[PATCH v2.1] x86/amd_node, platform/x86/amd/hsmp: Have HSMP use SMN through AMD_NODE

Yazen Ghannam
2024-12-12T17:27:30Z

The HSMP interface is just an SMN interface with different offsets.

Define an HSMP wrapper in the SMN code and have the HSMP platform driver
use that rather than a local solution.

Also, remove the "root" member from AMD_NB, since there are no more
users of it.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---

Notes:
Link:
https://lore.kernel.org/20241206161210.163701-15-yazen.ghannam@amd.com

v2->v2.1:
* Include static_assert() and comment for sysfs attributes.

v1->v2:
* Rebase on recent HSMP rework.

arch/x86/include/asm/amd_nb.h | 1 -
arch/x86/include/asm/amd_node.h | 3 +++
arch/x86/kernel/amd_nb.c | 1 -
arch/x86/kernel/amd_node.c | 9 +++++++
drivers/platform/x86/amd/hsmp/Kconfig | 2 +-
drivers/platform/x86/amd/hsmp/acpi.c | 7 +++---
drivers/platform/x86/amd/hsmp/hsmp.c | 1 -
drivers/platform/x86/amd/hsmp/hsmp.h | 3 ---
drivers/platform/x86/amd/hsmp/plat.c | 35 +++++++++------------------
9 files changed, 28 insertions(+), 34 deletions(-)

diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index 4c4efb93045e..adfa0854cf2d 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_node.h b/arch/x86/include/asm/amd_node.h
index 113ad3e8ee40..5fe9c6537434 100644
--- a/arch/x86/include/asm/amd_node.h
+++ b/arch/x86/include/asm/amd_node.h
@@ -33,4 +33,7 @@ static inline u16 amd_num_nodes(void)
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_NODE_H_*/
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 2729e99806ec..3a20312062af 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_node.c b/arch/x86/kernel/amd_node.c
index d2ec7fd555c5..65045f223c10 100644
--- a/arch/x86/kernel/amd_node.c
+++ b/arch/x86/kernel/amd_node.c
@@ -97,6 +97,9 @@ 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
@@ -179,6 +182,12 @@ 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/hsmp/Kconfig b/drivers/platform/x86/amd/hsmp/Kconfig
index 7d10d4462a45..d6f7a62d55b5 100644
--- a/drivers/platform/x86/amd/hsmp/Kconfig
+++ b/drivers/platform/x86/amd/hsmp/Kconfig
@@ -7,7 +7,7 @@ config AMD_HSMP
tristate

menu "AMD HSMP Driver"
- depends on AMD_NB || COMPILE_TEST
+ depends on AMD_NODE || COMPILE_TEST

config AMD_HSMP_ACPI
tristate "AMD HSMP ACPI device driver"
diff --git a/drivers/platform/x86/amd/hsmp/acpi.c b/drivers/platform/x86/amd/hsmp/acpi.c
index e981d45e1c12..28565ca78afd 100644
--- a/drivers/platform/x86/amd/hsmp/acpi.c
+++ b/drivers/platform/x86/amd/hsmp/acpi.c
@@ -10,7 +10,6 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <asm/amd_hsmp.h>
-#include <asm/amd_nb.h>

#include <linux/acpi.h>
#include <linux/device.h>
@@ -24,6 +23,8 @@

#include <uapi/asm-generic/errno-base.h>

+#include <asm/amd_node.h>
+
#include "hsmp.h"

#define DRIVER_NAME "amd_hsmp"
@@ -321,8 +322,8 @@ static int hsmp_acpi_probe(struct platform_device *pdev)
return -ENOMEM;

if (!hsmp_pdev->is_probed) {
- hsmp_pdev->num_sockets = amd_nb_num();
- if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_SOCKETS)
+ hsmp_pdev->num_sockets = amd_num_nodes();
+ if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_NUM_NODES)
return -ENODEV;

hsmp_pdev->sock = devm_kcalloc(&pdev->dev, hsmp_pdev->num_sockets,
diff --git a/drivers/platform/x86/amd/hsmp/hsmp.c b/drivers/platform/x86/amd/hsmp/hsmp.c
index 227b4ad4a51a..e04c613ad5d6 100644
--- a/drivers/platform/x86/amd/hsmp/hsmp.c
+++ b/drivers/platform/x86/amd/hsmp/hsmp.c
@@ -8,7 +8,6 @@
*/

