x86/process: Convert rdmsr() to rdmsrq() in arch_post_acpi_subsys_init() to address...

arch_post_acpi_subsys_init() reads MSR_K8_INT_PENDING_MSG with rdmsr()
into a lo/hi pair but only uses the low 32 bits: K8_INTP_C1E_ACTIVE_MASK
(0x18000000) lies entirely within them. The 'hi' half is never consumed,
which triggers a -Wunused-but-set-variable warning under W=1:

  arch/x86/kernel/process.c: In function 'arch_post_acpi_subsys_init':
  arch/x86/kernel/process.c:972:17: warning: variable 'hi' set but not used

Read the full MSR into a single u64 with rdmsrq() and test the mask
against it, dropping the now-unnecessary lo/hi variables.

No functional change intended.

Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jürgen Groß <jgross@suse.com>
Link: https://patch.msgid.link/20260604150052.3337246-1-sammiee5311@gmail.com

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 4c718f8adc592d5f9db023ecc3f4307cdb726dfe..a554f19c99730dd8a1a9d395e37509465554ff94 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -969,7 +969,7 @@ void amd_e400_c1e_apic_setup(void)
 
 void __init arch_post_acpi_subsys_init(void)
 {
-       u32 lo, hi;
+       u64 val;
 
        if (!boot_cpu_has_bug(X86_BUG_AMD_E400))
                return;
@@ -979,8 +979,8 @@ void __init arch_post_acpi_subsys_init(void)
         * the machine is affected K8_INTP_C1E_ACTIVE_MASK bits are set in
         * MSR_K8_INT_PENDING_MSG.
         */
-       rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
-       if (!(lo & K8_INTP_C1E_ACTIVE_MASK))
+       rdmsrq(MSR_K8_INT_PENDING_MSG, val);
+       if (!(val & K8_INTP_C1E_ACTIVE_MASK))
                return;
 
        boot_cpu_set_bug(X86_BUG_AMD_APIC_C1E);