Staging
v0.6.0
v0.6.0
https://github.com/torvalds/linux
Tip revision: 45a3e24f65e90a047bef86f927ebdc4c710edaa1 authored by Linus Torvalds on 18 June 2023, 21:06:27 UTC
Linux 6.4-rc7
Linux 6.4-rc7
Tip revision: 45a3e24
acpi.c
// SPDX-License-Identifier: GPL-2.0
#define BOOT_CTYPE_H
#include "misc.h"
#include "error.h"
#include "../string.h"
#include "efi.h"
#include <linux/numa.h>
/*
* Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0'
* for termination.
*/
#define MAX_ACPI_ARG_LENGTH 10
/*
* Immovable memory regions representation. Max amount of memory regions is
* MAX_NUMNODES*2.
*/
struct mem_vector immovable_mem[MAX_NUMNODES*2];
static acpi_physical_address
__efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len)
{
#ifdef CONFIG_EFI
unsigned long rsdp_addr;
int ret;
/*
* Search EFI system tables for RSDP. Preferred is ACPI_20_TABLE_GUID to
* ACPI_TABLE_GUID because it has more features.
*/
rsdp_addr = efi_find_vendor_table(boot_params, cfg_tbl_pa, cfg_tbl_len,
ACPI_20_TABLE_GUID);
if (rsdp_addr)
return (acpi_physical_address)rsdp_addr;
/* No ACPI_20_TABLE_GUID found, fallback to ACPI_TABLE_GUID. */
rsdp_addr = efi_find_vendor_table(boot_params, cfg_tbl_pa, cfg_tbl_len,
ACPI_TABLE_GUID);
if (rsdp_addr)
return (acpi_physical_address)rsdp_addr;
debug_putstr("Error getting RSDP address.\n");
#endif
return 0;
}
static acpi_physical_address efi_get_rsdp_addr(void)
{
#ifdef CONFIG_EFI
unsigned long cfg_tbl_pa = 0;
unsigned int cfg_tbl_len;
unsigned long systab_pa;
unsigned int nr_tables;
enum efi_type et;
int ret;
et = efi_get_type(boot_params);
if (et == EFI_TYPE_NONE)
return 0;
systab_pa = efi_get_system_table(boot_params);
if (!systab_pa)
error("EFI support advertised, but unable to locate system table.");
ret = efi_get_conf_table(boot_params, &cfg_tbl_pa, &cfg_tbl_len);
if (ret || !cfg_tbl_pa)
error("EFI config table not found.");
return __efi_get_rsdp_addr(cfg_tbl_pa, cfg_tbl_len);
#else
return 0;
#endif
}
static u8 compute_checksum(u8 *buffer, u32 length)
{
u8 *end = buffer + length;
u8 sum = 0;
while (buffer < end)
sum += *(buffer++);
return sum;
}
/* Search a block of memory for the RSDP signature. */
static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
{
struct acpi_table_rsdp *rsdp;
u8 *address, *end;
end = start + length;
/* Search from given start address for the requested length */
for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) {
/*
* Both RSDP signature and checksum must be correct.
* Note: Sometimes there exists more than one RSDP in memory;
* the valid RSDP has a valid checksum, all others have an
* invalid checksum.
*/
rsdp = (struct acpi_table_rsdp *)address;
/* BAD Signature */
if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
continue;
/* Check the standard checksum */
if (compute_checksum((u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
continue;
/* Check extended checksum if table version >= 2 */
if ((rsdp->revision >= 2) &&
(compute_checksum((u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
continue;
/* Signature and checksum valid, we have found a real RSDP */
return address;
}
return NULL;
}
/* Search RSDP address in EBDA. */
static acpi_physical_address bios_get_rsdp_addr(void)
{
unsigned long address;
u8 *rsdp;
/* Get the location of the Extended BIOS Data Area (EBDA) */
address = *(u16 *)ACPI_EBDA_PTR_LOCATION;
address <<= 4;
/*
* Search EBDA paragraphs (EBDA is required to be a minimum of
* 1K length)
*/
if (address > 0x400) {
rsdp = scan_mem_for_rsdp((u8 *)address, ACPI_EBDA_WINDOW_SIZE);
if (rsdp)
return (acpi_physical_address)(unsigned long)rsdp;
}
/* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
rsdp = scan_mem_for_rsdp((u8 *) ACPI_HI_RSDP_WINDOW_BASE,
ACPI_HI_RSDP_WINDOW_SIZE);
if (rsdp)
return (acpi_physical_address)(unsigned long)rsdp;
return 0;
}
/* Return RSDP address on success, otherwise 0. */
acpi_physical_address get_rsdp_addr(void)
{
acpi_physical_address pa;
pa = boot_params->acpi_rsdp_addr;
if (!pa)
pa = efi_get_rsdp_addr();
if (!pa)
pa = bios_get_rsdp_addr();
return pa;
}
#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE)
/*
* Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex
* digits, and '\0' for termination.
