HSMP interface is supported only on few x86 processors from AMD. Accessing HSMP registers on rest of the platforms might cause unexpected behaviour. So add a check. Also unavailability of this interface on rest of the processors is not an error. Hence, use pr_info() instead of the pr_err() to log the message. Signed-off-by: Suma Hegde <suma.hegde@xxxxxxx> Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@xxxxxxx> --- This patch addresses review comments from Mario Limonciello for "Check HSMP support on AMD family of processors" patch at <https://lore.kernel.org/platform-driver-x86/20240423091434.2063246-2-suma.hegde@xxxxxxx/> Please ignore the patch "platform/x86/amd/hsmp: Split the ACPI and non-ACPI code" in the above series. <https://lore.kernel.org/platform-driver-x86/20240423091434.2063246-3-suma.hegde@xxxxxxx/> We are working on addressing Hans comments on sysfs patch "Remove devm_* call for sysfs and use dev_groups" <https://lore.kernel.org/platform-driver-x86/20240410121746.1955500-1-suma.hegde@xxxxxxx/> drivers/platform/x86/amd/hsmp.c | 50 ++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 7 deletions(-) diff --git a/drivers/platform/x86/amd/hsmp.c b/drivers/platform/x86/amd/hsmp.c index d84ea66eecc6..8fcf38eed7f0 100644 --- a/drivers/platform/x86/amd/hsmp.c +++ b/drivers/platform/x86/amd/hsmp.c @@ -907,16 +907,44 @@ static int hsmp_plat_dev_register(void) return ret; } +/* + * This check is only needed for backward compatibility of previous platforms. + * All new platforms are expected to support ACPI based probing. + */ +static bool legacy_hsmp_support(void) +{ + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) + return false; + + switch (boot_cpu_data.x86) { + case 0x19: + switch (boot_cpu_data.x86_model) { + case 0x00 ... 0x1F: + case 0x30 ... 0x3F: + case 0x90 ... 0x9F: + case 0xA0 ... 0xAF: + return true; + default: + return false; + } + case 0x1A: + switch (boot_cpu_data.x86_model) { + case 0x00 ... 0x1F: + return true; + default: + return false; + } + default: + return false; + } + + return false; +} + static int __init hsmp_plt_init(void) { int ret = -ENODEV; - if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD || boot_cpu_data.x86 < 0x19) { - pr_err("HSMP is not supported on Family:%x model:%x\n", - boot_cpu_data.x86, boot_cpu_data.x86_model); - return ret; - } - /* * amd_nb_num() returns number of SMN/DF interfaces present in the system * if we have N SMN/DF interfaces that ideally means N sockets @@ -930,7 +958,15 @@ static int __init hsmp_plt_init(void) return ret; if (!plat_dev.is_acpi_device) { - ret = hsmp_plat_dev_register(); + if (legacy_hsmp_support()) { + /* Not ACPI device, but supports HSMP, register a plat_dev */ + ret = hsmp_plat_dev_register(); + } else { + /* Not ACPI, Does not support HSMP */ + pr_info("HSMP is not supported on Family:%x model:%x\n", + boot_cpu_data.x86, boot_cpu_data.x86_model); + ret = -ENODEV; + } if (ret) platform_driver_unregister(&amd_hsmp_driver); } -- 2.25.1
