linux/drivers/scsi/ibmvscsi/rpa_vscsi.c
Dave C Boutcher bb58596f68 [SCSI] ibmvscsi kexec fix
This makes ibmvscsi work correctly with the recent set of kexec
patches that went in.  This is based on work by Michael Ellerman, who
chased this initially.  He validated that it works during kexec.

Handle kexec correctly in ibmvscsi.   During kexec the adapter
will not get cleaned up correctly, so we may need to reset it
to make it sane again.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-07 09:30:01 -05:00

319 lines
8.8 KiB
C

/* ------------------------------------------------------------
* rpa_vscsi.c
* (C) Copyright IBM Corporation 1994, 2003
* Authors: Colin DeVilbiss (devilbis@us.ibm.com)
* Santiago Leon (santil@us.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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
* ------------------------------------------------------------
* RPA-specific functions of the SCSI host adapter for Virtual I/O devices
*
* This driver allows the Linux SCSI peripheral drivers to directly
* access devices in the hosting partition, either on an iSeries
* hypervisor system or a converged hypervisor system.
*/
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/hvcall.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include "ibmvscsi.h"
#include "srp.h"
static char partition_name[97] = "UNKNOWN";
static unsigned int partition_number = -1;
/* ------------------------------------------------------------
* Routines for managing the command/response queue
*/
/**
* ibmvscsi_handle_event: - Interrupt handler for crq events
* @irq: number of irq to handle, not used
* @dev_instance: ibmvscsi_host_data of host that received interrupt
* @regs: pt_regs with registers
*
* Disables interrupts and schedules srp_task
* Always returns IRQ_HANDLED
*/
static irqreturn_t ibmvscsi_handle_event(int irq,
void *dev_instance,
struct pt_regs *regs)
{
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)dev_instance;
vio_disable_interrupts(to_vio_dev(hostdata->dev));
tasklet_schedule(&hostdata->srp_task);
return IRQ_HANDLED;
}
/**
* release_crq_queue: - Deallocates data and unregisters CRQ
* @queue: crq_queue to initialize and register
* @host_data: ibmvscsi_host_data of host
*
* Frees irq, deallocates a page for messages, unmaps dma, and unregisters
* the crq with the hypervisor.
*/
void ibmvscsi_release_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata,
int max_requests)
{
long rc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
free_irq(vdev->irq, (void *)hostdata);
tasklet_kill(&hostdata->srp_task);
do {
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while ((rc == H_Busy) || (H_isLongBusy(rc)));
dma_unmap_single(hostdata->dev,
queue->msg_token,
queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
free_page((unsigned long)queue->msgs);
}
/**
* crq_queue_next_crq: - Returns the next entry in message queue
* @queue: crq_queue to use
*
* Returns pointer to next entry in queue, or NULL if there are no new
* entried in the CRQ.
*/
static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
{
struct viosrp_crq *crq;
unsigned long flags;
spin_lock_irqsave(&queue->lock, flags);
crq = &queue->msgs[queue->cur];
if (crq->valid & 0x80) {
if (++queue->cur == queue->size)
queue->cur = 0;
} else
crq = NULL;
spin_unlock_irqrestore(&queue->lock, flags);
return crq;
}
/**
* ibmvscsi_send_crq: - Send a CRQ
* @hostdata: the adapter
* @word1: the first 64 bits of the data
* @word2: the second 64 bits of the data
*/
int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
{
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
}
/**
* ibmvscsi_task: - Process srps asynchronously
* @data: ibmvscsi_host_data of host
*/
static void ibmvscsi_task(void *data)
{
struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
struct viosrp_crq *crq;
int done = 0;
while (!done) {
/* Pull all the valid messages off the CRQ */
while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
ibmvscsi_handle_crq(crq, hostdata);
