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-rw-r--r--arch/arm64/include/asm/arm_generic.h100
-rw-r--r--arch/arm64/include/asm/timex.h29
-rw-r--r--arch/arm64/kernel/time.c65
-rw-r--r--drivers/clocksource/Kconfig5
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/arm_generic.c232
-rw-r--r--include/clocksource/arm_generic.h21
7 files changed, 453 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/arm_generic.h b/arch/arm64/include/asm/arm_generic.h
new file mode 100644
index 000000000000..e4cec9d30f27
--- /dev/null
+++ b/arch/arm64/include/asm/arm_generic.h
@@ -0,0 +1,100 @@
1/*
2 * arch/arm64/include/asm/arm_generic.h
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author: Marc Zyngier <marc.zyngier@arm.com>
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#ifndef __ASM_ARM_GENERIC_H
20#define __ASM_ARM_GENERIC_H
21
22#include <linux/clocksource.h>
23
24#define ARCH_TIMER_CTRL_ENABLE (1 << 0)
25#define ARCH_TIMER_CTRL_IMASK (1 << 1)
26#define ARCH_TIMER_CTRL_ISTATUS (1 << 2)
27
28#define ARCH_TIMER_REG_CTRL 0
29#define ARCH_TIMER_REG_FREQ 1
30#define ARCH_TIMER_REG_TVAL 2
31
32static inline void arch_timer_reg_write(int reg, u32 val)
33{
34 switch (reg) {
35 case ARCH_TIMER_REG_CTRL:
36 asm volatile("msr cntp_ctl_el0, %0" : : "r" (val));
37 break;
38 case ARCH_TIMER_REG_TVAL:
39 asm volatile("msr cntp_tval_el0, %0" : : "r" (val));
40 break;
41 default:
42 BUILD_BUG();
43 }
44
45 isb();
46}
47
48static inline u32 arch_timer_reg_read(int reg)
49{
50 u32 val;
51
52 switch (reg) {
53 case ARCH_TIMER_REG_CTRL:
54 asm volatile("mrs %0, cntp_ctl_el0" : "=r" (val));
55 break;
56 case ARCH_TIMER_REG_FREQ:
57 asm volatile("mrs %0, cntfrq_el0" : "=r" (val));
58 break;
59 case ARCH_TIMER_REG_TVAL:
60 asm volatile("mrs %0, cntp_tval_el0" : "=r" (val));
61 break;
62 default:
63 BUILD_BUG();
64 }
65
66 return val;
67}
68
69static inline void __cpuinit arch_counter_enable_user_access(void)
70{
71 u32 cntkctl;
72
73 /* Disable user access to the timers and the virtual counter. */
74 asm volatile("mrs %0, cntkctl_el1" : "=r" (cntkctl));
75 cntkctl &= ~((3 << 8) | (1 << 1));
76
77 /* Enable user access to the physical counter and frequency. */
78 cntkctl |= 1;
79 asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl));
80}
81
82static inline cycle_t arch_counter_get_cntpct(void)
83{
84 cycle_t cval;
85
86 asm volatile("mrs %0, cntpct_el0" : "=r" (cval));
87
88 return cval;
89}
90
91static inline cycle_t arch_counter_get_cntvct(void)
92{
93 cycle_t cval;
94
95 asm volatile("mrs %0, cntvct_el0" : "=r" (cval));
96
97 return cval;
98}
99
100#endif
diff --git a/arch/arm64/include/asm/timex.h b/arch/arm64/include/asm/timex.h
new file mode 100644
index 000000000000..b24a31a7e2c9
--- /dev/null
+++ b/arch/arm64/include/asm/timex.h
@@ -0,0 +1,29 @@
1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16#ifndef __ASM_TIMEX_H
17#define __ASM_TIMEX_H
18
19/*
20 * Use the current timer as a cycle counter since this is what we use for
21 * the delay loop.
