
return zfcp_qdio_sbal_chain(fsf_req, sbtype);
fsf_req->sbale_curr++;
return zfcp_qdio_sbale_curr(fsf_req);
}
/**
* zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
* with zero from
*/
static inline int
zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
{
struct qdio_buffer **buf = queue->buffer;
int curr = first;
int count = 0;
for(;;) {
curr %= QDIO_MAX_BUFFERS_PER_Q;
count++;
memset(buf[curr], 0, sizeof(struct qdio_buffer));
if (curr == last)
break;
curr++;
}
return count;
}
/**
* zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
*/
static inline int
zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
{
return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
fsf_req->sbal_first, fsf_req->sbal_curr);
}
/**
* zfcp_qdio_sbale_fill - set address and lenght in current SBALE
* on request_queue
*/
static inline void
zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
void *addr, int length)
{
volatile struct qdio_buffer_element *sbale;
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->addr = addr;
sbale->length = length;
}
/**
* zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @start_addr: address of memory segment
* @total_length: length of memory segment
*
* Alignment and length of the segment determine how many SBALEs are needed
* for the memory segment.
*/
static inline int
zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
void *start_addr, unsigned long total_length)
{
unsigned long remaining, length;
void *addr;
/* split segment up heeding page boundaries */
for (addr = start_addr, remaining = total_length; remaining > 0;
addr += length, remaining -= length) {
/* get next free SBALE for new piece */
if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
/* no SBALE left, clean up and leave */
zfcp_qdio_sbals_wipe(fsf_req);
return -EINVAL;
}
/* calculate length of new piece */
length = min(remaining,
(PAGE_SIZE - ((unsigned long) addr &
(PAGE_SIZE - 1))));
/* fill current SBALE with calculated piece */
zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
}
return total_length;
}
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @sg: scatter-gather list
* @sg_count: number of elements in scatter-gather list
* @max_sbals: upper bound for number of SBALs to be used
*/
inline int
zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
struct scatterlist *sg, int sg_count, int max_sbals)
{
int sg_index;
struct scatterlist *sg_segment;
int retval;
volatile struct qdio_buffer_element *sbale;
int bytes = 0;
/* figure out last allowed SBAL */
zfcp_qdio_sbal_limit(fsf_req, max_sbals);
/* set storage-block type for current SBAL */
sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
sbale->flags |= sbtype;
/* process all segements of scatter-gather list */
for (sg_index = 0, sg_segment = sg, bytes = 0;
sg_index < sg_count;
sg_index++, sg_segment++) {
retval = zfcp_qdio_sbals_from_segment(
fsf_req,
sbtype,
zfcp_sg_to_address(sg_segment),
sg_segment->length);
if (retval < 0) {
bytes = retval;
goto out;
} else
bytes += retval;
}
/* assume that no other SBALEs are to follow in the same SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
out:
return bytes;
}
/**
* zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @buffer: data buffer
* @length: length of buffer
* @max_sbals: upper bound for number of SBALs to be used
*/
static inline int
zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
void *buffer, unsigned long length, int max_sbals)
{
struct scatterlist sg_segment;
zfcp_address_to_sg(buffer, &sg_segment);
sg_segment.length = length;
return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
max_sbals);
}
/**
* zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @scsi_cmnd: either scatter-gather list or buffer contained herein is used
* to fill SBALs
*/
inline int
zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
{
if (scsi_cmnd->use_sg) {
return zfcp_qdio_sbals_from_sg(fsf_req, sbtype,
(struct scatterlist *)
scsi_cmnd->request_buffer,
scsi_cmnd->use_sg,
ZFCP_MAX_SBALS_PER_REQ);
} else {
return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
scsi_cmnd->request_buffer,
scsi_cmnd->request_bufflen,
ZFCP_MAX_SBALS_PER_REQ);
}
}
/**
* zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
*/
int
zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
struct zfcp_fsf_req *fsf_req)
{
int new_distance_from_int;
int pci_pos;
volatile struct qdio_buffer_element *sbale;
new_distance_from_int = req_queue->distance_from_int +
fsf_req->sbal_number;
if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
pci_pos = fsf_req->sbal_first;
pci_pos += fsf_req->sbal_number;
pci_pos -= new_distance_from_int;
pci_pos -= 1;
pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
sbale->flags |= SBAL_FLAGS0_PCI;
}
return new_distance_from_int;
}
/*
* function: zfcp_zero_sbals
*
* purpose: zeros specified range of SBALs
*
* returns:
*/
void
zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
{
int cur_pos;
int index;
for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
memset(buf[index], 0, sizeof (struct qdio_buffer));
ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
index, buf[index]);
}
}
#undef ZFCP_LOG_AREA
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