ACPI supports writing a UUID in a special format. Add a function to handle this.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v1: None
include/acpi/acpigen.h | 13 +++++++++++++ lib/acpi/acpigen.c | 38 ++++++++++++++++++++++++++++++++++++++ test/dm/acpigen.c | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 84 insertions(+)
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h index 0fecb7d57a..f35467f029 100644 --- a/include/acpi/acpigen.h +++ b/include/acpi/acpigen.h @@ -24,6 +24,7 @@ enum { DWORD_PREFIX = 0x0c, STRING_PREFIX = 0x0d, QWORD_PREFIX = 0x0e, + BUFFER_OP = 0x11, PACKAGE_OP = 0x12, DUAL_NAME_PREFIX = 0x2e, MULTI_NAME_PREFIX = 0x2f, @@ -182,4 +183,16 @@ void acpigen_emit_namestring(struct acpi_ctx *ctx, const char *namepath); * @namepath: Name / path to emit */ void acpigen_write_name(struct acpi_ctx *ctx, const char *namepath); + +/** + * acpigen_write_uuid() - Write a UUID + * + * This writes out a UUID in the format used by ACPI, with a BUFFER_OP prefix. + * + * @ctx: ACPI context pointer + * @uuid: UUID to write in the form aabbccdd-eeff-gghh-iijj-kkllmmnnoopp + * @return 0 if OK, -EINVAL if the format is incorrect + */ +int acpigen_write_uuid(struct acpi_ctx *ctx, const char *uuid); + #endif diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c index 07bd569f26..a61496a095 100644 --- a/lib/acpi/acpigen.c +++ b/lib/acpi/acpigen.c @@ -247,3 +247,41 @@ 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 + */ +#define UUID_LEN 16 +int acpigen_write_uuid(struct acpi_ctx *ctx, const char *uuid) +{ + u8 buf[UUID_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_LEN); + + /* Output UUID in expected order */ + acpigen_emit_stream(ctx, (char *)buf, UUID_LEN); + + acpigen_pop_len(ctx); + + return 0; +} diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c index 0f56262a28..db8cad47d8 100644 --- a/test/dm/acpigen.c +++ b/test/dm/acpigen.c @@ -588,3 +588,36 @@ static int dm_test_acpi_name(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_acpi_name, 0); + +/* Test writing a UUID */ +static int dm_test_acpi_uuid(struct unit_test_state *uts) +{ + struct acpi_ctx *ctx; + u8 *ptr; + + ut_assertok(alloc_context(&ctx)); + + ptr = acpigen_get_current(ctx); + + ut_assertok(acpigen_write_uuid(ctx, + "dbb8e3e6-5886-4ba6-8795-1319f52a966b")); + ut_asserteq(23, acpigen_get_current(ctx) - ptr); + ut_asserteq(BUFFER_OP, ptr[0]); + ut_asserteq(22, get_length(ptr + 1)); + ut_asserteq(0xdbb8e3e6, get_unaligned((u32 *)(ptr + 7))); + ut_asserteq(0x5886, get_unaligned((u16 *)(ptr + 11))); + ut_asserteq(0x4ba6, get_unaligned((u16 *)(ptr + 13))); + ut_asserteq(0x9587, get_unaligned((u16 *)(ptr + 15))); + ut_asserteq(0x2af51913, get_unaligned((u32 *)(ptr + 17))); + ut_asserteq(0x6b96, get_unaligned((u16 *)(ptr + 21))); + + /* Try a bad UUID */ + ut_asserteq(-EINVAL, + acpigen_write_uuid(ctx, + "dbb8e3e6-5886-4ba6x8795-1319f52a966b")); + + free_context(&ctx); + + return 0; +} +DM_TEST(dm_test_acpi_uuid, 0);