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linux/drivers/clocksource/timer-riscv.c

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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 10:23:19 +02:00
riscv: don't use the rdtime(h) pseudo-instructions If we just use the CSRs that these map to directly the code is simpler and doesn't require extra inline assembly code. Also fix up the top-level comment in timer-riscv.c to not talk about the cycle count or mention details of the clocksource interface, of which this file is just a consumer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-21 23:58:36 +09:00
riscv: add support for MMIO access to the timer registers When running in M-mode we can't use the SBI to set the timer, and don't have access to the time CSR as that usually is emulated by M-mode. Instead provide code that directly accesses the MMIO for the timer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource [paul.walmsley@sifive.com: updated to apply; fixed checkpatch issue; timex.h now includes asm/mmio.h to resolve header file problems] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-28 13:10:37 +01:00
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 10:23:19 +02:00
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
clocksource/timer-riscv: Add ACPI support Initialize the timer driver based on RHCT table on ACPI based platforms. Currently, ACPI doesn't support a flag to indicate that the timer interrupt can wake up the cpu irrespective of its power state. It will be added in future update. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-19-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:25 +05:30
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
RISC-V: KVM: Add timer functionality The RISC-V hypervisor specification doesn't have any virtual timer feature. Due to this, the guest VCPU timer will be programmed via SBI calls. The host will use a separate hrtimer event for each guest VCPU to provide timer functionality. We inject a virtual timer interrupt to the guest VCPU whenever the guest VCPU hrtimer event expires. This patch adds guest VCPU timer implementation along with ONE_REG interface to access VCPU timer state from user space. 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> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-09-27 17:10:11 +05:30
clocksource/drivers/riscv_timer: Provide the sched_clock Currently, we don't have a sched_clock registered for RISC-V systems. This means Linux time keeping will use jiffies (running at HZ) as the default sched_clock. To avoid this, we explicity provide sched_clock using RISC-V rdtime instruction (similar to riscv_timer clocksource). Signed-off-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2018-12-04 15:59:52 +05:30
riscv: add support for MMIO access to the timer registers When running in M-mode we can't use the SBI to set the timer, and don't have access to the time CSR as that usually is emulated by M-mode. Instead provide code that directly accesses the MMIO for the timer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource [paul.walmsley@sifive.com: updated to apply; fixed checkpatch issue; timex.h now includes asm/mmio.h to resolve header file problems] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-28 13:10:37 +01:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource: timer-riscv: Don't enable/disable timer interrupt Currently, we enable/disable timer interrupt at runtime to start/stop timer events. This makes timer interrupt state go out-of-sync with the Linux interrupt subsystem. To address the above issue, we can stop a per-HART timer interrupt by setting U64_MAX in timecmp CSR (or sbi_set_timer()) at the time of handling timer interrupt. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230710131902.1459180-2-apatel@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-10 18:49:01 +05:30
RISC-V: KVM: Add timer functionality The RISC-V hypervisor specification doesn't have any virtual timer feature. Due to this, the guest VCPU timer will be programmed via SBI calls. The host will use a separate hrtimer event for each guest VCPU to provide timer functionality. We inject a virtual timer interrupt to the guest VCPU whenever the guest VCPU hrtimer event expires. This patch adds guest VCPU timer implementation along with ONE_REG interface to access VCPU timer state from user space. 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> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-09-27 17:10:11 +05:30
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>
2018-10-02 12:15:05 -07:00
riscv: Rearrange hwcap.h and cpufeature.h Now hwcap.h and cpufeature.h are mutually including each other, and most of the variable/API declarations in hwcap.h are implemented in cpufeature.c, so, it's better to move them into cpufeature.h and leave only macros for ISA extension logical IDs in hwcap.h. BTW, the riscv_isa_extension_mask macro is not used now, so this patch removes it. Suggested-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Xiao Wang <xiao.w.wang@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20231031064553.2319688-2-xiao.w.wang@intel.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-31 14:45:52 +08:00
