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22 commits

Author SHA1 Message Date
Christoph Hellwig
fcdc653751 riscv: provide native clint access for M-mode
RISC-V has the concept of a cpu level interrupt controller.  The
interface for it is split between a standardized part that is exposed
as bits in the mstatus/sstatus register and the mie/mip/sie/sip
CRS.  But the bit to actually trigger IPIs is not standardized and
just mentioned as implementable using MMIO.

Add support for IPIs using MMIO using the SiFive clint layout (which
is also shared by Ariane, Kendryte and the Qemu virt platform).
Additionally the MMIO block also supports the time value and timer
compare registers, so they are also set up using the same OF node.
Support for other layouts should also be relatively easy to add in the
future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
[paul.walmsley@sifive.com: update include guard format; fix checkpatch
 issues; minor commit message cleanup]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17 15:17:39 -08:00
Paul Walmsley
f307307992 riscv: for C functions called only from assembly, mark with __visible
Rather than adding prototypes for C functions called only by assembly
code, mark them as __visible.  This avoids adding prototypes that will
never be used by the callers.  Resolves the following sparse warnings:

arch/riscv/kernel/irq.c:27:29: warning: symbol 'do_IRQ' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:151:6: warning: symbol 'do_syscall_trace_enter' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:165:6: warning: symbol 'do_syscall_trace_exit' was not declared. Should it be static?
arch/riscv/kernel/signal.c:295:17: warning: symbol 'do_notify_resume' was not declared. Should it be static?
arch/riscv/kernel/traps.c:92:1: warning: symbol 'do_trap_unknown' was not declared. Should it be static?
arch/riscv/kernel/traps.c:94:1: warning: symbol 'do_trap_insn_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:96:1: warning: symbol 'do_trap_insn_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:98:1: warning: symbol 'do_trap_insn_illegal' was not declared. Should it be static?
arch/riscv/kernel/traps.c💯1: warning: symbol 'do_trap_load_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:102:1: warning: symbol 'do_trap_load_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:104:1: warning: symbol 'do_trap_store_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:106:1: warning: symbol 'do_trap_store_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:108:1: warning: symbol 'do_trap_ecall_u' was not declared. Should it be static?
arch/riscv/kernel/traps.c:110:1: warning: symbol 'do_trap_ecall_s' was not declared. Should it be static?
arch/riscv/kernel/traps.c:112:1: warning: symbol 'do_trap_ecall_m' was not declared. Should it be static?
arch/riscv/kernel/traps.c:124:17: warning: symbol 'do_trap_break' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:136:24: warning: symbol 'smp_callin' was not declared. Should it be static?

Based on a suggestion from Luc Van Oostenryck.

This version includes changes based on feedback from Christoph Hellwig
<hch@lst.de>.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de> # for do_syscall_trace_*
2019-10-28 00:46:02 -07:00
Paul Walmsley
5ed881bc3a riscv: add missing header file includes
sparse identifies several missing prototypes caused by missing
preprocessor include directives:

arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static?
arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static?
arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static?
arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static?
arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static?
arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static?
arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static?
arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static?
arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static?

Fix by including the appropriate header files in the appropriate
source files.

This patch should have no functional impact.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-10-28 00:46:01 -07:00
Paul Walmsley
ffaee2728f riscv: add prototypes for assembly language functions from head.S
Add prototypes for assembly language functions defined in head.S,
and include these prototypes into C source files that call those
functions.

This patch resolves the following warnings from sparse:

arch/riscv/kernel/setup.c:39:10: warning: symbol 'hart_lottery' was not declared. Should it be static?
arch/riscv/kernel/setup.c:42:13: warning: symbol 'parse_dtb' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:33:6: warning: symbol '__cpu_up_stack_pointer' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:34:6: warning: symbol '__cpu_up_task_pointer' was not declared. Should it be static?
arch/riscv/mm/fault.c:25:17: warning: symbol 'do_page_fault' was not declared. Should it be static?

This change should have no functional impact.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-28 00:46:00 -07:00
Atish Patra
03f11f03db RISC-V: Parse cpu topology during boot.
Currently, there are no topology defined for RISC-V.
Parse the cpu-map node from device tree and setup the
cpu topology.

CPU topology after applying the patch.
$cat /sys/devices/system/cpu/cpu2/topology/core_siblings_list
0-3
$cat /sys/devices/system/cpu/cpu3/topology/core_siblings_list
0-3
$cat /sys/devices/system/cpu/cpu3/topology/physical_package_id
0
$cat /sys/devices/system/cpu/cpu3/topology/core_id
3

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-07-22 09:36:30 -07:00
Thomas Gleixner
1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00
Atish Patra
8b4302a442
RISC-V: Support nr_cpus command line option.
If nr_cpus command line option is set, maximum possible cpu should be
set to that value.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-16 20:42:04 -07:00
Atish Patra
ab3d265005
RISC-V: Implement nosmp commandline option.
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: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-30 09:47:45 -07:00
Atish Patra
291debb38d
RISC-V: Compare cpuid with NR_CPUS before mapping.
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: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-04 10:40:39 -08:00
Atish Patra
e15c6e3706
RISC-V: Do not wait indefinitely in __cpu_up
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: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-04 10:40:36 -08:00
Johan Hovold
dd81c8ab81
riscv: use for_each_of_cpu_node iterator
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: Johan Hovold <johan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11 15:35:52 -08:00
Andreas Schwab
2bb10639f1
RISC-V: fix bad use of of_node_put
of_find_node_by_type already calls of_node_put, don't call it again.

Fixes: 94f9bf118f ("RISC-V: Fix of_node_* refcount")
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-23 12:56:19 -08:00
Atish Patra
94f9bf118f
RISC-V: Fix of_node_* refcount
Fix of_node* refcount at various places by using of_node_put.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21 08:10:49 -08:00
Atish Patra
f99fb607fb
RISC-V: Use Linux logical CPU number instead of hartid
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: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Atish Patra
a37d56fc40
RISC-V: Use WRITE_ONCE instead of direct access
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: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Palmer Dabbelt
46373cb442
RISC-V: Use mmgrab()
commit f1f1007644 ("mm: add new mmgrab() helper") added a
helper that we missed out on.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
177fae4515
RISC-V: Rename im_okay_therefore_i_am to found_boot_cpu
The old name was a bit odd.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
b2f8cfa7ac
RISC-V: Rename riscv_of_processor_hart to riscv_of_processor_hartid
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: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Atish Patra
6db170ff4c
RISC-V: Disable preemption before enabling interrupts
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: Palmer Dabbelt <palmer@sifive.com>
[Atish: Commit text and code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
b18d6f0525
RISC-V: Comment on the TLB flush in smp_callin()
This isn't readily apparent from reading the code.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
62b0194368
clocksource: new RISC-V SBI timer driver
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: Dmitriy Cherkasov <dmitriy@oss-tech.org>
Signed-off-by: Palmer 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: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Palmer Dabbelt
76d2a0493a RISC-V: Init and Halt Code
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: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:44 -07:00