22 */
23#define get_cycles() ({ cycles_t c; read_current_timer(&c); c; })
24
25#include <asm-generic/timex.h>
26
27#define ARCH_HAS_READ_CURRENT_TIMER
28
29#endif
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
new file mode 100644
index 000000000000..3b4b7258f492
--- /dev/null
+++ b/arch/arm64/kernel/time.c
@@ -0,0 +1,65 @@
1/*
2 * Based on arch/arm/kernel/time.c
3 *
4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
5 * Modifications for ARM (C) 1994-2001 Russell King
6 * Copyright (C) 2012 ARM Ltd.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21#include <linux/export.h>
22#include <linux/kernel.h>
23#include <linux/interrupt.h>
24#include <linux/time.h>
25#include <linux/init.h>
26#include <linux/sched.h>
27#include <linux/smp.h>
28#include <linux/timex.h>
29#include <linux/errno.h>
30#include <linux/profile.h>
31#include <linux/syscore_ops.h>
32#include <linux/timer.h>
33#include <linux/irq.h>
34
35#include <clocksource/arm_generic.h>
36
37#include <asm/thread_info.h>
38#include <asm/stacktrace.h>
39
40#ifdef CONFIG_SMP
41unsigned long profile_pc(struct pt_regs *regs)
42{
43 struct stackframe frame;
44
45 if (!in_lock_functions(regs->pc))
46 return regs->pc;
47
48 frame.fp = regs->regs[29];
49 frame.sp = regs->sp;
50 frame.pc = regs->pc;
51 do {
52 int ret = unwind_frame(&frame);
53 if (ret < 0)
54 return 0;
55 } while (in_lock_functions(frame.pc));
56
57 return frame.pc;
58}
59EXPORT_SYMBOL(profile_pc);
60#endif
61
62void __init time_init(void)
63{
64 arm_generic_timer_init();
65}
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index d53cd0afc200..6a78073c3808 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -35,3 +35,8 @@ config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
35 default y 35 default y
36 help 36 help
37 Use the always on PRCMU Timer as sched_clock 37 Use the always on PRCMU Timer as sched_clock
38
39config CLKSRC_ARM_GENERIC
40 def_bool y if ARM64
41 help
42 This option enables support for the ARM generic timer.
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index b65d0c56ab35..65919901a301 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
13obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o 13obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o
14obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o 14obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o
15obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o 15obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o
16obj-$(CONFIG_CLKSRC_ARM_GENERIC) += arm_generic.o
diff --git a/drivers/clocksource/arm_generic.c b/drivers/clocksource/arm_generic.c
new file mode 100644
index 000000000000..c4d9f9566c64
--- /dev/null
+++ b/drivers/clocksource/arm_generic.c
@@ -0,0 +1,232 @@
1/*
2 * Generic timers support
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author: Marc Zyngier <marc.zyngier@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/delay.h>
23#include <linux/device.h>
24#include <linux/smp.h>
25#include <linux/cpu.h>
26#include <linux/jiffies.h>
27#include <linux/interrupt.h>
28#include <linux/clockchips.h>
29#include <linux/of_irq.h>
30#include <linux/io.h>
31
32#include <clocksource/arm_generic.h>
33
34#include <asm/arm_generic.h>
35
36static u32 arch_timer_rate;
37static u64 sched_clock_mult __read_mostly;
38static DEFINE_PER_CPU(struct clock_event_device, arch_timer_evt);
39static int arch_timer_ppi;
40
41static irqreturn_t arch_timer_handle_irq(int irq, void *dev_id)
42{
43 struct clock_event_device *evt = dev_id;
44 unsigned long ctrl;
45
46 ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
47 if (ctrl & ARCH_TIMER_CTRL_ISTATUS) {
48 ctrl |= ARCH_TIMER_CTRL_IMASK;
49 arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
50 evt->event_handler(evt);
51 return IRQ_HANDLED;
52 }
53
54 return IRQ_NONE;
55}
56
57static void arch_timer_stop(void)
58{
59 unsigned long ctrl;
60
61 ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
62 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
63 arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
64}
65
66static void arch_timer_set_mode(enum clock_event_mode mode,
67 struct clock_event_device *clk)
68{
69 switch (mode) {
70 case CLOCK_EVT_MODE_UNUSED:
71 case CLOCK_EVT_MODE_SHUTDOWN:
72 arch_timer_stop();
73 break;
74 default:
75 break;
76 }
77}
78
79static int arch_timer_set_next_event(unsigned long evt,
80 struct clock_event_device *unused)
81{
82 unsigned long ctrl;
83
84 ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
85 ctrl |= ARCH_TIMER_CTRL_ENABLE;
86 ctrl &= ~ARCH_TIMER_CTRL_IMASK;
87
