[PATCH 12/19] cxl/region: Factor out interleave ways setup

From: Dan Williams <dan.j.williams@intel.com>
To: linux-cxl@vger.kernel.org
Cc: ira.weiny@intel.com, navneet.singh@intel.com
Subject: [PATCH 12/19] cxl/region: Factor out interleave ways setup
Date: Sun, 04 Jun 2023 16:32:44 -0700	[thread overview]
Message-ID: <168592156445.1948938.13669058823244900070.stgit@dwillia2-xfh.jf.intel.com> (raw)
In-Reply-To: <168592149709.1948938.8663425987110396027.stgit@dwillia2-xfh.jf.intel.com>

In preparation for kernel driven region creation, factor out a common
helper from the user-sysfs region setup for interleave_ways.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/cxl/core/region.c |   46 ++++++++++++++++++++++++++-------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index bd3c3d4b2683..821c2d90154f 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -338,22 +338,14 @@ static ssize_t interleave_ways_show(struct device *dev,
 
 static const struct attribute_group *get_cxl_region_target_group(void);
 
-static ssize_t interleave_ways_store(struct device *dev,
-				     struct device_attribute *attr,
-				     const char *buf, size_t len)
+static int set_interleave_ways(struct cxl_region *cxlr, int val)
 {
-	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent);
+	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
 	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
-	struct cxl_region *cxlr = to_cxl_region(dev);
 	struct cxl_region_params *p = &cxlr->params;
-	unsigned int val, save;
-	int rc;
+	int save, rc;
 	u8 iw;
 
-	rc = kstrtouint(buf, 0, &val);
-	if (rc)
-		return rc;
-
 	rc = ways_to_eiw(val, &iw);
 	if (rc)
 		return rc;
@@ -368,21 +360,37 @@ static ssize_t interleave_ways_store(struct device *dev,
 		return -EINVAL;
 	}
 
-	rc = down_write_killable(&cxl_region_rwsem);
-	if (rc)
-		return rc;
-	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
-		rc = -EBUSY;
-		goto out;
-	}
+	lockdep_assert_held_write(&cxl_region_rwsem);
+	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
+		return -EBUSY;
 
 	save = p->interleave_ways;
 	p->interleave_ways = val;
 	rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
 	if (rc)
 		p->interleave_ways = save;
-out:
+	return rc;
+}
+
+static ssize_t interleave_ways_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	struct cxl_region *cxlr = to_cxl_region(dev);
+	unsigned int val;
+	int rc;
+
+	rc = kstrtouint(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	rc = down_write_killable(&cxl_region_rwsem);
+	if (rc)
+		return rc;
+
+	rc = set_interleave_ways(cxlr, val);
 	up_write(&cxl_region_rwsem);
+
 	if (rc)
 		return rc;
 	return len;

