linux-kernel - [PATCH v5 05/27] cxl/hdm: Use guard() in cxl_dpa_set

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Message-Id: <20241029-dcd-type2-upstream-v5-5-8739cb67c374@intel.com>
Date: Tue, 29 Oct 2024 15:34:40 -0500
From: Ira Weiny <ira.weiny@...el.com>
To: Dave Jiang <dave.jiang@...el.com>, Fan Ni <fan.ni@...sung.com>, 
 Jonathan Cameron <Jonathan.Cameron@...wei.com>, 
 Navneet Singh <navneet.singh@...el.com>, Jonathan Corbet <corbet@....net>, 
 Andrew Morton <akpm@...ux-foundation.org>
Cc: Dan Williams <dan.j.williams@...el.com>, 
 Davidlohr Bueso <dave@...olabs.net>, 
 Alison Schofield <alison.schofield@...el.com>, 
 Vishal Verma <vishal.l.verma@...el.com>, Ira Weiny <ira.weiny@...el.com>, 
 linux-cxl@...r.kernel.org, linux-doc@...r.kernel.org, 
 nvdimm@...ts.linux.dev, linux-kernel@...r.kernel.org, 
 Jonathan Cameron <Jonathan.Cameron@...wei.com>
Subject: [PATCH v5 05/27] cxl/hdm: Use guard() in cxl_dpa_set_mode()

Additional DCD functionality is being added to this call which will be
simplified by the use of guard() with the cxl_dpa_rwsem.

Convert the function to use guard() prior to adding DCD functionality.

Suggested-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Signed-off-by: Ira Weiny <ira.weiny@...el.com>

---
Changes:
[Jonathan: new patch]
---
 drivers/cxl/core/hdm.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 3df10517a3278f228c7535fcbdb607d7b75bc879..463ba2669cea55194e2be2c26d02af75dde8d145 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -424,7 +424,6 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
 	struct device *dev = &cxled->cxld.dev;
-	int rc;
 
 	switch (mode) {
 	case CXL_DECODER_RAM:
@@ -435,11 +434,9 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 		return -EINVAL;
 	}
 
-	down_write(&cxl_dpa_rwsem);
-	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
-		rc = -EBUSY;
-		goto out;
-	}
+	guard(rwsem_write)(&cxl_dpa_rwsem);
+	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE)
+		return -EBUSY;
 
 	/*
 	 * Only allow modes that are supported by the current partition
@@ -447,21 +444,15 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 	 */
 	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
 		dev_dbg(dev, "no available pmem capacity\n");
-		rc = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
 		dev_dbg(dev, "no available ram capacity\n");
-		rc = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 
 	cxled->mode = mode;
-	rc = 0;
-out:
-	up_write(&cxl_dpa_rwsem);
-
-	return rc;
+	return 0;
 }
 
 int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size)

-- 
2.47.0