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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/clocksource/timer-riscv.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'drivers/clocksource/timer-riscv.c')
| -rw-r--r-- | drivers/clocksource/timer-riscv.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c new file mode 100644 index 000000000..b310e6721 --- /dev/null +++ b/drivers/clocksource/timer-riscv.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2012 Regents of the University of California + * Copyright (C) 2017 SiFive + * + * All RISC-V systems have a timer attached to every hart. These timers can + * either be read from the "time" and "timeh" CSRs, and can use the SBI to + * setup events, or directly accessed using MMIO registers. + */ + +#define pr_fmt(fmt) "riscv-timer: " fmt + +#include <linux/acpi.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/cpu.h> +#include <linux/delay.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/module.h> +#include <linux/sched_clock.h> +#include <linux/io-64-nonatomic-lo-hi.h> +#include <linux/interrupt.h> +#include <linux/of_irq.h> +#include <linux/limits.h> +#include <clocksource/timer-riscv.h> +#include <asm/smp.h> +#include <asm/cpufeature.h> +#include <asm/sbi.h> +#include <asm/timex.h> + +static DEFINE_STATIC_KEY_FALSE(riscv_sstc_available); +static bool riscv_timer_cannot_wake_cpu; + +static void riscv_clock_event_stop(void) +{ + if (static_branch_likely(&riscv_sstc_available)) { + csr_write(CSR_STIMECMP, ULONG_MAX); + if (IS_ENABLED(CONFIG_32BIT)) + csr_write(CSR_STIMECMPH, ULONG_MAX); + } else { + sbi_set_timer(U64_MAX); + } +} + +static int riscv_clock_next_event(unsigned long delta, + struct clock_event_device *ce) +{ + u64 next_tval = get_cycles64() + delta; + + if (static_branch_likely(&riscv_sstc_available)) { +#if defined(CONFIG_32BIT) + csr_write(CSR_STIMECMP, ULONG_MAX); + csr_write(CSR_STIMECMPH, next_tval >> 32); + csr_write(CSR_STIMECMP, next_tval & 0xFFFFFFFF); +#else + csr_write(CSR_STIMECMP, next_tval); +#endif + } else + sbi_set_timer(next_tval); + + return 0; +} + +static int riscv_clock_shutdown(struct clock_event_device *evt) +{ + riscv_clock_event_stop(); + return 0; +} + +static unsigned int riscv_clock_event_irq; +static DEFINE_PER_CPU(struct clock_event_device, riscv_clock_event) = { + .name = "riscv_timer_clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT, + .rating = 100, + .set_next_event = riscv_clock_next_event, + .set_state_shutdown = riscv_clock_shutdown, +}; + +/* + * It is guaranteed that all the timers across all the harts are synchronized + * within one tick of each other, so while this could technically go + * backwards when hopping between CPUs, practically it won't happen. + */ +static unsigned long long riscv_clocksource_rdtime(struct clocksource *cs) +{ + return get_cycles64(); +} + +static u64 notrace riscv_sched_clock(void) +{ + return get_cycles64(); +} + +static struct clocksource riscv_clocksource = { + .name = "riscv_clocksource", + .rating = 400, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .read = riscv_clocksource_rdtime, + .vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER, +}; + +static int riscv_timer_starting_cpu(unsigned int cpu) +{ + struct clock_event_device *ce = per_cpu_ptr(&riscv_clock_event, cpu); + + /* Clear timer interrupt */ + riscv_clock_event_stop(); + + ce->cpumask = cpumask_of(cpu); + ce->irq = riscv_clock_event_irq; + if (riscv_timer_cannot_wake_cpu) + ce->features |= CLOCK_EVT_FEAT_C3STOP; + if (static_branch_likely(&riscv_sstc_available)) + ce->rating = 450; + clockevents_config_and_register(ce, riscv_timebase, 100, ULONG_MAX); + + enable_percpu_irq(riscv_clock_event_irq, + irq_get_trigger_type(riscv_clock_event_irq)); + return 0; +} + +static int riscv_timer_dying_cpu(unsigned int cpu) +{ + /* + * Stop the timer when the cpu is going to be offline otherwise + * the timer interrupt may be pending while performing power-down. + */ + riscv_clock_event_stop(); + disable_percpu_irq(riscv_clock_event_irq); + + return 0; +} + +void riscv_cs_get_mult_shift(u32 *mult, u32 *shift) +{ + *mult = riscv_clocksource.mult; + *shift = riscv_clocksource.shift; +} +EXPORT_SYMBOL_GPL(riscv_cs_get_mult_shift); + +/* called directly from the low-level interrupt handler */ +static irqreturn_t riscv_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evdev = this_cpu_ptr(&riscv_clock_event); + + riscv_clock_event_stop(); + evdev->event_handler(evdev); + + return IRQ_HANDLED; +} + +static int __init riscv_timer_init_common(void) +{ + int error; + struct irq_domain *domain; + struct fwnode_handle *intc_fwnode = riscv_get_intc_hwnode(); + + domain = irq_find_matching_fwnode(intc_fwnode, DOMAIN_BUS_ANY); + if (!domain) { + pr_err("Failed to find irq_domain for INTC node [%pfwP]\n", + intc_fwnode); + return -ENODEV; + } + + riscv_clock_event_irq = irq_create_mapping(domain, RV_IRQ_TIMER); + if (!riscv_clock_event_irq) { + pr_err("Failed to map timer interrupt for node [%pfwP]\n", intc_fwnode); + return -ENODEV; + } + + error = clocksource_register_hz(&riscv_clocksource, riscv_timebase); + if (error) { + pr_err("RISCV timer registration failed [%d]\n", error); + return error; + } + + sched_clock_register(riscv_sched_clock, 64, riscv_timebase); + + error = request_percpu_irq(riscv_clock_event_irq, + riscv_timer_interrupt, + "riscv-timer", &riscv_clock_event); + if (error) { + pr_err("registering percpu irq failed [%d]\n", error); + return error; + } + + if (riscv_isa_extension_available(NULL, SSTC)) { + pr_info("Timer interrupt in S-mode is available via sstc extension\n"); + static_branch_enable(&riscv_sstc_available); + } + + error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING, + "clockevents/riscv/timer:starting", + riscv_timer_starting_cpu, riscv_timer_dying_cpu); + if (error) + pr_err("cpu hp setup state failed for RISCV timer [%d]\n", + error); + + return error; +} + +static int __init riscv_timer_init_dt(struct device_node *n) +{ + int cpuid, error; + unsigned long hartid; + struct device_node *child; + + error = riscv_of_processor_hartid(n, &hartid); + if (error < 0) { + pr_warn("Invalid hartid for node [%pOF] error = [%lu]\n", + n, hartid); + return error; + } + + cpuid = riscv_hartid_to_cpuid(hartid); + if (cpuid < 0) { + pr_warn("Invalid cpuid for hartid [%lu]\n", hartid); + return cpuid; + } + + if (cpuid != smp_processor_id()) + return 0; + + child = of_find_compatible_node(NULL, NULL, "riscv,timer"); + if (child) { + riscv_timer_cannot_wake_cpu = of_property_read_bool(child, + "riscv,timer-cannot-wake-cpu"); + of_node_put(child); + } + + return riscv_timer_init_common(); +} + +TIMER_OF_DECLARE(riscv_timer, "riscv", riscv_timer_init_dt); + +#ifdef CONFIG_ACPI +static int __init riscv_timer_acpi_init(struct acpi_table_header *table) +{ + struct acpi_table_rhct *rhct = (struct acpi_table_rhct *)table; + + riscv_timer_cannot_wake_cpu = rhct->flags & ACPI_RHCT_TIMER_CANNOT_WAKEUP_CPU; + + return riscv_timer_init_common(); +} + +TIMER_ACPI_DECLARE(aclint_mtimer, ACPI_SIG_RHCT, riscv_timer_acpi_init); + +#endif |
