u-boot/lib/acpi/acpigen.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Generation of ACPI (Advanced Configuration and Power Interface) tables
*
* Copyright 2019 Google LLC
* Mostly taken from coreboot
*/
#define LOG_CATEGORY LOGC_ACPI
#include <common.h>
#include <dm.h>
#include <log.h>
#include <uuid.h>
#include <acpi/acpigen.h>
#include <dm/acpi.h>
u8 *acpigen_get_current(struct acpi_ctx *ctx)
{
return ctx->current;
}
void acpigen_emit_byte(struct acpi_ctx *ctx, uint data)
{
*(u8 *)ctx->current++ = data;
}
void acpigen_emit_word(struct acpi_ctx *ctx, uint data)
{
acpigen_emit_byte(ctx, data & 0xff);
acpigen_emit_byte(ctx, (data >> 8) & 0xff);
}
void acpigen_emit_dword(struct acpi_ctx *ctx, uint data)
{
/* Output the value in little-endian format */
acpigen_emit_byte(ctx, data & 0xff);
acpigen_emit_byte(ctx, (data >> 8) & 0xff);
acpigen_emit_byte(ctx, (data >> 16) & 0xff);
acpigen_emit_byte(ctx, (data >> 24) & 0xff);
}
/*
* Maximum length for an ACPI object generated by this code,
*
* If you need to change this, change acpigen_write_len_f(ctx) and
* acpigen_pop_len(ctx)
*/
#define ACPIGEN_MAXLEN 0xfffff
void acpigen_write_len_f(struct acpi_ctx *ctx)
{
assert(ctx->ltop < (ACPIGEN_LENSTACK_SIZE - 1));
ctx->len_stack[ctx->ltop++] = ctx->current;
acpigen_emit_byte(ctx, 0);
acpigen_emit_byte(ctx, 0);
acpigen_emit_byte(ctx, 0);
}
void acpigen_pop_len(struct acpi_ctx *ctx)
{
int len;
char *p;
assert(ctx->ltop > 0);
p = ctx->len_stack[--ctx->ltop];
len = ctx->current - (void *)p;
assert(len <= ACPIGEN_MAXLEN);
/* generate store length for 0xfffff max */
p[0] = ACPI_PKG_LEN_3_BYTES | (len & 0xf);
p[1] = len >> 4 & 0xff;
p[2] = len >> 12 & 0xff;
}
char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el)
{
char *p;
acpigen_emit_byte(ctx, PACKAGE_OP);
acpigen_write_len_f(ctx);
p = ctx->current;
acpigen_emit_byte(ctx, nr_el);
return p;
}
void acpigen_write_byte(struct acpi_ctx *ctx, unsigned int data)
{
acpigen_emit_byte(ctx, BYTE_PREFIX);
acpigen_emit_byte(ctx, data & 0xff);
}
void acpigen_write_word(struct acpi_ctx *ctx, unsigned int data)
{
acpigen_emit_byte(ctx, WORD_PREFIX);
acpigen_emit_word(ctx, data);
}
void acpigen_write_dword(struct acpi_ctx *ctx, unsigned int data)
{
acpigen_emit_byte(ctx, DWORD_PREFIX);
acpigen_emit_dword(ctx, data);
}
void acpigen_write_qword(struct acpi_ctx *ctx, u64 data)
{
acpigen_emit_byte(ctx, QWORD_PREFIX);
acpigen_emit_dword(ctx, data & 0xffffffff);
acpigen_emit_dword(ctx, (data >> 32) & 0xffffffff);
}
void acpigen_write_zero(struct acpi_ctx *ctx)
{
acpigen_emit_byte(ctx, ZERO_OP);
}
void acpigen_write_one(struct acpi_ctx *ctx)
{
acpigen_emit_byte(ctx, ONE_OP);
}
void acpigen_write_integer(struct acpi_ctx *ctx, u64 data)
{
if (data == 0)
acpigen_write_zero(ctx);
else if (data == 1)
acpigen_write_one(ctx);
else if (data <= 0xff)
acpigen_write_byte(ctx, (unsigned char)data);
else if (data <= 0xffff)
acpigen_write_word(ctx, (unsigned int)data);
else if (data <= 0xffffffff)
acpigen_write_dword(ctx, (unsigned int)data);
else
acpigen_write_qword(ctx, data);
}
void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size)
{
int i;
for (i = 0; i < size; i++)
acpigen_emit_byte(ctx, data[i]);
}
void acpigen_emit_string(struct acpi_ctx *ctx, const char *str)
{
acpigen_emit_stream(ctx, str, str ? strlen(str) : 0);
acpigen_emit_byte(ctx, '\0');
}
void acpigen_write_string(struct acpi_ctx *ctx, const char *str)
{
acpigen_emit_byte(ctx, STRING_PREFIX);
acpigen_emit_string(ctx, str);
}
/*
* The naming conventions for ACPI namespace names are a bit tricky as
* each element has to be 4 chars wide ("All names are a fixed 32 bits.")
