acpi/acpigen: introduce and use ACPIGEN_RSVD_PKGLEN_BYTES
Use a define instead of magic numbers.
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I2c6d17bd78a0e207f9130102b43ba78aa55ce377
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79046
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/acpi/acpigen.c b/src/acpi/acpigen.c
index e5d76ba..7479dce 100644
--- a/src/acpi/acpigen.c
+++ b/src/acpi/acpigen.c
@@ -3,12 +3,9 @@
/* How much nesting do we support? */
#define ACPIGEN_LENSTACK_SIZE 10
-/*
- * If you need to change this, change acpigen_write_len_f and
- * acpigen_pop_len
- */
-
-#define ACPIGEN_MAXLEN 0xfffff
+/* If you need to change this, change acpigen_pop_len too */
+#define ACPIGEN_RSVD_PKGLEN_BYTES 3
+#define ACPIGEN_MAXLEN 0xfffff
#include <lib.h>
#include <string.h>
@@ -29,11 +26,10 @@
{
ASSERT(ltop < (ACPIGEN_LENSTACK_SIZE - 1))
len_stack[ltop++] = gencurrent;
- /* Reserve 3 bytes for PkgLength. The actual byte values will be written later in the
- acpigen_pop_len call. */
- acpigen_emit_byte(0);
- acpigen_emit_byte(0);
- acpigen_emit_byte(0);
+ /* Reserve ACPIGEN_RSVD_PKGLEN_BYTES bytes for PkgLength. The actual byte values will
+ be written later in the corresponding acpigen_pop_len call. */
+ for (size_t i = 0; i < ACPIGEN_RSVD_PKGLEN_BYTES; i++)
+ acpigen_emit_byte(0);
}
void acpigen_pop_len(void)
@@ -43,13 +39,14 @@
char *p = len_stack[--ltop];
len = gencurrent - p;
ASSERT(len <= ACPIGEN_MAXLEN)
- const size_t payload_len = len - 3;
+ const size_t payload_len = len - ACPIGEN_RSVD_PKGLEN_BYTES;
if (len <= 0x3f + 2) {
/* PkgLength of up to 0x3f can be encoded in one PkgLength byte instead of the
reserved 3 bytes. Since only 1 PkgLength byte will be written, the payload
data needs to be moved by 2 bytes */
- memmove(&p[1], &p[3], payload_len);
+ memmove(&p[ACPIGEN_RSVD_PKGLEN_BYTES - 2],
+ &p[ACPIGEN_RSVD_PKGLEN_BYTES], payload_len);
/* Adjust the PkgLength to take into account that we only use 1 of the 3
reserved bytes */
len -= 2;
@@ -63,7 +60,8 @@
/* PkgLength of up to 0xfff can be encoded in 2 PkgLength bytes instead of the
reserved 3 bytes. Since only 2 PkgLength bytes will be written, the payload
data needs to be moved by 1 byte */
- memmove(&p[2], &p[3], payload_len);
+ memmove(&p[ACPIGEN_RSVD_PKGLEN_BYTES - 1],
+ &p[ACPIGEN_RSVD_PKGLEN_BYTES], payload_len);
/* Adjust the PkgLength to take into account that we only use 2 of the 3
reserved bytes */
len -= 1;