qla_iocb.c

h内核

/******************************************************************************
 *                  QLOGIC LINUX SOFTWARE
 *
 * QLogic ISP2x00 device driver for Linux 2.6.x
 * Copyright (C) 2003-2004 QLogic Corporation
 * (www.qlogic.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.
 *
 ******************************************************************************/

#include "qla_def.h"

#include <linux/blkdev.h>
#include <linux/delay.h>

#include <scsi/scsi_tcq.h>

static inline uint16_t qla2x00_get_cmd_direction(struct scsi_cmnd *cmd);
static inline cont_entry_t *qla2x00_prep_cont_type0_iocb(scsi_qla_host_t *);
static inline cont_a64_entry_t *qla2x00_prep_cont_type1_iocb(scsi_qla_host_t *);
static request_t *qla2x00_req_pkt(scsi_qla_host_t *ha);

/**
 * qla2x00_get_cmd_direction() - Determine control_flag data direction.
 * @cmd: SCSI command
 *
 * Returns the proper CF_* direction based on CDB.
 */
static inline uint16_t
qla2x00_get_cmd_direction(struct scsi_cmnd *cmd)
{
	uint16_t cflags;

	cflags = 0;

	/* Set transfer direction */
	if (cmd->sc_data_direction == DMA_TO_DEVICE)
		cflags = CF_WRITE;
	else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
		cflags = CF_READ;
	return (cflags);
}

/**
 * qla2x00_calc_iocbs_32() - Determine number of Command Type 2 and
 * Continuation Type 0 IOCBs to allocate.
 *
 * @dsds: number of data segment decriptors needed
 *
 * Returns the number of IOCB entries needed to store @dsds.
 */
uint16_t
qla2x00_calc_iocbs_32(uint16_t dsds)
{
	uint16_t iocbs;

	iocbs = 1;
	if (dsds > 3) {
		iocbs += (dsds - 3) / 7;
		if ((dsds - 3) % 7)
			iocbs++;
	}
	return (iocbs);
}

/**
 * qla2x00_calc_iocbs_64() - Determine number of Command Type 3 and
 * Continuation Type 1 IOCBs to allocate.
 *
 * @dsds: number of data segment decriptors needed
 *
 * Returns the number of IOCB entries needed to store @dsds.
 */
uint16_t
qla2x00_calc_iocbs_64(uint16_t dsds)
{
	uint16_t iocbs;

	iocbs = 1;
	if (dsds > 2) {
		iocbs += (dsds - 2) / 5;
		if ((dsds - 2) % 5)
			iocbs++;
	}
	return (iocbs);
}

/**
 * qla2x00_prep_cont_type0_iocb() - Initialize a Continuation Type 0 IOCB.
 * @ha: HA context
 *
 * Returns a pointer to the Continuation Type 0 IOCB packet.
 */
static inline cont_entry_t *
qla2x00_prep_cont_type0_iocb(scsi_qla_host_t *ha)
{
	cont_entry_t *cont_pkt;

	/* Adjust ring index. */
	ha->req_ring_index++;
	if (ha->req_ring_index == ha->request_q_length) {
		ha->req_ring_index = 0;
		ha->request_ring_ptr = ha->request_ring;
	} else {
		ha->request_ring_ptr++;
	}

	cont_pkt = (cont_entry_t *)ha->request_ring_ptr;

	/* Load packet defaults. */
	*((uint32_t *)(&cont_pkt->entry_type)) =
	    __constant_cpu_to_le32(CONTINUE_TYPE);

	return (cont_pkt);
}

/**
 * qla2x00_prep_cont_type1_iocb() - Initialize a Continuation Type 1 IOCB.
 * @ha: HA context
 *
 * Returns a pointer to the continuation type 1 IOCB packet.
 */
static inline cont_a64_entry_t *
qla2x00_prep_cont_type1_iocb(scsi_qla_host_t *ha)
{
	cont_a64_entry_t *cont_pkt;

	/* Adjust ring index. */
	ha->req_ring_index++;
	if (ha->req_ring_index == ha->request_q_length) {
		ha->req_ring_index = 0;
		ha->request_ring_ptr = ha->request_ring;
	} else {
		ha->request_ring_ptr++;
	}

	cont_pkt = (cont_a64_entry_t *)ha->request_ring_ptr;

	/* Load packet defaults. */
	*((uint32_t *)(&cont_pkt->entry_type)) =
	    __constant_cpu_to_le32(CONTINUE_A64_TYPE);

	return (cont_pkt);
}

/**
 * qla2x00_build_scsi_iocbs_32() - Build IOCB command utilizing 32bit
 * capable IOCB types.
 *
 * @sp: SRB command to process
 * @cmd_pkt: Command type 2 IOCB
 * @tot_dsds: Total number of segments to transfer
 */
void qla2x00_build_scsi_iocbs_32(srb_t *sp, cmd_entry_t *cmd_pkt,
    uint16_t tot_dsds)
{
	uint16_t	avail_dsds;
	uint32_t	*cur_dsd;
	scsi_qla_host_t	*ha;
	struct scsi_cmnd *cmd;

	cmd = sp->cmd;

	/* Update entry type to indicate Command Type 2 IOCB */
	*((uint32_t *)(&cmd_pkt->entry_type)) =
	    __constant_cpu_to_le32(COMMAND_TYPE);

	/* No data transfer */
	if (cmd->request_bufflen == 0 || cmd->sc_data_direction == DMA_NONE) {
		cmd_pkt->byte_count = __constant_cpu_to_le32(0);
		return;
	}

	ha = sp->ha;

	cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(cmd));

	/* Three DSDs are available in the Command Type 2 IOCB */
	avail_dsds = 3;
	cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;

	/* Load data segments */
	if (cmd->use_sg != 0) {
		struct	scatterlist *cur_seg;
		struct	scatterlist *end_seg;

		cur_seg = (struct scatterlist *)cmd->request_buffer;
		end_seg = cur_seg + tot_dsds;
		while (cur_seg < end_seg) {
			cont_entry_t	*cont_pkt;

			/* Allocate additional continuation packets? */
			if (avail_dsds == 0) {
				/*
				 * Seven DSDs are available in the Continuation
				 * Type 0 IOCB.
				 */
				cont_pkt = qla2x00_prep_cont_type0_iocb(ha);
				cur_dsd = (uint32_t *)&cont_pkt->dseg_0_address;
				avail_dsds = 7;
			}

			*cur_dsd++ = cpu_to_le32(sg_dma_address(cur_seg));
			*cur_dsd++ = cpu_to_le32(sg_dma_len(cur_seg));
			avail_dsds--;

			cur_seg++;
		}
	} else {
		dma_addr_t	req_dma;
		struct page	*page;
		unsigned long	offset;

		page = virt_to_page(cmd->request_buffer);
		offset = ((unsigned long)cmd->request_buffer & ~PAGE_MASK);
		req_dma = pci_map_page(ha->pdev, page, offset,
		    cmd->request_bufflen, cmd->sc_data_direction);

		sp->dma_handle = req_dma;

		*cur_dsd++ = cpu_to_le32(req_dma);
		*cur_dsd++ = cpu_to_le32(cmd->request_bufflen);
	}
}

/**
 * qla2x00_build_scsi_iocbs_64() - Build IOCB command utilizing 64bit
 * capable IOCB types.
 *
 * @sp: SRB command to process
 * @cmd_pkt: Command type 3 IOCB
 * @tot_dsds: Total number of segments to transfer
 */
void qla2x00_build_scsi_iocbs_64(srb_t *sp, cmd_entry_t *cmd_pkt,
    uint16_t tot_dsds)
{
	uint16_t	avail_dsds;
	uint32_t	*cur_dsd;
	scsi_qla_host_t	*ha;
	struct scsi_cmnd *cmd;

	cmd = sp->cmd;

	/* Update entry type to indicate Command Type 3 IOCB */
	*((uint32_t *)(&cmd_pkt->entry_type)) =
	    __constant_cpu_to_le32(COMMAND_A64_TYPE);

	/* No data transfer */
	if (cmd->request_bufflen == 0 || cmd->sc_data_direction == DMA_NONE) {
		cmd_pkt->byte_count = __constant_cpu_to_le32(0);
		return;
	}

	ha = sp->ha;

	cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(cmd));

	/* Two DSDs are available in the Command Type 3 IOCB */
	avail_dsds = 2;
	cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;

	/* Load data segments */
	if (cmd->use_sg != 0) {
		struct	scatterlist *cur_seg;
		struct	scatterlist *end_seg;

		cur_seg = (struct scatterlist *)cmd->request_buffer;
		end_seg = cur_seg + tot_dsds;
		while (cur_seg < end_seg) {
			dma_addr_t	sle_dma;
			cont_a64_entry_t *cont_pkt;

			/* Allocate additional continuation packets? */
			if (avail_dsds == 0) {
				/*
				 * Five DSDs are available in the Continuation
				 * Type 1 IOCB.
				 */
				cont_pkt = qla2x00_prep_cont_type1_iocb(ha);
				cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
				avail_dsds = 5;
			}

			sle_dma = sg_dma_address(cur_seg);
			*cur_dsd++ = cpu_to_le32(LSD(sle_dma));
			*cur_dsd++ = cpu_to_le32(MSD(sle_dma));
			*cur_dsd++ = cpu_to_le32(sg_dma_len(cur_seg));
			avail_dsds--;

			cur_seg++;
		}
	} else {
		dma_addr_t	req_dma;
		struct page	*page;
		unsigned long	offset;

		page = virt_to_page(cmd->request_buffer);
		offset = ((unsigned long)cmd->request_buffer & ~PAGE_MASK);
		req_dma = pci_map_page(ha->pdev, page, offset,
		    cmd->request_bufflen, cmd->sc_data_direction);

		sp->dma_handle = req_dma;

		*cur_dsd++ = cpu_to_le32(LSD(req_dma));
		*cur_dsd++ = cpu_to_le32(MSD(req_dma));
		*cur_dsd++ = cpu_to_le32(cmd->request_bufflen);
	}
}