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linux/drivers/scsi/ibmvscsi/ibmvscsi.c

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/* ------------------------------------------------------------
* ibmvscsi.c
* (C) Copyright IBM Corporation 1994, 2004
* Authors: Colin DeVilbiss (devilbis@us.ibm.com)
* Santiago Leon (santil@us.ibm.com)
* Dave Boutcher (sleddog@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
*
* ------------------------------------------------------------
* Emulation of a SCSI host adapter for Virtual I/O devices
*
* This driver supports the SCSI adapter implemented by the IBM
* Power5 firmware. That SCSI adapter is not a physical adapter,
* but allows Linux SCSI peripheral drivers to directly
* access devices in another logical partition on the physical system.
*
* The virtual adapter(s) are present in the open firmware device
* tree just like real adapters.
*
* One of the capabilities provided on these systems is the ability
* to DMA between partitions. The architecture states that for VSCSI,
* the server side is allowed to DMA to and from the client. The client
* is never trusted to DMA to or from the server directly.
*
* Messages are sent between partitions on a "Command/Response Queue"
* (CRQ), which is just a buffer of 16 byte entries in the receiver's
* Senders cannot access the buffer directly, but send messages by
* making a hypervisor call and passing in the 16 bytes. The hypervisor
* puts the message in the next 16 byte space in round-robbin fashion,
* turns on the high order bit of the message (the valid bit), and
* generates an interrupt to the receiver (if interrupts are turned on.)
* The receiver just turns off the valid bit when they have copied out
* the message.
*
* The VSCSI client builds a SCSI Remote Protocol (SRP) Information Unit
* (IU) (as defined in the T10 standard available at www.t10.org), gets
* a DMA address for the message, and sends it to the server as the
* payload of a CRQ message. The server DMAs the SRP IU and processes it,
* including doing any additional data transfers. When it is done, it
* DMAs the SRP response back to the same address as the request came from,
* and sends a CRQ message back to inform the client that the request has
* completed.
*
* Note that some of the underlying infrastructure is different between
* machines conforming to the "RS/6000 Platform Architecture" (RPA) and
* the older iSeries hypervisor models. To support both, some low level
* routines have been broken out into rpa_vscsi.c and iseries_vscsi.c.
* The Makefile should pick one, not two, not zero, of these.
*
* TODO: This is currently pretty tied to the IBM i/pSeries hypervisor
* interfaces. It would be really nice to abstract this above an RDMA
* layer.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <asm/vio.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include "ibmvscsi.h"
/* The values below are somewhat arbitrary default values, but
* OS/400 will use 3 busses (disks, CDs, tapes, I think.)
* Note that there are 3 bits of channel value, 6 bits of id, and
* 5 bits of LUN.
*/
static int max_id = 64;
static int max_channel = 3;
static int init_timeout = 5;
static int max_requests = 50;
#define IBMVSCSI_VERSION "1.5.5"
MODULE_DESCRIPTION("IBM Virtual SCSI");
MODULE_AUTHOR("Dave Boutcher");
MODULE_LICENSE("GPL");
MODULE_VERSION(IBMVSCSI_VERSION);
module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(max_id, "Largest ID value for each channel");
module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(max_channel, "Largest channel value");
module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
module_param_named(max_requests, max_requests, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
/* ------------------------------------------------------------
* Routines for the event pool and event structs
*/
/**
* initialize_event_pool: - Allocates and initializes the event pool for a host
* @pool: event_pool to be initialized
* @size: Number of events in pool
* @hostdata: ibmvscsi_host_data who owns the event pool
*
* Returns zero on success.
*/
static int initialize_event_pool(struct event_pool *pool,
int size, struct ibmvscsi_host_data *hostdata)
{
int i;
pool->size = size;
pool->next = 0;
pool->events = kmalloc(pool->size * sizeof(*pool->events), GFP_KERNEL);
if (!pool->events)
return -ENOMEM;
memset(pool->events, 0x00, pool->size * sizeof(*pool->events));
pool->iu_storage =
dma_alloc_coherent(hostdata->dev,
pool->size * sizeof(*pool->iu_storage),
&pool->iu_token, 0);
if (!pool->iu_storage) {
kfree(pool->events);
return -ENOMEM;
}
for (i = 0; i < pool->size; ++i) {
struct srp_event_struct *evt = &pool->events[i];
memset(&evt->crq, 0x00, sizeof(evt->crq));
atomic_set(&evt->free, 1);
evt->crq.valid = 0x80;
evt->crq.IU_length = sizeof(*evt->xfer_iu);
evt->crq.IU_data_ptr = pool->iu_token +
sizeof(*evt->xfer_iu) * i;
evt->xfer_iu = pool->iu_storage + i;
evt->hostdata = hostdata;
}
return 0;
}
/**
* release_event_pool: - Frees memory of an event pool of a host
* @pool: event_pool to be released
* @hostdata: ibmvscsi_host_data who owns the even pool
*
* Returns zero on success.
