From: Thomas Gleixner tglx@linutronix.de
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ 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@dominikbrodowski.net Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Linus Torvalds torvalds@linuxfoundation.org Cc: Peter Zijlstra peterz@infradead.org Link: http://lkml.kernel.org/r/20171230211829.586548655@linutronix.de Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- 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.