From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752670AbeEUKLp (ORCPT ); Mon, 21 May 2018 06:11:45 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:55747 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752256AbeEUKLj (ORCPT ); Mon, 21 May 2018 06:11:39 -0400 From: John Garry To: , CC: , , , Xiang Chen , "John Garry" Subject: [PATCH 02/13] scsi: hisi_sas: change slot index allocation mode Date: Mon, 21 May 2018 18:09:14 +0800 Message-ID: <1526897365-228549-3-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1526897365-228549-1-git-send-email-john.garry@huawei.com> References: <1526897365-228549-1-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiang Chen Currently we find the lowest available empty bit in the IPTT bitmap to allocate the IPTT for a command. To reduce possibility of hitting unknown SoC bugs and also aid in the debugging of those same bugs, change the allocation mode. The next allocation method is to use the next free slot adjacent to the most recently allocated slot, in a round-robin fashion. Signed-off-by: Xiang Chen Signed-off-by: John Garry --- drivers/scsi/hisi_sas/hisi_sas.h | 1 + drivers/scsi/hisi_sas/hisi_sas_main.c | 13 ++++++++++--- 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h index 52fc709..3c88400 100644 --- a/drivers/scsi/hisi_sas/hisi_sas.h +++ b/drivers/scsi/hisi_sas/hisi_sas.h @@ -274,6 +274,7 @@ struct hisi_hba { struct workqueue_struct *wq; int slot_index_count; + int last_slot_index; unsigned long *slot_index_tags; unsigned long reject_stp_links_msk; diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index f822d6f..1d300a2 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -195,11 +195,18 @@ static int hisi_sas_slot_index_alloc(struct hisi_hba *hisi_hba, int *slot_idx) unsigned int index; void *bitmap = hisi_hba->slot_index_tags; - index = find_first_zero_bit(bitmap, hisi_hba->slot_index_count); - if (index >= hisi_hba->slot_index_count) - return -SAS_QUEUE_FULL; + index = find_next_zero_bit(bitmap, hisi_hba->slot_index_count, + hisi_hba->last_slot_index + 1); + if (index >= hisi_hba->slot_index_count) { + index = find_next_zero_bit(bitmap, hisi_hba->slot_index_count, + 0); + if (index >= hisi_hba->slot_index_count) + return -SAS_QUEUE_FULL; + } hisi_sas_slot_index_set(hisi_hba, index); *slot_idx = index; + hisi_hba->last_slot_index = index; + return 0; } -- 1.9.1