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path: root/lib/sbi/sbi_timer.c
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2026-05-09lib: sbi_timer: Introduce sbi_timer_compute_delta() and friendsAnup Patel
The users of timer event have to compute next_event (aka timer value in the future) based on desired units and unit frequency. Introduce sbi_timer_compute_delta() and friends to simplify computing next_event for timer event users. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Nicholas Piggin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2026-05-09lib: sbi_timer: Add support for timer eventsAnup Patel
Currently, the sbi_timer only supports timer events configured via SBI calls. Introduce struct sbi_timer_event and related functions to allow configuring timer events from any part of OpenSBI. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Nicholas Piggin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2026-05-09lib: sbi_timer: Introduce per-HART timer stateAnup Patel
Currently, only time_delta is per-HART so introduce per-HART timer state for having more per-HART timer information. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Nicholas Piggin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-05-20lib: sbi: hart: Detect existence of cycle and instret CSRs for ZicntrYao Zi
Zicntr extension specifies three read-only CSRs, time, cycle and instret. It isn't sufficient to report Zicntr is fully supported with only time CSR detected. This patch introduces a bitmap to sbi_hart_features to record availability of these CSRs, which are detected using traps. Zicntr is reported as present if and only if three CSRs are all available on the HARTs. Sites originally depending on SBI_HART_EXT_ZICNTR for detecting existence of time CSR are switched to detect SBI_HART_CSR_TIME instead. Suggested-by: Anup Patel <[email protected]> Signed-off-by: Yao Zi <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-04-30lib: sbi: use 64 bit csr macrosRadim Krčmář
Switch the most obvious cases to new macros. Reviewed-by: Anup Patel <[email protected]> Signed-off-by: Radim Krčmář <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2024-11-05platform: Drop timer warm init and exit hooksSamuel Holland
Now that driver lifecycle is managed from within the SBI timer core, platforms need only to initialize the driver once during cold init. Remove the remaining platform hooks that are no longer used. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2024-11-05lib: sbi_timer: Call driver warm_init from SBI coreSamuel Holland
Currently, the platform's timer device is tracked in two places: the core SBI implementation has `timer_dev`, and the FDT timer layer has `current_driver`. The latter is used for warm initialization of the timer device. However, this warm init is not specific to FDT-based platforms; other platforms call exactly the same functions from the same point in the boot sequence. The code is simplified and made common across platforms by treating warm init and exit as properties of the driver, not the platform. Then the platform's only role is to select and prepare a driver during cold boot. For now, only add a .warm_init hook, since none of the existing drivers need an .exit hook. It could be added in the future if needed. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2024-09-20lib: sbi: Fix writes to emulated 32-bit htimedelta CSRSamuel Holland
Writes to the low half CSR should not affect the high half of the value. Make this separation explicit by writing to the delta in memory as two adjacent XLEN-sized values. Fixes: 1e9f88889f8b ("lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSR") Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2023-07-09lib: sbi: Add Zicntr as a HART ISA extensionAnup Patel
Recently ratified Zicntr ISA extension covers cycle, time and instret CSRs so we replace the "time" ISA extension with "zicntr" ISA extension in OpenSBI. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Xiang W <[email protected]>
2022-07-08lib: sbi_timer: Added a conditional wait function which can timeoutAdnan Rahman Chowdhury
Motivation: Suppose a peripheral needs to be configured to transmit data. There is an SFR bit which indicates that the peripheral is ready to transmit. The firmware should check the bit and will only transmit data when the peripheral is ready. When the firmware starts polling the SFR, the peripheral could be busy transmitting/receiving other data so the firmware must wait till that completes. Assuming that there is no other way, the firmware shouldn't wait indefinitely. The function sbi_timer_waitms_until() will constantly check whether a certain condition is satisfied, or timeout occurs. It can be used for the cases when a timeout is required. Signed-off-by: Adnan Rahman Chowdhury <[email protected]> Reviewed-by: Xiang W <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2022-05-30lib: sbi_timer: Drop unnecessary get_platform_ticks wrapperSamuel Holland
