diff options
| author | Li RongQing <lirongqing@baidu.com> | 2026-03-03 02:46:35 -0500 |
|---|---|---|
| committer | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2026-03-23 14:48:57 +0200 |
| commit | 9f11d9b15efb5f77e810b6dfbeb01b4650a79eae (patch) | |
| tree | dde4c1350eb5dbc981441a19fdf604ca4c066aa1 /drivers | |
| parent | 435da773966c80e1b2b6aea75460ef0e893fd9e9 (diff) | |
platform/x86: ISST: Check HWP support before MSR access
On some systems, HWP can be explicitly disabled in the BIOS settings
When HWP is disabled by firmware, the HWP CPUID bit is not set, and
attempting to read MSR_PM_ENABLE will result in a General Protection
(GP) fault.
unchecked MSR access error: RDMSR from 0x770 at rIP: 0xffffffffc33db92e (disable_dynamic_sst_features+0xe/0x50 [isst_tpmi_core])
Call Trace:
<TASK>
? ex_handler_msr+0xf6/0x150
? fixup_exception+0x1ad/0x340
? gp_try_fixup_and_notify+0x1e/0xb0
? exc_general_protection+0xc9/0x390
? terminate_walk+0x64/0x100
? asm_exc_general_protection+0x22/0x30
? disable_dynamic_sst_features+0xe/0x50 [isst_tpmi_core]
isst_if_def_ioctl+0xece/0x1050 [isst_tpmi_core]
? ioctl_has_perm.constprop.42+0xe0/0x130
isst_if_def_ioctl+0x10d/0x1a0 [isst_if_common]
__se_sys_ioctl+0x86/0xc0
do_syscall_64+0x8a/0x100
entry_SYSCALL_64_after_hwframe+0x78/0xe2
RIP: 0033:0x7f36eaef54a7
Add a check for X86_FEATURE_HWP before accessing the MSR. If HWP is
not available, return true safely.
Fixes: 12a7d2cb811d ("platform/x86: ISST: Add SST-CP support via TPMI")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/20260303074635.2218-1-lirongqing@baidu.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c index b8cdaa233ea9..6f46cbb2898f 100644 --- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c +++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c @@ -558,6 +558,9 @@ static bool disable_dynamic_sst_features(void) { u64 value; + if (!static_cpu_has(X86_FEATURE_HWP)) + return true; + rdmsrq(MSR_PM_ENABLE, value); return !(value & 0x1); } |