1 // SPDX-License-Identifier: GPL-2.0
3  * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
19 static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)  in pci_dev_base()  argument
21 	struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);  in pci_dev_base()
23 	if (cfg && cfg->virt)  in pci_dev_base()
24 		return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));  in pci_dev_base()
28 static int pci_mmcfg_read(unsigned int seg, unsigned int bus,  in pci_mmcfg_read()  argument
31 	char __iomem *addr;  in pci_mmcfg_read()  local
33 	/* Why do we have this when nobody checks it. How about a BUG()!? -AK */  in pci_mmcfg_read()
34 	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {  in pci_mmcfg_read()
35 err:		*value = -1;  in pci_mmcfg_read()
36 		return -EINVAL;  in pci_mmcfg_read()
40 	addr = pci_dev_base(seg, bus, devfn);  in pci_mmcfg_read()
41 	if (!addr) {  in pci_mmcfg_read()
48 		*value = mmio_config_readb(addr + reg);  in pci_mmcfg_read()
51 		*value = mmio_config_readw(addr + reg);  in pci_mmcfg_read()
54 		*value = mmio_config_readl(addr + reg);  in pci_mmcfg_read()
62 static int pci_mmcfg_write(unsigned int seg, unsigned int bus,  in pci_mmcfg_write()  argument
65 	char __iomem *addr;  in pci_mmcfg_write()  local
67 	/* Why do we have this when nobody checks it. How about a BUG()!? -AK */  in pci_mmcfg_write()
68 	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))  in pci_mmcfg_write()
69 		return -EINVAL;  in pci_mmcfg_write()
72 	addr = pci_dev_base(seg, bus, devfn);  in pci_mmcfg_write()
73 	if (!addr) {  in pci_mmcfg_write()
75 		return -EINVAL;  in pci_mmcfg_write()
80 		mmio_config_writeb(addr + reg, value);  in pci_mmcfg_write()
83 		mmio_config_writew(addr + reg, value);  in pci_mmcfg_write()
86 		mmio_config_writel(addr + reg, value);  in pci_mmcfg_write()
101 	void __iomem *addr;  in mcfg_ioremap()  local
105 	start = cfg->address + PCI_MMCFG_BUS_OFFSET(cfg->start_bus);  in mcfg_ioremap()
106 	num_buses = cfg->end_bus - cfg->start_bus + 1;  in mcfg_ioremap()
108 	addr = ioremap(start, size);  in mcfg_ioremap()
109 	if (addr)  in mcfg_ioremap()
110 		addr -= PCI_MMCFG_BUS_OFFSET(cfg->start_bus);  in mcfg_ioremap()
111 	return addr;  in mcfg_ioremap()
139 	cfg->virt = mcfg_ioremap(cfg);  in pci_mmcfg_arch_map()
140 	if (!cfg->virt) {  in pci_mmcfg_arch_map()
141 		pr_err(PREFIX "can't map MMCONFIG at %pR\n", &cfg->res);  in pci_mmcfg_arch_map()
142 		return -ENOMEM;  in pci_mmcfg_arch_map()
150 	if (cfg && cfg->virt) {  in pci_mmcfg_arch_unmap()
151 		iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));  in pci_mmcfg_arch_unmap()
152 		cfg->virt = NULL;  in pci_mmcfg_arch_unmap()