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[SCSI] megaraid: simplify internal command handling
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We don't use the passed in scsi command for anything, so just add a adapter-
wide internal status to go along with the internal scb that is used unter
int_mtx to pass back the return value and get rid of all the complexities
and abuse of the scsi_cmnd structure.

This gets rid of the only user of scsi_allocate_command/scsi_free_command,
which can now be removed.

[jejb: checkpatch fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Christoph Hellwig authored and James Bottomley committed Mar 27, 2014
1 parent c38c007 commit 0f2bb84
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Showing 4 changed files with 32 additions and 150 deletions.
120 changes: 31 additions & 89 deletions drivers/scsi/megaraid.c
View file
Expand Up @@ -531,13 +531,6 @@ mega_build_cmd(adapter_t *adapter, Scsi_Cmnd *cmd, int *busy)
int target = 0;
int ldrv_num = 0; /* logical drive number */


/*
* filter the internal and ioctl commands
*/
if((cmd->cmnd[0] == MEGA_INTERNAL_CMD))
return (scb_t *)cmd->host_scribble;

/*
* We know what channels our logical drives are on - mega_find_card()
*/
Expand Down Expand Up @@ -1439,19 +1432,22 @@ mega_cmd_done(adapter_t *adapter, u8 completed[], int nstatus, int status)

cmdid = completed[i];

if( cmdid == CMDID_INT_CMDS ) { /* internal command */
/*
* Only free SCBs for the commands coming down from the
* mid-layer, not for which were issued internally
*
* For internal command, restore the status returned by the
* firmware so that user can interpret it.
*/
if (cmdid == CMDID_INT_CMDS) {
scb = &adapter->int_scb;
cmd = scb->cmd;
mbox = (mbox_t *)scb->raw_mbox;

/*
* Internal command interface do not fire the extended
* passthru or 64-bit passthru
*/
pthru = scb->pthru;
list_del_init(&scb->list);
scb->state = SCB_FREE;

}
else {
adapter->int_status = status;
complete(&adapter->int_waitq);
} else {
scb = &adapter->scb_list[cmdid];

/*
Expand Down Expand Up @@ -1640,25 +1636,7 @@ mega_cmd_done(adapter_t *adapter, u8 completed[], int nstatus, int status)
cmd->result |= (DID_BAD_TARGET << 16)|status;
}

/*
* Only free SCBs for the commands coming down from the
* mid-layer, not for which were issued internally
*
* For internal command, restore the status returned by the
* firmware so that user can interpret it.
*/
if( cmdid == CMDID_INT_CMDS ) { /* internal command */
cmd->result = status;

/*
* Remove the internal command from the pending list
*/
list_del_init(&scb->list);
scb->state = SCB_FREE;
}
else {
mega_free_scb(adapter, scb);
}
mega_free_scb(adapter, scb);

/* Add Scsi_Command to end of completed queue */
list_add_tail(SCSI_LIST(cmd), &adapter->completed_list);
Expand Down Expand Up @@ -4133,23 +4111,15 @@ mega_internal_dev_inquiry(adapter_t *adapter, u8 ch, u8 tgt,
* The last argument is the address of the passthru structure if the command
* to be fired is a passthru command
*
* lockscope specifies whether the caller has already acquired the lock. Of
* course, the caller must know which lock we are talking about.
*
* Note: parameter 'pthru' is null for non-passthru commands.
*/
static int
mega_internal_command(adapter_t *adapter, megacmd_t *mc, mega_passthru *pthru)
{
Scsi_Cmnd *scmd;
struct scsi_device *sdev;
unsigned long flags;
scb_t *scb;
int rval;

scmd = scsi_allocate_command(GFP_KERNEL);
if (!scmd)
return -ENOMEM;

/*
* The internal commands share one command id and hence are
* serialized. This is so because we want to reserve maximum number of
Expand All @@ -4160,73 +4130,45 @@ mega_internal_command(adapter_t *adapter, megacmd_t *mc, mega_passthru *pthru)
scb = &adapter->int_scb;
memset(scb, 0, sizeof(scb_t));

sdev = kzalloc(sizeof(struct scsi_device), GFP_KERNEL);
scmd->device = sdev;

memset(adapter->int_cdb, 0, sizeof(adapter->int_cdb));
scmd->cmnd = adapter->int_cdb;
scmd->device->host = adapter->host;
scmd->host_scribble = (void *)scb;
scmd->cmnd[0] = MEGA_INTERNAL_CMD;

scb->state |= SCB_ACTIVE;
scb->cmd = scmd;
scb->idx = CMDID_INT_CMDS;
scb->state |= SCB_ACTIVE | SCB_PENDQ;

memcpy(scb->raw_mbox, mc, sizeof(megacmd_t));

