u-boot/arch/x86/lib/sfi.c

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/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Intel Simple Firmware Interface (SFI)
*
* Yet another way to pass information to the Linux kernel.
*
* See https://simplefirmware.org/ for details
*/
#include <common.h>
#include <cpu.h>
#include <dm.h>
#include <asm/cpu.h>
#include <asm/ioapic.h>
#include <asm/sfi.h>
#include <asm/tables.h>
#include <dm/uclass-internal.h>
struct table_info {
u32 base;
int ptr;
u32 entry_start;
u64 table[SFI_TABLE_MAX_ENTRIES];
int count;
};
static void *get_entry_start(struct table_info *tab)
{
if (tab->count == SFI_TABLE_MAX_ENTRIES)
return NULL;
tab->entry_start = tab->base + tab->ptr;
tab->table[tab->count] = tab->entry_start;
tab->entry_start += sizeof(struct sfi_table_header);
return (void *)(uintptr_t)tab->entry_start;
}
static void finish_table(struct table_info *tab, const char *sig, void *entry)
{
struct sfi_table_header *hdr;
hdr = (struct sfi_table_header *)(uintptr_t)(tab->base + tab->ptr);
strcpy(hdr->sig, sig);
hdr->len = sizeof(*hdr) + ((ulong)entry - tab->entry_start);
hdr->rev = 1;
strncpy(hdr->oem_id, "U-Boot", SFI_OEM_ID_SIZE);
strncpy(hdr->oem_table_id, "Table v1", SFI_OEM_TABLE_ID_SIZE);
hdr->csum = 0;
hdr->csum = table_compute_checksum(hdr, hdr->len);
tab->ptr += hdr->len;
tab->ptr = ALIGN(tab->ptr, 16);
tab->count++;
}
static int sfi_write_system_header(struct table_info *tab)
{
u64 *entry = get_entry_start(tab);
int i;
if (!entry)
return -ENOSPC;
for (i = 0; i < tab->count; i++)
*entry++ = tab->table[i];
finish_table(tab, SFI_SIG_SYST, entry);
return 0;
}
static int sfi_write_cpus(struct table_info *tab)
{
struct sfi_cpu_table_entry *entry = get_entry_start(tab);
struct udevice *dev;
int count = 0;
if (!entry)
return -ENOSPC;
for (uclass_find_first_device(UCLASS_CPU, &dev);
dev;
uclass_find_next_device(&dev)) {
struct cpu_platdata *plat = dev_get_parent_platdata(dev);
if (!device_active(dev))
continue;
entry->apic_id = plat->cpu_id;
entry++;
count++;
}
/* Omit the table if there is only one CPU */
if (count > 1)
finish_table(tab, SFI_SIG_CPUS, entry);
return 0;
}
static int sfi_write_apic(struct table_info *tab)
{
struct sfi_apic_table_entry *entry = get_entry_start(tab);
if (!entry)
return -ENOSPC;
entry->phys_addr = IO_APIC_ADDR;
entry++;
finish_table(tab, SFI_SIG_APIC, entry);
return 0;
}
static int sfi_write_xsdt(struct table_info *tab)
{
struct sfi_xsdt_header *entry = get_entry_start(tab);
if (!entry)
return -ENOSPC;
entry->oem_revision = 1;
entry->creator_id = 1;
entry->creator_revision = 1;
entry++;
finish_table(tab, SFI_SIG_XSDT, entry);
return 0;
}
ulong write_sfi_table(ulong base)
{
struct table_info table;
table.base = base;
table.ptr = 0;
table.count = 0;
sfi_write_cpus(&table);
sfi_write_apic(&table);
/*
* The SFI specification marks the XSDT table as option, but Linux 4.0
* crashes on start-up when it is not provided.
*/
sfi_write_xsdt(&table);
/* Finally, write out the system header which points to the others */
sfi_write_system_header(&table);
return base + table.ptr;
}