From 72ede9b18967e7a8a62a88f164f003193f6d891f Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sun, 18 Mar 2007 01:01:39 +0900 Subject: [PATCH] [MIPS] Qemu: Fix Symmetric Uniprocessor support. Might be useful for SMP debugging. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle [Rewritten Kconfig bits to deal better fit in the usual pattern of doing things - Ralf] Signed-off-by: Ralf Baechle --- arch/mips/Kconfig | 15 ++++++++++++--- arch/mips/qemu/q-smp.c | 7 +++++++ 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 5f29018..656f0ca 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -542,6 +542,8 @@ config QEMU select SYS_SUPPORTS_LITTLE_ENDIAN select ARCH_SPARSEMEM_ENABLE select GENERIC_HARDIRQS_NO__DO_IRQ + select NR_CPUS_DEFAULT_1 + select SYS_SUPPORTS_SMP help Qemu is a software emulator which among other architectures also can simulate a MIPS32 4Kc system. This patch adds support for the @@ -1805,6 +1807,9 @@ config SMP config SYS_SUPPORTS_SMP bool +config NR_CPUS_DEFAULT_1 + bool + config NR_CPUS_DEFAULT_2 bool @@ -1825,8 +1830,9 @@ config NR_CPUS_DEFAULT_64 config NR_CPUS int "Maximum number of CPUs (2-64)" - range 2 64 + range 1 64 if NR_CPUS_DEFAULT_1 depends on SMP + default "1" if NR_CPUS_DEFAULT_1 default "2" if NR_CPUS_DEFAULT_2 default "4" if NR_CPUS_DEFAULT_4 default "8" if NR_CPUS_DEFAULT_8 @@ -1837,10 +1843,13 @@ config NR_CPUS This allows you to specify the maximum number of CPUs which this kernel will support. The maximum supported value is 32 for 32-bit kernel and 64 for 64-bit kernels; the minimum value which makes - sense is 2. + sense is 1 for Qemu (useful only for kernel debugging purposes) + and 2 for all others. This is purely to save memory - each supported CPU adds - approximately eight kilobytes to the kernel image. + approximately eight kilobytes to the kernel image. For best + performance should round up your number of processors to the next + power of two. # # Timer Interrupt Frequency Configuration diff --git a/arch/mips/qemu/q-smp.c b/arch/mips/qemu/q-smp.c index 5a12354..786bbfa 100644 --- a/arch/mips/qemu/q-smp.c +++ b/arch/mips/qemu/q-smp.c @@ -46,3 +46,10 @@ void __init prom_prepare_cpus(unsigned int max_cpus) void prom_boot_secondary(int cpu, struct task_struct *idle) { } + +void __init plat_smp_setup(void) +{ +} +void __init plat_prepare_cpus(unsigned int max_cpus) +{ +} -- 2.7.4