linux_dsm_epyc7002/arch/arm/mach-mvebu/coherency.h
Thomas Petazzoni b21dcafea3 arm: mvebu: remove dependency of SMP init on static I/O mapping
The ->smp_init_cpus() function is called very early during boot, at a
point where dynamic I/O mappings are not yet possible. However, in the
Armada 370/XP implementation of this function, we have to get the
number of CPUs. We used to do that by accessing a hardware register,
which requires relying on a static I/O mapping set up by
->map_io(). Not only this requires hardcoding a virtual address, but
it also prevents us from removing the static I/O mapping.

So this commit changes the way used to get the number of CPUs: we now
use the Device Tree, which is a representation of the hardware, and
provides us the number of available CPUs. This is also more accurate,
because it potentially allows to boot the Linux kernel on only a
number of CPUs given by the Device Tree, instead of unconditionally on
all CPUs.

As a consequence, the coherency_get_cpu_count() function becomes no
longer used, so we remove it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2013-06-13 17:48:13 +00:00

21 lines
543 B
C

/*
* arch/arm/mach-mvebu/include/mach/coherency.h
*
*
* Coherency fabric (Aurora) support for Armada 370 and XP platforms.
*
* Copyright (C) 2012 Marvell
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#ifndef __MACH_370_XP_COHERENCY_H
#define __MACH_370_XP_COHERENCY_H
int set_cpu_coherent(int cpu_id, int smp_group_id);
int coherency_init(void);
#endif /* __MACH_370_XP_COHERENCY_H */