FVP: Add support for multi-threaded CPUs
ARM CPUs with multi-threading implementation has more than one
Processing Element in a single physical CPU. Such an implementation will
reflect the following changes in the MPIDR register:
- The MT bit set;
- Affinity levels pertaining to cluster and CPUs occupy one level
higher than in a single-threaded implementation, and the lowest
affinity level pertains to hardware threads. MPIDR affinity level
fields essentially appear shifted to left than otherwise.
The FVP port henceforth assumes that both properties above to be
concomitant on a given FVP platform.
To accommodate for varied MPIDR formats at run time, this patch
re-implements the FVP platform-specific functions that translates MPIDR
values to a linear indices, along with required validation. The same
treatment is applied for GICv3 MPIDR hashing function as well.
An FVP-specific build option FVP_MAX_PE_PER_CPU is introduced which
specifies the maximum number of threads implemented per CPU. For
backwards compatibility, its value defaults to 1.
Change-Id: I729b00d3e121d16ce9a03de4f9db36dfac580e3f
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/plat/arm/board/fvp/aarch32/fvp_helpers.S b/plat/arm/board/fvp/aarch32/fvp_helpers.S
index e80e199..143972d 100644
--- a/plat/arm/board/fvp/aarch32/fvp_helpers.S
+++ b/plat/arm/board/fvp/aarch32/fvp_helpers.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -13,6 +13,7 @@
.globl plat_secondary_cold_boot_setup
.globl plat_get_my_entrypoint
.globl plat_is_my_cpu_primary
+ .globl plat_arm_calc_core_pos
/* --------------------------------------------------------------------
* void plat_secondary_cold_boot_setup (void);
@@ -95,10 +96,43 @@
*/
func plat_is_my_cpu_primary
ldcopr r0, MPIDR
- ldr r1, =(MPIDR_CLUSTER_MASK | MPIDR_CPU_MASK)
+ ldr r1, =MPIDR_AFFINITY_MASK
and r0, r1
cmp r0, #FVP_PRIMARY_CPU
moveq r0, #1
movne r0, #0
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) +
+ * (CPUId * FVP_MAX_PE_PER_CPU) +
+ * ThreadId
+ * -----------------------------------------------------
+ */
+func plat_arm_calc_core_pos
+ mov r3, r0
+
+ /*
+ * Check for MT bit in MPIDR. If not set, shift MPIDR to left to make it
+ * look as if in a multi-threaded implementation
+ */
+ tst r0, #MPIDR_MT_MASK
+ 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
+
+ bx lr
+endfunc plat_arm_calc_core_pos