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>
12 #include <linux/rcupdate.h>
13 #include <asm/e820/api.h>
14 #include <asm/pci_x86.h>
16 #define PREFIX "PCI: "
18 static char __iomem
*pci_dev_base(unsigned int seg
, unsigned int bus
, unsigned int devfn
)
20 struct pci_mmcfg_region
*cfg
= pci_mmconfig_lookup(seg
, bus
);
23 return cfg
->virt
+ (PCI_MMCFG_BUS_OFFSET(bus
) | (devfn
<< 12));
27 static int pci_mmcfg_read(unsigned int seg
, unsigned int bus
,
28 unsigned int devfn
, int reg
, int len
, u32
*value
)
32 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
33 if (unlikely((bus
> 255) || (devfn
> 255) || (reg
> 4095))) {
39 addr
= pci_dev_base(seg
, bus
, devfn
);
47 *value
= mmio_config_readb(addr
+ reg
);
50 *value
= mmio_config_readw(addr
+ reg
);
53 *value
= mmio_config_readl(addr
+ reg
);
61 static int pci_mmcfg_write(unsigned int seg
, unsigned int bus
,
62 unsigned int devfn
, int reg
, int len
, u32 value
)
66 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
67 if (unlikely((bus
> 255) || (devfn
> 255) || (reg
> 4095)))
71 addr
= pci_dev_base(seg
, bus
, devfn
);
79 mmio_config_writeb(addr
+ reg
, value
);
82 mmio_config_writew(addr
+ reg
, value
);
85 mmio_config_writel(addr
+ reg
, value
);
93 const struct pci_raw_ops pci_mmcfg
= {
94 .read
= pci_mmcfg_read
,
95 .write
= pci_mmcfg_write
,
98 static void __iomem
*mcfg_ioremap(struct pci_mmcfg_region
*cfg
)
104 start
= cfg
->address
+ PCI_MMCFG_BUS_OFFSET(cfg
->start_bus
);
105 num_buses
= cfg
->end_bus
- cfg
->start_bus
+ 1;
106 size
= PCI_MMCFG_BUS_OFFSET(num_buses
);
107 addr
= ioremap_nocache(start
, size
);
109 addr
-= PCI_MMCFG_BUS_OFFSET(cfg
->start_bus
);
113 int __init
pci_mmcfg_arch_init(void)
115 struct pci_mmcfg_region
*cfg
;
117 list_for_each_entry(cfg
, &pci_mmcfg_list
, list
)
118 if (pci_mmcfg_arch_map(cfg
)) {
119 pci_mmcfg_arch_free();
123 raw_pci_ext_ops
= &pci_mmcfg
;
128 void __init
pci_mmcfg_arch_free(void)
130 struct pci_mmcfg_region
*cfg
;
132 list_for_each_entry(cfg
, &pci_mmcfg_list
, list
)
133 pci_mmcfg_arch_unmap(cfg
);
136 int pci_mmcfg_arch_map(struct pci_mmcfg_region
*cfg
)
138 cfg
->virt
= mcfg_ioremap(cfg
);
140 pr_err(PREFIX
"can't map MMCONFIG at %pR\n", &cfg
->res
);
147 void pci_mmcfg_arch_unmap(struct pci_mmcfg_region
*cfg
)
149 if (cfg
&& cfg
->virt
) {
150 iounmap(cfg
->virt
+ PCI_MMCFG_BUS_OFFSET(cfg
->start_bus
));