#include <asm/amd_hsmp.h>
-#include <asm/amd_nb.h>

#include <linux/acpi.h>
#include <linux/delay.h>
diff --git a/drivers/platform/x86/amd/hsmp/hsmp.h b/drivers/platform/x86/amd/hsmp/hsmp.h
index e852f0a947e4..af8b21f821d6 100644
--- a/drivers/platform/x86/amd/hsmp/hsmp.h
+++ b/drivers/platform/x86/amd/hsmp/hsmp.h
@@ -21,8 +21,6 @@

#define HSMP_ATTR_GRP_NAME_SIZE 10

-#define MAX_AMD_SOCKETS 8
-
#define HSMP_CDEV_NAME "hsmp_cdev"
#define HSMP_DEVNODE_NAME "hsmp"

@@ -41,7 +39,6 @@ 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;
int (*amd_hsmp_rdwr)(struct hsmp_socket *sock, u32 off, u32 *val, bool rw);
diff --git a/drivers/platform/x86/amd/hsmp/plat.c b/drivers/platform/x86/amd/hsmp/plat.c
index a61f815c9f80..32921092b0c8 100644
--- a/drivers/platform/x86/amd/hsmp/plat.c
+++ b/drivers/platform/x86/amd/hsmp/plat.c
@@ -10,7 +10,6 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <asm/amd_hsmp.h>
-#include <asm/amd_nb.h>

#include <linux/device.h>
#include <linux/module.h>
@@ -18,6 +17,8 @@
#include <linux/platform_device.h>
#include <linux/sysfs.h>

+#include <asm/amd_node.h>
+
#include "hsmp.h"

#define DRIVER_NAME "amd_hsmp"
@@ -34,28 +35,12 @@
#define SMN_HSMP_MSG_RESP 0x0010980
#define SMN_HSMP_MSG_DATA 0x00109E0

-#define HSMP_INDEX_REG 0xc4
-#define HSMP_DATA_REG 0xc8
-
static struct hsmp_plat_device *hsmp_pdev;

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 ssize_t hsmp_metric_tbl_plat_read(struct file *filp, struct kobject *kobj,
@@ -95,7 +80,12 @@ static umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
* Static array of 8 + 1(for NULL) elements is created below
* to create sysfs groups for sockets.
* is_bin_visible function is used to show / hide the necessary groups.
+ *
+ * Validate the maximum number against MAX_AMD_NUM_NODES. If this changes,
+ * then the attributes and groups below must be adjusted.
*/
+static_assert(MAX_AMD_NUM_NODES == 8);
+
#define HSMP_BIN_ATTR(index, _list) \
static struct bin_attribute attr##index = { \
.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444}, \
@@ -159,10 +149,7 @@ static int init_platform_device(struct device *dev)
int ret, i;

for (i = 0; i < hsmp_pdev->num_sockets; i++) {
- if (!node_to_amd_nb(i))
- return -ENODEV;
sock = &hsmp_pdev->sock[i];
- sock->root = node_to_amd_nb(i)->root;
sock->sock_ind = i;
sock->dev = dev;
sock->mbinfo.base_addr = SMN_HSMP_BASE;
@@ -305,11 +292,11 @@ static int __init hsmp_plt_init(void)
return -ENOMEM;

/*
- * 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
*/
- hsmp_pdev->num_sockets = amd_nb_num();
- if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_SOCKETS)
+ hsmp_pdev->num_sockets = amd_num_nodes();
+ if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_NUM_NODES)
return ret;

ret = platform_driver_register(&amd_hsmp_driver);
--
2.43.0