summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-mvebu/coherency.c
blob: 4c24303ec4816bfb6f1c4bc0695f57450a624517 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * Coherency fabric (Aurora) support for Armada 370 and XP platforms.
 *
 * Copyright (C) 2012 Marvell
 *
 * Yehuda Yitschak <yehuday@marvell.com>
 * Gregory Clement <gregory.clement@free-electrons.com>
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 *
 * The Armada 370 and Armada XP SOCs have a coherency fabric which is
 * responsible for ensuring hardware coherency between all CPUs and between
 * CPUs and I/O masters. This file initializes the coherency fabric and
 * supplies basic routines for configuring and controlling hardware coherency
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/smp.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <asm/smp_plat.h>
#include <asm/cacheflush.h>
#include "armada-370-xp.h"

unsigned long coherency_phys_base;
static void __iomem *coherency_base;
static void __iomem *coherency_cpu_base;

/* Coherency fabric registers */
#define COHERENCY_FABRIC_CFG_OFFSET		   0x4

#define IO_SYNC_BARRIER_CTL_OFFSET		   0x0

static struct of_device_id of_coherency_table[] = {
	{.compatible = "marvell,coherency-fabric"},
	{ /* end of list */ },
};

/* Function defined in coherency_ll.S */
int ll_set_cpu_coherent(void __iomem *base_addr, unsigned int hw_cpu_id);

int set_cpu_coherent(unsigned int hw_cpu_id, int smp_group_id)
{
	if (!coherency_base) {
		pr_warn("Can't make CPU %d cache coherent.\n", hw_cpu_id);
		pr_warn("Coherency fabric is not initialized\n");
		return 1;
	}

	return ll_set_cpu_coherent(coherency_base, hw_cpu_id);
}

static inline void mvebu_hwcc_sync_io_barrier(void)
{
	writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
	while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
}

static dma_addr_t mvebu_hwcc_dma_map_page(struct device *dev, struct page *page,
				  unsigned long offset, size_t size,
				  enum dma_data_direction dir,
				  struct dma_attrs *attrs)
{
	if (dir != DMA_TO_DEVICE)
		mvebu_hwcc_sync_io_barrier();
	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
}


static void mvebu_hwcc_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
			      size_t size, enum dma_data_direction dir,
			      struct dma_attrs *attrs)
{
	if (dir != DMA_TO_DEVICE)
		mvebu_hwcc_sync_io_barrier();
}

static void mvebu_hwcc_dma_sync(struct device *dev, dma_addr_t dma_handle,
			size_t size, enum dma_data_direction dir)
{
	if (dir != DMA_TO_DEVICE)
		mvebu_hwcc_sync_io_barrier();
}

static struct dma_map_ops mvebu_hwcc_dma_ops = {
	.alloc			= arm_dma_alloc,
	.free			= arm_dma_free,
	.mmap			= arm_dma_mmap,
	.map_page		= mvebu_hwcc_dma_map_page,
	.unmap_page		= mvebu_hwcc_dma_unmap_page,
	.get_sgtable		= arm_dma_get_sgtable,
	.map_sg			= arm_dma_map_sg,
	.unmap_sg		= arm_dma_unmap_sg,
	.sync_single_for_cpu	= mvebu_hwcc_dma_sync,
	.sync_single_for_device	= mvebu_hwcc_dma_sync,
	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
	.set_dma_mask		= arm_dma_set_mask,
};

static int mvebu_hwcc_platform_notifier(struct notifier_block *nb,
				       unsigned long event, void *__dev)
{
	struct device *dev = __dev;

	if (event != BUS_NOTIFY_ADD_DEVICE)
		return NOTIFY_DONE;
	set_dma_ops(dev, &mvebu_hwcc_dma_ops);

	return NOTIFY_OK;
}

static struct notifier_block mvebu_hwcc_platform_nb = {
	.notifier_call = mvebu_hwcc_platform_notifier,
};

int __init coherency_init(void)
{
	struct device_node *np;

	np = of_find_matching_node(NULL, of_coherency_table);
	if (np) {
		struct resource res;
		pr_info("Initializing Coherency fabric\n");
		of_address_to_resource(np, 0, &res);
		coherency_phys_base = res.start;
		/*
		 * Ensure secondary CPUs will see the updated value,
		 * which they read before they join the coherency
		 * fabric, and therefore before they are coherent with
		 * the boot CPU cache.
		 */
		sync_cache_w(&coherency_phys_base);
		coherency_base = of_iomap(np, 0);
		coherency_cpu_base = of_iomap(np, 1);
		set_cpu_coherent(cpu_logical_map(smp_processor_id()), 0);
	}

	return 0;
}

static int __init coherency_late_init(void)
{
	if (of_find_matching_node(NULL, of_coherency_table))
		bus_register_notifier(&platform_bus_type,
				      &mvebu_hwcc_platform_nb);
	return 0;
}

postcore_initcall(coherency_late_init);
OpenPOWER on IntegriCloud