qemu/aarch64/plat_helpers.S : calculate the position shift
Rather than re-create this file in multiple qemu variants instead
caclulate the shift needed to convert MPIDR to position.
Add a new PLATFORM_CPU_PER_CLUSTER_SHIFT define in platform_def.h
for both qemu and qemu_sbsa to enable this calculation.
Signed-off-by: Graeme Gregory <graeme@nuviainc.com>
Change-Id: I0e3a86354aa716d95150a3a34b15287cd70c8fd2
diff --git a/plat/qemu/common/aarch64/plat_helpers.S b/plat/qemu/common/aarch64/plat_helpers.S
index b546173..08b2817 100644
--- a/plat/qemu/common/aarch64/plat_helpers.S
+++ b/plat/qemu/common/aarch64/plat_helpers.S
@@ -32,7 +32,8 @@
func plat_qemu_calc_core_pos
and x1, x0, #MPIDR_CPU_MASK
and x0, x0, #MPIDR_CLUSTER_MASK
- add x0, x1, x0, LSR #6
+ add x0, x1, x0, LSR #(MPIDR_AFFINITY_BITS -\
+ PLATFORM_CPU_PER_CLUSTER_SHIFT)
ret
endfunc plat_qemu_calc_core_pos
diff --git a/plat/qemu/qemu/include/platform_def.h b/plat/qemu/qemu/include/platform_def.h
index ed4b748..e6bb1e6 100644
--- a/plat/qemu/qemu/include/platform_def.h
+++ b/plat/qemu/qemu/include/platform_def.h
@@ -24,6 +24,14 @@
#define PLATFORM_CLUSTER1_CORE_COUNT U(0)
#else
#define PLATFORM_MAX_CPUS_PER_CLUSTER U(4)
+/*
+ * Define the number of cores per cluster used in calculating core position.
+ * The cluster number is shifted by this value and added to the core ID,
+ * so its value represents log2(cores/cluster).
+ * Default is 2**(2) = 4 cores per cluster.
+ */
+#define PLATFORM_CPU_PER_CLUSTER_SHIFT U(2)
+
#define PLATFORM_CLUSTER_COUNT U(2)
#define PLATFORM_CLUSTER0_CORE_COUNT PLATFORM_MAX_CPUS_PER_CLUSTER
#define PLATFORM_CLUSTER1_CORE_COUNT PLATFORM_MAX_CPUS_PER_CLUSTER
diff --git a/plat/qemu/qemu_sbsa/include/platform_def.h b/plat/qemu/qemu_sbsa/include/platform_def.h
index db394c0..8471024 100644
--- a/plat/qemu/qemu_sbsa/include/platform_def.h
+++ b/plat/qemu/qemu_sbsa/include/platform_def.h
@@ -17,6 +17,13 @@
#define PLATFORM_STACK_SIZE 0x1000
#define PLATFORM_MAX_CPUS_PER_CLUSTER U(4)
+/*
+ * Define the number of cores per cluster used in calculating core position.
+ * The cluster number is shifted by this value and added to the core ID,
+ * so its value represents log2(cores/cluster).
+ * Default is 2**(2) = 4 cores per cluster.
+ */
+#define PLATFORM_CPU_PER_CLUSTER_SHIFT U(2)
#define PLATFORM_CLUSTER_COUNT U(2)
#define PLATFORM_CLUSTER0_CORE_COUNT PLATFORM_MAX_CPUS_PER_CLUSTER
#define PLATFORM_CLUSTER1_CORE_COUNT PLATFORM_MAX_CPUS_PER_CLUSTER