Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b5bef297 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Greg Kroah-Hartman
Browse files

x86/smpboot: Remove stale TLB flush invocations 



commit 322f8b8b340c824aef891342b0f5795d15e11562 upstream.

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
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: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e798502c

arch/x86/kernel/smpboot.c

+0 −9
Original line number Diff line number Diff line
@@ -128,25 +128,16 @@ 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.