Commit 126a4fe0 authored by Lee Duncan's avatar Lee Duncan Committed by Martin K. Petersen

scsi: Use ida for host number management

Update the SCSI hosts module to use ida to manage its host_no index
instead of an atomic integer. This means that the SCSI host number will
now be reclaimable.

Use the ida "simple" mechanism, since there should be no need for a
separate spin lock current usage. Ida was chosen over idr because the
hosts module already has its own instance and locking mechanisms that
aren't easily changed.
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarLee Duncan <lduncan@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d92ca9d3
...@@ -33,7 +33,7 @@ ...@@ -33,7 +33,7 @@
#include <linux/transport_class.h> #include <linux/transport_class.h>
#include <linux/platform_device.h> #include <linux/platform_device.h>
#include <linux/pm_runtime.h> #include <linux/pm_runtime.h>
#include <linux/idr.h>
#include <scsi/scsi_device.h> #include <scsi/scsi_device.h>
#include <scsi/scsi_host.h> #include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h> #include <scsi/scsi_transport.h>
...@@ -42,7 +42,7 @@ ...@@ -42,7 +42,7 @@
#include "scsi_logging.h" #include "scsi_logging.h"
static atomic_t scsi_host_next_hn = ATOMIC_INIT(0); /* host_no for next new host */ static DEFINE_IDA(host_index_ida);
static void scsi_host_cls_release(struct device *dev) static void scsi_host_cls_release(struct device *dev)
...@@ -355,6 +355,8 @@ static void scsi_host_dev_release(struct device *dev) ...@@ -355,6 +355,8 @@ static void scsi_host_dev_release(struct device *dev)
kfree(shost->shost_data); kfree(shost->shost_data);
ida_simple_remove(&host_index_ida, shost->host_no);
if (parent) if (parent)
put_device(parent); put_device(parent);
kfree(shost); kfree(shost);
...@@ -388,6 +390,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) ...@@ -388,6 +390,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
{ {
struct Scsi_Host *shost; struct Scsi_Host *shost;
gfp_t gfp_mask = GFP_KERNEL; gfp_t gfp_mask = GFP_KERNEL;
int index;
if (sht->unchecked_isa_dma && privsize) if (sht->unchecked_isa_dma && privsize)
gfp_mask |= __GFP_DMA; gfp_mask |= __GFP_DMA;
...@@ -406,11 +409,11 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) ...@@ -406,11 +409,11 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
init_waitqueue_head(&shost->host_wait); init_waitqueue_head(&shost->host_wait);
mutex_init(&shost->scan_mutex); mutex_init(&shost->scan_mutex);
/* index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
* subtract one because we increment first then return, but we need to if (index < 0)
* know what the next host number was before increment goto fail_kfree;
*/ shost->host_no = index;
shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
shost->dma_channel = 0xff; shost->dma_channel = 0xff;
/* These three are default values which can be overridden */ /* These three are default values which can be overridden */
...@@ -495,7 +498,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) ...@@ -495,7 +498,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
shost_printk(KERN_WARNING, shost, shost_printk(KERN_WARNING, shost,
"error handler thread failed to spawn, error = %ld\n", "error handler thread failed to spawn, error = %ld\n",
PTR_ERR(shost->ehandler)); PTR_ERR(shost->ehandler));
goto fail_kfree; goto fail_index_remove;
} }
shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
...@@ -511,6 +514,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) ...@@ -511,6 +514,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
fail_kthread: fail_kthread:
kthread_stop(shost->ehandler); kthread_stop(shost->ehandler);
fail_index_remove:
ida_simple_remove(&host_index_ida, shost->host_no);
fail_kfree: fail_kfree:
kfree(shost); kfree(shost);
return NULL; return NULL;
...@@ -606,6 +611,7 @@ int scsi_init_hosts(void) ...@@ -606,6 +611,7 @@ int scsi_init_hosts(void)
void scsi_exit_hosts(void) void scsi_exit_hosts(void)
{ {
class_unregister(&shost_class); class_unregister(&shost_class);
ida_destroy(&host_index_ida);
} }
int scsi_is_host_device(const struct device *dev) int scsi_is_host_device(const struct device *dev)
......
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