1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 */
7#include <linux/init.h>
8#include <linux/cpu.h>
9#include <linux/smp.h>
10#include <linux/proc_fs.h>
11#include <linux/oprofile.h>
12#include <linux/spinlock.h>
13#include <linux/interrupt.h>
14#include <asm/uaccess.h>
15#include <irq.h>
16#include <loongson.h>
17#include "op_impl.h"
18
19#define LOONGSON3_PERFCNT_OVERFLOW	(1ULL << 63)
20
21#define LOONGSON3_PERFCTRL_EXL		(1UL << 0)
22#define LOONGSON3_PERFCTRL_KERNEL	(1UL << 1)
23#define LOONGSON3_PERFCTRL_SUPERVISOR	(1UL << 2)
24#define LOONGSON3_PERFCTRL_USER		(1UL << 3)
25#define LOONGSON3_PERFCTRL_ENABLE	(1UL << 4)
26#define LOONGSON3_PERFCTRL_W		(1UL << 30)
27#define LOONGSON3_PERFCTRL_M		(1UL << 31)
28#define LOONGSON3_PERFCTRL_EVENT(idx, event) \
29	(((event) & (idx ? 0x0f : 0x3f)) << 5)
30
31/* Loongson-3 PerfCount performance counter1 register */
32#define read_c0_perflo1() __read_64bit_c0_register($25, 0)
33#define write_c0_perflo1(val) __write_64bit_c0_register($25, 0, val)
34#define read_c0_perfhi1() __read_64bit_c0_register($25, 1)
35#define write_c0_perfhi1(val) __write_64bit_c0_register($25, 1, val)
36
37/* Loongson-3 PerfCount performance counter2 register */
38#define read_c0_perflo2() __read_64bit_c0_register($25, 2)
39#define write_c0_perflo2(val) __write_64bit_c0_register($25, 2, val)
40#define read_c0_perfhi2() __read_64bit_c0_register($25, 3)
41#define write_c0_perfhi2(val) __write_64bit_c0_register($25, 3, val)
42
43static int (*save_perf_irq)(void);
44
45static struct loongson3_register_config {
46	unsigned int control1;
47	unsigned int control2;
48	unsigned long long reset_counter1;
49	unsigned long long reset_counter2;
50	int ctr1_enable, ctr2_enable;
51} reg;
52
53static void reset_counters(void *arg)
54{
55	write_c0_perfhi1(0);
56	write_c0_perfhi2(0);
57	write_c0_perflo1(0xc0000000);
58	write_c0_perflo2(0x40000000);
59}
60
61/* Compute all of the registers in preparation for enabling profiling. */
62static void loongson3_reg_setup(struct op_counter_config *ctr)
63{
64	unsigned int control1 = 0;
65	unsigned int control2 = 0;
66
67	reg.reset_counter1 = 0;
68	reg.reset_counter2 = 0;
69	/* Compute the performance counter control word. */
70	/* For now count kernel and user mode */
71	if (ctr[0].enabled) {
72		control1 |= LOONGSON3_PERFCTRL_EVENT(0, ctr[0].event) |
73					LOONGSON3_PERFCTRL_ENABLE;
74		if (ctr[0].kernel)
75			control1 |= LOONGSON3_PERFCTRL_KERNEL;
76		if (ctr[0].user)
77			control1 |= LOONGSON3_PERFCTRL_USER;
78		reg.reset_counter1 = 0x8000000000000000ULL - ctr[0].count;
79	}
80
81	if (ctr[1].enabled) {
82		control2 |= LOONGSON3_PERFCTRL_EVENT(1, ctr[1].event) |
83					LOONGSON3_PERFCTRL_ENABLE;
84		if (ctr[1].kernel)
85			control2 |= LOONGSON3_PERFCTRL_KERNEL;
86		if (ctr[1].user)
87			control2 |= LOONGSON3_PERFCTRL_USER;
88		reg.reset_counter2 = 0x8000000000000000ULL - ctr[1].count;
89	}
90
91	if (ctr[0].enabled)
92		control1 |= LOONGSON3_PERFCTRL_EXL;
93	if (ctr[1].enabled)
94		control2 |= LOONGSON3_PERFCTRL_EXL;
95
96	reg.control1 = control1;
97	reg.control2 = control2;
98	reg.ctr1_enable = ctr[0].enabled;
