linux-kernel - [PATCH v2 1/7] cxl/core: Use guard() to replace open-coded down

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Message-Id: <20250217144828.30651-2-ming.li@zohomail.com>
Date: Mon, 17 Feb 2025 22:48:22 +0800
From: Li Ming <ming.li@...omail.com>
To: dave@...olabs.net,
	jonathan.cameron@...wei.com,
	dave.jiang@...el.com,
	alison.schofield@...el.com,
	vishal.l.verma@...el.com,
	ira.weiny@...el.com,
	dan.j.williams@...el.com
Cc: linux-cxl@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Li Ming <ming.li@...omail.com>,
	Jonathan Cameron <Jonathan.Cameron@...wei.com>
Subject: [PATCH v2 1/7] cxl/core: Use guard() to replace open-coded down_read/write()

Some down/up_read() and down/up_write() cases can be replaced by a
guard() simply to drop explicit unlock invoked. It helps to align coding
style with current CXL subsystem's.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Signed-off-by: Li Ming <ming.li@...omail.com>
---
v2:
- Drop some local variables. (Jonathan)
---
 drivers/cxl/core/hdm.c    | 15 +++++----------
 drivers/cxl/core/memdev.c |  9 +++------
 drivers/cxl/core/port.c   |  8 ++------
 drivers/cxl/core/region.c |  8 +++-----
 4 files changed, 13 insertions(+), 27 deletions(-)

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 50e6a45b30ba..4a578092377e 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -213,13 +213,12 @@ void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds)
 {
 	struct resource *p1, *p2;
 
-	down_read(&cxl_dpa_rwsem);
+	guard(rwsem_read)(&cxl_dpa_rwsem);
 	for (p1 = cxlds->dpa_res.child; p1; p1 = p1->sibling) {
 		__cxl_dpa_debug(file, p1, 0);
 		for (p2 = p1->child; p2; p2 = p2->sibling)
 			__cxl_dpa_debug(file, p2, 1);
 	}
-	up_read(&cxl_dpa_rwsem);
 }
 EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, "CXL");
 
@@ -250,9 +249,8 @@ static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
 
 static void cxl_dpa_release(void *cxled)
 {
-	down_write(&cxl_dpa_rwsem);
+	guard(rwsem_write)(&cxl_dpa_rwsem);
 	__cxl_dpa_release(cxled);
-	up_write(&cxl_dpa_rwsem);
 }
 
 /*
@@ -362,14 +360,11 @@ EXPORT_SYMBOL_NS_GPL(devm_cxl_dpa_reserve, "CXL");
 
 resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled)
 {
-	resource_size_t size = 0;
-
-	down_read(&cxl_dpa_rwsem);
+	guard(rwsem_read)(&cxl_dpa_rwsem);
 	if (cxled->dpa_res)
-		size = resource_size(cxled->dpa_res);
-	up_read(&cxl_dpa_rwsem);
+		return resource_size(cxled->dpa_res);
 
-	return size;
+	return 0;
 }
 
 resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled)
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index ae3dfcbe8938..98c05426aa4a 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -564,10 +564,9 @@ EXPORT_SYMBOL_NS_GPL(is_cxl_memdev, "CXL");
 void set_exclusive_cxl_commands(struct cxl_memdev_state *mds,
 				unsigned long *cmds)
 {
-	down_write(&cxl_memdev_rwsem);
+	guard(rwsem_write)(&cxl_memdev_rwsem);
 	bitmap_or(mds->exclusive_cmds, mds->exclusive_cmds, cmds,
 		  CXL_MEM_COMMAND_ID_MAX);
-	up_write(&cxl_memdev_rwsem);
 }
 EXPORT_SYMBOL_NS_GPL(set_exclusive_cxl_commands, "CXL");
 
@@ -579,10 +578,9 @@ EXPORT_SYMBOL_NS_GPL(set_exclusive_cxl_commands, "CXL");
 void clear_exclusive_cxl_commands(struct cxl_memdev_state *mds,
 				  unsigned long *cmds)
 {
-	down_write(&cxl_memdev_rwsem);
+	guard(rwsem_write)(&cxl_memdev_rwsem);
 	bitmap_andnot(mds->exclusive_cmds, mds->exclusive_cmds, cmds,
 		      CXL_MEM_COMMAND_ID_MAX);
-	up_write(&cxl_memdev_rwsem);
 }
 EXPORT_SYMBOL_NS_GPL(clear_exclusive_cxl_commands, "CXL");
 
@@ -590,9 +588,8 @@ static void cxl_memdev_shutdown(struct device *dev)
 {
 	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
 
-	down_write(&cxl_memdev_rwsem);
+	guard(rwsem_write)(&cxl_memdev_rwsem);
 	cxlmd->cxlds = NULL;
-	up_write(&cxl_memdev_rwsem);
 }
 
 static void cxl_memdev_unregister(void *_cxlmd)
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 78a5c2c25982..2c59d65bc18b 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -549,13 +549,9 @@ static ssize_t decoders_committed_show(struct device *dev,
 				       struct device_attribute *attr, char *buf)
 {
 	struct cxl_port *port = to_cxl_port(dev);
-	int rc;
-
-	down_read(&cxl_region_rwsem);
-	rc = sysfs_emit(buf, "%d\n", cxl_num_decoders_committed(port));
-	up_read(&cxl_region_rwsem);
 
-	return rc;
+	guard(rwsem_read)(&cxl_region_rwsem);
+	return sysfs_emit(buf, "%d\n", cxl_num_decoders_committed(port));
 }
 
 static DEVICE_ATTR_RO(decoders_committed);
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index e8d11a988fd9..d8a71f9f9fa5 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3208,7 +3208,6 @@ static int match_region_by_range(struct device *dev, const void *data)
 	struct cxl_region_params *p;
 	struct cxl_region *cxlr;
 	const struct range *r = data;
-	int rc = 0;
 
 	if (!is_cxl_region(dev))
 		return 0;
@@ -3216,12 +3215,11 @@ static int match_region_by_range(struct device *dev, const void *data)
 	cxlr = to_cxl_region(dev);
 	p = &cxlr->params;
 
-	down_read(&cxl_region_rwsem);
+	guard(rwsem_read)(&cxl_region_rwsem);
 	if (p->res && p->res->start == r->start && p->res->end == r->end)
-		rc = 1;
-	up_read(&cxl_region_rwsem);
+		return 1;
 
-	return rc;
+	return 0;
 }
 
 /* Establish an empty region covering the given HPA range */
-- 
2.34.1