crq->valid = 0x00;
}
vio_enable_interrupts(vdev);
if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
vio_disable_interrupts(vdev);
ibmvscsi_handle_crq(crq, hostdata);
crq->valid = 0x00;
} else {
done = 1;
}
}
}
static void gather_partition_info(void)
{
struct device_node *rootdn;
char *ppartition_name;
unsigned int *p_number_ptr;
/* Retrieve information about this partition */
rootdn = find_path_device("/");
if (!rootdn) {
return;
}
ppartition_name =
get_property(rootdn, "ibm,partition-name", NULL);
if (ppartition_name)
strncpy(partition_name, ppartition_name,
sizeof(partition_name));
p_number_ptr =
(unsigned int *)get_property(rootdn, "ibm,partition-no",
NULL);
if (p_number_ptr)
partition_number = *p_number_ptr;
}
static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
{
memset(&hostdata->madapter_info, 0x00,
sizeof(hostdata->madapter_info));
printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
strncpy(hostdata->madapter_info.partition_name, partition_name,
sizeof(hostdata->madapter_info.partition_name));
hostdata->madapter_info.partition_number = partition_number;
hostdata->madapter_info.mad_version = 1;
hostdata->madapter_info.os_type = 2;
}
/**
* initialize_crq_queue: - Initializes and registers CRQ with hypervisor
* @queue: crq_queue to initialize and register
* @hostdata: ibmvscsi_host_data of host
*
* Allocates a page for messages, maps it for dma, and registers
* the crq with the hypervisor.
* Returns zero on success.
*/
int ibmvscsi_init_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata,
int max_requests)
{
int rc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
if (!queue->msgs)
goto malloc_failed;
queue->size = PAGE_SIZE / sizeof(*queue->msgs);
queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
queue->size * sizeof(*queue->msgs),
DMA_BIDIRECTIONAL);
if (dma_mapping_error(queue->msg_token))
goto map_failed;
gather_partition_info();
set_adapter_info(hostdata);
rc = plpar_hcall_norets(H_REG_CRQ,
vdev->unit_address,
queue->msg_token, PAGE_SIZE);
if (rc == H_Resource)
/* maybe kexecing and resource is busy. try a reset */
rc = ibmvscsi_reset_crq_queue(queue,
hostdata);
if (rc == 2) {
/* Adapter is good, but other end is not ready */
printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
} else if (rc != 0) {
printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
goto reg_crq_failed;
}
if (request_irq(vdev->irq,
ibmvscsi_handle_event,
0, "ibmvscsi", (void *)hostdata) != 0) {
printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
vdev->irq);
goto req_irq_failed;
}
rc = vio_enable_interrupts(vdev);
if (rc != 0) {
printk(KERN_ERR "ibmvscsi: Error %d enabling interrupts!!!\n",
rc);
goto req_irq_failed;
}
queue->cur = 0;
spin_lock_init(&queue->lock);
tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
(unsigned long)hostdata);
return 0;
req_irq_failed:
do {
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while ((rc == H_Busy) || (H_isLongBusy(rc)));
reg_crq_failed:
dma_unmap_single(hostdata->dev,
queue->msg_token,
queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
map_failed:
free_page((unsigned long)queue->msgs);
malloc_failed:
return -1;
}
/**
* reset_crq_queue: - resets a crq after a failure
* @queue: crq_queue to initialize and register
* @hostdata: ibmvscsi_host_data of host
*
*/
int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata)
{
int rc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
/* Close the CRQ */
do {
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while ((rc == H_Busy) || (H_isLongBusy(rc)));
/* Clean out the queue */
memset(queue->msgs, 0x00, PAGE_SIZE);
queue->cur = 0;
set_adapter_info(hostdata);
/* And re-open it again */
rc = plpar_hcall_norets(H_REG_CRQ,
vdev->unit_address,
queue->msg_token, PAGE_SIZE);
if (rc == 2) {
/* Adapter is good, but other end is not ready */
printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
} else if (rc != 0) {
printk(KERN_WARNING
"ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
}
return rc;
}