/*
* Is it a passthru command
*/
if( mc->cmd == MEGA_MBOXCMD_PASSTHRU ) {

if (mc->cmd == MEGA_MBOXCMD_PASSTHRU)
scb->pthru = pthru;
}

scb->idx = CMDID_INT_CMDS;

megaraid_queue_lck(scmd, mega_internal_done);
spin_lock_irqsave(&adapter->lock, flags);
list_add_tail(&scb->list, &adapter->pending_list);
/*
* Check if the HBA is in quiescent state, e.g., during a
* delete logical drive opertion. If it is, don't run
* the pending_list.
*/
if (atomic_read(&adapter->quiescent) == 0)
mega_runpendq(adapter);
spin_unlock_irqrestore(&adapter->lock, flags);

wait_for_completion(&adapter->int_waitq);

rval = scmd->result;
mc->status = scmd->result;
kfree(sdev);
mc->status = rval = adapter->int_status;

/*
* Print a debug message for all failed commands. Applications can use
* this information.
*/
if( scmd->result && trace_level ) {
if (rval && trace_level) {
printk("megaraid: cmd [%x, %x, %x] status:[%x]\n",
mc->cmd, mc->opcode, mc->subopcode, scmd->result);
mc->cmd, mc->opcode, mc->subopcode, rval);
}

mutex_unlock(&adapter->int_mtx);

scsi_free_command(GFP_KERNEL, scmd);

return rval;
}


/**
* mega_internal_done()
* @scmd - internal scsi command
*
* Callback routine for internal commands.
*/
static void
mega_internal_done(Scsi_Cmnd *scmd)
{
adapter_t *adapter;

adapter = (adapter_t *)scmd->device->host->hostdata;

complete(&adapter->int_waitq);

}


static struct scsi_host_template megaraid_template = {
.module = THIS_MODULE,
.name = "MegaRAID",
Expand Down
3 changes: 1 addition & 2 deletions drivers/scsi/megaraid.h
View file
Expand Up @@ -853,10 +853,10 @@ typedef struct {

u8 sglen; /* f/w supported scatter-gather list length */

unsigned char int_cdb[MAX_COMMAND_SIZE];
scb_t int_scb;
struct mutex int_mtx; /* To synchronize the internal
commands */
int int_status; /* status of internal cmd */
struct completion int_waitq; /* wait queue for internal
cmds */

Expand Down Expand Up @@ -1004,7 +1004,6 @@ static int mega_del_logdrv(adapter_t *, int);
static int mega_do_del_logdrv(adapter_t *, int);
static void mega_get_max_sgl(adapter_t *);
static int mega_internal_command(adapter_t *, megacmd_t *, mega_passthru *);
static void mega_internal_done(Scsi_Cmnd *);
static int mega_support_cluster(adapter_t *);
#endif

Expand Down
56 changes: 0 additions & 56 deletions drivers/scsi/scsi.c
View file
Expand Up @@ -402,62 +402,6 @@ static void scsi_put_host_cmd_pool(gfp_t gfp_mask)
mutex_unlock(&host_cmd_pool_mutex);
}

/**
* scsi_allocate_command - get a fully allocated SCSI command
* @gfp_mask: allocation mask
*
* This function is for use outside of the normal host based pools.
* It allocates the relevant command and takes an additional reference
* on the pool it used. This function *must* be paired with
* scsi_free_command which also has the identical mask, otherwise the
* free pool counts will eventually go wrong and you'll trigger a bug.
*
* This function should *only* be used by drivers that need a static
* command allocation at start of day for internal functions.
*/
struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask)
{
struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);

if (!pool)
return NULL;

return scsi_pool_alloc_command(pool, gfp_mask);
}
EXPORT_SYMBOL(scsi_allocate_command);

/**
* scsi_free_command - free a command allocated by scsi_allocate_command
* @gfp_mask: mask used in the original allocation
* @cmd: command to free
*
* Note: using the original allocation mask is vital because that's
* what determines which command pool we use to free the command. Any
* mismatch will cause the system to BUG eventually.
*/
void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd)
{
struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);

/*
* this could trigger if the mask to scsi_allocate_command
* doesn't match this mask. Otherwise we're guaranteed that this
* succeeds because scsi_allocate_command must have taken a reference
* on the pool
*/
BUG_ON(!pool);

scsi_pool_free_command(pool, cmd);
/*
* scsi_put_host_cmd_pool is called twice; once to release the
* reference we took above, and once to release the reference
* originally taken by scsi_allocate_command
*/
scsi_put_host_cmd_pool(gfp_mask);
scsi_put_host_cmd_pool(gfp_mask);
}
EXPORT_SYMBOL(scsi_free_command);

/**
* scsi_setup_command_freelist - Setup the command freelist for a scsi host.
* @shost: host to allocate the freelist for.
Expand Down
3 changes: 0 additions & 3 deletions include/scsi/scsi_cmnd.h
View file
Expand Up @@ -155,9 +155,6 @@ extern void scsi_release_buffers(struct scsi_cmnd *cmd);
extern int scsi_dma_map(struct scsi_cmnd *cmd);
extern void scsi_dma_unmap(struct scsi_cmnd *cmd);

struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);

static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
{
return cmd->sdb.table.nents;
Expand Down

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