[Minios-devel] [UNIKRAFT PATCH v2 1/8] include/plat: Helpers for iterating over memory regions

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Introduces two helpers for iterating over memory region descriptors:
- One helper to find a memory region from a given starting point that
  fulfill given flags
- A `foreach` macro to iterate over regions that fulfill given
  flags

Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
---
 include/uk/plat/memory.h | 49 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/include/uk/plat/memory.h b/include/uk/plat/memory.h
index 60e52e6d..51b1b234 100644
--- a/include/uk/plat/memory.h
+++ b/include/uk/plat/memory.h
@@ -78,6 +78,55 @@ int ukplat_memregion_count(void);
  */
 int ukplat_memregion_get(int i, struct ukplat_memregion_desc *mrd);
 
+/**
+ * Searches for the next memory region after `i` that has at least `sflags`
+ * flags set.
+ * @param i Memory region number to start searching
+ *        To start searching from the beginning, set `i` to `-1`
+ * @param sflags Find only memory regions that have at least `sflags` flags 
set.
+ *        If no flags are given (`0x0`), any found region is returned
+ * @Param mrd Pointer to memory region descriptor that will be filled out
+ * @return On success the function returns the next region number after `i`
+ *         that fulfills `sflags`. `mrd` is filled out with the memory region
+ *         details. A value < 0 is returned if no more region could be found
+ *         that fulfills the search criteria. `mrd` may be filled out with
+ *         undefined values.
+ */
+static inline int ukplat_memregion_find_next(int i, int sflags,
+                                            struct ukplat_memregion_desc *mrd)
+{
+       int rc, count;
+
+       count = ukplat_memregion_count();
+
+       if (i >= count)
+               return -1;
+
+       do
+               rc = ukplat_memregion_get(++i, mrd);
+       while (i < count && (rc < 0 || ((mrd->flags & sflags) != sflags)));
+
+       if (i == count)
+               return -1;
+       return i;
+}
+
+/**
+ * Iterates over all memory regions that have at least `sflags` flags set.
+ * @param mrd Pointer to memory region descriptor that will be filled out
+ *        during iteration
+ * @param sflags Iterate only over memory regions that have at least `sflags`
+ *        flags set. If no flags are given (`0x0`), every existing region is
+ *        iterated.
+ */
+#define ukplat_memregion_foreach(mrd, sflags)                          \
+       for (int __ukplat_memregion_foreach_i                           \
+                    = ukplat_memregion_find_next(-1, (sflags), (mrd)); \
+            __ukplat_memregion_foreach_i >= 0;                         \
+            __ukplat_memregion_foreach_i                               \
+                    = ukplat_memregion_find_next(__ukplat_memregion_foreach_i,\
+                                                 (sflags), (mrd)))
+
 /**
  * Sets the platform memory allocator and triggers the platform memory mappings
  * for which an allocator is needed.
-- 
2.20.1


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