[PATCH v4 17/35] acpi: Support writing a name
Simon Glass
sjg at chromium.org
Tue Jul 7 21:11:54 CEST 2020
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 at chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
Changes in v4:
- s/nul/null/ in the comment
include/acpi/acpigen.h | 25 +++++++++++
include/test/ut.h | 17 ++++++++
lib/acpi/acpigen.c | 96 ++++++++++++++++++++++++++++++++++++++++++
test/dm/acpigen.c | 93 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 231 insertions(+)
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index 14b96203a9..24aec7fad6 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -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
diff --git a/include/test/ut.h b/include/test/ut.h
index 7ddd6e8872..99bbb1230c 100644
--- a/include/test/ut.h
+++ b/include/test/ut.h
@@ -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); \
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index b254ef6c9a..0a6c1e37c5 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -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);
+}
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index c360f55dd3..adfcf88765 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -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);
--
2.27.0.383.g050319c2ae-goog
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