Merge branch 'for-6.15/amd_sfh' into for-linus

From: Mario Limonciello <mario.limonciello@amd.com>

Some platforms include a human presence detection (HPD) sensor. When
enabled and a user is detected a wake event will be emitted from the
sensor fusion hub that software can react to.

Example use cases are "wake from suspend on approach" or to "lock
when leaving".

This is currently enabled by default on supported systems, but users
can't control it. This essentially means that wake on approach is
enabled which is a really surprising behavior to users that don't
expect it.

Instead of defaulting to enabled add a sysfs knob that users can
use to enable the feature if desirable and set it to disabled by
default.

1 files changed, 76 insertions, 315 deletions

diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c
index 87b064e8ca5a..e6124498b195 100644
--- a/drivers/platform/x86/amd/pmc/pmc.c
+++ b/drivers/platform/x86/amd/pmc/pmc.c
@@ -11,6 +11,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/acpi.h>
+#include <linux/array_size.h>
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/debugfs.h>
@@ -41,24 +42,9 @@
 #define AMD_PMC_SCRATCH_REG_1AH		0xF14
 
 /* STB Registers */
-#define AMD_PMC_STB_PMI_0		0x03E30600
 #define AMD_PMC_STB_S2IDLE_PREPARE	0xC6000001
 #define AMD_PMC_STB_S2IDLE_RESTORE	0xC6000002
 #define AMD_PMC_STB_S2IDLE_CHECK	0xC6000003
-#define AMD_PMC_STB_DUMMY_PC		0xC6000007
-
-/* STB S2D(Spill to DRAM) has different message port offset */
-#define AMD_S2D_REGISTER_MESSAGE	0xA20
-#define AMD_S2D_REGISTER_RESPONSE	0xA80
-#define AMD_S2D_REGISTER_ARGUMENT	0xA88
-
-/* STB Spill to DRAM Parameters */
-#define S2D_TELEMETRY_BYTES_MAX		0x100000U
-#define S2D_RSVD_RAM_SPACE		0x100000
-#define S2D_TELEMETRY_DRAMBYTES_MAX	0x1000000
-
-/* STB Spill to DRAM Message Definition */
-#define STB_FORCE_FLUSH_DATA		0xCF
 
 /* Base address of SMU for mapping physical address to virtual address */
 #define AMD_PMC_MAPPING_SIZE		0x01000
@@ -98,7 +84,6 @@
 
 #define DELAY_MIN_US		2000
 #define DELAY_MAX_US		3000
-#define FIFO_SIZE		4096
 
 enum amd_pmc_def {
 	MSG_TEST = 0x01,
@@ -106,24 +91,39 @@ enum amd_pmc_def {
 	MSG_OS_HINT_RN,
 };
 
-enum s2d_arg {
-	S2D_TELEMETRY_SIZE = 0x01,
-	S2D_PHYS_ADDR_LOW,
-	S2D_PHYS_ADDR_HIGH,
-	S2D_NUM_SAMPLES,
-	S2D_DRAM_SIZE,
-};
-
-struct amd_pmc_stb_v2_data {
-	size_t size;
-	u8 data[] __counted_by(size);
-};
-
 struct amd_pmc_bit_map {
 	const char *name;
 	u32 bit_mask;
 };
 
