[PATCH v2 1/7] cxl/core: Use guard() to replace open-coded down_read/write()

From: Li Ming
Date: Mon Feb 17 2025 - 09:50:37 EST


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@xxxxxxxxxx>
Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>
---
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