From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 322f8b8b340c824aef891342b0f5795d15e11562 ] smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector() invoke local_flush_tlb() for no obvious reason. Digging in history revealed that the original code in the 2.1 era added those because the code manipulated a swapper_pg_dir pagetable entry. The pagetable manipulation was removed long ago in the 2.3 timeframe, but the TLB flush invocations stayed around forever. Remove them along with the pointless pr_debug()s which come from the same 2.1 change. Reported-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20171230211829.586548655@xxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- arch/x86/kernel/smpboot.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 50e547eac8cd..f6911cc90a81 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -107,25 +107,16 @@ static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(0xa, 0xf); spin_unlock_irqrestore(&rtc_lock, flags); - local_flush_tlb(); - pr_debug("1.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = start_eip >> 4; - pr_debug("2.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = start_eip & 0xf; - pr_debug("3.\n"); } static inline void smpboot_restore_warm_reset_vector(void) { unsigned long flags; - /* - * Install writable page 0 entry to set BIOS data area. - */ - local_flush_tlb(); - /* * Paranoid: Set warm reset code and vector here back * to default values. -- 2.14.1