+static const struct amd_pmc_bit_map soc15_ip_blk_v2[] = {
+	{"DISPLAY",     BIT(0)},
+	{"CPU",         BIT(1)},
+	{"GFX",         BIT(2)},
+	{"VDD",         BIT(3)},
+	{"VDD_CCX",     BIT(4)},
+	{"ACP",         BIT(5)},
+	{"VCN_0",       BIT(6)},
+	{"VCN_1",       BIT(7)},
+	{"ISP",         BIT(8)},
+	{"NBIO",        BIT(9)},
+	{"DF",          BIT(10)},
+	{"USB3_0",      BIT(11)},
+	{"USB3_1",      BIT(12)},
+	{"LAPIC",       BIT(13)},
+	{"USB3_2",      BIT(14)},
+	{"USB4_RT0",	BIT(15)},
+	{"USB4_RT1",	BIT(16)},
+	{"USB4_0",      BIT(17)},
+	{"USB4_1",      BIT(18)},
+	{"MPM",         BIT(19)},
+	{"JPEG_0",      BIT(20)},
+	{"JPEG_1",      BIT(21)},
+	{"IPU",         BIT(22)},
+	{"UMSCH",       BIT(23)},
+	{"VPE",         BIT(24)},
+};
+
 static const struct amd_pmc_bit_map soc15_ip_blk[] = {
 	{"DISPLAY",	BIT(0)},
 	{"CPU",		BIT(1)},
@@ -147,25 +147,13 @@ static const struct amd_pmc_bit_map soc15_ip_blk[] = {
 	{"IPU",		BIT(19)},
 	{"UMSCH",	BIT(20)},
 	{"VPE",		BIT(21)},
-	{}
 };
 
-static bool enable_stb;
-module_param(enable_stb, bool, 0644);
-MODULE_PARM_DESC(enable_stb, "Enable the STB debug mechanism");
-
 static bool disable_workarounds;
 module_param(disable_workarounds, bool, 0644);
 MODULE_PARM_DESC(disable_workarounds, "Disable workarounds for platform bugs");
 
-static bool dump_custom_stb;
-module_param(dump_custom_stb, bool, 0644);
-MODULE_PARM_DESC(dump_custom_stb, "Enable to dump full STB buffer");
-
 static struct amd_pmc_dev pmc;
-static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool ret);
-static int amd_pmc_read_stb(struct amd_pmc_dev *dev, u32 *buf);
-static int amd_pmc_write_stb(struct amd_pmc_dev *dev, u32 data);
 
 static inline u32 amd_pmc_reg_read(struct amd_pmc_dev *dev, int reg_offset)
 {
@@ -194,155 +182,6 @@ struct smu_metrics {
 	u64 timecondition_notmet_totaltime[32];
 } __packed;
 
