diff options
Diffstat (limited to 'include/clocksource')
| -rw-r--r-- | include/clocksource/hyperv_timer.h | 107 | ||||
| -rw-r--r-- | include/clocksource/timer-davinci.h | 44 |
2 files changed, 151 insertions, 0 deletions
diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h new file mode 100644 index 000000000000..a821deb8ecb2 --- /dev/null +++ b/include/clocksource/hyperv_timer.h @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Definitions for the clocksource provided by the Hyper-V + * hypervisor to guest VMs, as described in the Hyper-V Top + * Level Functional Spec (TLFS). + * + * Copyright (C) 2019, Microsoft, Inc. + * + * Author: Michael Kelley <mikelley@microsoft.com> + */ + +#ifndef __CLKSOURCE_HYPERV_TIMER_H +#define __CLKSOURCE_HYPERV_TIMER_H + +#include <linux/clocksource.h> +#include <linux/math64.h> +#include <asm/mshyperv.h> + +#define HV_MAX_MAX_DELTA_TICKS 0xffffffff +#define HV_MIN_DELTA_TICKS 1 + +/* Routines called by the VMbus driver */ +extern int hv_stimer_alloc(int sint); +extern void hv_stimer_free(void); +extern void hv_stimer_init(unsigned int cpu); +extern void hv_stimer_cleanup(unsigned int cpu); +extern void hv_stimer_global_cleanup(void); +extern void hv_stimer0_isr(void); + +#if IS_ENABLED(CONFIG_HYPERV) +extern struct clocksource *hyperv_cs; +extern void hv_init_clocksource(void); +#endif /* CONFIG_HYPERV */ + +#ifdef CONFIG_HYPERV_TSCPAGE +extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); + +static inline notrace u64 +hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, u64 *cur_tsc) +{ + u64 scale, offset; + u32 sequence; + + /* + * The protocol for reading Hyper-V TSC page is specified in Hypervisor + * Top-Level Functional Specification ver. 3.0 and above. To get the + * reference time we must do the following: + * - READ ReferenceTscSequence + * A special '0' value indicates the time source is unreliable and we + * need to use something else. The currently published specification + * versions (up to 4.0b) contain a mistake and wrongly claim '-1' + * instead of '0' as the special value, see commit c35b82ef0294. + * - ReferenceTime = + * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset + * - READ ReferenceTscSequence again. In case its value has changed + * since our first reading we need to discard ReferenceTime and repeat + * the whole sequence as the hypervisor was updating the page in + * between. + */ + do { + sequence = READ_ONCE(tsc_pg->tsc_sequence); + if (!sequence) + return U64_MAX; + /* + * Make sure we read sequence before we read other values from + * TSC page. + */ + smp_rmb(); + + scale = READ_ONCE(tsc_pg->tsc_scale); + offset = READ_ONCE(tsc_pg->tsc_offset); + *cur_tsc = hv_get_raw_timer(); + + /* + * Make sure we read sequence after we read all other values + * from TSC page. + */ + smp_rmb(); + + } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence); + + return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset; +} + +static inline notrace u64 +hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) +{ + u64 cur_tsc; + + return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc); +} + +#else /* CONFIG_HYPERV_TSC_PAGE */ +static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) +{ + return NULL; +} + +static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, + u64 *cur_tsc) +{ + return U64_MAX; +} +#endif /* CONFIG_HYPERV_TSCPAGE */ + +#endif diff --git a/include/clocksource/timer-davinci.h b/include/clocksource/timer-davinci.h new file mode 100644 index 000000000000..1dcc1333fbc8 --- /dev/null +++ b/include/clocksource/timer-davinci.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * TI DaVinci clocksource driver + * + * Copyright (C) 2019 Texas Instruments + * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com> + */ + +#ifndef __TIMER_DAVINCI_H__ +#define __TIMER_DAVINCI_H__ + +#include <linux/clk.h> +#include <linux/ioport.h> + +enum { + DAVINCI_TIMER_CLOCKEVENT_IRQ, + DAVINCI_TIMER_CLOCKSOURCE_IRQ, + DAVINCI_TIMER_NUM_IRQS, +}; + +/** + * struct davinci_timer_cfg - davinci clocksource driver configuration struct + * @reg: register range resource + * @irq: clockevent and clocksource interrupt resources + * @cmp_off: if set - it specifies the compare register used for clockevent + * + * Note: if the compare register is specified, the driver will use the bottom + * clock half for both clocksource and clockevent and the compare register + * to generate event irqs. The user must supply the correct compare register + * interrupt number. + * + * This is only used by da830 the DSP of which uses the top half. The timer + * driver still configures the top half to run in free-run mode. + */ +struct davinci_timer_cfg { + struct resource reg; + struct resource irq[DAVINCI_TIMER_NUM_IRQS]; + unsigned int cmp_off; +}; + +int __init davinci_timer_register(struct clk *clk, + const struct davinci_timer_cfg *data); + +#endif /* __TIMER_DAVINCI_H__ */ |