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
This uses the 'wait' instruction to pause instruction execution when
idle until an interrupt occurs.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/Z5xtl1m_Gqc-HLjY@thinks.paulus.ozlabs.org
ppc_md.calibrate_decr() is a mandatory item. Its nullity is never
checked so it must be non null on all platforms.
Most platforms define generic_calibrate_decr() as their
ppc_md.calibrate_decr(). Have time_init() call
generic_calibrate_decr() when ppc_md.calibrate_decr() is NULL,
and remove default assignment from all machines.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/6cb9865d916231c38401ba34ad1a98c249fae135.1676711562.git.christophe.leroy@csgroup.eu
Use the new 'compatible' property for simple cases.
checkpatch complains about the new compatible being undocumented
but in reality nothing is new so just ignore it for the time
being.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/6cb9865d916231c38401ba34ad1a98c249fae135.1676711562.git.christophe.leroy@csgroup.eu
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
This adds support to the Microwatt platform to use the standard
16550-style UART which available in the standalone Microwatt FPGA.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwXGCTzedpQje7r@thinks.paulus.ozlabs.org
This is a simple native ICS backend that matches the layout of
the Microwatt implementation of ICS.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Add empty ics_native_init() to unbreak non-microwatt builds]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
fixup-ics
Link: https://lore.kernel.org/r/YMwW8cxrwB2W5EUN@thinks.paulus.ozlabs.org
Just like any other embedded platform.
Add an empty soc node.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwWx98+PMibZq/G@thinks.paulus.ozlabs.org
Microwatt is a FPGA-based implementation of the Power ISA. It
currently only implements little-endian 64-bit mode, and does
not (yet) support SMP, VMX, VSX or transactional memory. It has an
optional FPU, and an optional MMU (required for running Linux,
obviously) which implements a configurable radix tree but not
hypervisor mode or nested radix translation.
This adds a new machine type to support FPGA-based SoCs with a
Microwatt core. CONFIG_MATH_EMULATION can be selected for Microwatt
SOCs which don't have the FPU.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwWbZVREsVug9R0@thinks.paulus.ozlabs.org