-static int amd_pmc_stb_debugfs_open(struct inode *inode, struct file *filp)
-{
-	struct amd_pmc_dev *dev = filp->f_inode->i_private;
-	u32 size = FIFO_SIZE * sizeof(u32);
-	u32 *buf;
-	int rc;
-
-	buf = kzalloc(size, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	rc = amd_pmc_read_stb(dev, buf);
-	if (rc) {
-		kfree(buf);
-		return rc;
-	}
-
-	filp->private_data = buf;
-	return rc;
-}
-
-static ssize_t amd_pmc_stb_debugfs_read(struct file *filp, char __user *buf, size_t size,
-					loff_t *pos)
-{
-	if (!filp->private_data)
-		return -EINVAL;
-
-	return simple_read_from_buffer(buf, size, pos, filp->private_data,
-				       FIFO_SIZE * sizeof(u32));
-}
-
-static int amd_pmc_stb_debugfs_release(struct inode *inode, struct file *filp)
-{
-	kfree(filp->private_data);
-	return 0;
-}
-
-static const struct file_operations amd_pmc_stb_debugfs_fops = {
-	.owner = THIS_MODULE,
-	.open = amd_pmc_stb_debugfs_open,
-	.read = amd_pmc_stb_debugfs_read,
-	.release = amd_pmc_stb_debugfs_release,
-};
-
-/* Enhanced STB Firmware Reporting Mechanism */
-static int amd_pmc_stb_handle_efr(struct file *filp)
-{
-	struct amd_pmc_dev *dev = filp->f_inode->i_private;
-	struct amd_pmc_stb_v2_data *stb_data_arr;
-	u32 fsize;
-
-	fsize = dev->dram_size - S2D_RSVD_RAM_SPACE;
-	stb_data_arr = kmalloc(struct_size(stb_data_arr, data, fsize), GFP_KERNEL);
-	if (!stb_data_arr)
-		return -ENOMEM;
-
-	stb_data_arr->size = fsize;
-	memcpy_fromio(stb_data_arr->data, dev->stb_virt_addr, fsize);
-	filp->private_data = stb_data_arr;
-
-	return 0;
-}
-
-static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp)
-{
-	struct amd_pmc_dev *dev = filp->f_inode->i_private;
-	u32 fsize, num_samples, val, stb_rdptr_offset = 0;
-	struct amd_pmc_stb_v2_data *stb_data_arr;
-	int ret;
-
-	/* Write dummy postcode while reading the STB buffer */
-	ret = amd_pmc_write_stb(dev, AMD_PMC_STB_DUMMY_PC);
-	if (ret)
-		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;
-
-	ret = amd_pmc_send_cmd(dev, 0, &val, STB_FORCE_FLUSH_DATA, 1);
-	if (ret)
-		dev_dbg_once(dev->dev, "S2D force flush not supported: %d\n", ret);
-
-	/*
-	 * We have a custom stb size and the PMFW is supposed to give
-	 * the enhanced dram size. Note that we land here only for the
-	 * platforms that support enhanced dram size reporting.
-	 */
-	if (dump_custom_stb)
-		return amd_pmc_stb_handle_efr(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;
-	if (ret) {
-		dev_err(dev->dev, "error: S2D_NUM_SAMPLES not supported : %d\n", ret);
-		return ret;
-	}
-
-	fsize = min(num_samples, S2D_TELEMETRY_BYTES_MAX);
-	stb_data_arr = kmalloc(struct_size(stb_data_arr, data, fsize), GFP_KERNEL);
-	if (!stb_data_arr)
-		return -ENOMEM;
-
-	stb_data_arr->size = fsize;
-
-	/*
-	 * Start capturing data from the last push location.
-	 * This is for general cases, where the stb limits
-	 * are meant for standard usage.
-	 */
-	if (num_samples > S2D_TELEMETRY_BYTES_MAX) {
-		/* First read oldest data starting 1 behind last write till end of ringbuffer */
-		stb_rdptr_offset = num_samples % S2D_TELEMETRY_BYTES_MAX;
-		fsize = S2D_TELEMETRY_BYTES_MAX - stb_rdptr_offset;
-
-		memcpy_fromio(stb_data_arr->data, dev->stb_virt_addr + stb_rdptr_offset, fsize);
-		/* Second copy the newer samples from offset 0 - last write */
-		memcpy_fromio(stb_data_arr->data + fsize, dev->stb_virt_addr, stb_rdptr_offset);
-	} else {
-		memcpy_fromio(stb_data_arr->data, dev->stb_virt_addr, fsize);
-	}
-
-	filp->private_data = stb_data_arr;
-
-	return 0;
-}
-
-static ssize_t amd_pmc_stb_debugfs_read_v2(struct file *filp, char __user *buf, size_t size,
-					   loff_t *pos)
-{
-	struct amd_pmc_stb_v2_data *data = filp->private_data;
-
-	return simple_read_from_buffer(buf, size, pos, data->data, data->size);
-}
-
-static int amd_pmc_stb_debugfs_release_v2(struct inode *inode, struct file *filp)
-{
-	kfree(filp->private_data);
-	return 0;
-}
-
-static const struct file_operations amd_pmc_stb_debugfs_fops_v2 = {
-	.owner = THIS_MODULE,
-	.open = amd_pmc_stb_debugfs_open_v2,
-	.read = amd_pmc_stb_debugfs_read_v2,
-	.release = amd_pmc_stb_debugfs_release_v2,
-};
-
 static void amd_pmc_get_ip_info(struct amd_pmc_dev *dev)
 {
 	switch (dev->cpu_id) {
@@ -351,18 +190,23 @@ static void amd_pmc_get_ip_info(struct amd_pmc_dev *dev)
 	case AMD_CPU_ID_YC:
 	case AMD_CPU_ID_CB:
 		dev->num_ips = 12;
-		dev->s2d_msg_id = 0xBE;
+		dev->ips_ptr = soc15_ip_blk;
 		dev->smu_msg = 0x538;
 		break;
 	case AMD_CPU_ID_PS:
 		dev->num_ips = 21;
-		dev->s2d_msg_id = 0x85;
+		dev->ips_ptr = soc15_ip_blk;
 		dev->smu_msg = 0x538;
 		break;
 	case PCI_DEVICE_ID_AMD_1AH_M20H_ROOT:
 	case PCI_DEVICE_ID_AMD_1AH_M60H_ROOT:
-		dev->num_ips = 22;
-		dev->s2d_msg_id = 0xDE;
+		if (boot_cpu_data.x86_model == 0x70) {
+			dev->num_ips = ARRAY_SIZE(soc15_ip_blk_v2);
+			dev->ips_ptr = soc15_ip_blk_v2;
+		} else {
+			dev->num_ips = ARRAY_SIZE(soc15_ip_blk);
+			dev->ips_ptr = soc15_ip_blk;
+		}
 		dev->smu_msg = 0x938;
 		break;
 	}
@@ -530,8 +374,8 @@ static int smu_fw_info_show(struct seq_file *s, void *unused)
 
