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acrn-kernel/arch/riscv/kernel/time.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 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 <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29 22:18:00 +08:00
// SPDX-License-Identifier: GPL-2.0-only
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>
2017-07-11 09:00:26 +08:00
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*/
riscv: Fix kernel time_init() 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 <damien.lemoal@wdc.com> Acked-by: Stephen Boyd <sboyd@kernel.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-12-13 21:50:34 +08:00
#include <linux/of_clk.h>
RISC-V: time: initialize hrtimer based broadcast clock event device [ Upstream commit 8b3b8fbb4896984b5564789a42240e4b3caddb61 ] Similarly to commit 022eb8ae8b5e ("ARM: 8938/1: kernel: initialize broadcast hrtimer based clock event device"), RISC-V needs to initiate hrtimer based broadcast clock event device before C3STOP can be used. Otherwise, the introduction of C3STOP for the RISC-V arch timer in commit 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend") leaves us without any broadcast timer registered. This prevents the kernel from entering oneshot mode, which breaks timer behaviour, for example clock_nanosleep(). A test app that sleeps each cpu for 6, 5, 4, 3 ms respectively, HZ=250 & C3STOP enabled, the sleep times are rounded up to the next jiffy: == CPU: 1 == == CPU: 2 == == CPU: 3 == == CPU: 4 == Mean: 7.974992 Mean: 7.976534 Mean: 7.962591 Mean: 3.952179 Std Dev: 0.154374 Std Dev: 0.156082 Std Dev: 0.171018 Std Dev: 0.076193 Hi: 9.472000 Hi: 10.495000 Hi: 8.864000 Hi: 4.736000 Lo: 6.087000 Lo: 6.380000 Lo: 4.872000 Lo: 3.403000 Samples: 521 Samples: 521 Samples: 521 Samples: 521 Link: https://lore.kernel.org/linux-riscv/YzYTNQRxLr7Q9JR0@spud/ Fixes: 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend") Suggested-by: Samuel Holland <samuel@sholland.org> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Samuel Holland <samuel@sholland.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230103141102.772228-2-apatel@ventanamicro.com Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-03 22:11:00 +08:00
#include <linux/clockchips.h>
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>
2017-07-11 09:00:26 +08:00
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <asm/sbi.h>
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>
2019-10-18 06:21:28 +08:00
#include <asm/processor.h>
riscv: time: Fix no prototype for time_init 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 <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-05 19:33:28 +08:00
#include <asm/timex.h>
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>
2017-07-11 09:00:26 +08:00
riscv: Mark some global variables __ro_after_init All of these are never modified after init, so they can be __ro_after_init. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-30 02:22:51 +08:00
unsigned long riscv_timebase __ro_after_init;
RISC-V: Export kernel symbols for kvm Export a few symbols used by kvm module. Without this, kvm cannot be compiled as a module. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> [paul.walmsley@sifive.com: updated to apply; clarified short patch description] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-05 00:14:06 +08:00
EXPORT_SYMBOL_GPL(riscv_timebase);
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>
2017-07-11 09:00:26 +08:00
void __init time_init(void)
{
struct device_node *cpu;
u32 prop;
cpu = of_find_node_by_path("/cpus");
if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
RISC-V: add of_node_put() use of_node_put() to release the refcount. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-11-20 22:11:02 +08:00
of_node_put(cpu);
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>
2017-07-11 09:00:26 +08:00
riscv_timebase = prop;
lpj_fine = riscv_timebase / HZ;
riscv: Fix kernel time_init() 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 <damien.lemoal@wdc.com> Acked-by: Stephen Boyd <sboyd@kernel.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-12-13 21:50:34 +08:00
of_clk_init(NULL);
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>
2018-08-04 16:23:19 +08:00
timer_probe();
RISC-V: time: initialize hrtimer based broadcast clock event device [ Upstream commit 8b3b8fbb4896984b5564789a42240e4b3caddb61 ] Similarly to commit 022eb8ae8b5e ("ARM: 8938/1: kernel: initialize broadcast hrtimer based clock event device"), RISC-V needs to initiate hrtimer based broadcast clock event device before C3STOP can be used. Otherwise, the introduction of C3STOP for the RISC-V arch timer in commit 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend") leaves us without any broadcast timer registered. This prevents the kernel from entering oneshot mode, which breaks timer behaviour, for example clock_nanosleep(). A test app that sleeps each cpu for 6, 5, 4, 3 ms respectively, HZ=250 & C3STOP enabled, the sleep times are rounded up to the next jiffy: == CPU: 1 == == CPU: 2 == == CPU: 3 == == CPU: 4 == Mean: 7.974992 Mean: 7.976534 Mean: 7.962591 Mean: 3.952179 Std Dev: 0.154374 Std Dev: 0.156082 Std Dev: 0.171018 Std Dev: 0.076193 Hi: 9.472000 Hi: 10.495000 Hi: 8.864000 Hi: 4.736000 Lo: 6.087000 Lo: 6.380000 Lo: 4.872000 Lo: 3.403000 Samples: 521 Samples: 521 Samples: 521 Samples: 521 Link: https://lore.kernel.org/linux-riscv/YzYTNQRxLr7Q9JR0@spud/ Fixes: 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend") Suggested-by: Samuel Holland <samuel@sholland.org> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Samuel Holland <samuel@sholland.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230103141102.772228-2-apatel@ventanamicro.com Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-03 22:11:00 +08:00
tick_setup_hrtimer_broadcast();
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>
2017-07-11 09:00:26 +08:00
}
riscv: use vDSO common flow to reduce the latency of the time-related functions 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 <vincent.chen@sifive.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 22:14:48 +08:00
void clocksource_arch_init(struct clocksource *cs)
{
#ifdef CONFIG_GENERIC_GETTIMEOFDAY
cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
#else
cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
#endif
}