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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/clocksource/timer-clint.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/clocksource/timer-clint.c')
| -rw-r--r-- | drivers/clocksource/timer-clint.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-clint.c b/drivers/clocksource/timer-clint.c new file mode 100644 index 000000000..0bdd9d7ec --- /dev/null +++ b/drivers/clocksource/timer-clint.c @@ -0,0 +1,277 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + * + * Most of the M-mode (i.e. NoMMU) RISC-V systems usually have a + * CLINT MMIO timer device. + */ + +#define pr_fmt(fmt) "clint: " fmt +#include <linux/bitops.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/cpu.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/sched_clock.h> +#include <linux/io-64-nonatomic-lo-hi.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> +#include <linux/of_irq.h> +#include <linux/smp.h> +#include <linux/timex.h> + +#ifndef CONFIG_RISCV_M_MODE +#include <asm/clint.h> +#endif + +#define CLINT_IPI_OFF 0 +#define CLINT_TIMER_CMP_OFF 0x4000 +#define CLINT_TIMER_VAL_OFF 0xbff8 + +/* CLINT manages IPI and Timer for RISC-V M-mode */ +static u32 __iomem *clint_ipi_base; +static unsigned int clint_ipi_irq; +static u64 __iomem *clint_timer_cmp; +static u64 __iomem *clint_timer_val; +static unsigned long clint_timer_freq; +static unsigned int clint_timer_irq; + +#ifdef CONFIG_RISCV_M_MODE +u64 __iomem *clint_time_val; +EXPORT_SYMBOL(clint_time_val); +#endif + +#ifdef CONFIG_SMP +static void clint_send_ipi(unsigned int cpu) +{ + writel(1, clint_ipi_base + cpuid_to_hartid_map(cpu)); +} + +static void clint_clear_ipi(void) +{ + writel(0, clint_ipi_base + cpuid_to_hartid_map(smp_processor_id())); +} + +static void clint_ipi_interrupt(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + + chained_irq_enter(chip, desc); + + clint_clear_ipi(); + ipi_mux_process(); + + chained_irq_exit(chip, desc); +} +#endif + +#ifdef CONFIG_64BIT +#define clint_get_cycles() readq_relaxed(clint_timer_val) +#else +#define clint_get_cycles() readl_relaxed(clint_timer_val) +#define clint_get_cycles_hi() readl_relaxed(((u32 *)clint_timer_val) + 1) +#endif + +#ifdef CONFIG_64BIT +static u64 notrace clint_get_cycles64(void) +{ + return clint_get_cycles(); +} +#else /* CONFIG_64BIT */ +static u64 notrace clint_get_cycles64(void) +{ + u32 hi, lo; + + do { + hi = clint_get_cycles_hi(); + lo = clint_get_cycles(); + } while (hi != clint_get_cycles_hi()); + + return ((u64)hi << 32) | lo; +} +#endif /* CONFIG_64BIT */ + +static u64 clint_rdtime(struct clocksource *cs) +{ + return clint_get_cycles64(); +} + +static struct clocksource clint_clocksource = { + .name = "clint_clocksource", + .rating = 300, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .read = clint_rdtime, +}; + +static int clint_clock_next_event(unsigned long delta, + struct clock_event_device *ce) +{ + void __iomem *r = clint_timer_cmp + + cpuid_to_hartid_map(smp_processor_id()); + + csr_set(CSR_IE, IE_TIE); + writeq_relaxed(clint_get_cycles64() + delta, r); + return 0; +} + +static DEFINE_PER_CPU(struct clock_event_device, clint_clock_event) = { + .name = "clint_clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT, + .rating = 100, + .set_next_event = clint_clock_next_event, +}; + +static int clint_timer_starting_cpu(unsigned int cpu) +{ + struct clock_event_device *ce = per_cpu_ptr(&clint_clock_event, cpu); + + ce->cpumask = cpumask_of(cpu); + clockevents_config_and_register(ce, clint_timer_freq, 