platform/x86/amd/hsmp: Cache pci_dev in struct hsmp_socket

Cache pci_dev obj during probe as part of struct hsmp_socket
and use in amd_hsmp_rdwr(). This change will make it easier to
support both non-ACPI and ACPI devices.

Also add a check for sock_index agsint number of sockets
in the hsmp_send_message().
Signed-off-by: Suma Hegde <suma.hegde@amd.com>
Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240106022532.1746932-2-suma.hegde@amd.comSigned-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

drivers/platform/x86/amd/hsmp.c

@@ -58,6 +58,7 @@ struct hsmp_socket {
 	void __iomem *metric_tbl_addr;
 	struct semaphore hsmp_sem;
 	char name[HSMP_ATTR_GRP_NAME_SIZE];
+	struct pci_dev *root;
 	u16 sock_ind;
 };
 
@@ -71,17 +72,20 @@ struct hsmp_plat_device {
 
 static struct hsmp_plat_device plat_dev;
 
-static int amd_hsmp_rdwr(struct pci_dev *root, u32 address,
+static int amd_hsmp_rdwr(struct hsmp_socket *sock, u32 address,
 			 u32 *value, bool write)
 {
 	int ret;
 
-	ret = pci_write_config_dword(root, HSMP_INDEX_REG, address);
+	if (!sock->root)
+		return -ENODEV;
+
+	ret = pci_write_config_dword(sock->root, HSMP_INDEX_REG, address);
 	if (ret)
 		return ret;
 
-	ret = (write ? pci_write_config_dword(root, HSMP_DATA_REG, *value)
-		     : pci_read_config_dword(root, HSMP_DATA_REG, value));
+	ret = (write ? pci_write_config_dword(sock->root, HSMP_DATA_REG, *value)
+		     : pci_read_config_dword(sock->root, HSMP_DATA_REG, value));
 
 	return ret;
 }
@@ -95,7 +99,7 @@ static int amd_hsmp_rdwr(struct pci_dev *root, u32 address,
  * Returns 0 for success and populates the requested number of arguments.
  * Returns a negative error code for failure.
  */
-static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg)
+static int __hsmp_send_message(struct hsmp_socket *sock, struct hsmp_message *msg)
 {
 	unsigned long timeout, short_sleep;
 	u32 mbox_status;
@@ -104,7 +108,7 @@ static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg)
 
 	/* Clear the status register */
 	mbox_status = HSMP_STATUS_NOT_READY;
-	ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_RESP, &mbox_status, HSMP_WR);
+	ret = amd_hsmp_rdwr(sock, SMN_HSMP_MSG_RESP, &mbox_status, HSMP_WR);
 	if (ret) {
 		pr_err("Error %d clearing mailbox status register\n", ret);
 		return ret;
@@ -113,7 +117,7 @@ static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg)
 	index = 0;
 	/* Write any message arguments */
 	while (index < msg->num_args) {
-		ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_DATA + (index << 2),
+		ret = amd_hsmp_rdwr(sock, SMN_HSMP_MSG_DATA + (index << 2),
 				    &msg->args[index], HSMP_WR);
 		if (ret) {
 			pr_err("Error %d writing message argument %d\n", ret, index);
@@ -123,7 +127,7 @@ static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg)
 	}
 
 	/* Write the message ID which starts the operation */
-	ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_ID, &msg->msg_id, HSMP_WR);
+	ret = amd_hsmp_rdwr(sock, SMN_HSMP_MSG_ID, &msg->msg_id, HSMP_WR);
 	if (ret) {
 		pr_err("Error %d writing message ID %u\n", ret, msg->msg_id);
 		return ret;
@@ -140,7 +144,7 @@ static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg)
 	timeout	= jiffies + msecs_to_jiffies(HSMP_MSG_TIMEOUT);
 
 	while (time_before(jiffies, timeout)) {
-		ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_RESP, &mbox_status, HSMP_RD);
+		ret = amd_hsmp_rdwr(sock, SMN_HSMP_MSG_RESP, &mbox_status, HSMP_RD);
 		if (ret) {
 			pr_err("Error %d reading mailbox status\n", ret);
 			return ret;
@@ -175,7 +179,7 @@ static int __hsmp_send_message(struct pci_dev *root, struct hsmp_message *msg)
 	 */
 	index = 0;
 	while (index < msg->response_sz) {
-		ret = amd_hsmp_rdwr(root, SMN_HSMP_MSG_DATA + (index << 2),
+		ret = amd_hsmp_rdwr(sock, SMN_HSMP_MSG_DATA + (index << 2),
 				    &msg->args[index], HSMP_RD);
 		if (ret) {
 			pr_err("Error %d reading response %u for message ID:%u\n",
@@ -208,21 +212,19 @@ static int validate_message(struct hsmp_message *msg)
 
 int hsmp_send_message(struct hsmp_message *msg)
 {
-	struct hsmp_socket *sock = &plat_dev.sock[msg->sock_ind];
-	struct amd_northbridge *nb;
+	struct hsmp_socket *sock;
 	int ret;
 
 	if (!msg)
 		return -EINVAL;
-
-	nb = node_to_amd_nb(msg->sock_ind);
-	if (!nb || !nb->root)
-		return -ENODEV;
-
 	ret = validate_message(msg);
 	if (ret)
 		return ret;
 
+	if (!plat_dev.sock || msg->sock_ind >= plat_dev.num_sockets)
+		return -ENODEV;
+	sock = &plat_dev.sock[msg->sock_ind];
+
 	/*
 	 * The time taken by smu operation to complete is between
 	 * 10us to 1ms. Sometime it may take more time.
@@ -233,7 +235,7 @@ int hsmp_send_message(struct hsmp_message *msg)
 	if (ret < 0)
 		return ret;
 
-	ret = __hsmp_send_message(nb->root, msg);
+	ret = __hsmp_send_message(sock, msg);
 
 	up(&sock->hsmp_sem);
 
@@ -500,6 +502,10 @@ static int hsmp_pltdrv_probe(struct platform_device *pdev)
 		sema_init(&plat_dev.sock[i].hsmp_sem, 1);
 		plat_dev.sock[i].sock_ind = i;
 
+		if (!node_to_amd_nb(i))
+			return -ENODEV;
+		plat_dev.sock[i].root = node_to_amd_nb(i)->root;
+
 		/* Test the hsmp interface on each socket */
 		ret = hsmp_test(i, 0xDEADBEEF);
 		if (ret) {