linux-kernel - [PATCH 10/11] RAS/CEC: Add CONFIG_RAS_CEC_DEBUG and move CEC debug features there

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Date:   Thu,  9 May 2019 20:09:25 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Tony Luck <tony.luck@...el.com>
Cc:     linux-edac <linux-edac@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 10/11] RAS/CEC: Add CONFIG_RAS_CEC_DEBUG and move CEC debug features there

From: Tony Luck <tony.luck@...el.com>

The pfn and array files in (debugfs)/ras/cec are intended for debugging
the CEC code itself. They are not needed on production systems, so the
default setting for this CONFIG option is "n".

 [ bp: Have it with less ifdeffery by using IS_ENABLED(). ]

Signed-off-by: Tony Luck <tony.luck@...el.com>
Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/ras/Kconfig | 10 ++++++++++
 drivers/ras/cec.c    | 26 ++++++++++++++------------
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/arch/x86/ras/Kconfig b/arch/x86/ras/Kconfig
index a9c3db125222..9ad6842de4b4 100644
--- a/arch/x86/ras/Kconfig
+++ b/arch/x86/ras/Kconfig
@@ -11,3 +11,13 @@ config RAS_CEC
 
 	  Bear in mind that this is absolutely useless if your platform doesn't
 	  have ECC DIMMs and doesn't have DRAM ECC checking enabled in the BIOS.
+
+config RAS_CEC_DEBUG
+	bool "CEC debugging machinery"
+	default n
+	depends on RAS_CEC
+	help
+	  Add extra files to (debugfs)/ras/cec to test the correctable error
+	  collector feature. "pfn" is a writable file that allows user to
+	  simulate an error in a particular page frame. "array" is a read-only
+	  file that dumps out the current state of all pages logged so far.
diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index 71f3e14c35d8..c4505c0893a7 100644
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -486,18 +486,6 @@ static int __init create_debugfs_nodes(void)
 		return -1;
 	}
 
-	pfn = debugfs_create_file("pfn", S_IRUSR | S_IWUSR, d, &dfs_pfn, &pfn_ops);
-	if (!pfn) {
-		pr_warn("Error creating pfn debugfs node!\n");
-		goto err;
-	}
-
-	array = debugfs_create_file("array", S_IRUSR, d, NULL, &array_ops);
-	if (!array) {
-		pr_warn("Error creating array debugfs node!\n");
-		goto err;
-	}
-
 	decay = debugfs_create_file("decay_interval", S_IRUSR | S_IWUSR, d,
 				    &decay_interval, &decay_interval_ops);
 	if (!decay) {
@@ -512,6 +500,20 @@ static int __init create_debugfs_nodes(void)
 		goto err;
 	}
 
+	if (!IS_ENABLED(CONFIG_RAS_CEC_DEBUG))
+		return 0;
+
+	pfn = debugfs_create_file("pfn", S_IRUSR | S_IWUSR, d, &dfs_pfn, &pfn_ops);
+	if (!pfn) {
+		pr_warn("Error creating pfn debugfs node!\n");
+		goto err;
+	}
+
+	array = debugfs_create_file("array", S_IRUSR, d, NULL, &array_ops);
+	if (!array) {
+		pr_warn("Error creating array debugfs node!\n");
+		goto err;
+	}
 
 	return 0;
 
-- 
2.21.0