| Message ID | 1358149970-28156-2-git-send-email-hdoyu@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 14, 2013 at 09:52:50AM +0200, Hiroshi Doyu wrote: > + if (!arm_dt_cpu_map_valid()) > + set_cpu_possible(0, true); You don't need to do any of this (and, therefore, I don't think you even need the first patch.) The generic boot code will set CPU0 as possible, present and online. Think about it: you're booting on that very CPU so it better be possible, present and online. If it isn't, what CPU is executing your code? arm_dt_init_cpu_maps() will only ever set _additional_ CPUs in the possible map. Ergo, by the time the above code is run, CPU0 will already be marked as possible. Therefore, the above code and arm_dt_cpu_map_valid() is not required.
diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c index 6867030..456e7cc 100644 --- a/arch/arm/mach-tegra/platsmp.c +++ b/arch/arm/mach-tegra/platsmp.c @@ -24,6 +24,7 @@ #include <asm/mach-types.h> #include <asm/smp_scu.h> #include <asm/smp_plat.h> +#include <asm/prom.h> #include <mach/powergate.h> @@ -177,22 +178,10 @@ done: return status; } -/* - * Initialise the CPU possible map early - this describes the CPUs - * which may be present or become present in the system. - */ static void __init tegra_smp_init_cpus(void) { - unsigned int i, ncores = scu_get_core_count(scu_base); - - if (ncores > nr_cpu_ids) { - pr_warn("SMP: %u cores greater than maximum (%u), clipping\n", - ncores, nr_cpu_ids); - ncores = nr_cpu_ids; - } - - for (i = 0; i < ncores; i++) - set_cpu_possible(i, true); + if (!arm_dt_cpu_map_valid()) + set_cpu_possible(0, true); set_smp_cross_call(gic_raise_softirq); }
SCU based detection only works with Cortex-A9 MP and it doesn't support ones with multiple clusters. The only way to detect number of CPU core correctly is with DT /cpu node. If DT /cpu node based detection fails, we just simply fall back a single core in Tegra SoCs. Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> --- Based on the discussion: http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/140608.html --- arch/arm/mach-tegra/platsmp.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-)