*/
static void release_event_pool(struct event_pool *pool,
struct ibmvscsi_host_data *hostdata)
{
int i, in_use = 0;
for (i = 0; i < pool->size; ++i)
if (atomic_read(&pool->events[i].free) != 1)
++in_use;
if (in_use)
printk(KERN_WARNING
"ibmvscsi: releasing event pool with %d "
"events still in use?\n", in_use);
kfree(pool->events);
dma_free_coherent(hostdata->dev,
pool->size * sizeof(*pool->iu_storage),
pool->iu_storage, pool->iu_token);
}
/**
* valid_event_struct: - Determines if event is valid.
* @pool: event_pool that contains the event
* @evt: srp_event_struct to be checked for validity
*
* Returns zero if event is invalid, one otherwise.
*/
static int valid_event_struct(struct event_pool *pool,
struct srp_event_struct *evt)
{
int index = evt - pool->events;
if (index < 0 || index >= pool->size) /* outside of bounds */
return 0;
if (evt != pool->events + index) /* unaligned */
return 0;
return 1;
}
/**
* ibmvscsi_free-event_struct: - Changes status of event to "free"
* @pool: event_pool that contains the event
* @evt: srp_event_struct to be modified
*
*/
static void free_event_struct(struct event_pool *pool,
struct srp_event_struct *evt)
{
if (!valid_event_struct(pool, evt)) {
printk(KERN_ERR
"ibmvscsi: Freeing invalid event_struct %p "
"(not in pool %p)\n", evt, pool->events);
return;
}
if (atomic_inc_return(&evt->free) != 1) {
printk(KERN_ERR
"ibmvscsi: Freeing event_struct %p "
"which is not in use!\n", evt);
return;
}
}
/**
* get_evt_struct: - Gets the next free event in pool
* @pool: event_pool that contains the events to be searched
*
* Returns the next event in "free" state, and NULL if none are free.
* Note that no synchronization is done here, we assume the host_lock
* will syncrhonze things.
*/
static struct srp_event_struct *get_event_struct(struct event_pool *pool)
{
int i;
int poolsize = pool->size;
int offset = pool->next;
for (i = 0; i < poolsize; i++) {
offset = (offset + 1) % poolsize;
if (!atomic_dec_if_positive(&pool->events[offset].free)) {
pool->next = offset;
return &pool->events[offset];
}
}
printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
return NULL;
}
/**
* init_event_struct: Initialize fields in an event struct that are always
* required.
* @evt: The event
* @done: Routine to call when the event is responded to
* @format: SRP or MAD format
* @timeout: timeout value set in the CRQ
*/
static void init_event_struct(struct srp_event_struct *evt_struct,
void (*done) (struct srp_event_struct *),
u8 format,
int timeout)
{
evt_struct->cmnd = NULL;
evt_struct->cmnd_done = NULL;
evt_struct->sync_srp = NULL;
evt_struct->crq.format = format;
evt_struct->crq.timeout = timeout;
evt_struct->done = done;
}
/* ------------------------------------------------------------
* Routines for receiving SCSI responses from the hosting partition
*/
/**
* set_srp_direction: Set the fields in the srp related to data
* direction and number of buffers based on the direction in
* the scsi_cmnd and the number of buffers
*/
static void set_srp_direction(struct scsi_cmnd *cmd,
struct srp_cmd *srp_cmd,
int numbuf)
{
if (numbuf == 0)
return;
if (numbuf == 1) {
if (cmd->sc_data_direction == DMA_TO_DEVICE)
srp_cmd->data_out_format = SRP_DIRECT_BUFFER;
else
srp_cmd->data_in_format = SRP_DIRECT_BUFFER;
} else {
if (cmd->sc_data_direction == DMA_TO_DEVICE) {
srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
srp_cmd->data_out_count = numbuf;
} else {
srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
srp_cmd->data_in_count = numbuf;
}
}
}
/**
* unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
* @cmd: srp_cmd whose additional_data member will be unmapped
* @dev: device for which the memory is mapped
*
*/
static void unmap_cmd_data(struct srp_cmd *cmd, struct device *dev)
{
int i;
if ((cmd->data_out_format == SRP_NO_BUFFER) &&
(cmd->data_in_format == SRP_NO_BUFFER))
return;
else if ((cmd->data_out_format == SRP_DIRECT_BUFFER) ||
(cmd->data_in_format == SRP_DIRECT_BUFFER)) {
struct memory_descriptor *data =
(struct memory_descriptor *)cmd->additional_data;
dma_unmap_single(dev, data->virtual_address, data->length,
DMA_BIDIRECTIONAL);
} else {
struct indirect_descriptor *indirect =
(struct indirect_descriptor *)cmd->additional_data;
int num_mapped = indirect->head.length /
sizeof(indirect->list[0]);
for (i = 0; i < num_mapped; ++i) {
struct memory_descriptor *data = &indirect->list[i];
dma_unmap_single(dev,
data->virtual_address,
data->length, DMA_BIDIRECTIONAL);
}
}
}
/**
* map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
* @cmd: Scsi_Cmnd with the scatterlist
* @srp_cmd: srp_cmd that contains the memory descriptor
* @dev: device for which to map dma memory
*
* Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
* Returns 1 on success.
