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From:   Serge Semin <fancer.lancer@gmail.com>
To:     Michal Simek <michal.simek@amd.com>,
        Alexander Stein <alexander.stein@ew.tq-group.com>,
        Borislav Petkov <bp@alien8.de>,
        Tony Luck <tony.luck@intel.com>,
        James Morse <james.morse@arm.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Robert Richter <rric@kernel.org>
Cc:     Serge Semin <fancer.lancer@gmail.com>,
        Punnaiah Choudary Kalluri 
        <punnaiah.choudary.kalluri@xilinx.com>,
        Dinh Nguyen <dinguyen@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-kernel@lists.infradead.org, linux-edac@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v4 01/18] EDAC/synopsys: Convert sysfs nodes to debugfs ones
Date:   Wed, 20 Sep 2023 22:26:46 +0300
Message-ID: <20230920192806.29960-2-fancer.lancer@gmail.com>
In-Reply-To: <20230920192806.29960-1-fancer.lancer@gmail.com>
References: <20230920192806.29960-1-fancer.lancer@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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The DW uMCTL2 DDRC EDAC driver supports creating two sysfs nodes:
"inject_data_error" and "inject_data_poison". First of them is responsible
for setting the error-injecting physical address up. The second one is
supposed to be used to enable the hardware capability of the correctable
and uncorrectable errors injection. The semantics of these nodes is pure
debug. They are even created only if the EDAC_DEBUG kernel config is
enabled. Thus there is no point in having these nodes exported in the
sysfs especially seeing they aren't listed in the sysfs ABI. Just move
them to the device private directory in DebugFS.

While at it move the address map initialization procedure call to the
DebugFS nodes creating function (it's useless with no DebugFS nodes being
available anyway) and create an empty snps_create_debugfs_nodes() method
in case if the EDAC_DEBUG config is disabled. Thus the DW uMCTL2 DDRC EDAC
probe procedure will get to be a bit simpler and redundant work won't be
performed.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
 drivers/edac/synopsys_edac.c | 221 +++++++++++++++++++----------------
 1 file changed, 122 insertions(+), 99 deletions(-)

diff --git a/drivers/edac/synopsys_edac.c b/drivers/edac/synopsys_edac.c
index 327023e35d42..10716f365c6f 100644
--- a/drivers/edac/synopsys_edac.c
+++ b/drivers/edac/synopsys_edac.c
@@ -9,6 +9,7 @@
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/edac.h>
+#include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
@@ -641,6 +642,16 @@ static int snps_setup_irq(struct mem_ctl_info *mci, struct platform_device *pdev
 
 #ifdef CONFIG_EDAC_DEBUG
 
+#define SNPS_DEBUGFS_FOPS(__name, __read, __write) \
+	static const struct file_operations __name = {	\
+		.owner = THIS_MODULE,		\
+		.open = simple_open,		\
+		.read = __read,			\
+		.write = __write,		\
+	}
+
+#define SNPS_DBGFS_BUF_LEN 128
+
 /**
  * snps_data_poison_setup - Update poison registers.
  * @priv:		DDR memory controller private instance data.
@@ -701,90 +712,6 @@ static void snps_data_poison_setup(struct snps_edac_priv *priv)
 	writel(regval, priv->baseaddr + ECC_POISON1_OFST);
 }
 
