linux-kernel - [PATCH 11/12] megaraid_sas: Convert instance->issuepend_done to atomic

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Date:	Sun, 19 Dec 2010 13:22:06 -0800
From:	"Nicholas A. Bellinger" <nab@...ux-iscsi.org>
To:	linux-scsi <linux-scsi@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	James Bottomley <James.Bottomley@...e.de>,
	Jeff Garzik <jeff@...zik.org>, Christoph Hellwig <hch@....de>,
	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>,
	Hannes Reinecke <hare@...e.de>,
	Mike Christie <michaelc@...wisc.edu>
Cc:	Mike Anderson <andmike@...ux.vnet.ibm.com>,
	Tejun Heo <tj@...nel.org>, Vasu Dev <vasu.dev@...ux.intel.com>,
	Tim Chen <tim.c.chen@...ux.intel.com>,
	Andi Kleen <ak@...ux.intel.com>,
	Ravi Anand <ravi.anand@...gic.com>,
	Andrew Vasquez <andrew.vasquez@...gic.com>,
	Joe Eykholt <jeykholt@...co.com>,
	James Smart <james.smart@...lex.com>,
	Douglas Gilbert <dgilbert@...erlog.com>,
	adam radford <aradford@...il.com>,
	Kashyap Desai <Kashyap.Desai@....com>,
	MPTFusionLinux <DL-MPTFusionLinux@....com>,
	Nicholas Bellinger <nab@...ux-iscsi.org>
Subject: [PATCH 11/12] megaraid_sas: Convert instance->issuepend_done to atomic_t

From: Nicholas Bellinger <nab@...ux-iscsi.org>

This patch converts struct megasas_instance->issuepend_done to
an atomic_t fw_issuepend_done.  This is because ->issuepend_done is
being used as a check to determine if SCSI_MLQUEUE_HOST_BUSY should
be returned during megasas_queue_command_lck().  So in order for a
conversion to lock-less operation to occur, this bit needs to be
handled in an atomic manner.

Signed-off-by: Nicholas A. Bellinger <nab@...ux-iscsi.org>
---
 drivers/scsi/megaraid/megaraid_sas.c |   13 ++++++-------
 drivers/scsi/megaraid/megaraid_sas.h |    2 +-
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 31c5419..da0d3e3 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -1344,7 +1344,7 @@ megasas_queue_command_lck(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd
 	instance = (struct megasas_instance *)
 	    scmd->device->host->hostdata;
 
-	if (instance->issuepend_done == 0)
+	if (atomic_read(&instance->fw_issuepend_done) == 0)
 		return SCSI_MLQUEUE_HOST_BUSY;
 
 	spin_lock_irqsave(&instance->hba_lock, flags);
@@ -1590,8 +1590,7 @@ void megasas_do_ocr(struct megasas_instance *instance)
 	}
 	instance->instancet->disable_intr(instance->reg_set);
 	instance->adprecovery   = MEGASAS_ADPRESET_SM_INFAULT;
-	instance->issuepend_done = 0;
-
+	atomic_set(&instance->fw_issuepend_done, 0);
 	atomic_set(&instance->fw_outstanding, 0);
 	megasas_internal_reset_defer_cmds(instance);
 	process_fw_state_change_wq(&instance->work_init);
@@ -1941,7 +1940,7 @@ megasas_service_aen(struct megasas_instance *instance, struct megasas_cmd *cmd)
 	megasas_return_cmd(instance, cmd);
 
 	if ((instance->unload == 0) &&
-		((instance->issuepend_done == 1))) {
+		((atomic_read(&instance->fw_issuepend_done) == 1))) {
 		struct megasas_aen_event *ev;
 		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 		if (!ev) {
@@ -2357,7 +2356,7 @@ process_fw_state_change_wq(struct work_struct *work)
 		instance->instancet->enable_intr(instance->reg_set);
 
 		megasas_issue_pending_cmds_again(instance);
-		instance->issuepend_done = 1;
+		atomic_set(&instance->fw_issuepend_done, 1);
 	}
 	return ;
 }
@@ -2417,8 +2416,8 @@ megasas_deplete_reply_queue(struct megasas_instance *instance,
 
 			instance->instancet->disable_intr(instance->reg_set);
 			instance->adprecovery	= MEGASAS_ADPRESET_SM_INFAULT;
-			instance->issuepend_done = 0;
 
+			atomic_set(&instance->fw_issuepend_done, 0);
 			atomic_set(&instance->fw_outstanding, 0);
 			megasas_internal_reset_defer_cmds(instance);
 
@@ -3798,7 +3797,7 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	megasas_poll_wait_aen = 0;
 	instance->flag_ieee = 0;
 	instance->ev = NULL;
-	instance->issuepend_done = 1;
+	atomic_set(&instance->fw_issuepend_done, 1);
 	instance->adprecovery = MEGASAS_HBA_OPERATIONAL;
 	megasas_poll_wait_aen = 0;
 
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index ad16f5e..eaeb873 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1303,6 +1303,7 @@ struct megasas_instance {
 
 	atomic_t fw_outstanding;
 	atomic_t fw_reset_no_pci_access;
+	atomic_t fw_issuepend_done;
 
 	struct megasas_instance_template *instancet;
 	struct tasklet_struct isr_tasklet;
@@ -1311,7 +1312,6 @@ struct megasas_instance {
 	u8 flag;
 	u8 unload;
 	u8 flag_ieee;
-	u8 issuepend_done;
 	u8 disableOnlineCtrlReset;
 	u8 adprecovery;
 	unsigned long last_time;
-- 
1.7.3.4

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