*/
static int map_sg_data(struct scsi_cmnd *cmd,
struct srp_cmd *srp_cmd, struct device *dev)
{
int i, sg_mapped;
u64 total_length = 0;
struct scatterlist *sg = cmd->request_buffer;
struct memory_descriptor *data =
(struct memory_descriptor *)srp_cmd->additional_data;
struct indirect_descriptor *indirect =
(struct indirect_descriptor *)data;
sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
if (sg_mapped == 0)
return 0;
set_srp_direction(cmd, srp_cmd, sg_mapped);
/* special case; we can use a single direct descriptor */
if (sg_mapped == 1) {
data->virtual_address = sg_dma_address(&sg[0]);
data->length = sg_dma_len(&sg[0]);
data->memory_handle = 0;
return 1;
}
if (sg_mapped > MAX_INDIRECT_BUFS) {
printk(KERN_ERR
"ibmvscsi: More than %d mapped sg entries, got %d\n",
MAX_INDIRECT_BUFS, sg_mapped);
return 0;
}
indirect->head.virtual_address = 0;
indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
indirect->head.memory_handle = 0;
for (i = 0; i < sg_mapped; ++i) {
struct memory_descriptor *descr = &indirect->list[i];
struct scatterlist *sg_entry = &sg[i];
descr->virtual_address = sg_dma_address(sg_entry);
descr->length = sg_dma_len(sg_entry);
descr->memory_handle = 0;
total_length += sg_dma_len(sg_entry);
}
indirect->total_length = total_length;
return 1;
}
/**
* map_single_data: - Maps memory and initializes memory decriptor fields
* @cmd: struct scsi_cmnd with the memory to be mapped
* @srp_cmd: srp_cmd that contains the memory descriptor
* @dev: device for which to map dma memory
*
* Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
* Returns 1 on success.
*/
static int map_single_data(struct scsi_cmnd *cmd,
struct srp_cmd *srp_cmd, struct device *dev)
{
struct memory_descriptor *data =
(struct memory_descriptor *)srp_cmd->additional_data;
data->virtual_address =
dma_map_single(dev, cmd->request_buffer,
cmd->request_bufflen,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(data->virtual_address)) {
printk(KERN_ERR
"ibmvscsi: Unable to map request_buffer for command!\n");
return 0;
}
data->length = cmd->request_bufflen;
data->memory_handle = 0;
set_srp_direction(cmd, srp_cmd, 1);
return 1;
}
/**
* map_data_for_srp_cmd: - Calls functions to map data for srp cmds
* @cmd: struct scsi_cmnd with the memory to be mapped
* @srp_cmd: srp_cmd that contains the memory descriptor
* @dev: dma device for which to map dma memory
*
* Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds
* Returns 1 on success.
*/
static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
struct srp_cmd *srp_cmd, struct device *dev)
{
switch (cmd->sc_data_direction) {
case DMA_FROM_DEVICE:
case DMA_TO_DEVICE:
break;
case DMA_NONE:
return 1;
case DMA_BIDIRECTIONAL:
printk(KERN_ERR
"ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
return 0;
default:
printk(KERN_ERR
"ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
cmd->sc_data_direction);
return 0;
}
if (!cmd->request_buffer)
return 1;
if (cmd->use_sg)
return map_sg_data(cmd, srp_cmd, dev);
return map_single_data(cmd, srp_cmd, dev);
}
/* ------------------------------------------------------------
* Routines for sending and receiving SRPs
*/
/**
* ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
* @evt_struct: evt_struct to be sent
* @hostdata: ibmvscsi_host_data of host
*
* Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
* Note that this routine assumes that host_lock is held for synchronization
*/
static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
struct ibmvscsi_host_data *hostdata)
{
struct scsi_cmnd *cmnd;
u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
int rc;
/* If we have exhausted our request limit, just fail this request.
* Note that there are rare cases involving driver generated requests
* (such as task management requests) that the mid layer may think we
* can handle more requests (can_queue) when we actually can't
*/
if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
(atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
/* See if the adapter is disabled */
if (atomic_read(&hostdata->request_limit) < 0)
goto send_error;
printk(KERN_WARNING
"ibmvscsi: Warning, request_limit exceeded\n");
unmap_cmd_data(&evt_struct->iu.srp.cmd,
hostdata->dev);
free_event_struct(&hostdata->pool, evt_struct);
return SCSI_MLQUEUE_HOST_BUSY;
}
/* Copy the IU into the transfer area */
*evt_struct->xfer_iu = evt_struct->iu;
evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;
/* Add this to the sent list. We need to do this
* before we actually send
* in case it comes back REALLY fast
*/
list_add_tail(&evt_struct->list, &hostdata->sent);
if ((rc =
ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
list_del(&evt_struct->list);
printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
rc);
goto send_error;
}
return 0;
send_error:
unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);
if ((cmnd = evt_struct->cmnd) != NULL) {
cmnd->result = DID_ERROR << 16;
evt_struct->cmnd_done(cmnd);
} else if (evt_struct->done)
evt_struct->done(evt_struct);
free_event_struct(&hostdata->pool, evt_struct);
return 0;
}
/**
* handle_cmd_rsp: - Handle responses from commands
* @evt_struct: srp_event_struct to be handled
*
* Used as a callback by when sending scsi cmds.
