linux.git/arch/riscv/kernel/time.c, branch v5.19

Merge tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2021-05-06T16:24:18+00:00

Pull RISC-V updates from Palmer Dabbelt:

- Support for the memtest= kernel command-line argument.

- Support for building the kernel with FORTIFY_SOURCE.

- Support for generic clockevent broadcasts.

- Support for the buildtar build target.

- Some build system cleanups to pass more LLVM-friendly arguments.

- Support for kprobes.

- A rearranged kernel memory map, the first part of supporting sv48
systems.

- Improvements to kexec, along with support for kdump and crash
kernels.

- An alternatives-based errata framework, along with support for
handling a pair of errata that manifest on some SiFive designs
(including the HiFive Unmatched).

- Support for XIP.

- A device tree for the Microchip PolarFire ICICLE SoC and associated
dev board.

... along with a bunch of cleanups. There are already a handful of fixes
on the list so there will likely be a part 2.

* tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (45 commits)
RISC-V: Always define XIP_FIXUP
riscv: Remove 32b kernel mapping from page table dump
riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=y
RISC-V: Fix error code returned by riscv_hartid_to_cpuid()
RISC-V: Enable Microchip PolarFire ICICLE SoC
RISC-V: Initial DTS for Microchip ICICLE board
dt-bindings: riscv: microchip: Add YAML documentation for the PolarFire SoC
RISC-V: Add Microchip PolarFire SoC kconfig option
RISC-V: enable XIP
RISC-V: Add crash kernel support
RISC-V: Add kdump support
RISC-V: Improve init_resources()
RISC-V: Add kexec support
RISC-V: Add EM_RISCV to kexec UAPI header
riscv: vdso: fix and clean-up Makefile
riscv/mm: Use BUG_ON instead of if condition followed by BUG.
riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe
riscv: Set ARCH_HAS_STRICT_MODULE_RWX if MMU
riscv: module: Create module allocations without exec permissions
riscv: bpf: Avoid breaking W^X
...

riscv: Mark some global variables __ro_after_init

2021-04-26T15:25:08+00:00

All of these are never modified after init, so they can be
__ro_after_init.

Signed-off-by: Jisheng Zhang 
Signed-off-by: Palmer Dabbelt

riscv: time: Fix no prototype for time_init

2021-03-10T04:46:03+00:00

Fix the following W=1 compilation warning:
arch/riscv/kernel/time.c:16:13: warning: no previous prototype for ‘time_init’ [-Wmissing-prototypes]
   16 | void __init time_init(void)
      |             ^~~~~~~~~

Reported-by: Hulk Robot 
Signed-off-by: Nanyong Sun 
Signed-off-by: Palmer Dabbelt

riscv: Fix kernel time_init()

2021-01-08T02:01:36+00:00

If of_clk_init() is not called in time_init(), clock providers defined
in the system device tree are not initialized, resulting in failures for
other devices to initialize due to missing clocks.
Similarly to other architectures and to the default kernel time_init()
implementation, call of_clk_init() before executing timer_probe() in
time_init().

Signed-off-by: Damien Le Moal 
Acked-by: Stephen Boyd 
Reviewed-by: Palmer Dabbelt 
Signed-off-by: Palmer Dabbelt

riscv: use vDSO common flow to reduce the latency of the time-related functions

2020-06-11T02:47:16+00:00

Even if RISC-V has supported the vDSO feature, the latency of the functions
for obtaining the system time is still expensive. It is because these
functions still trigger a corresponding system call in the process, which
slows down the response time. If we want to remove the system call to
reduce the latency, the kernel should have the ability to output the system
clock information to userspace. This patch introduces the vDSO common flow
to enable the kernel to achieve the above feature and uses "rdtime"
instruction to obtain the current time in the user space. Under this
condition, the latency cost by the ecall from U-mode to S-mode can be
eliminated. After applying this patch, the latency of gettimeofday()
measured on the HiFive unleashed board can be reduced by %61.

Signed-off-by: Vincent Chen 
Reviewed-by: Atish Patra 
Signed-off-by: Palmer Dabbelt

riscv: add missing header file includes

2019-10-28T07:46:01+00:00

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 
Reviewed-by: Christoph Hellwig

RISC-V: Export kernel symbols for kvm

2019-09-20T15:36:39+00:00

Export a few symbols used by kvm module. Without this, kvm cannot
be compiled as a module.

Signed-off-by: Atish Patra 
Signed-off-by: Anup Patel 
Acked-by: Paolo Bonzini 
Reviewed-by: Paolo Bonzini 
Reviewed-by: Alexander Graf 
[paul.walmsley@sifive.com: updated to apply; clarified short patch
 description]
Signed-off-by: Paul Walmsley

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286

2019-06-05T15:36:37+00:00

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 as published by
  the free software foundation version 2 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 97 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Alexios Zavras 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman

RISC-V: add of_node_put()

2018-12-21T16:11:08+00:00

use of_node_put() to release the refcount.

Signed-off-by: Yangtao Li 
Signed-off-by: Palmer Dabbelt

clocksource: new RISC-V SBI timer driver

2018-08-13T15:31:31+00:00

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 .

Signed-off-by: Dmitriy Cherkasov 
Signed-off-by: Palmer Dabbelt 
[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 
Acked-by: Thomas Gleixner 
Reviewed-by: Atish Patra 
Signed-off-by: Palmer Dabbelt