From: Dan Williams <dan.j.williams@intel.com>
Date: Wed, 13 Feb 2019 09:57:22 -0800
Subject: [PATCH] nfit/ars: Introduce scrub_flags
Patch-mainline: v5.1-rc1
Git-commit: e34b8252a3d2893ca55c82dbfcdaa302fa03d400
References: jsc#SLE-5433

In preparation for introducing new flags to gate whether ARS results are
stale, or poll the completion state, convert the existing flags to an
unsigned long with enumerated values. This conversion allows the flags
to be atomically updated outside of ->init_mutex.

Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/acpi/nfit/core.c |   30 +++++++++++++++++-------------
 drivers/acpi/nfit/nfit.h |    8 ++++++--
 2 files changed, 23 insertions(+), 15 deletions(-)

--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1299,19 +1299,23 @@ static ssize_t scrub_show(struct device
 		struct device_attribute *attr, char *buf)
 {
 	struct nvdimm_bus_descriptor *nd_desc;
+	struct acpi_nfit_desc *acpi_desc;
 	ssize_t rc = -ENXIO;
+	bool busy;
 
 	device_lock(dev);
 	nd_desc = dev_get_drvdata(dev);
-	if (nd_desc) {
-		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
-
-		mutex_lock(&acpi_desc->init_mutex);
-		rc = sprintf(buf, "%d%s", acpi_desc->scrub_count,
-				acpi_desc->scrub_busy
-				&& !acpi_desc->cancel ? "+\n" : "\n");
-		mutex_unlock(&acpi_desc->init_mutex);
+	if (!nd_desc) {
+		device_unlock(dev);
+		return rc;
 	}
+	acpi_desc = to_acpi_desc(nd_desc);
+
+	mutex_lock(&acpi_desc->init_mutex);
+	busy = test_bit(ARS_BUSY, &acpi_desc->scrub_flags)
+		&& !test_bit(ARS_CANCEL, &acpi_desc->scrub_flags);
+	rc = sprintf(buf, "%d%s", acpi_desc->scrub_count, busy ? "+\n" : "\n");
+	mutex_unlock(&acpi_desc->init_mutex);
 	device_unlock(dev);
 	return rc;
 }
@@ -2951,7 +2955,7 @@ static unsigned int __acpi_nfit_scrub(st
 
 	lockdep_assert_held(&acpi_desc->init_mutex);
 
-	if (acpi_desc->cancel)
+	if (test_bit(ARS_CANCEL, &acpi_desc->scrub_flags))
 		return 0;
 
 	if (query_rc == -EBUSY) {
@@ -3025,7 +3029,7 @@ static void __sched_ars(struct acpi_nfit
 {
 	lockdep_assert_held(&acpi_desc->init_mutex);
 
-	acpi_desc->scrub_busy = 1;
+	set_bit(ARS_BUSY, &acpi_desc->scrub_flags);
 	/* note this should only be set from within the workqueue */
 	if (tmo)
 		acpi_desc->scrub_tmo = tmo;
@@ -3041,7 +3045,7 @@ static void notify_ars_done(struct acpi_
 {
 	lockdep_assert_held(&acpi_desc->init_mutex);
 
-	acpi_desc->scrub_busy = 0;
+	clear_bit(ARS_BUSY, &acpi_desc->scrub_flags);
 	acpi_desc->scrub_count++;
 	if (acpi_desc->scrub_count_state)
 		sysfs_notify_dirent(acpi_desc->scrub_count_state);
@@ -3314,7 +3318,7 @@ int acpi_nfit_ars_rescan(struct acpi_nfi
 	struct nfit_spa *nfit_spa;
 
 	mutex_lock(&acpi_desc->init_mutex);
-	if (acpi_desc->cancel) {
+	if (test_bit(ARS_CANCEL, &acpi_desc->scrub_flags)) {
 		mutex_unlock(&acpi_desc->init_mutex);
 		return 0;
 	}
@@ -3394,7 +3398,7 @@ void acpi_nfit_shutdown(void *data)
 	mutex_unlock(&acpi_desc_lock);
 
 	mutex_lock(&acpi_desc->init_mutex);
-	acpi_desc->cancel = 1;
+	set_bit(ARS_CANCEL, &acpi_desc->scrub_flags);
 	cancel_delayed_work_sync(&acpi_desc->dwork);
 	mutex_unlock(&acpi_desc->init_mutex);
 
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -181,6 +181,11 @@ struct nfit_mem {
 	int family;
 };
 
+enum scrub_flags {
+	ARS_BUSY,
+	ARS_CANCEL,
+};
+
 struct acpi_nfit_desc {
 	struct nvdimm_bus_descriptor nd_desc;
 	struct acpi_table_header acpi_header;
@@ -203,8 +208,7 @@ struct acpi_nfit_desc {
 	unsigned int max_ars;
 	unsigned int scrub_count;
 	unsigned int scrub_mode;
-	unsigned int scrub_busy:1;
-	unsigned int cancel:1;
+	unsigned long scrub_flags;
 	unsigned long dimm_cmd_force_en;
 	unsigned long bus_cmd_force_en;
 	unsigned long bus_nfit_cmd_force_en;