[PATCH 14/16] x86/amd_smn, platform/x86/amd/hsmp: Have HSMP use SMN

Yazen Ghannam
2024-10-23T17:22:29Z

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>
---
arch/x86/include/asm/amd_nb.h | 1 -
arch/x86/include/asm/amd_smn.h | 3 +++
arch/x86/kernel/amd_nb.c | 1 -
arch/x86/kernel/amd_smn.c | 9 +++++++++
drivers/platform/x86/amd/Kconfig | 2 +-
drivers/platform/x86/amd/hsmp.c | 32 +++++---------------------------
6 files changed, 18 insertions(+), 30 deletions(-)

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);
--
2.43.0