[Xen-devel] [PATCH v7] libxl: provide libxl_bitmap_{or,and}

[Linda Jacobson <lindaj@xxxxxxxx>]

New functions to provide logical and and or of two bitmaps functions can be
used in vNUMA configuration check function. They are also generally useful, so
they have been made as public API.

Signed-off-by: Linda Jacobson <lindaj@xxxxxxxx>

---

v.1 The new functions were added.
v.2 The comments and format were corrected.
v.3 The bitmap functions were rewritten to manipulate bytes not bits.
v.4 Several non-modified parameters, and local variables were changed to const
    Also the code formatting was fixed.
v.5 The commit subject line now has versions and is simpler.
v.6 All descriptions in the commit history are now complete sentences.
    Extraneous blank lines are gone.
v.7 Added LIBXL_BIT_HAVE_AND_OR to libxl.h; deleted extraneous comment in
    libxl_utils.h; and updated the commit log to include the uses for these
    functions
---
 tools/libxl/libxl.h       |  9 ++++++
 tools/libxl/libxl_utils.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl_utils.h |  6 ++++
 3 files changed, 85 insertions(+)

diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 5eec092..1fb9549 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -84,6 +84,15 @@
 #define LIBXL_HAVE_CPUPOOL_QUALIFIER_TO_CPUPOOLID 1
 
 /*
+ *
+ * LIBXL_HAVE_BITMAP_AND_OR
+ *
+ * If this is defined, libxl has two libarary functions, libxl_bitmap_and
+ * and libxl_bitmap_or to compute the logical and and or of two bitmaps
+ */
+#define LIBXL_HAVE_BITMAP_AND_OR 1
+
+/*
  * LIBXL_HAVE_FIRMWARE_PASSTHROUGH indicates the feature for
  * passing in SMBIOS and ACPI firmware to HVM guests is present
  * in the library.
diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index 9053b27..f552700 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -691,6 +691,76 @@ void libxl_bitmap_reset(libxl_bitmap *bitmap, int bit)
     bitmap->map[bit / 8] &= ~(1 << (bit & 7));
 }
 
+int libxl_bitmap_or(libxl_ctx *ctx, libxl_bitmap *or_map,
+                    const libxl_bitmap *map1, const libxl_bitmap *map2)
+{
+    GC_INIT(ctx);
+    int rc;
+    uint32_t i;
+    const libxl_bitmap *large_map;
+    const libxl_bitmap *small_map;
+
+    if (map1->size > map2->size) {
+        large_map = map1;
+        small_map = map2;
+    } else {
+        large_map = map2;
+        small_map = map1;
+    }
+
+    rc = libxl_bitmap_alloc(ctx, or_map, large_map->size * 8);
+    if (rc)
+        goto out;
+
+    /*
+     *  If bitmaps aren't the same size, their union (logical or) will
+     *  be size of larger bit map.  Any bit past the end of the
+     *  smaller bit map, will match the larger one.
+     */
+    for (i = 0; i < small_map->size; i++)
+        or_map->map[i] = (small_map->map[i] | large_map->map[i]);
+
+    for (i = small_map->size; i < large_map->size; i++)
+        or_map->map[i] = large_map->map[i];
+
+out:
+    GC_FREE;
+    return rc;
+}
+
+int libxl_bitmap_and(libxl_ctx *ctx, libxl_bitmap *and_map,
+                     const libxl_bitmap *map1, const libxl_bitmap *map2)
+{
+    GC_INIT(ctx);    
+    int rc;
+    uint32_t i;
+    const libxl_bitmap *large_map;
+    const libxl_bitmap *small_map;
+
+    if (map1->size > map2->size) {
+        large_map = map1;
+        small_map = map2;
+    } else {
+        large_map = map2;
+        small_map = map1;
+    }
+
+    rc = libxl_bitmap_alloc(ctx, and_map, small_map->size * 8);
+    if (rc)
+        goto out;
+
+    /* 
+     *  If bitmaps aren't same size, their 'and' will be size of
+     *  smaller bit map
+     */
+    for (i = 0; i < and_map->size; i++)
+        and_map->map[i] = (large_map->map[i] & small_map->map[i]);
+
+out: 
+    GC_FREE;
+    return rc;
+}
+
 int libxl_bitmap_count_set(const libxl_bitmap *bitmap)
 {
     int i, nr_set_bits = 0;
diff --git a/tools/libxl/libxl_utils.h b/tools/libxl/libxl_utils.h
index acacdd9..f5a3168 100644
--- a/tools/libxl/libxl_utils.h
+++ b/tools/libxl/libxl_utils.h
@@ -90,6 +90,12 @@ int libxl_bitmap_test(const libxl_bitmap *bitmap, int bit);
 void libxl_bitmap_set(libxl_bitmap *bitmap, int bit);
 void libxl_bitmap_reset(libxl_bitmap *bitmap, int bit);
 int libxl_bitmap_count_set(const libxl_bitmap *cpumap);
+int libxl_bitmap_or(libxl_ctx *ctx, libxl_bitmap *or_map,
+                    const libxl_bitmap *map1, 
+                    const libxl_bitmap *map2); 
+int libxl_bitmap_and(libxl_ctx *ctx, libxl_bitmap *and_map,
+                     const libxl_bitmap *map1, 
+                     const libxl_bitmap *map2);
 char *libxl_bitmap_to_hex_string(libxl_ctx *ctx, const libxl_bitmap *cpumap);
 static inline void libxl_bitmap_set_any(libxl_bitmap *bitmap)
 {
-- 
1.9.1


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