99	reg.ctr2_enable = ctr[1].enabled;
100}
101
102/* Program all of the registers in preparation for enabling profiling. */
103static void loongson3_cpu_setup(void *args)
104{
105	uint64_t perfcount1, perfcount2;
106
107	perfcount1 = reg.reset_counter1;
108	perfcount2 = reg.reset_counter2;
109	write_c0_perfhi1(perfcount1);
110	write_c0_perfhi2(perfcount2);
111}
112
113static void loongson3_cpu_start(void *args)
114{
115	/* Start all counters on current CPU */
116	reg.control1 |= (LOONGSON3_PERFCTRL_W|LOONGSON3_PERFCTRL_M);
117	reg.control2 |= (LOONGSON3_PERFCTRL_W|LOONGSON3_PERFCTRL_M);
118
119	if (reg.ctr1_enable)
120		write_c0_perflo1(reg.control1);
121	if (reg.ctr2_enable)
122		write_c0_perflo2(reg.control2);
123}
124
125static void loongson3_cpu_stop(void *args)
126{
127	/* Stop all counters on current CPU */
128	write_c0_perflo1(0xc0000000);
129	write_c0_perflo2(0x40000000);
130	memset(&reg, 0, sizeof(reg));
131}
132
133static int loongson3_perfcount_handler(void)
134{
135	unsigned long flags;
136	uint64_t counter1, counter2;
137	uint32_t cause, handled = IRQ_NONE;
138	struct pt_regs *regs = get_irq_regs();
139
140	cause = read_c0_cause();
141	if (!(cause & CAUSEF_PCI))
142		return handled;
143
144	counter1 = read_c0_perfhi1();
145	counter2 = read_c0_perfhi2();
146
147	local_irq_save(flags);
148
149	if (counter1 & LOONGSON3_PERFCNT_OVERFLOW) {
150		if (reg.ctr1_enable)
151			oprofile_add_sample(regs, 0);
152		counter1 = reg.reset_counter1;
153	}
154	if (counter2 & LOONGSON3_PERFCNT_OVERFLOW) {
155		if (reg.ctr2_enable)
156			oprofile_add_sample(regs, 1);
157		counter2 = reg.reset_counter2;
158	}
159
160	local_irq_restore(flags);
161
162	write_c0_perfhi1(counter1);
163	write_c0_perfhi2(counter2);
164
165	if (!(cause & CAUSEF_TI))
166		handled = IRQ_HANDLED;
167
168	return handled;
169}
170
171static int loongson3_cpu_callback(struct notifier_block *nfb,
172	unsigned long action, void *hcpu)
173{
174	switch (action) {
175	case CPU_STARTING:
176	case CPU_STARTING_FROZEN:
177		write_c0_perflo1(reg.control1);
178		write_c0_perflo2(reg.control2);
179		break;
180	case CPU_DYING:
181	case CPU_DYING_FROZEN:
182		write_c0_perflo1(0xc0000000);
183		write_c0_perflo2(0x40000000);
184		break;
185	}
186
187	return NOTIFY_OK;
188}
189
190static struct notifier_block loongson3_notifier_block = {
191	.notifier_call = loongson3_cpu_callback
192};
193
194static int __init loongson3_init(void)
195{
196	on_each_cpu(reset_counters, NULL, 1);
197	register_hotcpu_notifier(&loongson3_notifier_block);
198	save_perf_irq = perf_irq;
199	perf_irq = loongson3_perfcount_handler;
200
201	return 0;
202}
203
204static void loongson3_exit(void)
205{
206	on_each_cpu(reset_counters, NULL, 1);
207	unregister_hotcpu_notifier(&loongson3_notifier_block);
208	perf_irq = save_perf_irq;
209}
210
211struct op_mips_model op_model_loongson3_ops = {
212	.reg_setup	= loongson3_reg_setup,
213	.cpu_setup	= loongson3_cpu_setup,
214	.init		= loongson3_init,
215	.exit		= loongson3_exit,
216	.cpu_start	= loongson3_cpu_start,
217	.cpu_stop	= loongson3_cpu_stop,
218	.cpu_type	= "mips/loongson3",
219	.num_counters	= 2
220};
221