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 10:23:19 +02:00
RISC-V: Remove CLINT related code from timer and arch Right now the RISC-V timer driver is convoluted to support: 1. Linux RISC-V S-mode (with MMU) where it will use TIME CSR for clocksource and SBI timer calls for clockevent device. 2. Linux RISC-V M-mode (without MMU) where it will use CLINT MMIO counter register for clocksource and CLINT MMIO compare register for clockevent device. We now have a separate CLINT timer driver which also provide CLINT based IPI operations so let's remove CLINT MMIO related code from arch/riscv directory and RISC-V timer driver. Signed-off-by: Anup Patel <anup.patel@wdc.com> Tested-by: Emil Renner Berhing <kernel@esmil.dk> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-08-17 18:12:50 +05:30
riscv: add support for MMIO access to the timer registers When running in M-mode we can't use the SBI to set the timer, and don't have access to the time CSR as that usually is emulated by M-mode. Instead provide code that directly accesses the MMIO for the timer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource [paul.walmsley@sifive.com: updated to apply; fixed checkpatch issue; timex.h now includes asm/mmio.h to resolve header file problems] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-28 13:10:37 +01:00
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
clocksource/drivers/timer-riscv: Set CLOCK_EVT_FEAT_C3STOP based on DT We should set CLOCK_EVT_FEAT_C3STOP for a clock_event_device only when riscv,timer-cannot-wake-cpu DT property is present in the RISC-V timer DT node. This way CLOCK_EVT_FEAT_C3STOP feature is set for clock_event_device based on RISC-V platform capabilities rather than having it set for all RISC-V platforms. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230103141102.772228-4-apatel@ventanamicro.com Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
2023-01-03 19:41:02 +05:30
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
clocksource: timer-riscv: Don't enable/disable timer interrupt Currently, we enable/disable timer interrupt at runtime to start/stop timer events. This makes timer interrupt state go out-of-sync with the Linux interrupt subsystem. To address the above issue, we can stop a per-HART timer interrupt by setting U64_MAX in timecmp CSR (or sbi_set_timer()) at the time of handling timer interrupt. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230710131902.1459180-2-apatel@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-10 18:49:01 +05:30
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 10:23:19 +02:00
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
riscv: clocksource: Fix stimecmp update hazard on RV32 On RV32, updating the 64-bit stimecmp (or vstimecmp) CSR requires two separate 32-bit writes. A race condition exists if the timer triggers during these two writes. The RISC-V Privileged Specification (e.g., Section 3.2.1 for mtimecmp) recommends a specific 3-step sequence to avoid spurious interrupts when updating 64-bit comparison registers on 32-bit systems: 1. Set the low-order bits (stimecmp) to all ones (ULONG_MAX). 2. Set the high-order bits (stimecmph) to the desired value. 3. Set the low-order bits (stimecmp) to the desired value. Current implementation writes the LSB first without ensuring a future value, which may lead to a transient state where the 64-bit comparison is incorrectly evaluated as "expired" by the hardware. This results in spurious timer interrupts. This patch adopts the spec-recommended 3-step sequence to ensure the intermediate 64-bit state is never smaller than the current time. Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available") Signed-off-by: Naohiko Shimizu <naohiko.shimizu@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://patch.msgid.link/20260104135938.524-2-naohiko.shimizu@gmail.com Signed-off-by: Paul Walmsley <pjw@kernel.org>
2026-01-04 22:59:36 +09:00
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
riscv: clocksource: Fix stimecmp update hazard on RV32 On RV32, updating the 64-bit stimecmp (or vstimecmp) CSR requires two separate 32-bit writes. A race condition exists if the timer triggers during these two writes. The RISC-V Privileged Specification (e.g., Section 3.2.1 for mtimecmp) recommends a specific 3-step sequence to avoid spurious interrupts when updating 64-bit comparison registers on 32-bit systems: 1. Set the low-order bits (stimecmp) to all ones (ULONG_MAX). 2. Set the high-order bits (stimecmph) to the desired value. 3. Set the low-order bits (stimecmp) to the desired value. Current implementation writes the LSB first without ensuring a future value, which may lead to a transient state where the 64-bit comparison is incorrectly evaluated as "expired" by the hardware. This results in spurious timer interrupts. This patch adopts the spec-recommended 3-step sequence to ensure the intermediate 64-bit state is never smaller than the current time. Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available") Signed-off-by: Naohiko Shimizu <naohiko.shimizu@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://patch.msgid.link/20260104135938.524-2-naohiko.shimizu@gmail.com Signed-off-by: Paul Walmsley <pjw@kernel.org>
