platform/x86/amd/pmc: Define enum for S2D/PMC msg_port and add helper function

To distinguish between the PMC message port and the S2D (Spill to DRAM)
message port, replace the use of 0 and 1 with an enum.

To avoid printing the S2D or PMC port multiple times in debug print,
add new routine to retrieve the message port information, which can be
used to print the right msg_port getting used.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20241108070822.3912689-5-Shyam-sundar.S-k@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

3 files changed, 27 insertions, 10 deletions

diff --git a/drivers/platform/x86/amd/pmc/mp1_stb.c b/drivers/platform/x86/amd/pmc/mp1_stb.c
index 5c03ac92558f..9ee629db9af9 100644
--- a/drivers/platform/x86/amd/pmc/mp1_stb.c
+++ b/drivers/platform/x86/amd/pmc/mp1_stb.c
@@ -155,7 +155,7 @@ static int amd_stb_debugfs_open_v2(struct inode *inode, struct file *filp)
 		dev_err(dev->dev, "error writing to STB: %d\n", ret);
 
 	/* Spill to DRAM num_samples uses separate SMU message port */
-	dev->msg_port = 1;
+	dev->msg_port = MSG_PORT_S2D;
 
 	ret = amd_pmc_send_cmd(dev, 0, &val, STB_FORCE_FLUSH_DATA, 1);
 	if (ret)
@@ -172,7 +172,7 @@ static int amd_stb_debugfs_open_v2(struct inode *inode, struct file *filp)
 	/* Get the num_samples to calculate the last push location */
 	ret = amd_pmc_send_cmd(dev, S2D_NUM_SAMPLES, &num_samples, dev->s2d_msg_id, true);
 	/* Clear msg_port for other SMU operation */
-	dev->msg_port = 0;
+	dev->msg_port = MSG_PORT_PMC;
 	if (ret) {
 		dev_err(dev->dev, "error: S2D_NUM_SAMPLES not supported : %d\n", ret);
 		return ret;
@@ -267,7 +267,7 @@ int amd_stb_s2d_init(struct amd_pmc_dev *dev)
 	}
 
 	/* Spill to DRAM feature uses separate SMU message port */
-	dev->msg_port = 1;
+	dev->msg_port = MSG_PORT_S2D;
 
 	amd_pmc_send_cmd(dev, S2D_TELEMETRY_SIZE, &size, dev->s2d_msg_id, true);
 	if (size != S2D_TELEMETRY_BYTES_MAX)
@@ -285,7 +285,7 @@ int amd_stb_s2d_init(struct amd_pmc_dev *dev)
 	stb_phys_addr = ((u64)phys_addr_hi << 32 | phys_addr_low);
 
 	/* Clear msg_port for other SMU operation */
-	dev->msg_port = 0;
+	dev->msg_port = MSG_PORT_PMC;
 
 	dev->stb_virt_addr = devm_ioremap(dev->dev, stb_phys_addr, dev->dram_size);
 	if (!dev->stb_virt_addr)
diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c
index ddef24da9a66..0c6d25e17d1b 100644
--- a/drivers/platform/x86/amd/pmc/pmc.c
+++ b/drivers/platform/x86/amd/pmc/pmc.c
@@ -449,11 +449,23 @@ static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
 			    &amd_pmc_idlemask_fops);
 }
 
+static char *amd_pmc_get_msg_port(struct amd_pmc_dev *dev)
+{
+	switch (dev->msg_port) {
+	case MSG_PORT_PMC:
+		return "PMC";
+	case MSG_PORT_S2D:
+		return "S2D";
+	default:
+		return "Invalid message port";
+	}
+}
+
 static void amd_pmc_dump_registers(struct amd_pmc_dev *dev)
 {
 	u32 value, message, argument, response;
 
-	if (dev->msg_port) {
+	if (dev->msg_port == MSG_PORT_S2D) {
 		message = AMD_S2D_REGISTER_MESSAGE;
 		argument = AMD_S2D_REGISTER_ARGUMENT;
 		response = AMD_S2D_REGISTER_RESPONSE;
@@ -464,13 +476,13 @@ static void amd_pmc_dump_registers(struct amd_pmc_dev *dev)
 	}
 
 	value = amd_pmc_reg_read(dev, response);
-	dev_dbg(dev->dev, "AMD_%s_REGISTER_RESPONSE:%x\n", dev->msg_port ? "S2D" : "PMC", value);
+	dev_dbg(dev->dev, "AMD_%s_REGISTER_RESPONSE:%x\n", amd_pmc_get_msg_port(dev), value);
 
 	value = amd_pmc_reg_read(dev, argument);
-	dev_dbg(dev->dev, "AMD_%s_REGISTER_ARGUMENT:%x\n", dev->msg_port ? "S2D" : "PMC", value);
+	dev_dbg(dev->dev, "AMD_%s_REGISTER_ARGUMENT:%x\n", amd_pmc_get_msg_port(dev), value);
 
 	value = amd_pmc_reg_read(dev, message);
-	dev_dbg(dev->dev, "AMD_%s_REGISTER_MESSAGE:%x\n", dev->msg_port ? "S2D" : "PMC", value);
+	dev_dbg(dev->dev, "AMD_%s_REGISTER_MESSAGE:%x\n", amd_pmc_get_msg_port(dev), value);
 }
 
 int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool ret)
@@ -480,7 +492,7 @@ int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool r
 
 	mutex_lock(&dev->lock);
 
-	if (dev->msg_port) {
+	if (dev->msg_port == MSG_PORT_S2D) {
 		message = AMD_S2D_REGISTER_MESSAGE;
 		argument = AMD_S2D_REGISTER_ARGUMENT;
 		response = AMD_S2D_REGISTER_RESPONSE;
diff --git a/drivers/platform/x86/amd/pmc/pmc.h b/drivers/platform/x86/amd/pmc/pmc.h
index 188284feca72..f22256db8290 100644
--- a/drivers/platform/x86/amd/pmc/pmc.h
+++ b/drivers/platform/x86/amd/pmc/pmc.h
@@ -14,6 +14,11 @@
 #include <linux/types.h>
 #include <linux/mutex.h>
 
+enum s2d_msg_port {
+	MSG_PORT_PMC,
+	MSG_PORT_S2D,
+};
+
 struct amd_mp2_dev {
 	void __iomem *mmio;
 	void __iomem *vslbase;
@@ -30,7 +35,6 @@ struct amd_pmc_dev {
 	void __iomem *smu_virt_addr;
 	void __iomem *stb_virt_addr;
 	void __iomem *fch_virt_addr;
-	bool msg_port;
 	u32 base_addr;
 	u32 cpu_id;
 	u32 active_ips;
@@ -43,6 +47,7 @@ struct amd_pmc_dev {
 	u8 major;
 	u8 minor;
 	u8 rev;
+	u8 msg_port;
 	struct device *dev;
 	struct pci_dev *rdev;
 	struct mutex lock; /* generic mutex lock */