* Gets called by ibmvscsi_handle_crq()
*/
static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
{
struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
struct scsi_cmnd *cmnd = evt_struct->cmnd;
if (unlikely(rsp->type != SRP_RSP_TYPE)) {
if (printk_ratelimit())
printk(KERN_WARNING
"ibmvscsi: bad SRP RSP type %d\n",
rsp->type);
}
if (cmnd) {
cmnd->result = rsp->status;
if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
memcpy(cmnd->sense_buffer,
rsp->sense_and_response_data,
rsp->sense_data_list_length);
unmap_cmd_data(&evt_struct->iu.srp.cmd,
evt_struct->hostdata->dev);
if (rsp->doover)
cmnd->resid = rsp->data_out_residual_count;
else if (rsp->diover)
cmnd->resid = rsp->data_in_residual_count;
}
if (evt_struct->cmnd_done)
evt_struct->cmnd_done(cmnd);
}
/**
* lun_from_dev: - Returns the lun of the scsi device
* @dev: struct scsi_device
*
*/
static inline u16 lun_from_dev(struct scsi_device *dev)
{
return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
}
/**
* ibmvscsi_queue: - The queuecommand function of the scsi template
* @cmd: struct scsi_cmnd to be executed
* @done: Callback function to be called when cmd is completed
*/
static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
void (*done) (struct scsi_cmnd *))
{
struct srp_cmd *srp_cmd;
struct srp_event_struct *evt_struct;
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
u16 lun = lun_from_dev(cmnd->device);
evt_struct = get_event_struct(&hostdata->pool);
if (!evt_struct)
return SCSI_MLQUEUE_HOST_BUSY;
init_event_struct(evt_struct,
handle_cmd_rsp,
VIOSRP_SRP_FORMAT,
cmnd->timeout);
evt_struct->cmnd = cmnd;
evt_struct->cmnd_done = done;
/* Set up the actual SRP IU */
srp_cmd = &evt_struct->iu.srp.cmd;
memset(srp_cmd, 0x00, sizeof(*srp_cmd));
srp_cmd->type = SRP_CMD_TYPE;
memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
srp_cmd->lun = ((u64) lun) << 48;
if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
free_event_struct(&hostdata->pool, evt_struct);
return SCSI_MLQUEUE_HOST_BUSY;
}
/* Fix up dma address of the buffer itself */
if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
(srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
struct indirect_descriptor *indirect =
(struct indirect_descriptor *)srp_cmd->additional_data;
indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
offsetof(struct srp_cmd, additional_data) +
offsetof(struct indirect_descriptor, list);
}
return ibmvscsi_send_srp_event(evt_struct, hostdata);
}
/* ------------------------------------------------------------
* Routines for driver initialization
*/
/**
* adapter_info_rsp: - Handle response to MAD adapter info request
* @evt_struct: srp_event_struct with the response
*
* Used as a "done" callback by when sending adapter_info. Gets called
* by ibmvscsi_handle_crq()
*/
static void adapter_info_rsp(struct srp_event_struct *evt_struct)
{
struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
dma_unmap_single(hostdata->dev,
evt_struct->iu.mad.adapter_info.buffer,
evt_struct->iu.mad.adapter_info.common.length,
DMA_BIDIRECTIONAL);
if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
printk("ibmvscsi: error %d getting adapter info\n",
evt_struct->xfer_iu->mad.adapter_info.common.status);
} else {
printk("ibmvscsi: host srp version: %s, "
"host partition %s (%d), OS %d, max io %u\n",
hostdata->madapter_info.srp_version,
hostdata->madapter_info.partition_name,
hostdata->madapter_info.partition_number,
hostdata->madapter_info.os_type,
hostdata->madapter_info.port_max_txu[0]);
if (hostdata->madapter_info.port_max_txu[0])
hostdata->host->max_sectors =
hostdata->madapter_info.port_max_txu[0] >> 9;
}
}
/**
* send_mad_adapter_info: - Sends the mad adapter info request
* and stores the result so it can be retrieved with
* sysfs. We COULD consider causing a failure if the
* returned SRP version doesn't match ours.
* @hostdata: ibmvscsi_host_data of host
*
* Returns zero if successful.
