thermal/drivers/int340x: Fix RFIM mailbox write commands

The existing mail mechanism only supports writing of workload types.

However, mailbox command for RFIM (cmd = 0x08) also requires write
operation which is ignored. This results in failing to store RFI
restriction.

Fixint this requires enhancing mailbox writes for non workload
commands too, so remove the check for MBOX_CMD_WORKLOAD_TYPE_WRITE
in mailbox write to allow this other write commands to be supoorted.

At the same time, however, we have to make sure that there is no
impact on read commands, by avoiding to write anything into the
mailbox data register.

To properly implement that, add two separate functions for mbox read
and write commands for the processor thermal workload command type.
This helps to distinguish the read and write workload command types
from each other while sending mbox commands.

Fixes: 5d6fbc96 ("thermal/drivers/int340x: processor_thermal: Export additional attributes")
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Cc: 5.14+ <stable@vger.kernel.org> # 5.14+
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/thermal/intel/int340x_thermal/processor_thermal_device.h

@@ -80,7 +80,8 @@ void proc_thermal_rfim_remove(struct pci_dev *pdev);
 int proc_thermal_mbox_add(struct pci_dev *pdev, struct proc_thermal_device *proc_priv);
 void proc_thermal_mbox_remove(struct pci_dev *pdev);
 
-int processor_thermal_send_mbox_cmd(struct pci_dev *pdev, u16 cmd_id, u32 cmd_data, u64 *cmd_resp);
+int processor_thermal_send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp);
+int processor_thermal_send_mbox_write_cmd(struct pci_dev *pdev, u16 id, u32 data);
 int proc_thermal_add(struct device *dev, struct proc_thermal_device *priv);
 void proc_thermal_remove(struct proc_thermal_device *proc_priv);
 int proc_thermal_suspend(struct device *dev);

drivers/thermal/intel/int340x_thermal/processor_thermal_mbox.c

@@ -24,19 +24,15 @@
 
 static DEFINE_MUTEX(mbox_lock);
 
-static int send_mbox_cmd(struct pci_dev *pdev, u16 cmd_id, u32 cmd_data, u64 *cmd_resp)
+static int wait_for_mbox_ready(struct proc_thermal_device *proc_priv)
 {
-	struct proc_thermal_device *proc_priv;
 	u32 retries, data;
 	int ret;
 
-	mutex_lock(&mbox_lock);
-	proc_priv = pci_get_drvdata(pdev);
-
 	/* Poll for rb bit == 0 */
 	retries = MBOX_RETRY_COUNT;
 	do {
-		data = readl((void __iomem *) (proc_priv->mmio_base + MBOX_OFFSET_INTERFACE));
+		data = readl(proc_priv->mmio_base + MBOX_OFFSET_INTERFACE);
 		if (data & BIT_ULL(MBOX_BUSY_BIT)) {
 			ret = -EBUSY;
 			continue;
@@ -45,53 +41,78 @@ static int send_mbox_cmd(struct pci_dev *pdev, u16 cmd_id, u32 cmd_data, u64 *cm
 		break;
 	} while (--retries);
 
+	return ret;
+}
+
+static int send_mbox_write_cmd(struct pci_dev *pdev, u16 id, u32 data)
+{
+	struct proc_thermal_device *proc_priv;
+	u32 reg_data;
+	int ret;
+
+	proc_priv = pci_get_drvdata(pdev);
+
+	mutex_lock(&mbox_lock);
+
+	ret = wait_for_mbox_ready(proc_priv);
 	if (ret)
 		goto unlock_mbox;
 
-	if (cmd_id == MBOX_CMD_WORKLOAD_TYPE_WRITE)
-		writel(cmd_data, (void __iomem *) ((proc_priv->mmio_base + MBOX_OFFSET_DATA)));
-
+	writel(data, (proc_priv->mmio_base + MBOX_OFFSET_DATA));
 	/* Write command register */
-	data = BIT_ULL(MBOX_BUSY_BIT) | cmd_id;
-	writel(data, (void __iomem *) ((proc_priv->mmio_base + MBOX_OFFSET_INTERFACE)));
+	reg_data = BIT_ULL(MBOX_BUSY_BIT) | id;
+	writel(reg_data, (proc_priv->mmio_base + MBOX_OFFSET_INTERFACE));
 