 	seq_puts(s, "\n=== Active time (in us) ===\n");
 	for (idx = 0 ; idx < dev->num_ips ; idx++) {
-		if (soc15_ip_blk[idx].bit_mask & dev->active_ips)
-			seq_printf(s, "%-8s : %lld\n", soc15_ip_blk[idx].name,
+		if (dev->ips_ptr[idx].bit_mask & dev->active_ips)
+			seq_printf(s, "%-8s : %lld\n", dev->ips_ptr[idx].name,
 				   table.timecondition_notmet_lastcapture[idx]);
 	}
 
@@ -626,20 +470,6 @@ static void amd_pmc_dbgfs_unregister(struct amd_pmc_dev *dev)
 	debugfs_remove_recursive(dev->dbgfs_dir);
 }
 
-static bool amd_pmc_is_stb_supported(struct amd_pmc_dev *dev)
-{
-	switch (dev->cpu_id) {
-	case AMD_CPU_ID_YC:
-	case AMD_CPU_ID_CB:
-	case AMD_CPU_ID_PS:
-	case PCI_DEVICE_ID_AMD_1AH_M20H_ROOT:
-	case PCI_DEVICE_ID_AMD_1AH_M60H_ROOT:
-		return true;
-	default:
-		return false;
-	}
-}
-
 static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
 {
 	dev->dbgfs_dir = debugfs_create_dir("amd_pmc", NULL);
@@ -649,14 +479,17 @@ static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
 			    &s0ix_stats_fops);
 	debugfs_create_file("amd_pmc_idlemask", 0644, dev->dbgfs_dir, dev,
 			    &amd_pmc_idlemask_fops);
-	/* Enable STB only when the module_param is set */
-	if (enable_stb) {
-		if (amd_pmc_is_stb_supported(dev))
-			debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
-					    &amd_pmc_stb_debugfs_fops_v2);
-		else
-			debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
-					    &amd_pmc_stb_debugfs_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";
 	}
 }
 
@@ -664,10 +497,10 @@ static void amd_pmc_dump_registers(struct amd_pmc_dev *dev)
 {
 	u32 value, message, argument, response;
 
-	if (dev->msg_port) {
-		message = AMD_S2D_REGISTER_MESSAGE;
-		argument = AMD_S2D_REGISTER_ARGUMENT;
-		response = AMD_S2D_REGISTER_RESPONSE;
+	if (dev->msg_port == MSG_PORT_S2D) {
+		message = dev->stb_arg.msg;
+		argument = dev->stb_arg.arg;
+		response = dev->stb_arg.resp;
 	} else {
 		message = dev->smu_msg;
 		argument = AMD_PMC_REGISTER_ARGUMENT;
@@ -675,26 +508,26 @@ 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);
 }
 