*/
static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
{
struct viosrp_adapter_info *req;
struct srp_event_struct *evt_struct;
memset(&hostdata->madapter_info, 0x00, sizeof(hostdata->madapter_info));
evt_struct = get_event_struct(&hostdata->pool);
if (!evt_struct) {
printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
"for ADAPTER_INFO_REQ!\n");
return;
}
init_event_struct(evt_struct,
adapter_info_rsp,
VIOSRP_MAD_FORMAT,
init_timeout * HZ);
req = &evt_struct->iu.mad.adapter_info;
memset(req, 0x00, sizeof(*req));
req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
req->common.length = sizeof(hostdata->madapter_info);
req->buffer = dma_map_single(hostdata->dev,
&hostdata->madapter_info,
sizeof(hostdata->madapter_info),
DMA_BIDIRECTIONAL);
if (dma_mapping_error(req->buffer)) {
printk(KERN_ERR
"ibmvscsi: Unable to map request_buffer "
"for adapter_info!\n");
free_event_struct(&hostdata->pool, evt_struct);
return;
}
if (ibmvscsi_send_srp_event(evt_struct, hostdata))
printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
};
/**
* login_rsp: - Handle response to SRP login request
* @evt_struct: srp_event_struct with the response
*
* Used as a "done" callback by when sending srp_login. Gets called
* by ibmvscsi_handle_crq()
*/
static void login_rsp(struct srp_event_struct *evt_struct)
{
struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
switch (evt_struct->xfer_iu->srp.generic.type) {
case SRP_LOGIN_RSP_TYPE: /* it worked! */
break;
case SRP_LOGIN_REJ_TYPE: /* refused! */
printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
/* Login failed. */
atomic_set(&hostdata->request_limit, -1);
return;
default:
printk(KERN_ERR
"ibmvscsi: Invalid login response typecode 0x%02x!\n",
evt_struct->xfer_iu->srp.generic.type);
/* Login failed. */
atomic_set(&hostdata->request_limit, -1);
return;
}
printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
(max_requests - 2))
evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
max_requests - 2;
/* Now we know what the real request-limit is */
atomic_set(&hostdata->request_limit,
evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
hostdata->host->can_queue =
evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
if (hostdata->host->can_queue < 1) {
printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
return;
}
send_mad_adapter_info(hostdata);
return;
}
/**
* send_srp_login: - Sends the srp login
* @hostdata: ibmvscsi_host_data of host
*
* Returns zero if successful.
*/
static int send_srp_login(struct ibmvscsi_host_data *hostdata)
{
int rc;
unsigned long flags;
struct srp_login_req *login;
struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
if (!evt_struct) {
printk(KERN_ERR
"ibmvscsi: couldn't allocate an event for login req!\n");
return FAILED;
}
init_event_struct(evt_struct,
login_rsp,
VIOSRP_SRP_FORMAT,
init_timeout * HZ);
login = &evt_struct->iu.srp.login_req;
login->type = SRP_LOGIN_REQ_TYPE;
login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
login->required_buffer_formats = 0x0006;
/* Start out with a request limit of 1, since this is negotiated in
* the login request we are just sending
*/
atomic_set(&hostdata->request_limit, 1);
spin_lock_irqsave(hostdata->host->host_lock, flags);
rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
spin_unlock_irqrestore(hostdata->host->host_lock, flags);
return rc;
};
/**
* sync_completion: Signal that a synchronous command has completed
* Note that after returning from this call, the evt_struct is freed.
* the caller waiting on this completion shouldn't touch the evt_struct
* again.
