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/* SPDX-License-Identifier: GPL-2.0-only */
#include <arch/bootblock.h>
#include <assert.h>
#include <device/pci_ops.h>
#include <soc/pci_devs.h>
#include <soc/systemagent.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 reg = CONFIG_MMCONF_BASE_ADDRESS | encode_pciexbar_length() | 1;
pci_io_write_config32(SA_DEV_ROOT, PCIEXBAR + 4, 0);
pci_io_write_config32(SA_DEV_ROOT, PCIEXBAR, reg);
}
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