diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index 55c03d3495bc..cbe31e316e39 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -27,7 +27,6 @@ struct amd_l3_cache {
 };
 
 struct amd_northbridge {
-	struct pci_dev *root;
 	struct pci_dev *misc;
 	struct pci_dev *link;
 	struct amd_l3_cache l3_cache;
diff --git a/arch/x86/include/asm/amd_smn.h b/arch/x86/include/asm/amd_smn.h
index 6850de69f863..f0eb12859c42 100644
--- a/arch/x86/include/asm/amd_smn.h
+++ b/arch/x86/include/asm/amd_smn.h
@@ -8,4 +8,7 @@
 int __must_check amd_smn_read(u16 node, u32 address, u32 *value);
 int __must_check amd_smn_write(u16 node, u32 address, u32 value);
 
+/* Should only be used by the HSMP driver. */
+int __must_check amd_smn_hsmp_rdwr(u16 node, u32 address, u32 *value, bool write);
+
 #endif /* _ASM_X86_AMD_SMN_H */
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 10cdeddeda02..4c22317a6dfe 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -73,7 +73,6 @@ static int amd_cache_northbridges(void)
 	amd_northbridges.nb = nb;
 
 	for (i = 0; i < amd_northbridges.num; i++) {
-		node_to_amd_nb(i)->root = amd_node_get_root(i);
 		node_to_amd_nb(i)->misc = amd_node_get_func(i, 3);
 		node_to_amd_nb(i)->link = amd_node_get_func(i, 4);
 	}
diff --git a/arch/x86/kernel/amd_smn.c b/arch/x86/kernel/amd_smn.c
index 997fd3edd9c0..527dda8e3a2b 100644
--- a/arch/x86/kernel/amd_smn.c
+++ b/arch/x86/kernel/amd_smn.c
@@ -18,6 +18,9 @@ static DEFINE_MUTEX(smn_mutex);
 #define SMN_INDEX_OFFSET	0x60
 #define SMN_DATA_OFFSET		0x64
 
+#define HSMP_INDEX_OFFSET	0xc4
+#define HSMP_DATA_OFFSET	0xc8
+
 /*
  * SMN accesses may fail in ways that are difficult to detect here in the called
  * functions amd_smn_read() and amd_smn_write(). Therefore, callers must do
@@ -100,6 +103,12 @@ int __must_check amd_smn_write(u16 node, u32 address, u32 value)
 }
 EXPORT_SYMBOL_GPL(amd_smn_write);
 
+int __must_check amd_smn_hsmp_rdwr(u16 node, u32 address, u32 *value, bool write)
+{
+	return __amd_smn_rw(HSMP_INDEX_OFFSET, HSMP_DATA_OFFSET, node, address, value, write);
+}
+EXPORT_SYMBOL_GPL(amd_smn_hsmp_rdwr);
+
 static int amd_cache_roots(void)
 {
 	u16 node, num_nodes = amd_num_nodes();
diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig
index f88682d36447..e100b315c62b 100644
--- a/drivers/platform/x86/amd/Kconfig
+++ b/drivers/platform/x86/amd/Kconfig
@@ -8,7 +8,7 @@ source "drivers/platform/x86/amd/pmc/Kconfig"
 
 config AMD_HSMP
 	tristate "AMD HSMP Driver"
-	depends on AMD_NB && X86_64 && ACPI
+	depends on AMD_SMN && X86_64 && ACPI
 	help
 	  The driver provides a way for user space tools to monitor and manage
 	  system management functionality on EPYC server CPUs from AMD.
diff --git a/drivers/platform/x86/amd/hsmp.c b/drivers/platform/x86/amd/hsmp.c
index 8fcf38eed7f0..544efb0255c0 100644
--- a/drivers/platform/x86/amd/hsmp.c
+++ b/drivers/platform/x86/amd/hsmp.c
@@ -10,7 +10,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <asm/amd_hsmp.h>
-#include <asm/amd_nb.h>
+#include <asm/amd_smn.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/miscdevice.h>
@@ -48,9 +48,6 @@
 #define SMN_HSMP_MSG_RESP	0x0010980
 #define SMN_HSMP_MSG_DATA	0x00109E0
 
-#define HSMP_INDEX_REG		0xc4
-#define HSMP_DATA_REG		0xc8
-
 #define HSMP_CDEV_NAME		"hsmp_cdev"
 #define HSMP_DEVNODE_NAME	"hsmp"
 #define HSMP_METRICS_TABLE_NAME	"metrics_bin"
@@ -62,8 +59,6 @@
 #define MSG_ARGOFF_STR		"MsgArgOffset"
 #define MSG_RESPOFF_STR		"MsgRspOffset"
 
-#define MAX_AMD_SOCKETS 8
-
 struct hsmp_mbaddr_info {
 	u32 base_addr;
 	u32 msg_id_off;
@@ -79,7 +74,6 @@ struct hsmp_socket {
 	void __iomem *virt_base_addr;
 	struct semaphore hsmp_sem;
 	char name[HSMP_ATTR_GRP_NAME_SIZE];
-	struct pci_dev *root;
 	struct device *dev;
 	u16 sock_ind;
 };
@@ -98,20 +92,7 @@ static struct hsmp_plat_device plat_dev;
 static int amd_hsmp_pci_rdwr(struct hsmp_socket *sock, u32 offset,
 			     u32 *value, bool write)
 {
-	int ret;
-
-	if (!sock->root)
-		return -ENODEV;
-
-	ret = pci_write_config_dword(sock->root, HSMP_INDEX_REG,
-				     sock->mbinfo.base_addr + offset);
-	if (ret)
-		return ret;
-
-	ret = (write ? pci_write_config_dword(sock->root, HSMP_DATA_REG, *value)
-		     : pci_read_config_dword(sock->root, HSMP_DATA_REG, value));
-
-	return ret;
+	return amd_smn_hsmp_rdwr(sock->sock_ind, sock->mbinfo.base_addr + offset, value, write);
 }
 
 static void amd_hsmp_acpi_rdwr(struct hsmp_socket *sock, u32 offset,
@@ -749,10 +730,7 @@ static int init_platform_device(struct device *dev)
 	int ret, i;
 
 	for (i = 0; i < plat_dev.num_sockets; i++) {
-		if (!node_to_amd_nb(i))
-			return -ENODEV;
 		sock = &plat_dev.sock[i];
-		sock->root			= node_to_amd_nb(i)->root;
 		sock->sock_ind			= i;
 		sock->dev			= dev;
 		sock->mbinfo.base_addr		= SMN_HSMP_BASE;
@@ -946,11 +924,11 @@ static int __init hsmp_plt_init(void)
 	int ret = -ENODEV;
 
 	/*
-	 * amd_nb_num() returns number of SMN/DF interfaces present in the system
+	 * amd_num_nodes() returns number of SMN/DF interfaces present in the system
 	 * if we have N SMN/DF interfaces that ideally means N sockets
 	 */
-	plat_dev.num_sockets = amd_nb_num();
-	if (plat_dev.num_sockets == 0 || plat_dev.num_sockets > MAX_AMD_SOCKETS)
+	plat_dev.num_sockets = amd_num_nodes();
+	if (plat_dev.num_sockets == 0 || plat_dev.num_sockets > MAX_AMD_NUM_NODES)
 		return ret;
 
 	ret = platform_driver_register(&amd_hsmp_driver);