* and "By convention, when an ASL compiler pads a name shorter than 4
* characters, it is done so with trailing underscores ('_')".
*
* Check sections 5.3, 20.2.2 and 20.4 of ACPI spec 6.3 for details.
*/
static void acpigen_emit_simple_namestring(struct acpi_ctx *ctx,
const char *name)
{
const char *ptr;
int i;
for (i = 0, ptr = name; i < 4; i++) {
if (!*ptr || *ptr == '.')
acpigen_emit_byte(ctx, '_');
else
acpigen_emit_byte(ctx, *ptr++);
}
}
static void acpigen_emit_double_namestring(struct acpi_ctx *ctx,
const char *name, int dotpos)
{
acpigen_emit_byte(ctx, DUAL_NAME_PREFIX);
acpigen_emit_simple_namestring(ctx, name);
acpigen_emit_simple_namestring(ctx, &name[dotpos + 1]);
}
static void acpigen_emit_multi_namestring(struct acpi_ctx *ctx,
const char *name)
{
unsigned char *pathlen;
int count = 0;
acpigen_emit_byte(ctx, MULTI_NAME_PREFIX);
pathlen = ctx->current;
acpigen_emit_byte(ctx, 0);
while (*name) {
acpigen_emit_simple_namestring(ctx, name);
/* find end or next entity */
while (*name != '.' && *name)
name++;
/* forward to next */
if (*name == '.')
name++;
count++;
}
*pathlen = count;
}
void acpigen_emit_namestring(struct acpi_ctx *ctx, const char *namepath)
{
int dotcount;
int dotpos;
int i;
/* We can start with a '\' */
if (*namepath == '\\') {
acpigen_emit_byte(ctx, '\\');
namepath++;
}
/* And there can be any number of '^' */
while (*namepath == '^') {
acpigen_emit_byte(ctx, '^');
namepath++;
}
for (i = 0, dotcount = 0; namepath[i]; i++) {
if (namepath[i] == '.') {
dotcount++;
dotpos = i;
}
}
/* If we have only \\ or only ^* then we need to add a null name */
if (!*namepath)
acpigen_emit_byte(ctx, ZERO_OP);
else if (dotcount == 0)
acpigen_emit_simple_namestring(ctx, namepath);
else if (dotcount == 1)
acpigen_emit_double_namestring(ctx, namepath, dotpos);
else
acpigen_emit_multi_namestring(ctx, namepath);
}
void acpigen_write_name(struct acpi_ctx *ctx, const char *namepath)
{
acpigen_emit_byte(ctx, NAME_OP);
acpigen_emit_namestring(ctx, namepath);
}
/*
* ToUUID(uuid)
*
* ACPI 6.3 Section 19.6.142 table 19-438 defines a special output order for the
* bytes that make up a UUID Buffer object:
*
* UUID byte order for input to this function:
* aabbccdd-eeff-gghh-iijj-kkllmmnnoopp
*
* UUID byte order output by this function:
* ddccbbaa-ffee-hhgg-iijj-kkllmmnnoopp
*/
int acpigen_write_uuid(struct acpi_ctx *ctx, const char *uuid)
{
u8 buf[UUID_BIN_LEN];
int ret;
/* Parse UUID string into bytes */
ret = uuid_str_to_bin(uuid, buf, UUID_STR_FORMAT_GUID);
if (ret)
return log_msg_ret("bad hex", -EINVAL);
/* BufferOp */
acpigen_emit_byte(ctx, BUFFER_OP);
acpigen_write_len_f(ctx);
/* Buffer length in bytes */
acpigen_write_word(ctx, UUID_BIN_LEN);
/* Output UUID in expected order */
acpigen_emit_stream(ctx, (char *)buf, UUID_BIN_LEN);
acpigen_pop_len(ctx);
return 0;
}