*/
static void sync_completion(struct srp_event_struct *evt_struct)
{
/* copy the response back */
if (evt_struct->sync_srp)
*evt_struct->sync_srp = *evt_struct->xfer_iu;
complete(&evt_struct->comp);
}
/**
* ibmvscsi_abort: Abort a command...from scsi host template
* send this over to the server and wait synchronously for the response
*/
static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
{
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)cmd->device->host->hostdata;
struct srp_tsk_mgmt *tsk_mgmt;
struct srp_event_struct *evt;
struct srp_event_struct *tmp_evt, *found_evt;
union viosrp_iu srp_rsp;
int rsp_rc;
u16 lun = lun_from_dev(cmd->device);
/* First, find this command in our sent list so we can figure
* out the correct tag
*/
found_evt = NULL;
list_for_each_entry(tmp_evt, &hostdata->sent, list) {
if (tmp_evt->cmnd == cmd) {
found_evt = tmp_evt;
break;
}
}
if (!found_evt)
return FAILED;
evt = get_event_struct(&hostdata->pool);
if (evt == NULL) {
printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
return FAILED;
}
init_event_struct(evt,
sync_completion,
VIOSRP_SRP_FORMAT,
init_timeout * HZ);
tsk_mgmt = &evt->iu.srp.tsk_mgmt;
/* Set up an abort SRP command */
memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
tsk_mgmt->lun = ((u64) lun) << 48;
tsk_mgmt->task_mgmt_flags = 0x01; /* ABORT TASK */
tsk_mgmt->managed_task_tag = (u64) found_evt;
printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
evt->sync_srp = &srp_rsp;
init_completion(&evt->comp);
if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
return FAILED;
}
wait_for_completion(&evt->comp);
/* make sure we got a good response */
if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
if (printk_ratelimit())
printk(KERN_WARNING
"ibmvscsi: abort bad SRP RSP type %d\n",
srp_rsp.srp.generic.type);
return FAILED;
}
if (srp_rsp.srp.rsp.rspvalid)
rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
else
rsp_rc = srp_rsp.srp.rsp.status;
if (rsp_rc) {
if (printk_ratelimit())
printk(KERN_WARNING
"ibmvscsi: abort code %d for task tag 0x%lx\n",
rsp_rc,
tsk_mgmt->managed_task_tag);
return FAILED;
}
/* Because we dropped the spinlock above, it's possible
* The event is no longer in our list. Make sure it didn't
* complete while we were aborting
*/
found_evt = NULL;
list_for_each_entry(tmp_evt, &hostdata->sent, list) {
if (tmp_evt->cmnd == cmd) {
found_evt = tmp_evt;
break;
}
}
if (found_evt == NULL) {
printk(KERN_INFO
"ibmvscsi: aborted task tag 0x%lx completed\n",
tsk_mgmt->managed_task_tag);
return SUCCESS;
}
printk(KERN_INFO
"ibmvscsi: successfully aborted task tag 0x%lx\n",
tsk_mgmt->managed_task_tag);
cmd->result = (DID_ABORT << 16);
list_del(&found_evt->list);
unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
free_event_struct(&found_evt->hostdata->pool, found_evt);
atomic_inc(&hostdata->request_limit);
return SUCCESS;
}
/**
* ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host
* template send this over to the server and wait synchronously for the
* response
*/
static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)cmd->device->host->hostdata;
struct srp_tsk_mgmt *tsk_mgmt;
struct srp_event_struct *evt;
struct srp_event_struct *tmp_evt, *pos;
union viosrp_iu srp_rsp;
int rsp_rc;
u16 lun = lun_from_dev(cmd->device);
evt = get_event_struct(&hostdata->pool);
if (evt == NULL) {
printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
return FAILED;
}
init_event_struct(evt,
sync_completion,
VIOSRP_SRP_FORMAT,
init_timeout * HZ);
tsk_mgmt = &evt->iu.srp.tsk_mgmt;
/* Set up a lun reset SRP command */
memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
tsk_mgmt->lun = ((u64) lun) << 48;
tsk_mgmt->task_mgmt_flags = 0x08; /* LUN RESET */
printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
tsk_mgmt->lun);
evt->sync_srp = &srp_rsp;
init_completion(&evt->comp);
if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
return FAILED;
}
wait_for_completion(&evt->comp);
/* make sure we got a good response */
if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
if (printk_ratelimit())
printk(KERN_WARNING
"ibmvscsi: reset bad SRP RSP type %d\n",
srp_rsp.srp.generic.type);
return FAILED;
}
if (srp_rsp.srp.rsp.rspvalid)
rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
else
rsp_rc = srp_rsp.srp.rsp.status;
if (rsp_rc) {
if (printk_ratelimit())
printk(KERN_WARNING
"ibmvscsi: reset code %d for task tag 0x%lx\n",
rsp_rc,
tsk_mgmt->managed_task_tag);
return FAILED;
}
/* We need to find all commands for this LUN that have not yet been
* responded to, and fail them with DID_RESET
*/
list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
if (tmp_evt->cmnd)
tmp_evt->cmnd->result = (DID_RESET << 16);
list_del(&tmp_evt->list);
unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt->hostdata->dev);
free_event_struct(&tmp_evt->hostdata->pool,
tmp_evt);
atomic_inc(&hostdata->request_limit);
if (tmp_evt->cmnd_done)
tmp_evt->cmnd_done(tmp_evt->cmnd);
else if (tmp_evt->done)
tmp_evt->done(tmp_evt);
}
}
return SUCCESS;
}
/**
* purge_requests: Our virtual adapter just shut down. purge any sent requests
* @hostdata: the adapter
*/
