From d686ce4204c5dc131396f1fca81beebc46cb8cdb Mon Sep 17 00:00:00 2001 From: Alan Tull Date: Tue, 14 Oct 2014 19:33:38 +0000 Subject: socfpga: hotplug: put cpu1 in wfi Use WFI when putting CPU1 to sleep. Don't hold CPU1 in reset since that results in increased power consumption. Reset CPU1 briefly during CPU1 bootup. This has been tested for hotplug and suspend/resume and results in no increased power consumption. Signed-off-by: Alan Tull Acked-by: Pavel Machek Signed-off-by: Dinh Nguyen Signed-off-by: Arnd Bergmann --- arch/arm/mach-socfpga/platsmp.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'arch/arm/mach-socfpga/platsmp.c') diff --git a/arch/arm/mach-socfpga/platsmp.c b/arch/arm/mach-socfpga/platsmp.c index 16ca97b039f9..c64d89b7c0ca 100644 --- a/arch/arm/mach-socfpga/platsmp.c +++ b/arch/arm/mach-socfpga/platsmp.c @@ -34,17 +34,21 @@ static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle) int trampoline_size = &secondary_trampoline_end - &secondary_trampoline; if (socfpga_cpu1start_addr) { + /* This will put CPU #1 into reset. */ + writel(RSTMGR_MPUMODRST_CPU1, + rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST); + memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size); - __raw_writel(virt_to_phys(socfpga_secondary_startup), - (sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff))); + writel(virt_to_phys(socfpga_secondary_startup), + sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff)); flush_cache_all(); smp_wmb(); outer_clean_range(0, trampoline_size); - /* This will release CPU #1 out of reset.*/ - __raw_writel(0, rst_manager_base_addr + 0x10); + /* This will release CPU #1 out of reset. */ + writel(0, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST); } return 0; @@ -86,10 +90,9 @@ static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus) */ static void socfpga_cpu_die(unsigned int cpu) { - cpu_do_idle(); - - /* We should have never returned from idle */ - panic("cpu %d unexpectedly exit from shutdown\n", cpu); + /* Do WFI. If we wake up early, go back into WFI */ + while (1) + cpu_do_idle(); } struct smp_operations socfpga_smp_ops __initdata = { -- cgit