FVP: Fix function for translating MPIDR to linear index
The current AArch32 version of plat_arm_calc_core_pos uses an incorrect
algorithm to calculate the linear position of a core / PE from its
MPIDR.
This patch corrects the algorithm to:
(ClusterId * FVP_MAX_CPUS_PER_CLUSTER) * FVP_MAX_PE_PER_CPU
+ (CPUId * FVP_MAX_PE_PER_CPU)
+ ThreadId
which supports cores where there are more than 1 PE per CPU.
NOTE: the AArch64 version was fixed in 39b21d1
Change-Id: I72aea89d8f72f8b1fef54e2177a0fa6fef0f5513
Signed-off-by: David Cunado <david.cunado@arm.com>
diff --git a/plat/arm/board/fvp/aarch32/fvp_helpers.S b/plat/arm/board/fvp/aarch32/fvp_helpers.S
index 143972d..5d88546 100644
--- a/plat/arm/board/fvp/aarch32/fvp_helpers.S
+++ b/plat/arm/board/fvp/aarch32/fvp_helpers.S
@@ -104,15 +104,20 @@
bx lr
endfunc plat_is_my_cpu_primary
- /* -----------------------------------------------------
+ /* ---------------------------------------------------------------------
* unsigned int plat_arm_calc_core_pos(u_register_t mpidr)
*
* Function to calculate the core position on FVP.
*
- * (ClusterId * FVP_MAX_CPUS_PER_CLUSTER) +
+ * (ClusterId * FVP_MAX_CPUS_PER_CLUSTER * FVP_MAX_PE_PER_CPU) +
* (CPUId * FVP_MAX_PE_PER_CPU) +
* ThreadId
- * -----------------------------------------------------
+ *
+ * which can be simplified as:
+ *
+ * ((ClusterId * FVP_MAX_CPUS_PER_CLUSTER + CPUId) * FVP_MAX_PE_PER_CPU)
+ * + ThreadId
+ * ---------------------------------------------------------------------
*/
func plat_arm_calc_core_pos
mov r3, r0
@@ -125,14 +130,15 @@
lsleq r3, r0, #MPIDR_AFFINITY_BITS
/* Extract individual affinity fields from MPIDR */
- mov r2, #FVP_MAX_PE_PER_CPU
ubfx r0, r3, #MPIDR_AFF0_SHIFT, #MPIDR_AFFINITY_BITS
ubfx r1, r3, #MPIDR_AFF1_SHIFT, #MPIDR_AFFINITY_BITS
- mla r0, r1, r2, r0
-
- mov r1, #FVP_MAX_CPUS_PER_CLUSTER
ubfx r2, r3, #MPIDR_AFF2_SHIFT, #MPIDR_AFFINITY_BITS
- mla r0, r1, r2, r0
+
+ /* Compute linear position */
+ mov r3, #FVP_MAX_CPUS_PER_CLUSTER
+ mla r1, r2, r3, r1
+ mov r3, #FVP_MAX_PE_PER_CPU
+ mla r0, r1, r3, r0
bx lr
endfunc plat_arm_calc_core_pos