diff options
| author | Lee Duncan <lduncan@suse.com> | 2016-01-20 20:48:00 +0100 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2016-02-24 03:27:02 +0100 |
| commit | 126a4fe010fd86cf3eaac9a481f0698e39dc3c0d (patch) | |
| tree | 1e14f372d7e8eac390dabcad683fea6fb0f19c6f /drivers/scsi/hosts.c | |
| parent | megaraid_sas: driver version upgrade (diff) | |
| download | linux-126a4fe010fd86cf3eaac9a481f0698e39dc3c0d.tar.xz linux-126a4fe010fd86cf3eaac9a481f0698e39dc3c0d.zip | |
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: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/hosts.c')
| -rw-r--r-- | drivers/scsi/hosts.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 82ac1cd818ac..94025c5cf797 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -33,7 +33,7 @@ #include <linux/transport_class.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> - +#include <linux/idr.h> #include <scsi/scsi_device.h> #include <scsi/scsi_host.h> #include <scsi/scsi_transport.h> @@ -42,7 +42,7 @@ #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) @@ -355,6 +355,8 @@ static void scsi_host_dev_release(struct device *dev) kfree(shost->shost_data); + ida_simple_remove(&host_index_ida, shost->host_no); + if (parent) put_device(parent); kfree(shost); @@ -388,6 +390,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) { struct Scsi_Host *shost; gfp_t gfp_mask = GFP_KERNEL; + int index; if (sht->unchecked_isa_dma && privsize) gfp_mask |= __GFP_DMA; @@ -406,11 +409,11 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) init_waitqueue_head(&shost->host_wait); mutex_init(&shost->scan_mutex); - /* - * subtract one because we increment first then return, but we need to - * know what the next host number was before increment - */ - shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; + index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); + if (index < 0) + goto fail_kfree; + shost->host_no = index; + shost->dma_channel = 0xff; /* 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) shost_printk(KERN_WARNING, shost, "error handler thread failed to spawn, error = %ld\n", PTR_ERR(shost->ehandler)); - goto fail_kfree; + goto fail_index_remove; } 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) fail_kthread: kthread_stop(shost->ehandler); + fail_index_remove: + ida_simple_remove(&host_index_ida, shost->host_no); fail_kfree: kfree(shost); return NULL; @@ -606,6 +611,7 @@ int scsi_init_hosts(void) void scsi_exit_hosts(void) { class_unregister(&shost_class); + ida_destroy(&host_index_ida); } int scsi_is_host_device(const struct device *dev) |