2026-01-04 22:59:36 +09:00
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
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 10:23:19 +02:00
clocksource/timer-riscv: Add riscv_clock_shutdown callback Add clocksource detach/shutdown callback to disable RISC-V timer interrupt when switching out riscv timer as clock source Signed-off-by: Joshua Yeong <joshua.yeong@starfivetech.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20231116105312.4800-1-joshua.yeong@starfivetech.com
2023-11-16 18:53:12 +08:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
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 10:23:19 +02:00
Revert "clocksource/drivers/riscv: Events are stopped during CPU suspend" This reverts commit 232ccac1bd9b5bfe73895f527c08623e7fa0752d. On the subject of suspend, the RISC-V SBI spec states: This does not cover whether any given events actually reach the hart or not, just what the hart will do if it receives an event. On PolarFire SoC, and potentially other SiFive based implementations, events from the RISC-V timer do reach a hart during suspend. This is not the case for the implementation on the Allwinner D1 - there timer events are not received during suspend. To fix this, the CLOCK_EVT_FEAT_C3STOP (mis)feature was enabled for the timer driver - but this has broken both RCU stall detection and timers generally on PolarFire SoC and potentially other SiFive based implementations. If an AXI read to the PCIe controller on PolarFire SoC times out, the system will stall, however, with CLOCK_EVT_FEAT_C3STOP active, the system just locks up without RCU stalling: io scheduler mq-deadline registered io scheduler kyber registered microchip-pcie 2000000000.pcie: host bridge /soc/pcie@2000000000 ranges: microchip-pcie 2000000000.pcie: MEM 0x2008000000..0x2087ffffff -> 0x0008000000 microchip-pcie 2000000000.pcie: sec error in pcie2axi buffer microchip-pcie 2000000000.pcie: ded error in pcie2axi buffer microchip-pcie 2000000000.pcie: axi read request error microchip-pcie 2000000000.pcie: axi read timeout microchip-pcie 2000000000.pcie: sec error in pcie2axi buffer microchip-pcie 2000000000.pcie: ded error in pcie2axi buffer microchip-pcie 2000000000.pcie: sec error in pcie2axi buffer microchip-pcie 2000000000.pcie: ded error in pcie2axi buffer microchip-pcie 2000000000.pcie: sec error in pcie2axi buffer microchip-pcie 2000000000.pcie: ded error in pcie2axi buffer Freeing initrd memory: 7332K Similarly issues were reported with clock_nanosleep() - with a test app that sleeps each cpu for 6, 5, 4, 3 ms respectively, HZ=250 & the blamed commit in place, 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 Fortunately, the D1 has a second timer, which is "currently used in preference to the RISC-V/SBI timer driver" so a revert here does not hurt operation of D1 in its current form. Ultimately, a DeviceTree property (or node) will be added to encode the behaviour of the timers, but until then revert the addition of CLOCK_EVT_FEAT_C3STOP. Fixes: 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend") Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Acked-by: Samuel Holland <samuel@sholland.org> Link: https://lore.kernel.org/linux-riscv/YzYTNQRxLr7Q9JR0@spud/ Link: https://github.com/riscv-non-isa/riscv-sbi-doc/issues/98/ Link: https://lore.kernel.org/linux-riscv/bf6d3b1f-f703-4a25-833e-972a44a04114@sholland.org/ Link: https://lore.kernel.org/r/20221122121620.3522431-1-conor.dooley@microchip.com
2022-11-22 12:16:21 +00:00
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 10:23:19 +02:00
clocksource/timer-riscv: Add riscv_clock_shutdown callback Add clocksource detach/shutdown callback to disable RISC-V timer interrupt when switching out riscv timer as clock source Signed-off-by: Joshua Yeong <joshua.yeong@starfivetech.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20231116105312.4800-1-joshua.yeong@starfivetech.com
2023-11-16 18:53:12 +08:00
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 10:23:19 +02:00
clocksource: riscv: add notrace to riscv_sched_clock When enabling ftrace graph tracer, it gets the tracing clock in ftrace_push_return_trace(). Eventually, it invokes riscv_sched_clock() to get the clock value. If riscv_sched_clock() isn't marked with 'notrace', it will call ftrace_push_return_trace() and cause infinite loop. The result of failure as follow: command: echo function_graph >current_tracer [ 46.176787] Unable to handle kernel paging request at virtual address ffffffe04fb38c48 [ 46.177309] Oops [#1] [ 46.177478] Modules linked in: [ 46.177770] CPU: 0 PID: 256 Comm: $d Not tainted 5.5.0-rc1 #47 [ 46.177981] epc: ffffffe00035e59a ra : ffffffe00035e57e sp : ffffffe03a7569b0 [ 46.178216] gp : ffffffe000d29b90 tp : ffffffe03a756180 t0 : ffffffe03a756968 [ 46.178430] t1 : ffffffe00087f408 t2 : ffffffe03a7569a0 s0 : ffffffe03a7569f0 [ 46.178643] s1 : ffffffe00087f408 a0 : 0000000ac054cda4 a1 : 000000000087f411 [ 46.178856] a2 : 0000000ac054cda4 a3 : 0000000000373ca0 a4 : ffffffe04fb38c48 [ 46.179099] a5 : 00000000153e22a8 a6 : 00000000005522ff a7 : 0000000000000005 [ 46.179338] s2 : ffffffe03a756a90 s3 : ffffffe00032811c s4 : ffffffe03a756a58 [ 46.179570] s5 : ffffffe000d29fe0 s6 : 0000000000000001 s7 : 0000000000000003 [ 46.179809] s8 : 0000000000000003 s9 : 0000000000000002 s10: 0000000000000004 [ 46.180053] s11: 0000000000000000 t3 : 0000003fc815749c t4 : 00000000000efc90 [ 46.180293] t5 : ffffffe000d29658 t6 : 0000000000040000 [ 46.180482] status: 0000000000000100 badaddr: ffffffe04fb38c48 cause: 000000000000000f Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> [paul.walmsley@sifive.com: cleaned up patch description] Fixes: 92e0d143fdef ("clocksource/drivers/riscv_timer: Provide the sched_clock") Cc: stable@vger.kernel.org Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-23 16:46:14 +08:00
