1/*
2 * Copyright (C) 2013 Imagination Technologies
3 * Author: Paul Burton <paul.burton@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation;  either version 2 of the  License, or (at your
8 * option) any later version.
9 */
10
11#include <linux/errno.h>
12#include <linux/percpu.h>
13#include <linux/spinlock.h>
14
15#include <asm/mips-cm.h>
16#include <asm/mips-cpc.h>
17
18void __iomem *mips_cpc_base;
19
20static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock);
21
22static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags);
23
24phys_addr_t __weak mips_cpc_phys_base(void)
25{
26	u32 cpc_base;
27
28	if (!mips_cm_present())
29		return 0;
30
31	if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX_MSK))
32		return 0;
33
34	/* If the CPC is already enabled, leave it so */
35	cpc_base = read_gcr_cpc_base();
36	if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK)
37		return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK;
38
39	/* Otherwise, give it the default address & enable it */
40	cpc_base = mips_cpc_default_phys_base();
41	write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK);
42	return cpc_base;
43}
44
45int mips_cpc_probe(void)
46{
47	phys_addr_t addr;
48	unsigned cpu;
49
50	for_each_possible_cpu(cpu)
51		spin_lock_init(&per_cpu(cpc_core_lock, cpu));
52
53	addr = mips_cpc_phys_base();
54	if (!addr)
55		return -ENODEV;
56
57	mips_cpc_base = ioremap_nocache(addr, 0x8000);
58	if (!mips_cpc_base)
59		return -ENXIO;
60
61	return 0;
62}
63
64void mips_cpc_lock_other(unsigned int core)
65{
66	unsigned curr_core;
67	preempt_disable();
68	curr_core = current_cpu_data.core;
69	spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
70			  per_cpu(cpc_core_lock_flags, curr_core));
71	write_cpc_cl_other(core << CPC_Cx_OTHER_CORENUM_SHF);
72}
73
74void mips_cpc_unlock_other(void)
75{
76	unsigned curr_core = current_cpu_data.core;
77	spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
78			       per_cpu(cpc_core_lock_flags, curr_core));
79	preempt_enable();
80}
81