The device's timer_value callback is already the right prototype to use for the get_time_val function pointer. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2022-05-07lib: sbi: Convert hart features into hart extensionsAnup Patel
Since past few years, we have been using "hart features" in OpenSBI to represent all optionalities and multi-letter extensions defined by the RISC-V specifications. The RISC-V profiles specification has taken a different approach and started assigning extension names for all optionalities which did not have any extension name previously. (Refer, https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc) Inspired from the RISC-V profiles specification, we convert OpenSBI hart features into hart extensions. Going forward, we align the extension naming with RISC-V profiles specification. Currently, only "time CSR" and "AIA CSR" have not been assigned extension name but for everything else we have a name. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Atish Patra <[email protected]>
2022-04-28lib: sbi: Implement Sstc extensionAtish Patra
Recently, Sstc extension was ratified. It defines stimecmp which allows the supervisor mode to directly update the timecmp value without the need of the SBI call. The hardware also can inject the S-mode timer interrupt direclty to the supervisor without going through the M-mode. To maintain backward compatibility with the older software, SBI call now uses stimecmp directly if the hardware supports. Implement the Sstc extension. Signed-off-by: Atish Patra <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2021-09-26lib: sbi: Add generic timer delay loop functionAnup Patel
We now have frequency of the timer device provided by the platform support so we can emulate desired delay using a loop where the number loop iterations are based on timer frequency. This patch provides sbi_timer_delay_loop() for above purpose. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Bin Meng <[email protected]> Reviewed-by: Xiang W <[email protected]>
2021-07-11lib: sbi: Implement firmware countersAtish Patra
RISC-V SBI v0.3 specification defines a set of firmware events that can provide additional information about the current firmware context. All of the firmware event monitoring are enabled now. The firmware events must be defined as raw perf event with MSB set as specified in the specification. Reviewed-by: Anup Patel <[email protected]> Signed-off-by: Atish Patra <[email protected]>
2021-06-02lib: sbi_scratch: remove owner from sbi_scratch_alloc_offsetHeinrich Schuchardt
The parameter owner of function sbi_scratch_alloc_offset() is never used. The scratch memory is small. We should not use it for debug information in future. Hence eliminate the parameter. Signed-off-by: Heinrich Schuchardt <[email protected]> Reviewed-by: Xiang W <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2021-04-28lib: sbi: Simplify timer platform operationsAnup Patel
Instead of having timer_value(), timer_event_start(), and timer_event_stop() callbacks in platform operations, it will be much simpler for timer driver to directly register these operations as device to the sbi_timer implementation. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Alistair Francis <[email protected]>
2020-05-19include: sbi: Use scratch pointer as parmeter in HART feature APIsAnup Patel
It makes more sense to have scratch pointer as parameter in HART feature APIs because: 1. We already have scratch pointer at places where these APIs are used. 2. This is consistent with lot of other APIs in sbi_hart.h Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Atish Patra <[email protected]>
2020-05-10lib: timer: Provide a hart based timer featureAtish Patra
As per the RISC-V specification, time value can be obtained from a time CSR implemented in hardware or a MMIO based IP block. Qemu virt machine already supports timer csr while CLINT provides the timer for other platforms. Implement a hart specific timer feature that can be detected at runtime. As CSR based timer implementation are faster than MMIO address based, it is always preferred over MMIO based one. Signed-off-by: Atish Patra <[email protected]> Tested-by: Jonathan Balkind <[email protected]> Reviewed-by: Anup Patel <[email protected]>
2020-03-28include: sbi_timer: Remove scratch parameter from most funcitonsAnup Patel
This patch removes scratch parameter from most sbi_timer functions. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Atish Patra <[email protected]>
2020-01-07lib: Add timer exit APIAnup Patel
We add sbi_timer_exit() API for OpenSBI exit path handling in sbi_exit() implementation. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Atish Patra <[email protected]>
2019-09-30lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSRAnup Patel
For platforms not having TIME CSR, we trap-n-emulate TIME CSR read/write in OpenSBI. Same rationale applies to HTIMEDELTA CSR as well so we trap-n-emulate HTIMEDELTA CSR for platforms not having TIME CSR. Signed-off-by: Anup Patel <[email protected]>
2019-06-19lib: Move sbi core library to lib/sbiAtish Patra
Signed-off-by: Atish Patra <[email protected]> Acked-by: Anup Patel <[email protected]>