MIPS: Make CONFIG_MIPS_MT_SMP default y

On systems that support MT ASE multithreading (ie. VPEs) we are very
likely to want to include that support as default. Rather than setting
it in various defconfigs, simply make CONFIG_MIPS_MT_SMP default y such
that systems which select CONFIG_SYS_SUPPORTS_MULTITHREADING get it by
default.

As well as allowing us to remove the selection of CONFIG_MIPS_MT_SMP
from various defconfigs, this also allows the generated generic
defconfigs which derive from generic_defconfig to automatically gain
support for MT ASE SMP when building for a suitable (pre-MIPSr6) ISA.

For malta_kvm_guest_defconfig CONFIG_MIPS_MT_SMP is explicitly disabled
since enabling SMP implicitly disables CONFIG_KVM_GUEST, which depends
on CONFIG_BROKEN_ON_SMP.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16947/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -2249,6 +2249,7 @@ config CPU_R4K_CACHE_TLB
 
 config MIPS_MT_SMP
 	bool "MIPS MT SMP support (1 TC on each available VPE)"
+	default y
 	depends on SYS_SUPPORTS_MULTITHREADING && !CPU_MIPSR6 && !CPU_MICROMIPS
 	select CPU_MIPSR2_IRQ_VI
 	select CPU_MIPSR2_IRQ_EI

arch/mips/configs/malta_defconfig

@@ -2,7 +2,6 @@ CONFIG_MIPS_MALTA=y
 CONFIG_CPU_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS32_R2=y
 CONFIG_PAGE_SIZE_16KB=y
-CONFIG_MIPS_MT_SMP=y
 CONFIG_NR_CPUS=8
 CONFIG_HZ_100=y
 CONFIG_SYSVIPC=y

arch/mips/configs/malta_kvm_defconfig

@@ -2,7 +2,6 @@ CONFIG_MIPS_MALTA=y
 CONFIG_CPU_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS32_R2=y
 CONFIG_PAGE_SIZE_16KB=y
-CONFIG_MIPS_MT_SMP=y
 CONFIG_NR_CPUS=8
 CONFIG_HZ_100=y
 CONFIG_SYSVIPC=y

arch/mips/configs/malta_kvm_guest_defconfig

@@ -3,6 +3,7 @@ CONFIG_CPU_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS32_R2=y
 CONFIG_KVM_GUEST=y
 CONFIG_PAGE_SIZE_16KB=y
+# CONFIG_MIPS_MT_SMP is not set
 CONFIG_HZ_100=y
 CONFIG_SYSVIPC=y
 CONFIG_NO_HZ=y

arch/mips/configs/maltasmvp_defconfig

@@ -2,7 +2,6 @@ CONFIG_MIPS_MALTA=y
 CONFIG_CPU_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS32_R2=y
 CONFIG_PAGE_SIZE_16KB=y
-CONFIG_MIPS_MT_SMP=y
 CONFIG_SCHED_SMT=y
 CONFIG_MIPS_CPS=y
 CONFIG_NR_CPUS=8

arch/mips/configs/maltasmvp_eva_defconfig

@@ -3,7 +3,6 @@ CONFIG_CPU_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS32_R2=y
 CONFIG_CPU_MIPS32_3_5_FEATURES=y
 CONFIG_PAGE_SIZE_16KB=y
-CONFIG_MIPS_MT_SMP=y
 CONFIG_SCHED_SMT=y
 CONFIG_MIPS_CPS=y
 CONFIG_NR_CPUS=8