-static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool ret)
+int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool ret)
 {
 	int rc;
 	u32 val, message, argument, response;
 
-	mutex_lock(&dev->lock);
+	guard(mutex)(&dev->lock);
 
-	if (dev->msg_port) {
-		message = AMD_S2D_REGISTER_MESSAGE;
-		argument = AMD_S2D_REGISTER_ARGUMENT;
-		response = AMD_S2D_REGISTER_RESPONSE;
+	if (dev->msg_port == MSG_PORT_S2D) {
+		message = dev->stb_arg.msg;
+		argument = dev->stb_arg.arg;
+		response = dev->stb_arg.resp;
 	} else {
 		message = dev->smu_msg;
 		argument = AMD_PMC_REGISTER_ARGUMENT;
@@ -707,7 +540,7 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg,
 				PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
 	if (rc) {
 		dev_err(dev->dev, "failed to talk to SMU\n");
-		goto out_unlock;
+		return rc;
 	}
 
 	/* Write zero to response register */
@@ -725,7 +558,7 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg,
 				PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
 	if (rc) {
 		dev_err(dev->dev, "SMU response timed out\n");
-		goto out_unlock;
+		return rc;
 	}
 
 	switch (val) {
@@ -739,21 +572,19 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg,
 	case AMD_PMC_RESULT_CMD_REJECT_BUSY:
 		dev_err(dev->dev, "SMU not ready. err: 0x%x\n", val);
 		rc = -EBUSY;
-		goto out_unlock;
+		break;
 	case AMD_PMC_RESULT_CMD_UNKNOWN:
 		dev_err(dev->dev, "SMU cmd unknown. err: 0x%x\n", val);
 		rc = -EINVAL;
-		goto out_unlock;
+		break;
 	case AMD_PMC_RESULT_CMD_REJECT_PREREQ:
 	case AMD_PMC_RESULT_FAILED:
 	default:
 		dev_err(dev->dev, "SMU cmd failed. err: 0x%x\n", val);
 		rc = -EIO;
-		goto out_unlock;
+		break;
 	}
 
-out_unlock:
-	mutex_unlock(&dev->lock);
 	amd_pmc_dump_registers(dev);
 	return rc;
 }
@@ -882,7 +713,7 @@ static void amd_pmc_s2idle_prepare(void)
 		return;
 	}
 
-	rc = amd_pmc_write_stb(pdev, AMD_PMC_STB_S2IDLE_PREPARE);
+	rc = amd_stb_write(pdev, AMD_PMC_STB_S2IDLE_PREPARE);
 	if (rc)
 		dev_err(pdev->dev, "error writing to STB: %d\n", rc);
 }
@@ -901,7 +732,7 @@ static void amd_pmc_s2idle_check(void)
 	/* Dump the IdleMask before we add to the STB */
 	amd_pmc_idlemask_read(pdev, pdev->dev, NULL);
 
-	rc = amd_pmc_write_stb(pdev, AMD_PMC_STB_S2IDLE_CHECK);
+	rc = amd_stb_write(pdev, AMD_PMC_STB_S2IDLE_CHECK);
 	if (rc)
 		dev_err(pdev->dev, "error writing to STB: %d\n", rc);
 }
@@ -928,7 +759,7 @@ static void amd_pmc_s2idle_restore(void)
 	/* Let SMU know that we are looking for stats */
 	amd_pmc_dump_data(pdev);
 
-	rc = amd_pmc_write_stb(pdev, AMD_PMC_STB_S2IDLE_RESTORE);
+	rc = amd_stb_write(pdev, AMD_PMC_STB_S2IDLE_RESTORE);
 	if (rc)
 		dev_err(pdev->dev, "error writing to STB: %d\n", rc);
 
@@ -982,74 +813,6 @@ static const struct pci_device_id pmc_pci_ids[] = {
 	{ }
 };
 
