diff options
Diffstat (limited to 'arch/x86/pci/early.c')
| -rw-r--r-- | arch/x86/pci/early.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c new file mode 100644 index 0000000000..f5fc953e58 --- /dev/null +++ b/arch/x86/pci/early.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/pci.h> +#include <asm/pci-direct.h> +#include <asm/io.h> +#include <asm/pci_x86.h> + +/* Direct PCI access. This is used for PCI accesses in early boot before + the PCI subsystem works. */ + +u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset) +{ + u32 v; + outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); + v = inl(0xcfc); + return v; +} + +u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset) +{ + u8 v; + outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); + v = inb(0xcfc + (offset&3)); + return v; +} + +u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset) +{ + u16 v; + outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); + v = inw(0xcfc + (offset&2)); + return v; +} + +void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, + u32 val) +{ + outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); + outl(val, 0xcfc); +} + +void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val) +{ + outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); + outb(val, 0xcfc + (offset&3)); +} + +void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val) +{ + outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); + outw(val, 0xcfc + (offset&2)); +} + +int early_pci_allowed(void) +{ + return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) == + PCI_PROBE_CONF1; +} + |