static void purge_requests(struct ibmvscsi_host_data *hostdata)
{
struct srp_event_struct *tmp_evt, *pos;
unsigned long flags;
spin_lock_irqsave(hostdata->host->host_lock, flags);
list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
list_del(&tmp_evt->list);
if (tmp_evt->cmnd) {
tmp_evt->cmnd->result = (DID_ERROR << 16);
unmap_cmd_data(&tmp_evt->iu.srp.cmd,
tmp_evt->hostdata->dev);
if (tmp_evt->cmnd_done)
tmp_evt->cmnd_done(tmp_evt->cmnd);
} else {
if (tmp_evt->done) {
tmp_evt->done(tmp_evt);
}
}
free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
}
spin_unlock_irqrestore(hostdata->host->host_lock, flags);
}
/**
* ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
* @crq: Command/Response queue
* @hostdata: ibmvscsi_host_data of host
*
*/
void ibmvscsi_handle_crq(struct viosrp_crq *crq,
struct ibmvscsi_host_data *hostdata)
{
unsigned long flags;
struct srp_event_struct *evt_struct =
(struct srp_event_struct *)crq->IU_data_ptr;
switch (crq->valid) {
case 0xC0: /* initialization */
switch (crq->format) {
case 0x01: /* Initialization message */
printk(KERN_INFO "ibmvscsi: partner initialized\n");
/* Send back a response */
if (ibmvscsi_send_crq(hostdata,
0xC002000000000000LL, 0) == 0) {
/* Now login */
send_srp_login(hostdata);
} else {
printk(KERN_ERR
"ibmvscsi: Unable to send init rsp\n");
}
break;
case 0x02: /* Initialization response */
printk(KERN_INFO
"ibmvscsi: partner initialization complete\n");
/* Now login */
send_srp_login(hostdata);
break;
default:
printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
}
return;
case 0xFF: /* Hypervisor telling us the connection is closed */
printk(KERN_INFO "ibmvscsi: Virtual adapter failed!\n");
atomic_set(&hostdata->request_limit, -1);
purge_requests(hostdata);
ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
return;
case 0x80: /* real payload */
break;
default:
printk(KERN_ERR
"ibmvscsi: got an invalid message type 0x%02x\n",
crq->valid);
return;
}
/* The only kind of payload CRQs we should get are responses to
* things we send. Make sure this response is to something we
* actually sent
*/
if (!valid_event_struct(&hostdata->pool, evt_struct)) {
printk(KERN_ERR
"ibmvscsi: returned correlation_token 0x%p is invalid!\n",
(void *)crq->IU_data_ptr);
return;
}
if (atomic_read(&evt_struct->free)) {
printk(KERN_ERR
"ibmvscsi: received duplicate correlation_token 0x%p!\n",
(void *)crq->IU_data_ptr);
return;
}
if (crq->format == VIOSRP_SRP_FORMAT)
atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
&hostdata->request_limit);
if (evt_struct->done)
evt_struct->done(evt_struct);
else
printk(KERN_ERR
"ibmvscsi: returned done() is NULL; not running it!\n");
/*
* Lock the host_lock before messing with these structures, since we
* are running in a task context
*/
spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
list_del(&evt_struct->list);
free_event_struct(&evt_struct->hostdata->pool, evt_struct);
spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
}
/**
* ibmvscsi_get_host_config: Send the command to the server to get host
* configuration data. The data is opaque to us.
*/
static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
unsigned char *buffer, int length)
{
struct viosrp_host_config *host_config;
struct srp_event_struct *evt_struct;
int rc;
evt_struct = get_event_struct(&hostdata->pool);
if (!evt_struct) {
printk(KERN_ERR
"ibmvscsi: could't allocate event for HOST_CONFIG!\n");
return -1;
}
init_event_struct(evt_struct,
sync_completion,
VIOSRP_MAD_FORMAT,
init_timeout * HZ);
host_config = &evt_struct->iu.mad.host_config;
/* Set up a lun reset SRP command */
memset(host_config, 0x00, sizeof(*host_config));
host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
host_config->common.length = length;
host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(host_config->buffer)) {
printk(KERN_ERR
"ibmvscsi: dma_mapping error " "getting host config\n");
free_event_struct(&hostdata->pool, evt_struct);
return -1;
}
init_completion(&evt_struct->comp);
rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
if (rc == 0) {
wait_for_completion(&evt_struct->comp);
dma_unmap_single(hostdata->dev, host_config->buffer,
length, DMA_BIDIRECTIONAL);
}
return rc;
}
/* ------------------------------------------------------------
* sysfs attributes
*/
static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)shost->hostdata;
int len;
len = snprintf(buf, PAGE_SIZE, "%s\n",
hostdata->madapter_info.srp_version);
return len;
}
static struct class_device_attribute ibmvscsi_host_srp_version = {
.attr = {
.name = "srp_version",
.mode = S_IRUGO,
},
.show = show_host_srp_version,
};
static ssize_t show_host_partition_name(struct class_device *class_dev,
char *buf)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)shost->hostdata;
int len;
len = snprintf(buf, PAGE_SIZE, "%s\n",
hostdata->madapter_info.partition_name);
return len;
}
static struct class_device_attribute ibmvscsi_host_partition_name = {
.attr = {
.name = "partition_name",
.mode = S_IRUGO,
},
.show = show_host_partition_name,
};
static ssize_t show_host_partition_number(struct class_device *class_dev,
char *buf)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)shost->hostdata;
