acpi: Support writing a name

ACPI supports storing names which are made up of multiple path components.
Several special cases are supported. Add a function to emit a name.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2020-07-07 13:11:54 -06:00 committed by Bin Meng
parent 3df33bda5c
commit 7aed90d44c
4 changed files with 231 additions and 0 deletions

View File

@ -21,12 +21,15 @@ struct acpi_ctx;
enum {
ZERO_OP = 0x00,
ONE_OP = 0x01,
NAME_OP = 0x08,
BYTE_PREFIX = 0x0a,
WORD_PREFIX = 0x0b,
DWORD_PREFIX = 0x0c,
STRING_PREFIX = 0x0d,
QWORD_PREFIX = 0x0e,
PACKAGE_OP = 0x12,
DUAL_NAME_PREFIX = 0x2e,
MULTI_NAME_PREFIX = 0x2f,
};
/**
@ -165,4 +168,26 @@ void acpigen_write_integer(struct acpi_ctx *ctx, u64 data);
* @str: String to write
*/
void acpigen_write_string(struct acpi_ctx *ctx, const char *str);
/**
* acpigen_emit_namestring() - Emit an ACPI name
*
* This writes out an ACPI name or path in the required special format. It does
* not add the NAME_OP prefix.
*
* @ctx: ACPI context pointer
* @namepath: Name / path to emit
*/
void acpigen_emit_namestring(struct acpi_ctx *ctx, const char *namepath);
/**
* acpigen_write_name() - Write out an ACPI name
*
* This writes out an ACPI name or path in the required special format with a
* NAME_OP prefix.
*
* @ctx: ACPI context pointer
* @namepath: Name / path to emit
*/
void acpigen_write_name(struct acpi_ctx *ctx, const char *namepath);
#endif

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@ -134,6 +134,23 @@ int ut_check_console_dump(struct unit_test_state *uts, int total_bytes);
} \
}
/*
* Assert that two string expressions are equal, up to length of the
* first
*/
#define ut_asserteq_strn(expr1, expr2) { \
const char *_val1 = (expr1), *_val2 = (expr2); \
int _len = strlen(_val1); \
\
if (memcmp(_val1, _val2, _len)) { \
ut_failf(uts, __FILE__, __LINE__, __func__, \
#expr1 " = " #expr2, \
"Expected \"%.*s\", got \"%.*s\"", \
_len, _val1, _len, _val2); \
return CMD_RET_FAILURE; \
} \
}
/* Assert that two memory areas are equal */
#define ut_asserteq_mem(expr1, expr2, len) { \
const u8 *_val1 = (u8 *)(expr1), *_val2 = (u8 *)(expr2); \

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@ -153,3 +153,99 @@ 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);
}

View File

@ -505,3 +505,96 @@ static int dm_test_acpi_string(struct unit_test_state *uts)
return 0;
}
DM_TEST(dm_test_acpi_string, 0);
/* Test writing a name */
static int dm_test_acpi_name(struct unit_test_state *uts)
{
struct acpi_ctx *ctx;
u8 *ptr;
ut_assertok(alloc_context(&ctx));
ptr = acpigen_get_current(ctx);
/*
* The names here are made up for testing the various cases. The
* grammar is in the ACPI spec 6.3 section 19.2.2
*/
acpigen_write_name(ctx, "\\_SB");
acpigen_write_name(ctx, "\\_SB.I2C0");
acpigen_write_name(ctx, "\\_SB.I2C0.TPM2");
acpigen_write_name(ctx, "\\_SB.I2C0.TPM2.LONG");
acpigen_write_name(ctx, "^^^^SPI0.FLAS");
acpigen_write_name(ctx, "NN");
acpigen_write_name(ctx, "^AB.CD.D.EFG");
acpigen_write_name(ctx, "^^^^");
acpigen_write_name(ctx, "\\");
acpigen_write_name(ctx, "\\ABCD");
ut_asserteq(107, acpigen_get_current(ctx) - ptr);
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq_strn("\\_SB_", (char *)ptr + 1);
ptr += 6;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('\\', ptr[1]);
ut_asserteq(DUAL_NAME_PREFIX, ptr[2]);
ut_asserteq_strn("_SB_I2C0", (char *)ptr + 3);
ptr += 11;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('\\', ptr[1]);
ut_asserteq(MULTI_NAME_PREFIX, ptr[2]);
ut_asserteq(3, ptr[3]);
ut_asserteq_strn("_SB_I2C0TPM2", (char *)ptr + 4);
ptr += 16;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('\\', ptr[1]);
ut_asserteq(MULTI_NAME_PREFIX, ptr[2]);
ut_asserteq(4, ptr[3]);
ut_asserteq_strn("_SB_I2C0TPM2LONG", (char *)ptr + 4);
ptr += 20;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('^', ptr[1]);
ut_asserteq('^', ptr[2]);
ut_asserteq('^', ptr[3]);
ut_asserteq('^', ptr[4]);
ut_asserteq(DUAL_NAME_PREFIX, ptr[5]);
ut_asserteq_strn("SPI0FLAS", (char *)ptr + 6);
ptr += 14;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq_strn("NN__", (char *)ptr + 1);
ptr += 5;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('^', ptr[1]);
ut_asserteq(MULTI_NAME_PREFIX, ptr[2]);
ut_asserteq(4, ptr[3]);
ut_asserteq_strn("AB__CD__D___EFG_", (char *)ptr + 4);
ptr += 20;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('^', ptr[1]);
ut_asserteq('^', ptr[2]);
ut_asserteq('^', ptr[3]);
ut_asserteq('^', ptr[4]);
ut_asserteq(ZERO_OP, ptr[5]);
ptr += 6;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq('\\', ptr[1]);
ut_asserteq(ZERO_OP, ptr[2]);
ptr += 3;
ut_asserteq(NAME_OP, ptr[0]);
ut_asserteq_strn("\\ABCD", (char *)ptr + 1);
ptr += 5;
free_context(&ctx);
return 0;
}
DM_TEST(dm_test_acpi_name, 0);