1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/kernel.h> 3 #include <linux/pci.h> 4 #include <asm/pci-direct.h> 5 #include <asm/io.h> 6 #include <asm/pci_x86.h> 7 8 /* Direct PCI access. This is used for PCI accesses in early boot before 9 the PCI subsystem works. */ 10 11 u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset) 12 { 13 u32 v; 14 outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); 15 v = inl(0xcfc); 16 return v; 17 } 18 19 u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset) 20 { 21 u8 v; 22 outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); 23 v = inb(0xcfc + (offset&3)); 24 return v; 25 } 26 27 u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset) 28 { 29 u16 v; 30 outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); 31 v = inw(0xcfc + (offset&2)); 32 return v; 33 } 34 35 void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, 36 u32 val) 37 { 38 outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); 39 outl(val, 0xcfc); 40 } 41 42 void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val) 43 { 44 outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); 45 outb(val, 0xcfc + (offset&3)); 46 } 47 48 void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val) 49 { 50 outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); 51 outw(val, 0xcfc + (offset&2)); 52 } 53 54 int early_pci_allowed(void) 55 { 56 return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) == 57 PCI_PROBE_CONF1; 58 } 59 60 void early_dump_pci_device(u8 bus, u8 slot, u8 func) 61 { 62 int i; 63 int j; 64 u32 val; 65 66 printk(KERN_INFO "pci 0000:%02x:%02x.%d config space:", 67 bus, slot, func); 68 69 for (i = 0; i < 256; i += 4) { 70 if (!(i & 0x0f)) 71 printk("\n %02x:",i); 72 73 val = read_pci_config(bus, slot, func, i); 74 for (j = 0; j < 4; j++) { 75 printk(" %02x", val & 0xff); 76 val >>= 8; 77 } 78 } 79 printk("\n"); 80 } 81 82 void early_dump_pci_devices(void) 83 { 84 unsigned bus, slot, func; 85 86 if (!early_pci_allowed()) 87 return; 88 89 for (bus = 0; bus < 256; bus++) { 90 for (slot = 0; slot < 32; slot++) { 91 for (func = 0; func < 8; func++) { 92 u32 class; 93 u8 type; 94 95 class = read_pci_config(bus, slot, func, 96 PCI_CLASS_REVISION); 97 if (class == 0xffffffff) 98 continue; 99 100 early_dump_pci_device(bus, slot, func); 101 102 if (func == 0) { 103 type = read_pci_config_byte(bus, slot, 104 func, 105 PCI_HEADER_TYPE); 106 if (!(type & 0x80)) 107 break; 108 } 109 } 110 } 111 } 112 } 113