clocksource/drivers/riscv_timer: Provide the sched_clock Currently, we don't have a sched_clock registered for RISC-V systems. This means Linux time keeping will use jiffies (running at HZ) as the default sched_clock. To avoid this, we explicity provide sched_clock using RISC-V rdtime instruction (similar to riscv_timer clocksource). Signed-off-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2018-12-04 15:59:52 +05:30
RISC-V: Remove per cpu clocksource There is only one clocksource in RISC-V. The boot cpu initializes that clocksource. No need to keep a percpu data structure. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-08-02 21:27:20 -07:00
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 10:23:19 +02:00
clocksource/drivers/riscv: Increase the clock source rating RISC-V provides an architectural clock source via the time CSR. This clock source exposes a 64-bit counter synchronized across all CPUs. Because it is accessed using a CSR, it is much more efficient to read than MMIO clock sources. For example, on the Allwinner D1, reading the sun4i timer in a loop takes 131 cycles/iteration, while reading the RISC-V time CSR takes only 5 cycles/iteration. Adjust the RISC-V clock source rating so it is preferred over the various platform-specific MMIO clock sources. Signed-off-by: Samuel Holland <samuel@sholland.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20221228004444.61568-1-samuel@sholland.org Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
2022-12-27 18:44:44 -06:00
clocksource/drivers/riscv: Fix clocksource mask For all riscv architectures (RV32, RV64 and RV128), the clocksource is a 64 bit incrementing counter. Fix the clock source mask accordingly. Tested on both 64bit and 32 bit virt machine in QEMU. Fixes: 62b019436814 ("clocksource: new RISC-V SBI timer driver") Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Anup Patel <anup@brainfault.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-riscv@lists.infradead.org Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Anup Patel <Anup.Patel@wdc.com> Cc: Damien Le Moal <Damien.LeMoal@wdc.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190322215411.19362-1-atish.patra@wdc.com
2019-03-22 14:54:11 -07:00
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 10:23:19 +02:00
clocksource/drivers/riscv: Get rid of clocksource_arch_init() callback Having a clocksource_arch_init() callback always sets vdso_clock_mode to VDSO_CLOCKMODE_ARCHTIMER if GENERIC_GETTIMEOFDAY is enabled, this is required for the riscv-timer. This works for platforms where just riscv-timer clocksource is present. On platforms where other clock sources are available we want them to register with vdso_clock_mode set to VDSO_CLOCKMODE_NONE. On the Renesas RZ/Five SoC OSTM block can be used as clocksource [0], to avoid multiple clock sources being registered as VDSO_CLOCKMODE_ARCHTIMER move setting of vdso_clock_mode in the riscv-timer driver instead of doing this in clocksource_arch_init() callback as done similarly for ARM/64 architecture. [0] drivers/clocksource/renesas-ostm.c Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Tested-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Samuel Holland <samuel@sholland.org> Link: https://lore.kernel.org/r/20221229224601.103851-1-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2022-12-29 22:46:01 +00:00
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Clear timer interrupt on timer initialization In the RISC-V specification, the stimecmp register doesn't have a default value. To prevent the timer interrupt from being triggered during timer initialization, clear the timer interrupt by writing stimecmp with a maximum value. Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available") Cc: <stable@vger.kernel.org> Signed-off-by: Ley Foon Tan <leyfoon.tan@starfivetech.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20240306172330.255844-1-leyfoon.tan@starfivetech.com
2024-03-07 01:23:30 +08:00
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource/drivers/timer-riscv: Set CLOCK_EVT_FEAT_C3STOP based on DT We should set CLOCK_EVT_FEAT_C3STOP for a clock_event_device only when riscv,timer-cannot-wake-cpu DT property is present in the RISC-V timer DT node. This way CLOCK_EVT_FEAT_C3STOP feature is set for clock_event_device based on RISC-V platform capabilities rather than having it set for all RISC-V platforms. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230103141102.772228-4-apatel@ventanamicro.com Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
2023-01-03 19:41:02 +05:30
