linux/arch/arm64/kernel/acpi.c

144 lines
3.8 KiB
C

/*
* ARM64 Specific Low-Level ACPI Boot Support
*
* Copyright (C) 2013-2014, Linaro Ltd.
* Author: Al Stone <al.stone@linaro.org>
* Author: Graeme Gregory <graeme.gregory@linaro.org>
* Author: Hanjun Guo <hanjun.guo@linaro.org>
* Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
* Author: Naresh Bhat <naresh.bhat@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/acpi.h>
#include <linux/bootmem.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <linux/smp.h>
int acpi_noirq = 1; /* skip ACPI IRQ initialization */
int acpi_disabled = 1;
EXPORT_SYMBOL(acpi_disabled);
int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
EXPORT_SYMBOL(acpi_pci_disabled);
static bool param_acpi_off __initdata;
static bool param_acpi_force __initdata;
static int __init parse_acpi(char *arg)
{
if (!arg)
return -EINVAL;
/* "acpi=off" disables both ACPI table parsing and interpreter */
if (strcmp(arg, "off") == 0)
param_acpi_off = true;
else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
param_acpi_force = true;
else
return -EINVAL; /* Core will print when we return error */
return 0;
}
early_param("acpi", parse_acpi);
static int __init dt_scan_depth1_nodes(unsigned long node,
const char *uname, int depth,
void *data)
{
/*
* Return 1 as soon as we encounter a node at depth 1 that is
* not the /chosen node.
*/
if (depth == 1 && (strcmp(uname, "chosen") != 0))
return 1;
return 0;
}
/*
* __acpi_map_table() will be called before page_init(), so early_ioremap()
* or early_memremap() should be called here to for ACPI table mapping.
*/
char *__init __acpi_map_table(unsigned long phys, unsigned long size)
{
if (!size)
return NULL;
return early_memremap(phys, size);
}
void __init __acpi_unmap_table(char *map, unsigned long size)
{
if (!map || !size)
return;
early_memunmap(map, size);
}
static int __init acpi_parse_fadt(struct acpi_table_header *table)
{
struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
/*
* Revision in table header is the FADT Major revision, and there
* is a minor revision of FADT which was introduced by ACPI 5.1,
* we only deal with ACPI 5.1 or newer revision to get GIC and SMP
* boot protocol configuration data, or we will disable ACPI.
*/
if (table->revision > 5 ||
(table->revision == 5 && fadt->minor_revision >= 1))
return 0;
pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
table->revision, fadt->minor_revision);
disable_acpi();
return -EINVAL;
}
/*
* acpi_boot_table_init() called from setup_arch(), always.
* 1. find RSDP and get its address, and then find XSDT
* 2. extract all tables and checksums them all
* 3. check ACPI FADT revision
*
* We can parse ACPI boot-time tables such as MADT after
* this function is called.
*/
void __init acpi_boot_table_init(void)
{
/*
* Enable ACPI instead of device tree unless
* - ACPI has been disabled explicitly (acpi=off), or
* - the device tree is not empty (it has more than just a /chosen node)
* and ACPI has not been force enabled (acpi=force)
*/
if (param_acpi_off ||
(!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
return;
enable_acpi();
/* Initialize the ACPI boot-time table parser. */
if (acpi_table_init()) {
disable_acpi();
return;
}
if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) {
/* disable ACPI if no FADT is found */
disable_acpi();
pr_err("Can't find FADT\n");
}
}