[SeaBIOS] [PATCH 1/4] Add basic linked list operations

[Alexey Korolev]

This linked list implementation is partially based on kernel code. So it
should be quite stable

Signed-off-by: Alexey Korolev 
---
 src/util.h |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/src/util.h b/src/util.h
index 70d3c4c..17df3cf 100644
--- a/src/util.h
+++ b/src/util.h
@@ -195,6 +195,27 @@ struct descloc_s {
     u32 addr;
 } PACKED;

+// Double linked lists with a single pointer list head
+#define list_foreach_entry_safe(head, next, entry)    \
+        for (entry = head; entry && ({next=entry->next; 1;}); \
+            entry = next)
+
+#define list_del(entry) \
+       do { \
+           *(entry)->pprev = (entry)->next; \
+           if ((entry)->next) \
+               (entry)->next->pprev = (entry)->pprev; \
+       } while (0)
+
+#define list_add_head(phead, entry) \
+       do { \
+           (entry)->next = *(phead); \
+           if (*(phead)) \
+               (*(phead))->pprev = &(entry)->next; \
+           *(phead) = entry; \
+           (entry)->pprev = phead; \
+       } while (0)
+
 // util.c
 void cpuid(u32 index, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx);
 struct bregs;