88 arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt);
89 arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
90
91 return 0;
92}
93
94static void __cpuinit arch_timer_setup(struct clock_event_device *clk)
95{
96 /* Let's make sure the timer is off before doing anything else */
97 arch_timer_stop();
98
99 clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
100 clk->name = "arch_sys_timer";
101 clk->rating = 400;
102 clk->set_mode = arch_timer_set_mode;
103 clk->set_next_event = arch_timer_set_next_event;
104 clk->irq = arch_timer_ppi;
105 clk->cpumask = cpumask_of(smp_processor_id());
106
107 clockevents_config_and_register(clk, arch_timer_rate,
108 0xf, 0x7fffffff);
109
110 enable_percpu_irq(clk->irq, 0);
111
112 /* Ensure the physical counter is visible to userspace for the vDSO. */
113 arch_counter_enable_user_access();
114}
115
116static void __init arch_timer_calibrate(void)
117{
118 if (arch_timer_rate == 0) {
119 arch_timer_reg_write(ARCH_TIMER_REG_CTRL, 0);
120 arch_timer_rate = arch_timer_reg_read(ARCH_TIMER_REG_FREQ);
121
122 /* Check the timer frequency. */
123 if (arch_timer_rate == 0)
124 panic("Architected timer frequency is set to zero.\n"
125 "You must set this in your .dts file\n");
126 }
127
128 /* Cache the sched_clock multiplier to save a divide in the hot path. */
129
130 sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
131
132 pr_info("Architected local timer running at %u.%02uMHz.\n",
133 arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100);
134}
135
136static cycle_t arch_counter_read(struct clocksource *cs)
137{
138 return arch_counter_get_cntpct();
139}
140
141static struct clocksource clocksource_counter = {
142 .name = "arch_sys_counter",
143 .rating = 400,
144 .read = arch_counter_read,
145 .mask = CLOCKSOURCE_MASK(56),
146 .flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
147};
148
149int read_current_timer(unsigned long *timer_value)
150{
151 *timer_value = arch_counter_get_cntpct();
152 return 0;
153}
154
155unsigned long long notrace sched_clock(void)
156{
157 return arch_counter_get_cntvct() * sched_clock_mult;
158}
159
160static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
161 unsigned long action, void *hcpu)
162{
163 int cpu = (long)hcpu;
164 struct clock_event_device *clk = per_cpu_ptr(&arch_timer_evt, cpu);
165
166 switch(action) {
167 case CPU_STARTING:
168 case CPU_STARTING_FROZEN:
169 arch_timer_setup(clk);
170 break;
171
172 case CPU_DYING:
173 case CPU_DYING_FROZEN:
174 pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
175 clk->irq, cpu);
176 disable_percpu_irq(clk->irq);
177 arch_timer_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
178 break;
179 }
180
181 return NOTIFY_OK;
182}
183
184static struct notifier_block __cpuinitdata arch_timer_cpu_nb = {
185 .notifier_call = arch_timer_cpu_notify,
186};
187
188static const struct of_device_id arch_timer_of_match[] __initconst = {
189 { .compatible = "arm,armv8-timer" },
190 {},
191};
192
193int __init arm_generic_timer_init(void)
194{
195 struct device_node *np;
196 int err;
197 u32 freq;
198
199 np = of_find_matching_node(NULL, arch_timer_of_match);
200 if (!np) {
201 pr_err("arch_timer: can't find DT node\n");
202 return -ENODEV;
203 }
204
205 /* Try to determine the frequency from the device tree or CNTFRQ */
206 if (!of_property_read_u32(np, "clock-frequency", &freq))
207 arch_timer_rate = freq;
208 arch_timer_calibrate();
209
210 arch_timer_ppi = irq_of_parse_and_map(np, 0);
211 pr_info("arch_timer: found %s irq %d\n", np->name, arch_timer_ppi);
212
213 err = request_percpu_irq(arch_timer_ppi, arch_timer_handle_irq,
214 np->name, &arch_timer_evt);
215 if (err) {
216 pr_err("arch_timer: can't register interrupt %d (%d)\n",
217 arch_timer_ppi, err);
218 return err;
219 }
220
221 clocksource_register_hz(&clocksource_counter, arch_timer_rate);
222
223 /* Calibrate the delay loop directly */
224 lpj_fine = arch_timer_rate / HZ;
225
226 /* Immediately configure the timer on the boot CPU */
227 arch_timer_setup(per_cpu_ptr(&arch_timer_evt, smp_processor_id()));
228
229 register_cpu_notifier(&arch_timer_cpu_nb);
230
231 return 0;
232}
diff --git a/include/clocksource/arm_generic.h b/include/clocksource/arm_generic.h
new file mode 100644
index 000000000000..5b41b0d27f0f
--- /dev/null
+++ b/include/clocksource/arm_generic.h
@@ -0,0 +1,21 @@
1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16#ifndef __CLKSOURCE_ARM_GENERIC_H
17#define __CLKSOURCE_ARM_GENERIC_H
18
19extern int arm_generic_timer_init(void);
20
21#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-27 22:21:45 -0500