100, ULONG_MAX); + + enable_percpu_irq(clint_timer_irq, + irq_get_trigger_type(clint_timer_irq)); + enable_percpu_irq(clint_ipi_irq, + irq_get_trigger_type(clint_ipi_irq)); + return 0; +} + +static int clint_timer_dying_cpu(unsigned int cpu) +{ + disable_percpu_irq(clint_timer_irq); + /* + * Don't disable IPI when CPU goes offline because + * the masking/unmasking of virtual IPIs is done + * via generic IPI-Mux + */ + return 0; +} + +static irqreturn_t clint_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evdev = this_cpu_ptr(&clint_clock_event); + + csr_clear(CSR_IE, IE_TIE); + evdev->event_handler(evdev); + + return IRQ_HANDLED; +} + +static int __init clint_timer_init_dt(struct device_node *np) +{ + int rc; + u32 i, nr_irqs; + void __iomem *base; + struct of_phandle_args oirq; + + /* + * Ensure that CLINT device interrupts are either RV_IRQ_TIMER or + * RV_IRQ_SOFT. If it's anything else then we ignore the device. + */ + nr_irqs = of_irq_count(np); + for (i = 0; i < nr_irqs; i++) { + if (of_irq_parse_one(np, i, &oirq)) { + pr_err("%pOFP: failed to parse irq %d.\n", np, i); + continue; + } + + if ((oirq.args_count != 1) || + (oirq.args[0] != RV_IRQ_TIMER && + oirq.args[0] != RV_IRQ_SOFT)) { + pr_err("%pOFP: invalid irq %d (hwirq %d)\n", + np, i, oirq.args[0]); + return -ENODEV; + } + + /* Find parent irq domain and map ipi irq */ + if (!clint_ipi_irq && + oirq.args[0] == RV_IRQ_SOFT && + irq_find_host(oirq.np)) + clint_ipi_irq = irq_of_parse_and_map(np, i); + + /* Find parent irq domain and map timer irq */ + if (!clint_timer_irq && + oirq.args[0] == RV_IRQ_TIMER && + irq_find_host(oirq.np)) + clint_timer_irq = irq_of_parse_and_map(np, i); + } + + /* If CLINT ipi or timer irq not found then fail */ + if (!clint_ipi_irq || !clint_timer_irq) { + pr_err("%pOFP: ipi/timer irq not found\n", np); + return -ENODEV; + } + + base = of_iomap(np, 0); + if (!base) { + pr_err("%pOFP: could not map registers\n", np); + return -ENODEV; + } + + clint_ipi_base = base + CLINT_IPI_OFF; + clint_timer_cmp = base + CLINT_TIMER_CMP_OFF; + clint_timer_val = base + CLINT_TIMER_VAL_OFF; + clint_timer_freq = riscv_timebase; + +#ifdef CONFIG_RISCV_M_MODE + /* + * Yes, that's an odd naming scheme. time_val is public, but hopefully + * will die in favor of something cleaner. + */ + clint_time_val = clint_timer_val; +#endif + + pr_info("%pOFP: timer running at %ld Hz\n", np, clint_timer_freq); + + rc = clocksource_register_hz(&clint_clocksource, clint_timer_freq); + if (rc) { + pr_err("%pOFP: clocksource register failed [%d]\n", np, rc); + goto fail_iounmap; + } + + sched_clock_register(clint_get_cycles64, 64, clint_timer_freq); + + rc = request_percpu_irq(clint_timer_irq, clint_timer_interrupt, + "clint-timer", &clint_clock_event); + if (rc) { + pr_err("registering percpu irq failed [%d]\n", rc); + goto fail_iounmap; + } + +#ifdef CONFIG_SMP + rc = ipi_mux_create(BITS_PER_BYTE, clint_send_ipi); + if (rc <= 0) { + pr_err("unable to create muxed IPIs\n"); + rc = (rc < 0) ? rc : -ENODEV; + goto fail_free_irq; + } + + irq_set_chained_handler(clint_ipi_irq, clint_ipi_interrupt); + riscv_ipi_set_virq_range(rc, BITS_PER_BYTE); + clint_clear_ipi(); +#endif + + rc = cpuhp_setup_state(CPUHP_AP_CLINT_TIMER_STARTING, + "clockevents/clint/timer:starting", + clint_timer_starting_cpu, + clint_timer_dying_cpu); + if (rc) { + pr_err("%pOFP: cpuhp setup state failed [%d]\n", np, rc); + goto fail_free_irq; + } + + return 0; + +fail_free_irq: + free_percpu_irq(clint_timer_irq, &clint_clock_event); +fail_iounmap: + iounmap(base); + return rc; +} + +TIMER_OF_DECLARE(clint_timer, "riscv,clint0", clint_timer_init_dt); +TIMER_OF_DECLARE(clint_timer1, "sifive,clint0", clint_timer_init_dt); |