-static ssize_t inject_data_error_show(struct device *dev,
-				      struct device_attribute *mattr,
-				      char *data)
-{
-	struct mem_ctl_info *mci = to_mci(dev);
-	struct snps_edac_priv *priv = mci->pvt_info;
-
-	return sprintf(data, "Poison0 Addr: 0x%08x\n\rPoison1 Addr: 0x%08x\n\r"
-			"Error injection Address: 0x%lx\n\r",
-			readl(priv->baseaddr + ECC_POISON0_OFST),
-			readl(priv->baseaddr + ECC_POISON1_OFST),
-			priv->poison_addr);
-}
-
-static ssize_t inject_data_error_store(struct device *dev,
-				       struct device_attribute *mattr,
-				       const char *data, size_t count)
-{
-	struct mem_ctl_info *mci = to_mci(dev);
-	struct snps_edac_priv *priv = mci->pvt_info;
-
-	if (kstrtoul(data, 0, &priv->poison_addr))
-		return -EINVAL;
-
-	snps_data_poison_setup(priv);
-
-	return count;
-}
-
-static ssize_t inject_data_poison_show(struct device *dev,
-				       struct device_attribute *mattr,
-				       char *data)
-{
-	struct mem_ctl_info *mci = to_mci(dev);
-	struct snps_edac_priv *priv = mci->pvt_info;
-	const char *errstr;
-	u32 regval;
-
-	regval = readl(priv->baseaddr + ECC_CFG1_OFST);
-	errstr = FIELD_GET(ECC_CEPOISON_MASK, regval) == ECC_CEPOISON_MASK ?
-		 "Correctable Error" : "UnCorrectable Error";
-
-	return sprintf(data, "Data Poisoning: %s\n\r", errstr);
-}
-
-static ssize_t inject_data_poison_store(struct device *dev,
-					struct device_attribute *mattr,
-					const char *data, size_t count)
-{
-	struct mem_ctl_info *mci = to_mci(dev);
-	struct snps_edac_priv *priv = mci->pvt_info;
-
-	writel(0, priv->baseaddr + DDR_SWCTL);
-	if (strncmp(data, "CE", 2) == 0)
-		writel(ECC_CEPOISON_MASK, priv->baseaddr + ECC_CFG1_OFST);
-	else
-		writel(ECC_UEPOISON_MASK, priv->baseaddr + ECC_CFG1_OFST);
-	writel(1, priv->baseaddr + DDR_SWCTL);
-
-	return count;
-}
-
-static DEVICE_ATTR_RW(inject_data_error);
-static DEVICE_ATTR_RW(inject_data_poison);
-
-static int snps_create_sysfs_attributes(struct mem_ctl_info *mci)
-{
-	int rc;
-
-	rc = device_create_file(&mci->dev, &dev_attr_inject_data_error);
-	if (rc < 0)
-		return rc;
-	rc = device_create_file(&mci->dev, &dev_attr_inject_data_poison);
-	if (rc < 0)
-		return rc;
-	return 0;
-}
-
-static void snps_remove_sysfs_attributes(struct mem_ctl_info *mci)
-{
-	device_remove_file(&mci->dev, &dev_attr_inject_data_error);
-	device_remove_file(&mci->dev, &dev_attr_inject_data_poison);
-}
-
 static void snps_setup_row_address_map(struct snps_edac_priv *priv, u32 *addrmap)
 {
 	u32 addrmap_row_b2_10;
@@ -1005,7 +932,115 @@ static void snps_setup_address_map(struct snps_edac_priv *priv)
 
