| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <arch/bootblock.h> |
| #include <assert.h> |
| #include <device/pci_ops.h> |
| #include <types.h> |
| |
| #include "i945.h" |
| |
| static uint32_t encode_pciexbar_length(void) |
| { |
| switch (CONFIG_MMCONF_BUS_NUMBER) { |
| case 256: return 0 << 1; |
| case 128: return 1 << 1; |
| case 64: return 2 << 1; |
| default: return dead_code_t(uint32_t); |
| } |
| } |
| |
| void bootblock_early_northbridge_init(void) |
| { |
| /* |
| * The "io" variant of the config access is explicitly used to setup the PCIEXBAR |
| * because CONFIG(MMCONF_SUPPORT) is set to true. That way all subsequent non-explicit |
| * config accesses use MCFG. This code also assumes that bootblock_northbridge_init() is |
| * the first thing called in the non-asm boot block code. The final assumption is that |
| * no assembly code is using the CONFIG(MMCONF_SUPPORT) option to do PCI config accesses. |
| * |
| * The PCIEXBAR is assumed to live in the memory mapped IO space under 4GiB. |
| */ |
| const uint32_t reg32 = CONFIG_MMCONF_BASE_ADDRESS | encode_pciexbar_length() | 1; |
| pci_io_write_config32(HOST_BRIDGE, PCIEXBAR, reg32); |
| } |