If nr_cpus command line option is set, maximum possible cpu should be
set to that value.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

nosmp command line option sets max_cpus to zero. No secondary harts
will boot if this is enabled. But present cpu mask will still point to
all possible masks.

Fix present cpu mask for nosmp usecase.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

We should never have a cpuid greater that NR_CPUS. Compare with NR_CPUS
before creating the mapping between logical and physical CPU ids. This
is also mandatory as NR_CPUS check is removed from
riscv_of_processor_hartid.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NAnup Patel <anup@brainfault.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

In SMP path, __cpu_up waits for other CPU to come online indefinitely.
This is wrong as other CPU might be disabled in machine mode and
possible CPU is set to the cpus present in DT.

Introduce a completion variable and waits only for a second.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NAnup Patel <anup@brainfault.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Use the new for_each_of_cpu_node() helper to iterate over cpu nodes
instead of open coding. Note that this will allow matching also on the
node name instead of the (for FDT) deprecated device_type property.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

of_find_node_by_type already calls of_node_put, don't call it again.

Fixes: 94f9bf11 ("RISC-V: Fix of_node_* refcount")
Signed-off-by: NAndreas Schwab <schwab@suse.de>
Reviewed-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Fix of_node* refcount at various places by using of_node_put.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Setup the cpu_logical_map during boot. Moreover, every SBI call
and PLIC context are based on the physical hartid. Use the logical
CPU to hartid mapping to pass correct hartid to respective functions.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NAnup Patel <anup@brainfault.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The secondary harts spin on couple of per cpu variables until both of
these are non-zero so it's not necessary to have any ordering here.
However, WRITE_ONCE should be used to avoid tearing.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

commit f1f10076 ("mm: add new mmgrab() helper") added a
helper that we missed out on.
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The old name was a bit odd.
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

It's a bit confusing exactly what this function does: it actually
returns the hartid of an OF processor node, failing with -1 on invalid
nodes.  I've changed the name to _hartid() in order to make that a bit
more clear, as well as adding a comment.
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Currently, irq is enabled before preemption disabling happens.
If the scheduler fired right here and cpu is scheduled then it
may blow up.
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
[Atish: Commit text and code comment formatting update]
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This isn't readily apparent from reading the code.
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

Contains various improvements from Atish Patra <atish.patra@wdc.com>.
Signed-off-by: NDmitriy Cherkasov <dmitriy@oss-tech.org>
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>
[hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(),
 minor cleanups, merged  hotplug cpu support and other improvements
 from Atish]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>