[PATCH v4 2/6] platform/x86/amd/hsmp: Map the metric table with ioremap() and unmap it explicitly

[Muralidhara M K]

The metric table DRAM region is mapped with devm_ioremap(), tying its
lifetime to the socket device. An upcoming change lets the ACPI front-end
share the socket array across sockets and coordinate its own teardown, so
the mapping can no longer be pinned to a single per-socket devres scope.

Switch hsmp_get_tbl_dram_base() to plain ioremap() and add
hsmp_unmap_metric_tbls(), which drops every socket's metric_tbl_addr
mapping. On the platform driver register it with devm_add_action_or_reset()
so the mapping is released on both remove and probe failure; the socket
array itself stays devm-managed.

Signed-off-by: Muralidhara M K <muralidhara.mk@xxxxxxx>
---
 drivers/platform/x86/amd/hsmp/hsmp.c | 19 +++++++++++++++++--
 drivers/platform/x86/amd/hsmp/hsmp.h |  1 +
 drivers/platform/x86/amd/hsmp/plat.c | 14 ++++++++++++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/amd/hsmp/hsmp.c b/drivers/platform/x86/amd/hsmp/hsmp.c
index 1a87931136fd..4586d86f72a3 100644
--- a/drivers/platform/x86/amd/hsmp/hsmp.c
+++ b/drivers/platform/x86/amd/hsmp/hsmp.c
@@ -12,6 +12,7 @@
 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/io.h>
 #include <linux/semaphore.h>
 #include <linux/sysfs.h>
 
@@ -414,6 +415,21 @@ ssize_t hsmp_metric_tbl_read(struct hsmp_socket *sock, char *buf, size_t size)
 }
 EXPORT_SYMBOL_NS_GPL(hsmp_metric_tbl_read, "AMD_HSMP");
 
+void hsmp_unmap_metric_tbls(struct hsmp_plat_device *pdev)
+{
+	u16 i;
+
+	for (i = 0; i < pdev->num_sockets; i++) {
+		struct hsmp_socket *s = &pdev->sock[i];
+
+		if (s->metric_tbl_addr) {
+			iounmap(s->metric_tbl_addr);
+			s->metric_tbl_addr = NULL;
+		}
+	}
+}
+EXPORT_SYMBOL_NS_GPL(hsmp_unmap_metric_tbls, "AMD_HSMP");
+
 int hsmp_get_tbl_dram_base(u16 sock_ind)
 {
 	struct hsmp_socket *sock = &hsmp_pdev.sock[sock_ind];
@@ -438,8 +454,7 @@ int hsmp_get_tbl_dram_base(u16 sock_ind)
 		dev_err(sock->dev, "Invalid DRAM address for metric table\n");
 		return -ENOMEM;
 	}
-	sock->metric_tbl_addr = devm_ioremap(sock->dev, dram_addr,
-					     sizeof(struct hsmp_metric_table));
+	sock->metric_tbl_addr = ioremap(dram_addr, sizeof(struct hsmp_metric_table));
 	if (!sock->metric_tbl_addr) {
 		dev_err(sock->dev, "Failed to ioremap metric table addr\n");
 		return -ENOMEM;
diff --git a/drivers/platform/x86/amd/hsmp/hsmp.h b/drivers/platform/x86/amd/hsmp/hsmp.h
index 0509a442eaae..98c82a4c0cc3 100644
--- a/drivers/platform/x86/amd/hsmp/hsmp.h
+++ b/drivers/platform/x86/amd/hsmp/hsmp.h
@@ -64,6 +64,7 @@ void hsmp_misc_deregister(void);
 int hsmp_misc_register(struct device *dev);
 int hsmp_get_tbl_dram_base(u16 sock_ind);
 ssize_t hsmp_metric_tbl_read(struct hsmp_socket *sock, char *buf, size_t size);
+void hsmp_unmap_metric_tbls(struct hsmp_plat_device *pdev);
 struct hsmp_plat_device *get_hsmp_pdev(void);
 #if IS_ENABLED(CONFIG_HWMON)
 int hsmp_create_sensor(struct device *dev, u16 sock_ind);
diff --git a/drivers/platform/x86/amd/hsmp/plat.c b/drivers/platform/x86/amd/hsmp/plat.c
index e07f68575055..e7ee6e701e5a 100644
--- a/drivers/platform/x86/amd/hsmp/plat.c
+++ b/drivers/platform/x86/amd/hsmp/plat.c
@@ -201,6 +201,16 @@ static int init_platform_device(struct device *dev)
 	return 0;
 }
 
+/*
+ * The metric tables are mapped with ioremap() rather than devm, so release
+ * them explicitly. Registered as a devres action so it also runs on a probe
+ * failure after init_platform_device() has mapped some of them.
+ */
+static void hsmp_pltdrv_release(void *data)
+{
+	hsmp_unmap_metric_tbls(hsmp_pdev);
+}
+
 static int hsmp_pltdrv_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -211,6 +221,10 @@ static int hsmp_pltdrv_probe(struct platform_device *pdev)
 	if (!hsmp_pdev->sock)
 		return -ENOMEM;
 
+	ret = devm_add_action_or_reset(&pdev->dev, hsmp_pltdrv_release, NULL);
+	if (ret)
+		return ret;
+
 	ret = init_platform_device(&pdev->dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to init HSMP mailbox\n");
-- 
2.34.1