-	/* Poll for rb bit == 0 */
-	retries = MBOX_RETRY_COUNT;
-	do {
-		data = readl((void __iomem *) (proc_priv->mmio_base + MBOX_OFFSET_INTERFACE));
-		if (data & BIT_ULL(MBOX_BUSY_BIT)) {
-			ret = -EBUSY;
-			continue;
-		}
+	ret = wait_for_mbox_ready(proc_priv);
+
+unlock_mbox:
+	mutex_unlock(&mbox_lock);
+	return ret;
+}
 
-		if (data) {
-			ret = -ENXIO;
+static int send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp)
+{
+	struct proc_thermal_device *proc_priv;
+	u32 reg_data;
+	int ret;
+
+	proc_priv = pci_get_drvdata(pdev);
+
+	mutex_lock(&mbox_lock);
+
+	ret = wait_for_mbox_ready(proc_priv);
+	if (ret)
 		goto unlock_mbox;
-		}
 
-		ret = 0;
+	/* Write command register */
+	reg_data = BIT_ULL(MBOX_BUSY_BIT) | id;
+	writel(reg_data, (proc_priv->mmio_base + MBOX_OFFSET_INTERFACE));
 
-		if (!cmd_resp)
-			break;
+	ret = wait_for_mbox_ready(proc_priv);
+	if (ret)
+		goto unlock_mbox;
 
-		if (cmd_id == MBOX_CMD_WORKLOAD_TYPE_READ)
-			*cmd_resp = readl((void __iomem *) (proc_priv->mmio_base + MBOX_OFFSET_DATA));
+	if (id == MBOX_CMD_WORKLOAD_TYPE_READ)
+		*resp = readl(proc_priv->mmio_base + MBOX_OFFSET_DATA);
 	else
-			*cmd_resp = readq((void __iomem *) (proc_priv->mmio_base + MBOX_OFFSET_DATA));
-
-		break;
-	} while (--retries);
+		*resp = readq(proc_priv->mmio_base + MBOX_OFFSET_DATA);
 
 unlock_mbox:
 	mutex_unlock(&mbox_lock);
 	return ret;
 }
 
-int processor_thermal_send_mbox_cmd(struct pci_dev *pdev, u16 cmd_id, u32 cmd_data, u64 *cmd_resp)
+int processor_thermal_send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp)
 {
-	return send_mbox_cmd(pdev, cmd_id, cmd_data, cmd_resp);
+	return send_mbox_read_cmd(pdev, id, resp);
 }
-EXPORT_SYMBOL_GPL(processor_thermal_send_mbox_cmd);
+EXPORT_SYMBOL_NS_GPL(processor_thermal_send_mbox_read_cmd, INT340X_THERMAL);
+
+int processor_thermal_send_mbox_write_cmd(struct pci_dev *pdev, u16 id, u32 data)
+{
+	return send_mbox_write_cmd(pdev, id, data);
+}
+EXPORT_SYMBOL_NS_GPL(processor_thermal_send_mbox_write_cmd, INT340X_THERMAL);
 
 /* List of workload types */
 static const char * const workload_types[] = {
@@ -104,7 +125,6 @@ static const char * const workload_types[] = {
 	NULL
 };
 
-
 static ssize_t workload_available_types_show(struct device *dev,
 					       struct device_attribute *attr,
 					       char *buf)
@@ -146,7 +166,7 @@ static ssize_t workload_type_store(struct device *dev,
 
 	data |= ret;
 
