From patchwork Wed Jan 20 19:48:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Duncan X-Patchwork-Id: 8074101 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id F08509F818 for ; Wed, 20 Jan 2016 19:50:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 228BD2052A for ; Wed, 20 Jan 2016 19:50:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A0FA2057F for ; Wed, 20 Jan 2016 19:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755020AbcATTuq (ORCPT ); Wed, 20 Jan 2016 14:50:46 -0500 Received: from mx2.suse.de ([195.135.220.15]:49463 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752644AbcATTuo (ORCPT ); Wed, 20 Jan 2016 14:50:44 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 60434AB12; Wed, 20 Jan 2016 19:50:40 +0000 (UTC) Received: by worklaptop.gonzoleeman.net (Postfix, from userid 1000) id C2F7140C82; Wed, 20 Jan 2016 11:48:31 -0800 (PST) From: Lee Duncan To: Cc: , , , Hannes Reinecke , Johannes Thumshirn , Lee Duncan Subject: [PATCHv2] SCSI: usd ida for host number management Date: Wed, 20 Jan 2016 11:48:00 -0800 Message-Id: <1453319280-15417-1-git-send-email-lduncan@suse.com> X-Mailer: git-send-email 2.1.4 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. Changes from v1: * First version used regular ida routines Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Lee Duncan --- drivers/scsi/hosts.c | 22 ++++++++++++++-------- 1 file 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 #include #include - +#include #include #include #include @@ -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)