This adds support for Microwatt systems with more than one core, and
updates the device tree for a 2-core version.
The secondary CPUs are started and sent to spin in __secondary_hold
very early on, in the platform probe function. The reason for doing
this is so that they are there when smp_release_cpus() gets called,
which is before the platform init_smp function or even the platform
setup_arch function gets called.
Note that having two CPUs in the device tree doesn't preclude
operation with only one CPU. The SYSCON_CPU_CTRL register has a
read-only field which indicates the number of CPU cores, so
microwatt_init_smp() will only start as many CPU cores as are present
in the system, and any extra CPU device-tree nodes will just be
ignored.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/Z5xt8aooKyXZv6Kf@thinks.paulus.ozlabs.org
The platform's RNG must be available before random_init() in order to be
useful for initial seeding, which in turn means that it needs to be
called from setup_arch(), rather than from an init call. Fortunately,
each platform already has a setup_arch function pointer, which means
it's easy to wire this up. This commit also removes some noisy log
messages that don't add much.
Fixes: c25769fdda ("powerpc/microwatt: Add support for hardware random number generator")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220611151015.548325-2-Jason@zx2c4.com
