6.9-stable review patch. If anyone has any objections, please let me know.
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From: Suma Hegde suma.hegde@amd.com
[ Upstream commit 77f1972bdcf7513293e8bbe376b9fe837310ee9c ]
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@amd.com Reviewed-by: Naveen Krishna Chatradhi naveenkrishna.chatradhi@amd.com Link: https://lore.kernel.org/r/20240603081512.142909-1-suma.hegde@amd.com Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1927be901108e..272d32a95e216 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); }