clocksource: timer-riscv: Increase rating of clock_event_device for Sstc When Sstc is available the RISC-V timer clock_event_device should be the preferred clock_event_device hence we increase clock_event_device rating for Sstc. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230710131902.1459180-3-apatel@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-10 18:49:02 +05:30
clocksource: extend the max_delta_ns of timer-riscv and timer-clint to ULONG_MAX When registering the riscv-timer or clint-timer as a clock_event device, the driver needs to specify the value of max_delta_ticks. This value directly influences the max_delta_ns, which represents the maximum time interval for configuring subsequent clock events. Currently, both riscv-timer and clint-timer are set with a max_delta_ticks value of 0x7fff_ffff. When the timer operates at a high frequency, this values limists the system to sleep only for a short time. For the 1GHz case, the sleep cannot exceed two seconds. To address this limitation, refer to other timer implementations to extend it to 2^(bit-width of the timer) - 1. Because the bit-width of $mtimecmp is 64bit, this value becomes ULONG_MAX (0xffff_ffff_ffff_ffff). Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Link: https://lore.kernel.org/r/20230905070945.404653-1-vincent.chen@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-05 15:09:45 +08:00
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Stop stimecmp when cpu hotplug Stop the timer when the cpu is going to be offline otherwise the timer interrupt may be pending while performing power-down. Suggested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/lkml/20240829033904.477200-3-nick.hu@sifive.com/T/#u Signed-off-by: Nick Hu <nick.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20250219114135.27764-3-nick.hu@sifive.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-02-19 19:41:35 +08:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource/drivers/timer-riscv: Stop stimecmp when cpu hotplug Stop the timer when the cpu is going to be offline otherwise the timer interrupt may be pending while performing power-down. Suggested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/lkml/20240829033904.477200-3-nick.hu@sifive.com/T/#u Signed-off-by: Nick Hu <nick.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20250219114135.27764-3-nick.hu@sifive.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-02-19 19:41:35 +08:00
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 10:23:19 +02:00
RISC-V: KVM: Add timer functionality The RISC-V hypervisor specification doesn't have any virtual timer feature. Due to this, the guest VCPU timer will be programmed via SBI calls. The host will use a separate hrtimer event for each guest VCPU to provide timer functionality. We inject a virtual timer interrupt to the guest VCPU whenever the guest VCPU hrtimer event expires. This patch adds guest VCPU timer implementation along with ONE_REG interface to access VCPU timer state from user space. 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> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-09-27 17:10:11 +05:30
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
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 10:23:19 +02:00
clocksource: timer-riscv: Don't enable/disable timer interrupt Currently, we enable/disable timer interrupt at runtime to start/stop timer events. This makes timer interrupt state go out-of-sync with the Linux interrupt subsystem. To address the above issue, we can stop a per-HART timer interrupt by setting U64_MAX in timecmp CSR (or sbi_set_timer()) at the time of handling timer interrupt. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230710131902.1459180-2-apatel@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-10 18:49:01 +05:30
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 10:23:19 +02:00
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
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 10:23:19 +02:00
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
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 10:23:19 +02:00
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
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 10:23:19 +02:00
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
RISC-V: Remove per cpu clocksource There is only one clocksource in RISC-V. The boot cpu initializes that clocksource. No need to keep a percpu data structure. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-08-02 21:27:20 -07:00
clocksource/drivers/riscv: Add required checks during clock source init Currently, clocksource registration happens for an invalid cpu for non-smp kernels. This lead to kernel panic as cpu hotplug registration will fail for those cpus. Moreover, riscv_hartid_to_cpuid can return errors now. Do not proceed if hartid or cpuid is invalid. Take this opportunity to print appropriate error strings for different failure cases. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-02-13 12:18:10 -08:00
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
