Re: [PATCH v2 14/16] x86/amd_node, platform/x86/amd/hsmp: Have HSMP use SMN through AMD_NODE

Ilpo Järvinen
2024-12-09T13:32:11Z

On Fri, 6 Dec 2024, Yazen Ghannam wrote:

> 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/20241023172150.659002-15-yazen.ghannam@amd.com
>
> 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 | 30 ++++++---------------------
> 9 files changed, 23 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)

Hi,

Now that this define moves outside of hsmp files, it would be useful to
add static_assert() and a comment next to the attributes which are always
created for 0-7 sockets. That way, it can be detected on the build time if
the define changes and more entires would need to be added there.

Other than that, this seemed okay.

--
i.

> 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..42bd4553bffd 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,
> @@ -159,10 +144,7 @@ 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 +287,11 @@ 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);
>