summaryrefslogtreecommitdiff
path: root/arch/x86/pci/mmconfig_64.c
blob: 7a6231c3335e5513972f51b6f69ab2c2cc28fc63 (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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/*
 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
 *
 * This is an 64bit optimized version that always keeps the full mmconfig
 * space mapped. This allows lockless config space operation.
 */

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/bitmap.h>
#include <asm/e820.h>
#include <asm/pci_x86.h>

/* Static virtual mapping of the MMCONFIG aperture */
struct mmcfg_virt {
	struct pci_mmcfg_region *cfg;
	char __iomem *virt;
};
static struct mmcfg_virt *pci_mmcfg_virt;

static char __iomem *get_virt(unsigned int seg, unsigned bus)
{
	struct pci_mmcfg_region *cfg;
	int cfg_num;

	for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
		cfg = pci_mmcfg_virt[cfg_num].cfg;
		if (cfg->pci_segment == seg &&
		    (cfg->start_bus_number <= bus) &&
		    (cfg->end_bus_number >= bus))
			return pci_mmcfg_virt[cfg_num].virt;
	}

	/* Fall back to type 0 */
	return NULL;
}

static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
{
	char __iomem *addr;

	addr = get_virt(seg, bus);
	if (!addr)
		return NULL;
	return addr + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
}

static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
			  unsigned int devfn, int reg, int len, u32 *value)
{
	char __iomem *addr;

	/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
err:		*value = -1;
		return -EINVAL;
	}

	addr = pci_dev_base(seg, bus, devfn);
	if (!addr)
		goto err;

	switch (len) {
	case 1:
		*value = mmio_config_readb(addr + reg);
		break;
	case 2:
		*value = mmio_config_readw(addr + reg);
		break;
	case 4:
		*value = mmio_config_readl(addr + reg);
		break;
	}

	return 0;
}

static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
			   unsigned int devfn, int reg, int len, u32 value)
{
	char __iomem *addr;

	/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
		return -EINVAL;

	addr = pci_dev_base(seg, bus, devfn);
	if (!addr)
		return -EINVAL;

	switch (len) {
	case 1:
		mmio_config_writeb(addr + reg, value);
		break;
	case 2:
		mmio_config_writew(addr + reg, value);
		break;
	case 4:
		mmio_config_writel(addr + reg, value);
		break;
	}

	return 0;
}

static struct pci_raw_ops pci_mmcfg = {
	.read =		pci_mmcfg_read,
	.write =	pci_mmcfg_write,
};

static void __iomem * __init mcfg_ioremap(struct pci_mmcfg_region *cfg)
{
	void __iomem *addr;
	u64 start, size;
	int num_buses;

	start = cfg->address + PCI_MMCFG_BUS_OFFSET(cfg->start_bus_number);
	num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
	size = PCI_MMCFG_BUS_OFFSET(num_buses);
	addr = ioremap_nocache(start, size);
	if (addr) {
		printk(KERN_INFO "PCI: Using MMCONFIG at %Lx - %Lx\n",
		       start, start + size - 1);
		addr -= PCI_MMCFG_BUS_OFFSET(cfg->start_bus_number);
	}
	return addr;
}

int __init pci_mmcfg_arch_init(void)
{
	int i;
	pci_mmcfg_virt = kzalloc(sizeof(*pci_mmcfg_virt) *
				 pci_mmcfg_config_num, GFP_KERNEL);
	if (pci_mmcfg_virt == NULL) {
		printk(KERN_ERR "PCI: Can not allocate memory for mmconfig structures\n");
		return 0;
	}

	for (i = 0; i < pci_mmcfg_config_num; ++i) {
		pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
		pci_mmcfg_virt[i].virt = mcfg_ioremap(&pci_mmcfg_config[i]);
		if (!pci_mmcfg_virt[i].virt) {
			printk(KERN_ERR "PCI: Cannot map mmconfig aperture for "
					"segment %d\n",
				pci_mmcfg_config[i].pci_segment);
			pci_mmcfg_arch_free();
			return 0;
		}
	}
	raw_pci_ext_ops = &pci_mmcfg;
	return 1;
}

void __init pci_mmcfg_arch_free(void)
{
	int i;

	if (pci_mmcfg_virt == NULL)
		return;

	for (i = 0; i < pci_mmcfg_config_num; ++i) {
		if (pci_mmcfg_virt[i].virt) {
			iounmap(pci_mmcfg_virt[i].virt + PCI_MMCFG_BUS_OFFSET(pci_mmcfg_virt[i].cfg->start_bus_number));
			pci_mmcfg_virt[i].virt = NULL;
			pci_mmcfg_virt[i].cfg = NULL;
		}
	}

	kfree(pci_mmcfg_virt);
	pci_mmcfg_virt = NULL;
}