*/
#define MAX_ADDR_LEN 19
static unsigned long get_cmdline_acpi_rsdp(void)
{
unsigned long addr = 0;
#ifdef CONFIG_KEXEC
char val[MAX_ADDR_LEN] = { };
int ret;
ret = cmdline_find_option("acpi_rsdp", val, MAX_ADDR_LEN);
if (ret < 0)
return 0;
if (boot_kstrtoul(val, 16, &addr))
return 0;
#endif
return addr;
}
/* Compute SRAT address from RSDP. */
static unsigned long get_acpi_srat_table(void)
{
unsigned long root_table, acpi_table;
struct acpi_table_header *header;
struct acpi_table_rsdp *rsdp;
u32 num_entries, size, len;
char arg[10];
u8 *entry;
/*
* Check whether we were given an RSDP on the command line. We don't
* stash this in boot params because the kernel itself may have
* different ideas about whether to trust a command-line parameter.
*/
rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
if (!rsdp)
rsdp = (struct acpi_table_rsdp *)(long)
boot_params->acpi_rsdp_addr;
if (!rsdp)
return 0;
/* Get ACPI root table from RSDP.*/
if (!(cmdline_find_option("acpi", arg, sizeof(arg)) == 4 &&
!strncmp(arg, "rsdt", 4)) &&
rsdp->xsdt_physical_address &&
rsdp->revision > 1) {
root_table = rsdp->xsdt_physical_address;
size = ACPI_XSDT_ENTRY_SIZE;
} else {
root_table = rsdp->rsdt_physical_address;
size = ACPI_RSDT_ENTRY_SIZE;
}
if (!root_table)
return 0;
header = (struct acpi_table_header *)root_table;
len = header->length;
if (len < sizeof(struct acpi_table_header) + size)
return 0;
num_entries = (len - sizeof(struct acpi_table_header)) / size;
entry = (u8 *)(root_table + sizeof(struct acpi_table_header));
while (num_entries--) {
if (size == ACPI_RSDT_ENTRY_SIZE)
acpi_table = *(u32 *)entry;
else
acpi_table = *(u64 *)entry;
if (acpi_table) {
header = (struct acpi_table_header *)acpi_table;
if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_SRAT))
return acpi_table;
}
entry += size;
}
return 0;
}
/**
* count_immovable_mem_regions - Parse SRAT and cache the immovable
* memory regions into the immovable_mem array.
*
* Return the number of immovable memory regions on success, 0 on failure:
*
* - Too many immovable memory regions
* - ACPI off or no SRAT found
* - No immovable memory region found.
*/
int count_immovable_mem_regions(void)
{
unsigned long table_addr, table_end, table;
struct acpi_subtable_header *sub_table;
struct acpi_table_header *table_header;
char arg[MAX_ACPI_ARG_LENGTH];
int num = 0;
if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
!strncmp(arg, "off", 3))
return 0;
table_addr = get_acpi_srat_table();
if (!table_addr)
return 0;
table_header = (struct acpi_table_header *)table_addr;
table_end = table_addr + table_header->length;
table = table_addr + sizeof(struct acpi_table_srat);
while (table + sizeof(struct acpi_subtable_header) < table_end) {
sub_table = (struct acpi_subtable_header *)table;
if (!sub_table->length) {
debug_putstr("Invalid zero length SRAT subtable.\n");
return 0;
}
if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
struct acpi_srat_mem_affinity *ma;
ma = (struct acpi_srat_mem_affinity *)sub_table;
if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) {
immovable_mem[num].start = ma->base_address;
immovable_mem[num].size = ma->length;
num++;
}
if (num >= MAX_NUMNODES*2) {
debug_putstr("Too many immovable memory regions, aborting.\n");
return 0;
}
}
table += sub_table->length;
}
return num;
}
#endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */