261 lines
7.4 KiB
C
261 lines
7.4 KiB
C
![]() |
/* ------------------------------------------------------------
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* rpa_vscsi.c
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* (C) Copyright IBM Corporation 1994, 2003
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* Authors: Colin DeVilbiss (devilbis@us.ibm.com)
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* Santiago Leon (santil@us.ibm.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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* USA
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*
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* ------------------------------------------------------------
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* RPA-specific functions of the SCSI host adapter for Virtual I/O devices
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*
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* This driver allows the Linux SCSI peripheral drivers to directly
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* access devices in the hosting partition, either on an iSeries
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* hypervisor system or a converged hypervisor system.
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*/
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#include <asm/vio.h>
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#include <asm/iommu.h>
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#include <asm/hvcall.h>
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#include <linux/dma-mapping.h>
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#include <linux/interrupt.h>
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#include "ibmvscsi.h"
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/* ------------------------------------------------------------
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* Routines for managing the command/response queue
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*/
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/**
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* ibmvscsi_handle_event: - Interrupt handler for crq events
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* @irq: number of irq to handle, not used
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* @dev_instance: ibmvscsi_host_data of host that received interrupt
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* @regs: pt_regs with registers
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*
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* Disables interrupts and schedules srp_task
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* Always returns IRQ_HANDLED
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*/
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static irqreturn_t ibmvscsi_handle_event(int irq,
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void *dev_instance,
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struct pt_regs *regs)
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{
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struct ibmvscsi_host_data *hostdata =
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(struct ibmvscsi_host_data *)dev_instance;
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vio_disable_interrupts(to_vio_dev(hostdata->dev));
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tasklet_schedule(&hostdata->srp_task);
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return IRQ_HANDLED;
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}
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/**
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* release_crq_queue: - Deallocates data and unregisters CRQ
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* @queue: crq_queue to initialize and register
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* @host_data: ibmvscsi_host_data of host
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*
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* Frees irq, deallocates a page for messages, unmaps dma, and unregisters
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* the crq with the hypervisor.
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*/
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void ibmvscsi_release_crq_queue(struct crq_queue *queue,
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struct ibmvscsi_host_data *hostdata,
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int max_requests)
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{
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long rc;
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struct vio_dev *vdev = to_vio_dev(hostdata->dev);
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free_irq(vdev->irq, (void *)hostdata);
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tasklet_kill(&hostdata->srp_task);
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do {
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rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
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} while ((rc == H_Busy) || (H_isLongBusy(rc)));
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dma_unmap_single(hostdata->dev,
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queue->msg_token,
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queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
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free_page((unsigned long)queue->msgs);
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}
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/**
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* crq_queue_next_crq: - Returns the next entry in message queue
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* @queue: crq_queue to use
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*
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* Returns pointer to next entry in queue, or NULL if there are no new
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* entried in the CRQ.
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*/
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static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
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{
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struct viosrp_crq *crq;
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unsigned long flags;
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spin_lock_irqsave(&queue->lock, flags);
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crq = &queue->msgs[queue->cur];
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if (crq->valid & 0x80) {
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if (++queue->cur == queue->size)
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queue->cur = 0;
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} else
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crq = NULL;
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spin_unlock_irqrestore(&queue->lock, flags);
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return crq;
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}
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/**
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* ibmvscsi_send_crq: - Send a CRQ
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* @hostdata: the adapter
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* @word1: the first 64 bits of the data
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* @word2: the second 64 bits of the data
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*/
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int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
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{
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struct vio_dev *vdev = to_vio_dev(hostdata->dev);
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return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
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}
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/**
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* ibmvscsi_task: - Process srps asynchronously
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* @data: ibmvscsi_host_data of host
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*/
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static void ibmvscsi_task(void *data)
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{
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struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
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struct vio_dev *vdev = to_vio_dev(hostdata->dev);
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struct viosrp_crq *crq;
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int done = 0;
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while (!done) {
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/* Pull all the valid messages off the CRQ */
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while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
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ibmvscsi_handle_crq(crq, hostdata);
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crq->valid = 0x00;
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}
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vio_enable_interrupts(vdev);
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if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
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vio_disable_interrupts(vdev);
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ibmvscsi_handle_crq(crq, hostdata);
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crq->valid = 0x00;
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} else {
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done = 1;
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}
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}
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}
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/**
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* initialize_crq_queue: - Initializes and registers CRQ with hypervisor
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* @queue: crq_queue to initialize and register
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* @hostdata: ibmvscsi_host_data of host
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*
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* Allocates a page for messages, maps it for dma, and registers
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* the crq with the hypervisor.
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* Returns zero on success.
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*/
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int ibmvscsi_init_crq_queue(struct crq_queue *queue,
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struct ibmvscsi_host_data *hostdata,
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int max_requests)
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{
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int rc;
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struct vio_dev *vdev = to_vio_dev(hostdata->dev);
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queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
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if (!queue->msgs)
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goto malloc_failed;
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queue->size = PAGE_SIZE / sizeof(*queue->msgs);
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queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
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queue->size * sizeof(*queue->msgs),
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DMA_BIDIRECTIONAL);
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if (dma_mapping_error(queue->msg_token))
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goto map_failed;
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rc = plpar_hcall_norets(H_REG_CRQ,
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vdev->unit_address,
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queue->msg_token, PAGE_SIZE);
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if (rc == 2) {
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/* Adapter is good, but other end is not ready */
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printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
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} else if (rc != 0) {
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printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
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goto reg_crq_failed;
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}
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if (request_irq(vdev->irq,
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ibmvscsi_handle_event,
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0, "ibmvscsi", (void *)hostdata) != 0) {
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printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
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vdev->irq);
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goto req_irq_failed;
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}
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rc = vio_enable_interrupts(vdev);
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if (rc != 0) {
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printk(KERN_ERR "ibmvscsi: Error %d enabling interrupts!!!\n",
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rc);
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goto req_irq_failed;
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}
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queue->cur = 0;
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spin_lock_init(&queue->lock);
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tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
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(unsigned long)hostdata);
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return 0;
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req_irq_failed:
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do {
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rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
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} while ((rc == H_Busy) || (H_isLongBusy(rc)));
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reg_crq_failed:
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dma_unmap_single(hostdata->dev,
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queue->msg_token,
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queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
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map_failed:
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free_page((unsigned long)queue->msgs);
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malloc_failed:
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return -1;
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}
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/**
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* reset_crq_queue: - resets a crq after a failure
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* @queue: crq_queue to initialize and register
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* @hostdata: ibmvscsi_host_data of host
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*
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*/
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void ibmvscsi_reset_crq_queue(struct crq_queue *queue,
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struct ibmvscsi_host_data *hostdata)
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{
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int rc;
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struct vio_dev *vdev = to_vio_dev(hostdata->dev);
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/* Close the CRQ */
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do {
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rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
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} while ((rc == H_Busy) || (H_isLongBusy(rc)));
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/* Clean out the queue */
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memset(queue->msgs, 0x00, PAGE_SIZE);
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queue->cur = 0;
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/* And re-open it again */
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rc = plpar_hcall_norets(H_REG_CRQ,
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vdev->unit_address,
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queue->msg_token, PAGE_SIZE);
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if (rc == 2) {
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/* Adapter is good, but other end is not ready */
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printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
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} else if (rc != 0) {
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printk(KERN_WARNING
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"ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
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}
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}
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