[joro:sev-es-kexec 8/12] arch/x86/kernel/sev.c:699:17: warning: no previous prototype for 'sev_jumptable_ap_park'

From: kernel test robot
Date: Fri Jul 02 2021 - 19:27:14 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git sev-es-kexec
head: 3467dc3cdbe65c619cd9b5c8db47da63b0655300
commit: 700d0a170431bd18f1f3e1d10befe530bce97567 [8/12] x86/sev: Park APs on AP Jump Table with GHCB protocol version 2
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git/commit/?id=700d0a170431bd18f1f3e1d10befe530bce97567
git remote add joro https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git
git fetch --no-tags joro sev-es-kexec
git checkout 700d0a170431bd18f1f3e1d10befe530bce97567
# save the attached .config to linux build tree
make W=1 ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> arch/x86/kernel/sev.c:699:17: warning: no previous prototype for 'sev_jumptable_ap_park' [-Wmissing-prototypes]
699 | void __noreturn sev_jumptable_ap_park(void)
| ^~~~~~~~~~~~~~~~~~~~~
arch/x86/kernel/sev.c:794:13: warning: no previous prototype for 'sev_es_setup_ap_jump_table_data' [-Wmissing-prototypes]
794 | void __init sev_es_setup_ap_jump_table_data(void *base, u32 pa)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/sev_jumptable_ap_park +699 arch/x86/kernel/sev.c

697
698 #ifdef CONFIG_HOTPLUG_CPU
> 699 void __noreturn sev_jumptable_ap_park(void)
700 {
701 local_irq_disable();
702
703 write_cr3(real_mode_header->trampoline_pgd);
704
705 /* Exiting long mode will fail if CR4.PCIDE is set. */
706 if (boot_cpu_has(X86_FEATURE_PCID))
707 cr4_clear_bits(X86_CR4_PCIDE);
708
709 asm volatile("xorq %%r15, %%r15\n"
710 "xorq %%r14, %%r14\n"
711 "xorq %%r13, %%r13\n"
712 "xorq %%r12, %%r12\n"
713 "xorq %%r11, %%r11\n"
714 "xorq %%r10, %%r10\n"
715 "xorq %%r9, %%r9\n"
716 "xorq %%r8, %%r8\n"
717 "xorq %%rsi, %%rsi\n"
718 "xorq %%rdi, %%rdi\n"
719 "xorq %%rsp, %%rsp\n"
720 "xorq %%rbp, %%rbp\n"
721 "ljmpl *%0" : :
722 "m" (real_mode_header->sev_real_ap_park_asm),
723 "b" (sev_es_jump_table_pa >> 4));
724 unreachable();
725 }
726 STACK_FRAME_NON_STANDARD(sev_jumptable_ap_park);
727

---
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