1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org) |
4 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
5 | */ |
6 | #include <linux/bcd.h> |
7 | #include <linux/clockchips.h> |
8 | #include <linux/init.h> |
9 | #include <linux/kernel.h> |
10 | #include <linux/sched.h> |
11 | #include <linux/sched_clock.h> |
12 | #include <linux/interrupt.h> |
13 | #include <linux/kernel_stat.h> |
14 | #include <linux/param.h> |
15 | #include <linux/smp.h> |
16 | #include <linux/time.h> |
17 | #include <linux/timex.h> |
18 | #include <linux/mm.h> |
19 | #include <linux/platform_device.h> |
20 | |
21 | #include <asm/time.h> |
22 | #include <asm/sgialib.h> |
23 | #include <asm/sn/klconfig.h> |
24 | #include <asm/sn/arch.h> |
25 | #include <asm/sn/addrs.h> |
26 | #include <asm/sn/agent.h> |
27 | |
28 | #include "ip27-common.h" |
29 | |
30 | static int rt_next_event(unsigned long delta, struct clock_event_device *evt) |
31 | { |
32 | unsigned int cpu = smp_processor_id(); |
33 | int slice = cputoslice(cpu); |
34 | unsigned long cnt; |
35 | |
36 | cnt = LOCAL_HUB_L(PI_RT_COUNT); |
37 | cnt += delta; |
38 | LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); |
39 | |
40 | return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; |
41 | } |
42 | |
43 | static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); |
44 | static DEFINE_PER_CPU(char [11], hub_rt_name); |
45 | |
46 | static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) |
47 | { |
48 | unsigned int cpu = smp_processor_id(); |
49 | struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); |
50 | int slice = cputoslice(cpu); |
51 | |
52 | /* |
53 | * Ack |
54 | */ |
55 | LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); |
56 | cd->event_handler(cd); |
57 | |
58 | return IRQ_HANDLED; |
59 | } |
60 | |
61 | struct irqaction hub_rt_irqaction = { |
62 | .handler = hub_rt_counter_handler, |
63 | .percpu_dev_id = &hub_rt_clockevent, |
64 | .flags = IRQF_PERCPU | IRQF_TIMER, |
65 | .name = "hub-rt" , |
66 | }; |
67 | |
68 | /* |
69 | * This is a hack; we really need to figure these values out dynamically |
70 | * |
71 | * Since 800 ns works very well with various HUB frequencies, such as |
72 | * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. |
73 | * |
74 | * Ralf: which clock rate is used to feed the counter? |
75 | */ |
76 | #define NSEC_PER_CYCLE 800 |
77 | #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) |
78 | |
79 | void hub_rt_clock_event_init(void) |
80 | { |
81 | unsigned int cpu = smp_processor_id(); |
82 | struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); |
83 | unsigned char *name = per_cpu(hub_rt_name, cpu); |
84 | |
85 | sprintf(buf: name, fmt: "hub-rt %d" , cpu); |
86 | cd->name = name; |
87 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
88 | clockevent_set_clock(cd, CYCLES_PER_SEC); |
89 | cd->max_delta_ns = clockevent_delta2ns(latch: 0xfffffffffffff, evt: cd); |
90 | cd->max_delta_ticks = 0xfffffffffffff; |
91 | cd->min_delta_ns = clockevent_delta2ns(latch: 0x300, evt: cd); |
92 | cd->min_delta_ticks = 0x300; |
93 | cd->rating = 200; |
94 | cd->irq = IP27_RT_TIMER_IRQ; |
95 | cd->cpumask = cpumask_of(cpu); |
96 | cd->set_next_event = rt_next_event; |
97 | clockevents_register_device(dev: cd); |
98 | |
99 | enable_percpu_irq(irq: IP27_RT_TIMER_IRQ, type: IRQ_TYPE_NONE); |
100 | } |
101 | |
102 | static void __init hub_rt_clock_event_global_init(void) |
103 | { |
104 | irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq); |
105 | irq_set_percpu_devid(IP27_RT_TIMER_IRQ); |
106 | setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction); |
107 | } |
108 | |
109 | static u64 hub_rt_read(struct clocksource *cs) |
110 | { |
111 | return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); |
112 | } |
113 | |
114 | struct clocksource hub_rt_clocksource = { |
115 | .name = "HUB-RT" , |
116 | .rating = 200, |
117 | .read = hub_rt_read, |
118 | .mask = CLOCKSOURCE_MASK(52), |
119 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
120 | }; |
121 | |
122 | static u64 notrace hub_rt_read_sched_clock(void) |
123 | { |
124 | return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); |
125 | } |
126 | |
127 | static void __init hub_rt_clocksource_init(void) |
128 | { |
129 | struct clocksource *cs = &hub_rt_clocksource; |
130 | |
131 | clocksource_register_hz(cs, CYCLES_PER_SEC); |
132 | |
133 | sched_clock_register(read: hub_rt_read_sched_clock, bits: 52, CYCLES_PER_SEC); |
134 | } |
135 | |
136 | void __init plat_time_init(void) |
137 | { |
138 | hub_rt_clocksource_init(); |
139 | hub_rt_clock_event_global_init(); |
140 | hub_rt_clock_event_init(); |
141 | } |
142 | |
143 | void hub_rtc_init(nasid_t nasid) |
144 | { |
145 | |
146 | /* |
147 | * We only need to initialize the current node. |
148 | * If this is not the current node then it is a cpuless |
149 | * node and timeouts will not happen there. |
150 | */ |
151 | if (get_nasid() == nasid) { |
152 | LOCAL_HUB_S(PI_RT_EN_A, 1); |
153 | LOCAL_HUB_S(PI_RT_EN_B, 1); |
154 | LOCAL_HUB_S(PI_PROF_EN_A, 0); |
155 | LOCAL_HUB_S(PI_PROF_EN_B, 0); |
156 | LOCAL_HUB_S(PI_RT_COUNT, 0); |
157 | LOCAL_HUB_S(PI_RT_PEND_A, 0); |
158 | LOCAL_HUB_S(PI_RT_PEND_B, 0); |
159 | } |
160 | } |
161 | |