MIPS: smp-cps: hotplug support

This patch adds support for offlining CPUs via hotplug when using the
CONFIG_MIPS_CPS SMP implementation. When a CPU is offlined one of 2
things will happen:

  - If the CPU is part of a core which implements the MT ASE and there
    is at least one other VPE online within that core then the VPE will
    be halted by settings its TCHalt bit.

  - Otherwise if supported the core will be powered down via the CPC.

  - Otherwise the CPU will hang by executing an infinite loop.

Bringing CPUs back online is then a process of either clearing the
appropriate VPEs TCHalt bit or powering up the appropriate core via the
CPC. Throughout the process the struct core_boot_config vpe_mask field
must be maintained such that mips_cps_boot_vpes will start & stop the
correct VPEs.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c79e6a4a0075..860a1e9e8d92 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2059,9 +2059,11 @@ config MIPS_CPS
         depends on SYS_SUPPORTS_MIPS_CPS
         select MIPS_CM
         select MIPS_CPC
+        select MIPS_CPS_PM if HOTPLUG_CPU
         select MIPS_GIC_IPI
         select SMP
         select SYNC_R4K if (CEVT_R4K || CSRC_R4K)
+        select SYS_SUPPORTS_HOTPLUG_CPU
         select SYS_SUPPORTS_SMP
         select WEAK_ORDERING
         help