From b4e44590f0811e629faf2de4aea15e752d83ce3d Mon Sep 17 00:00:00 2001 From: Swen Schillig Date: Wed, 18 Jul 2007 10:55:13 +0200 Subject: [SCSI] zfcp: code cleanup improve code for buffer enqueue. easy readability and maintainability. Signed-off-by: Swen Schillig Signed-off-by: James Bottomley --- drivers/s390/scsi/zfcp_def.h | 1 + drivers/s390/scsi/zfcp_qdio.c | 113 ++++++++++++------------------------------ 2 files changed, 33 insertions(+), 81 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h index 22649639230..b36dfc40d9f 100644 --- a/drivers/s390/scsi/zfcp_def.h +++ b/drivers/s390/scsi/zfcp_def.h @@ -126,6 +126,7 @@ zfcp_address_to_sg(void *address, struct scatterlist *list) #define ZFCP_MIN_OUTPUT_THRESHOLD 1 /* ignored by QDIO layer */ #define QDIO_SCSI_QFMT 1 /* 1 for FSF */ +#define QBUFF_PER_PAGE (PAGE_SIZE / sizeof(struct qdio_buffer)) /********************* FSF SPECIFIC DEFINES *********************************/ diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c index bdf5782b8a7..c408badd2ae 100644 --- a/drivers/s390/scsi/zfcp_qdio.c +++ b/drivers/s390/scsi/zfcp_qdio.c @@ -47,103 +47,56 @@ static int zfcp_qdio_handler_error_check(struct zfcp_adapter *, #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. + * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array + * in the adapter struct sbuf is the pointer array. * - * 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) +static void +zfcp_qdio_buffers_dequeue(struct qdio_buffer **sbuf) { - 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; + int pos; - } - /* was initialised to zero */ - page_pos++; - page_pos %= qdio_buffers_per_page; - } - out: - return buf_pos; + for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) + free_page((unsigned long) sbuf[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 + * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t + * array in the adapter struct. + * Cur_buf is the pointer array * + * returns: zero on success else -ENOMEM * locks: must only be called with zfcp_data.config_sema taken */ -static void -zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count) +static int +zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbuf) { - 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); + int pos; - for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page) - free_page((unsigned long) cur_buf[buf_pos]); - return; + for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) { + sbuf[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL); + if (!sbuf[pos]) { + zfcp_qdio_buffers_dequeue(sbuf); + return -ENOMEM; + } + } + for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++) + if (pos % QBUFF_PER_PAGE) + sbuf[pos] = sbuf[pos - 1] + 1; + return 0; } /* 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; + int ret; - 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; + ret = zfcp_qdio_buffers_enqueue(adapter->request_queue.buffer); + if (ret) + return ret; + return zfcp_qdio_buffers_enqueue(adapter->response_queue.buffer); } /* locks: must only be called with zfcp_data.config_sema taken */ @@ -151,12 +104,10 @@ 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_qdio_buffers_dequeue(adapter->request_queue.buffer); ZFCP_LOG_TRACE("freeing response_queue buffers\n"); - zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]), - QDIO_MAX_BUFFERS_PER_Q); + zfcp_qdio_buffers_dequeue(adapter->response_queue.buffer); } int -- cgit v1.2.3