[v3,10/17] libxl/arm: Factor MPIDR computing codes out as a helper

Commit Message

Shannon Zhao July 5, 2016, 3:12 a.m. UTC

From: Shannon Zhao <[e-mail]>

Factor MPIDR computing codes out as a helper, so it could be shared
between DT and ACPI.

Signed-off-by: Shannon Zhao <[e-mail]>
---
 tools/libxl/libxl_arm.c |  8 +-------
 tools/libxl/libxl_arm.h | 11 +++++++++++
 2 files changed, 12 insertions(+), 7 deletions(-)

Patch

diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index 7c522e1..94cb773 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -309,13 +309,7 @@  static int make_cpus_node(libxl__gc *gc, void *fdt, int nr_cpus,
     for (i = 0; i < nr_cpus; i++) {
         const char *name;
 
-        /*
-         * According to ARM CPUs bindings, the reg field should match
-         * the MPIDR's affinity bits. We will use AFF0 and AFF1 when
-         * constructing the reg value of the guest at the moment, for it
-         * is enough for the current max vcpu number.
-         */
-        mpidr_aff = (i & 0x0f) | (((i >> 4) & 0xff) << 8);
+        mpidr_aff = libxl__compute_mpdir(i);
         name = GCSPRINTF("cpu@%"PRIx64, mpidr_aff);
 
         res = fdt_begin_node(fdt, name);
diff --git a/tools/libxl/libxl_arm.h b/tools/libxl/libxl_arm.h
index 1c01177..a91ff93 100644
--- a/tools/libxl/libxl_arm.h
+++ b/tools/libxl/libxl_arm.h
@@ -24,6 +24,17 @@  int libxl__prepare_acpi(libxl__gc *gc, libxl_domain_build_info *info,
                         libxl__domain_build_state *state,
                         struct xc_dom_image *dom);
 
+static inline uint64_t libxl__compute_mpdir(unsigned int cpuid)
+{
+    /*
+     * According to ARM CPUs bindings, the reg field should match
+     * the MPIDR's affinity bits. We will use AFF0 and AFF1 when
+     * constructing the reg value of the guest at the moment, for it
+     * is enough for the current max vcpu number.
+     */
+    return (cpuid & 0x0f) | (((cpuid >> 4) & 0xff) << 8);
+}
+
 /*
  * Local variables:
  * mode: C