-static int amd_pmc_s2d_init(struct amd_pmc_dev *dev)
-{
-	u32 phys_addr_low, phys_addr_hi;
-	u64 stb_phys_addr;
-	u32 size = 0;
-	int ret;
-
-	/* Spill to DRAM feature uses separate SMU message port */
-	dev->msg_port = 1;
-
-	amd_pmc_send_cmd(dev, S2D_TELEMETRY_SIZE, &size, dev->s2d_msg_id, true);
-	if (size != S2D_TELEMETRY_BYTES_MAX)
-		return -EIO;
-
-	/* Get DRAM size */
-	ret = amd_pmc_send_cmd(dev, S2D_DRAM_SIZE, &dev->dram_size, dev->s2d_msg_id, true);
-	if (ret || !dev->dram_size)
-		dev->dram_size = S2D_TELEMETRY_DRAMBYTES_MAX;
-
-	/* Get STB DRAM address */
-	amd_pmc_send_cmd(dev, S2D_PHYS_ADDR_LOW, &phys_addr_low, dev->s2d_msg_id, true);
-	amd_pmc_send_cmd(dev, S2D_PHYS_ADDR_HIGH, &phys_addr_hi, dev->s2d_msg_id, true);
-
-	if (!phys_addr_hi && !phys_addr_low) {
-		dev_err(dev->dev, "STB is not enabled on the system; disable enable_stb or contact system vendor\n");
-		return -EINVAL;
-	}
-
-	stb_phys_addr = ((u64)phys_addr_hi << 32 | phys_addr_low);
-
-	/* Clear msg_port for other SMU operation */
-	dev->msg_port = 0;
-
-	dev->stb_virt_addr = devm_ioremap(dev->dev, stb_phys_addr, dev->dram_size);
-	if (!dev->stb_virt_addr)
-		return -ENOMEM;
-
-	return 0;
-}
-
-static int amd_pmc_write_stb(struct amd_pmc_dev *dev, u32 data)
-{
-	int err;
-
-	err = amd_smn_write(0, AMD_PMC_STB_PMI_0, data);
-	if (err) {
-		dev_err(dev->dev, "failed to write data in stb: 0x%X\n", AMD_PMC_STB_PMI_0);
-		return pcibios_err_to_errno(err);
-	}
-
-	return 0;
-}
-
-static int amd_pmc_read_stb(struct amd_pmc_dev *dev, u32 *buf)
-{
-	int i, err;
-
-	for (i = 0; i < FIFO_SIZE; i++) {
-		err = amd_smn_read(0, AMD_PMC_STB_PMI_0, buf++);
-		if (err) {
-			dev_err(dev->dev, "error reading data from stb: 0x%X\n", AMD_PMC_STB_PMI_0);
-			return pcibios_err_to_errno(err);
-		}
-	}
-
-	return 0;
-}
-
 static int amd_pmc_probe(struct platform_device *pdev)
 {
 	struct amd_pmc_dev *dev = &pmc;
@@ -1107,12 +870,6 @@ static int amd_pmc_probe(struct platform_device *pdev)
 	/* Get num of IP blocks within the SoC */
 	amd_pmc_get_ip_info(dev);
 
-	if (enable_stb && amd_pmc_is_stb_supported(dev)) {
-		err = amd_pmc_s2d_init(dev);
-		if (err)
-			goto err_pci_dev_put;
-	}
-
 	platform_set_drvdata(pdev, dev);
 	if (IS_ENABLED(CONFIG_SUSPEND)) {
 		err = acpi_register_lps0_dev(&amd_pmc_s2idle_dev_ops);
@@ -1123,6 +880,10 @@ static int amd_pmc_probe(struct platform_device *pdev)
 	}
 
 	amd_pmc_dbgfs_register(dev);
+	err = amd_stb_s2d_init(dev);
+	if (err)
+		goto err_pci_dev_put;
+
 	if (IS_ENABLED(CONFIG_AMD_MP2_STB))
 		amd_mp2_stb_init(dev);
 	pm_report_max_hw_sleep(U64_MAX);