diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2023-05-12 23:07:53 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-05-15 13:45:03 +0200 |
| commit | f6f1ae9128d2a080ecdd55f85e8a0ca3ed1d58eb (patch) | |
| tree | 4555b22acd29516c4d70dcd7ec0d2c412b441730 /arch/x86/realmode/init.c | |
| parent | bea629d57d006733d155bdb65ba4867788da69b6 (diff) | |
x86/smpboot: Implement a bit spinlock to protect the realmode stack
Parallel AP bringup requires that the APs can run fully parallel through
the early startup code including the real mode trampoline.
To prepare for this implement a bit-spinlock to serialize access to the
real mode stack so that parallel upcoming APs are not going to corrupt each
others stack while going through the real mode startup code.
Co-developed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205257.355425551@linutronix.de
Diffstat (limited to 'arch/x86/realmode/init.c')
| -rw-r--r-- | arch/x86/realmode/init.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index af565816d2ba..788e5559549f 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -154,6 +154,9 @@ static void __init setup_real_mode(void) trampoline_header->flags = 0; + trampoline_lock = &trampoline_header->lock; + *trampoline_lock = 0; + trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd); /* Map the real mode stub as virtual == physical */ |