int len;
len = snprintf(buf, PAGE_SIZE, "%d\n",
hostdata->madapter_info.partition_number);
return len;
}
static struct class_device_attribute ibmvscsi_host_partition_number = {
.attr = {
.name = "partition_number",
.mode = S_IRUGO,
},
.show = show_host_partition_number,
};
static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)shost->hostdata;
int len;
len = snprintf(buf, PAGE_SIZE, "%d\n",
hostdata->madapter_info.mad_version);
return len;
}
static struct class_device_attribute ibmvscsi_host_mad_version = {
.attr = {
.name = "mad_version",
.mode = S_IRUGO,
},
.show = show_host_mad_version,
};
static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)shost->hostdata;
int len;
len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
return len;
}
static struct class_device_attribute ibmvscsi_host_os_type = {
.attr = {
.name = "os_type",
.mode = S_IRUGO,
},
.show = show_host_os_type,
};
static ssize_t show_host_config(struct class_device *class_dev, char *buf)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)shost->hostdata;
/* returns null-terminated host config data */
if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
return strlen(buf);
else
return 0;
}
static struct class_device_attribute ibmvscsi_host_config = {
.attr = {
.name = "config",
.mode = S_IRUGO,
},
.show = show_host_config,
};
static struct class_device_attribute *ibmvscsi_attrs[] = {
&ibmvscsi_host_srp_version,
&ibmvscsi_host_partition_name,
&ibmvscsi_host_partition_number,
&ibmvscsi_host_mad_version,
&ibmvscsi_host_os_type,
&ibmvscsi_host_config,
NULL
};
/* ------------------------------------------------------------
* SCSI driver registration
*/
static struct scsi_host_template driver_template = {
.module = THIS_MODULE,
.name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
.proc_name = "ibmvscsi",
.queuecommand = ibmvscsi_queuecommand,
.eh_abort_handler = ibmvscsi_eh_abort_handler,
.eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
.cmd_per_lun = 16,
.can_queue = 1, /* Updated after SRP_LOGIN */
.this_id = -1,
.sg_tablesize = MAX_INDIRECT_BUFS,
.use_clustering = ENABLE_CLUSTERING,
.shost_attrs = ibmvscsi_attrs,
};
/**
* Called by bus code for each adapter
*/
static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
struct ibmvscsi_host_data *hostdata;
struct Scsi_Host *host;
struct device *dev = &vdev->dev;
unsigned long wait_switch = 0;
vdev->dev.driver_data = NULL;
host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
if (!host) {
printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
goto scsi_host_alloc_failed;
}
hostdata = (struct ibmvscsi_host_data *)host->hostdata;
memset(hostdata, 0x00, sizeof(*hostdata));
INIT_LIST_HEAD(&hostdata->sent);
hostdata->host = host;
hostdata->dev = dev;
atomic_set(&hostdata->request_limit, -1);
hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
max_requests) != 0) {
printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
goto init_crq_failed;
}
if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
goto init_pool_failed;
}
host->max_lun = 8;
host->max_id = max_id;
host->max_channel = max_channel;
if (scsi_add_host(hostdata->host, hostdata->dev))
goto add_host_failed;
/* Try to send an initialization message. Note that this is allowed
* to fail if the other end is not acive. In that case we don't
* want to scan
*/
if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
/*
* Wait around max init_timeout secs for the adapter to finish
* initializing. When we are done initializing, we will have a
* valid request_limit. We don't want Linux scanning before
* we are ready.
*/
for (wait_switch = jiffies + (init_timeout * HZ);
time_before(jiffies, wait_switch) &&
atomic_read(&hostdata->request_limit) < 2;) {
msleep(10);
}
/* if we now have a valid request_limit, initiate a scan */
if (atomic_read(&hostdata->request_limit) > 0)
scsi_scan_host(host);
}
vdev->dev.driver_data = hostdata;
return 0;
add_host_failed:
release_event_pool(&hostdata->pool, hostdata);
init_pool_failed:
ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
init_crq_failed:
scsi_host_put(host);
scsi_host_alloc_failed:
return -1;
}
static int ibmvscsi_remove(struct vio_dev *vdev)
{
struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
release_event_pool(&hostdata->pool, hostdata);
ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
max_requests);
scsi_remove_host(hostdata->host);
scsi_host_put(hostdata->host);
return 0;
}
/**
* ibmvscsi_device_table: Used by vio.c to match devices in the device tree we
* support.
*/
static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
{"vscsi", "IBM,v-scsi"},
{0,}
};
MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
static struct vio_driver ibmvscsi_driver = {
.name = "ibmvscsi",
.id_table = ibmvscsi_device_table,
.probe = ibmvscsi_probe,
.remove = ibmvscsi_remove
};
int __init ibmvscsi_module_init(void)
{
return vio_register_driver(&ibmvscsi_driver);
}
void __exit ibmvscsi_module_exit(void)
{
vio_unregister_driver(&ibmvscsi_driver);
}
module_init(ibmvscsi_module_init);
module_exit(ibmvscsi_module_exit);
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