clocksource/drivers/riscv: Add required checks during clock source init Currently, clocksource registration happens for an invalid cpu for non-smp kernels. This lead to kernel panic as cpu hotplug registration will fail for those cpus. Moreover, riscv_hartid_to_cpuid can return errors now. Do not proceed if hartid or cpuid is invalid. Take this opportunity to print appropriate error strings for different failure cases. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-02-13 12:18:10 -08:00
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 10:23:19 +02:00
clocksource/drivers/riscv: Fix clocksource mask For all riscv architectures (RV32, RV64 and RV128), the clocksource is a 64 bit incrementing counter. Fix the clock source mask accordingly. Tested on both 64bit and 32 bit virt machine in QEMU. Fixes: 62b019436814 ("clocksource: new RISC-V SBI timer driver") Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Anup Patel <anup@brainfault.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-riscv@lists.infradead.org Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Anup Patel <Anup.Patel@wdc.com> Cc: Damien Le Moal <Damien.LeMoal@wdc.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190322215411.19362-1-atish.patra@wdc.com
2019-03-22 14:54:11 -07:00
clocksource/drivers/riscv_timer: Provide the sched_clock Currently, we don't have a sched_clock registered for RISC-V systems. This means Linux time keeping will use jiffies (running at HZ) as the default sched_clock. To avoid this, we explicity provide sched_clock using RISC-V rdtime instruction (similar to riscv_timer clocksource). Signed-off-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2018-12-04 15:59:52 +05:30
clocksource/drivers/timer-riscv: Use per-CPU timer interrupt Instead of directly calling RISC-V timer interrupt handler from RISC-V local interrupt conntroller driver, this patch implements RISC-V timer interrupt as a per-CPU interrupt using per-CPU APIs of Linux IRQ subsystem. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-01 14:45:41 +05:30
clocksource/drivers/riscv: Patch riscv_clock_next_event() jump before first use A static key is used to select between SBI and Sstc timer usage in riscv_clock_next_event(), but currently the direction is resolved after cpuhp_setup_state() is called (which sets the next event). The first event will therefore fall through the sbi_set_timer() path; this breaks Sstc-only systems. So, apply the jump patching before first use. Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available") Signed-off-by: Matt Evans <mev@rivosinc.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/CDDAB2D0-264E-42F3-8E31-BA210BEB8EC1@rivosinc.com Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-02-01 19:49:42 +00:00
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 10:23:19 +02:00
clocksource/drivers/riscv: Add required checks during clock source init Currently, clocksource registration happens for an invalid cpu for non-smp kernels. This lead to kernel panic as cpu hotplug registration will fail for those cpus. Moreover, riscv_hartid_to_cpuid can return errors now. Do not proceed if hartid or cpuid is invalid. Take this opportunity to print appropriate error strings for different failure cases. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-02-13 12:18:10 -08:00
RISC-V: Prefer sstc extension if available RISC-V ISA has sstc extension which allows updating the next clock event via a CSR (stimecmp) instead of an SBI call. This should happen dynamically if sstc extension is available. Otherwise, it will fallback to SBI call to maintain backward compatibility. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220722165047.519994-4-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-22 09:50:46 -07:00
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 10:23:19 +02:00
clocksource/timer-riscv: Refactor riscv_timer_init_dt() Refactor the timer init function such that few things can be shared by both DT and ACPI based platforms. Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-18-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:24 +05:30
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 10:23:19 +02:00
clocksource/timer-riscv: Add ACPI support Initialize the timer driver based on RHCT table on ACPI based platforms. Currently, ACPI doesn't support a flag to indicate that the timer interrupt can wake up the cpu irrespective of its power state. It will be added in future update. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-19-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:25 +05:30
clocksource/timer-riscv: ACPI: Add timer_cannot_wakeup_cpu The timer capability to wakeup the cpu irrespective of its idle state is provided by the flag in RHCT. Update the timer code to set this flag. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20230927170015.295232-5-sunilvl@ventanamicro.com
2023-09-27 22:30:15 +05:30
clocksource/timer-riscv: Add ACPI support Initialize the timer driver based on RHCT table on ACPI based platforms. Currently, ACPI doesn't support a flag to indicate that the timer interrupt can wake up the cpu irrespective of its power state. It will be added in future update. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230515054928.2079268-19-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-15 11:19:25 +05:30