From 39b21d19a01bc8eac3ab5f21a3cf96cd5e9a4f42 Mon Sep 17 00:00:00 2001 From: Wang Feng Date: Thu, 15 Mar 2018 15:32:41 +0800 Subject: [PATCH] FVP: change the method for translating MPIDR values to a linear indices x3 will be assigned by the folloing instructions. So the first instruction is not needed any more. old method: (ClusterId * FVP_MAX_CPUS_PER_CLUSTER) + (CPUId * FVP_MAX_PE_PER_CPU) + ThreadId it should be (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 Signed-off-by: Wang Feng --- plat/arm/board/fvp/aarch64/fvp_helpers.S | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/plat/arm/board/fvp/aarch64/fvp_helpers.S b/plat/arm/board/fvp/aarch64/fvp_helpers.S index 6ea45851..88fcdb1b 100644 --- a/plat/arm/board/fvp/aarch64/fvp_helpers.S +++ b/plat/arm/board/fvp/aarch64/fvp_helpers.S @@ -178,19 +178,22 @@ func plat_is_my_cpu_primary ret 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 x3, x0 - /* * Check for MT bit in MPIDR. If not set, shift MPIDR to left to make it * look as if in a multi-threaded implementation. @@ -205,9 +208,9 @@ func plat_arm_calc_core_pos ubfx x2, x3, #MPIDR_AFF2_SHIFT, #MPIDR_AFFINITY_BITS /* Compute linear position */ - mov x4, #FVP_MAX_PE_PER_CPU - madd x0, x1, x4, x0 - mov x5, #FVP_MAX_CPUS_PER_CLUSTER - madd x0, x2, x5, x0 + mov x4, #FVP_MAX_CPUS_PER_CLUSTER + madd x1, x2, x4, x1 + mov x5, #FVP_MAX_PE_PER_CPU + madd x0, x1, x5, x0 ret endfunc plat_arm_calc_core_pos -- 2.30.2