2 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
4 * This is an 64bit optimized version that always keeps the full mmconfig
5 * space mapped. This allows lockless config space operation.
9 #include <linux/init.h>
10 #include <linux/acpi.h>
11 #include <linux/bitmap.h>
13 #include <asm/pci_x86.h>
15 /* Static virtual mapping of the MMCONFIG aperture */
17 struct pci_mmcfg_region
*cfg
;
20 static struct mmcfg_virt
*pci_mmcfg_virt
;
22 static char __iomem
*get_virt(unsigned int seg
, unsigned bus
)
24 struct pci_mmcfg_region
*cfg
;
27 for (cfg_num
= 0; cfg_num
< pci_mmcfg_config_num
; cfg_num
++) {
28 cfg
= pci_mmcfg_virt
[cfg_num
].cfg
;
29 if (cfg
->segment
== seg
&&
30 (cfg
->start_bus
<= bus
) &&
31 (cfg
->end_bus
>= bus
))
32 return pci_mmcfg_virt
[cfg_num
].virt
;
35 /* Fall back to type 0 */
39 static char __iomem
*pci_dev_base(unsigned int seg
, unsigned int bus
, unsigned int devfn
)
43 addr
= get_virt(seg
, bus
);
46 return addr
+ (PCI_MMCFG_BUS_OFFSET(bus
) | (devfn
<< 12));
49 static int pci_mmcfg_read(unsigned int seg
, unsigned int bus
,
50 unsigned int devfn
, int reg
, int len
, u32
*value
)
54 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
55 if (unlikely((bus
> 255) || (devfn
> 255) || (reg
> 4095))) {
60 addr
= pci_dev_base(seg
, bus
, devfn
);
66 *value
= mmio_config_readb(addr
+ reg
);
69 *value
= mmio_config_readw(addr
+ reg
);
72 *value
= mmio_config_readl(addr
+ reg
);
79 static int pci_mmcfg_write(unsigned int seg
, unsigned int bus
,
80 unsigned int devfn
, int reg
, int len
, u32 value
)
84 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
85 if (unlikely((bus
> 255) || (devfn
> 255) || (reg
> 4095)))
88 addr
= pci_dev_base(seg
, bus
, devfn
);
94 mmio_config_writeb(addr
+ reg
, value
);
97 mmio_config_writew(addr
+ reg
, value
);
100 mmio_config_writel(addr
+ reg
, value
);
107 static struct pci_raw_ops pci_mmcfg
= {
108 .read
= pci_mmcfg_read
,
109 .write
= pci_mmcfg_write
,
112 static void __iomem
* __init
mcfg_ioremap(struct pci_mmcfg_region
*cfg
)
118 start
= cfg
->address
+ PCI_MMCFG_BUS_OFFSET(cfg
->start_bus
);
119 num_buses
= cfg
->end_bus
- cfg
->start_bus
+ 1;
120 size
= PCI_MMCFG_BUS_OFFSET(num_buses
);
121 addr
= ioremap_nocache(start
, size
);
123 printk(KERN_INFO
"PCI: Using MMCONFIG at %Lx - %Lx\n",
124 start
, start
+ size
- 1);
125 addr
-= PCI_MMCFG_BUS_OFFSET(cfg
->start_bus
);
130 int __init
pci_mmcfg_arch_init(void)
133 pci_mmcfg_virt
= kzalloc(sizeof(*pci_mmcfg_virt
) *
134 pci_mmcfg_config_num
, GFP_KERNEL
);
135 if (pci_mmcfg_virt
== NULL
) {
136 printk(KERN_ERR
"PCI: Can not allocate memory for mmconfig structures\n");
140 for (i
= 0; i
< pci_mmcfg_config_num
; ++i
) {
141 pci_mmcfg_virt
[i
].cfg
= &pci_mmcfg_config
[i
];
142 pci_mmcfg_virt
[i
].virt
= mcfg_ioremap(&pci_mmcfg_config
[i
]);
143 if (!pci_mmcfg_virt
[i
].virt
) {
144 printk(KERN_ERR
"PCI: Cannot map mmconfig aperture for "
146 pci_mmcfg_config
[i
].segment
);
147 pci_mmcfg_arch_free();
151 raw_pci_ext_ops
= &pci_mmcfg
;
155 void __init
pci_mmcfg_arch_free(void)
159 if (pci_mmcfg_virt
== NULL
)
162 for (i
= 0; i
< pci_mmcfg_config_num
; ++i
) {
163 if (pci_mmcfg_virt
[i
].virt
) {
164 iounmap(pci_mmcfg_virt
[i
].virt
+ PCI_MMCFG_BUS_OFFSET(pci_mmcfg_virt
[i
].cfg
->start_bus
));
165 pci_mmcfg_virt
[i
].virt
= NULL
;
166 pci_mmcfg_virt
[i
].cfg
= NULL
;
170 kfree(pci_mmcfg_virt
);
171 pci_mmcfg_virt
= NULL
;
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