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>

1 files changed, 0 insertions, 12 deletions

diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index 8278960066c..46d66c0a7dc 100644
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -47,18 +47,6 @@ static struct of_device_id of_coherency_table[] = {
 	{ /* end of list */ },
 };
 
-#ifdef CONFIG_SMP
-int coherency_get_cpu_count(void)
-{
-	int reg, cnt;
-
-	reg = readl(coherency_base + COHERENCY_FABRIC_CFG_OFFSET);
-	cnt = (reg & 0xF) + 1;
-
-	return cnt;
-}
-#endif
-
 /* Function defined in coherency_ll.S */
 int ll_set_cpu_coherent(void __iomem *base_addr, unsigned int hw_cpu_id);