-	ret = send_mbox_cmd(pdev, MBOX_CMD_WORKLOAD_TYPE_WRITE, data, NULL);
+	ret = send_mbox_write_cmd(pdev, MBOX_CMD_WORKLOAD_TYPE_WRITE, data);
 	if (ret)
 		return false;
 
@@ -161,7 +181,7 @@ static ssize_t workload_type_show(struct device *dev,
 	u64 cmd_resp;
 	int ret;
 
-	ret = send_mbox_cmd(pdev, MBOX_CMD_WORKLOAD_TYPE_READ, 0, &cmd_resp);
+	ret = send_mbox_read_cmd(pdev, MBOX_CMD_WORKLOAD_TYPE_READ, &cmd_resp);
 	if (ret)
 		return false;
 
@@ -186,8 +206,6 @@ static const struct attribute_group workload_req_attribute_group = {
 	.name = "workload_request"
 };
 
-
-
 static bool workload_req_created;
 
 int proc_thermal_mbox_add(struct pci_dev *pdev, struct proc_thermal_device *proc_priv)
@@ -196,7 +214,7 @@ int proc_thermal_mbox_add(struct pci_dev *pdev, struct proc_thermal_device *proc
 	int ret;
 
 	/* Check if there is a mailbox support, if fails return success */
-	ret = send_mbox_cmd(pdev, MBOX_CMD_WORKLOAD_TYPE_READ, 0, &cmd_resp);
+	ret = send_mbox_read_cmd(pdev, MBOX_CMD_WORKLOAD_TYPE_READ, &cmd_resp);
 	if (ret)
 		return 0;
 

drivers/thermal/intel/int340x_thermal/processor_thermal_rfim.c

@@ -9,6 +9,8 @@
 #include <linux/pci.h>
 #include "processor_thermal_device.h"
 
+MODULE_IMPORT_NS(INT340X_THERMAL);
+
 struct mmio_reg {
 	int read_only;
 	u32 offset;
@@ -194,8 +196,7 @@ static ssize_t rfi_restriction_store(struct device *dev,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
 {
-	u16 cmd_id = 0x0008;
-	u64 cmd_resp;
+	u16 id = 0x0008;
 	u32 input;
 	int ret;
 
@@ -203,7 +204,7 @@ static ssize_t rfi_restriction_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	ret = processor_thermal_send_mbox_cmd(to_pci_dev(dev), cmd_id, input, &cmd_resp);
+	ret = processor_thermal_send_mbox_write_cmd(to_pci_dev(dev), id, input);
 	if (ret)
 		return ret;
 
@@ -214,30 +215,30 @@ static ssize_t rfi_restriction_show(struct device *dev,
 				    struct device_attribute *attr,
 				    char *buf)
 {
-	u16 cmd_id = 0x0007;
-	u64 cmd_resp;
+	u16 id = 0x0007;
+	u64 resp;
 	int ret;
 
-	ret = processor_thermal_send_mbox_cmd(to_pci_dev(dev), cmd_id, 0, &cmd_resp);
+	ret = processor_thermal_send_mbox_read_cmd(to_pci_dev(dev), id, &resp);
 	if (ret)
 		return ret;
 
-	return sprintf(buf, "%llu\n", cmd_resp);
+	return sprintf(buf, "%llu\n", resp);
 }
 
 static ssize_t ddr_data_rate_show(struct device *dev,
 				  struct device_attribute *attr,
 				  char *buf)
 {
-	u16 cmd_id = 0x0107;
-	u64 cmd_resp;
+	u16 id = 0x0107;
+	u64 resp;
 	int ret;
 
-	ret = processor_thermal_send_mbox_cmd(to_pci_dev(dev), cmd_id, 0, &cmd_resp);
+	ret = processor_thermal_send_mbox_read_cmd(to_pci_dev(dev), id, &resp);
 	if (ret)
 		return ret;
 
-	return sprintf(buf, "%llu\n", cmd_resp);
+	return sprintf(buf, "%llu\n", resp);
 }
 
 static DEVICE_ATTR_RW(rfi_restriction);