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platform/x86/amd/hsmp: Check HSMP support on AMD family of processors

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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>
This commit is contained in:
Suma Hegde 2024-06-03 08:15:12 +00:00 committed by Hans de Goede
parent 306aec7eea
commit 77f1972bdc
1 changed files with 43 additions and 7 deletions
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50
drivers/platform/x86/amd/hsmp.c
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@ -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);
}