 	snps_setup_rank_address_map(priv, addrmap);
 }
-#endif /* CONFIG_EDAC_DEBUG */
+
+static ssize_t snps_inject_data_error_read(struct file *filep, char __user *ubuf,
+					   size_t size, loff_t *offp)
+{
+	struct mem_ctl_info *mci = filep->private_data;
+	struct snps_edac_priv *priv = mci->pvt_info;
+	char buf[SNPS_DBGFS_BUF_LEN];
+	int pos;
+
+	pos = scnprintf(buf, sizeof(buf), "Poison0 Addr: 0x%08x\n\r",
+			readl(priv->baseaddr + ECC_POISON0_OFST));
+	pos += scnprintf(buf + pos, sizeof(buf) - pos, "Poison1 Addr: 0x%08x\n\r",
+			 readl(priv->baseaddr + ECC_POISON1_OFST));
+	pos += scnprintf(buf + pos, sizeof(buf) - pos, "Error injection Address: 0x%lx\n\r",
+			 priv->poison_addr);
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static ssize_t snps_inject_data_error_write(struct file *filep, const char __user *ubuf,
+					    size_t size, loff_t *offp)
+{
+	struct mem_ctl_info *mci = filep->private_data;
+	struct snps_edac_priv *priv = mci->pvt_info;
+	int rc;
+
+	rc = kstrtoul_from_user(ubuf, size, 0, &priv->poison_addr);
+	if (rc)
+		return rc;
+
+	snps_data_poison_setup(priv);
+
+	return size;
+}
+
+SNPS_DEBUGFS_FOPS(snps_inject_data_error, snps_inject_data_error_read,
+		  snps_inject_data_error_write);
+
+static ssize_t snps_inject_data_poison_read(struct file *filep, char __user *ubuf,
+					    size_t size, loff_t *offp)
+{
+	struct mem_ctl_info *mci = filep->private_data;
+	struct snps_edac_priv *priv = mci->pvt_info;
+	char buf[SNPS_DBGFS_BUF_LEN];
+	const char *errstr;
+	u32 regval;
+	int pos;
+
+	regval = readl(priv->baseaddr + ECC_CFG1_OFST);
+	errstr = FIELD_GET(ECC_CEPOISON_MASK, regval) == ECC_CEPOISON_MASK ?
+		 "Correctable Error" : "UnCorrectable Error";
+
+	pos = scnprintf(buf, sizeof(buf), "Data Poisoning: %s\n\r", errstr);
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static ssize_t snps_inject_data_poison_write(struct file *filep, const char __user *ubuf,
+					     size_t size, loff_t *offp)
+{
+	struct mem_ctl_info *mci = filep->private_data;
+	struct snps_edac_priv *priv = mci->pvt_info;
+	char buf[SNPS_DBGFS_BUF_LEN];
+	int rc;
+
+	rc = simple_write_to_buffer(buf, sizeof(buf), offp, ubuf, size);
+	if (rc < 0)
+		return rc;
+
+	writel(0, priv->baseaddr + DDR_SWCTL);
+	if (strncmp(buf, "CE", 2) == 0)
+		writel(ECC_CEPOISON_MASK, priv->baseaddr + ECC_CFG1_OFST);
+	else
+		writel(ECC_UEPOISON_MASK, priv->baseaddr + ECC_CFG1_OFST);
+	writel(1, priv->baseaddr + DDR_SWCTL);
+
+	return size;
+}
+
+SNPS_DEBUGFS_FOPS(snps_inject_data_poison, snps_inject_data_poison_read,
+		  snps_inject_data_poison_write);
+
+/**
+ * snps_create_debugfs_nodes -	Create DebugFS nodes.
+ * @mci:	EDAC memory controller instance.
+ *
+ * Create DW uMCTL2 EDAC driver DebugFS nodes in the device private
+ * DebugFS directory.
+ *
+ * Return: none.
+ */
+static void snps_create_debugfs_nodes(struct mem_ctl_info *mci)
+{
+	struct snps_edac_priv *priv = mci->pvt_info;
+
+	snps_setup_address_map(priv);
+
+	edac_debugfs_create_file("inject_data_error", 0600, mci->debugfs, mci,
+				 &snps_inject_data_error);
+
+	edac_debugfs_create_file("inject_data_poison", 0600, mci->debugfs, mci,
+				 &snps_inject_data_poison);
+}
+
+#else /* !CONFIG_EDAC_DEBUG */
+
+static inline void snps_create_debugfs_nodes(struct mem_ctl_info *mci) {}
+
+#endif /* !CONFIG_EDAC_DEBUG */
 
 /**
  * snps_mc_probe - Check controller and bind driver.
@@ -1071,17 +1106,9 @@ static int snps_mc_probe(struct platform_device *pdev)
 		goto free_edac_mc;
 	}
 
-#ifdef CONFIG_EDAC_DEBUG
-	rc = snps_create_sysfs_attributes(mci);
-	if (rc) {
-		edac_printk(KERN_ERR, EDAC_MC, "Failed to create sysfs entries\n");
-		goto free_edac_mc;
-	}
+	snps_create_debugfs_nodes(mci);
 
-	snps_setup_address_map(priv);
-#endif
-
-	return rc;
+	return 0;
 
 free_edac_mc:
 	edac_mc_free(mci);
@@ -1102,10 +1129,6 @@ static int snps_mc_remove(struct platform_device *pdev)
 
 	snps_disable_irq(priv);
 
-#ifdef CONFIG_EDAC_DEBUG
-	snps_remove_sysfs_attributes(mci);
-#endif
-
 	edac_mc_del_mc(&pdev->dev);
 	edac_mc_free(mci);
 
-- 
2.41.0