Hi Andrew, On Mon, Jun 02, 2014 at 11:47:15AM +0200, Andrew Lunn wrote: > On Mon, Jun 02, 2014 at 11:21:02AM +0200, Antoine Ténart wrote: > > + > > +static inline void berlin_reset_cpu(unsigned int cpu) > > +{ > > + u32 val; > > + > > + val = readl(cpu_ctrl + CPU_RESET); > > + val |= BIT(cpu_logical_map(cpu)); > > + writel(val, cpu_ctrl + CPU_RESET); > > +} > > Is this performing a reset on the CPU, or is it taking it out of reset? > > If you are going to implement CPU hotplug at some point, you are going > to want to be able to put the CPU into reset, i.e. power it off, and > take it out of reset, i.e. power it on and getting it running. So it > might help if we get these function names clear now. It is performing a reset on the CPU. berlin_perform_reset_cpu() then? > > + > > +static void __init berlin_smp_prepare_cpus(unsigned int max_cpus) > > +{ > > + struct device_node *np; > > + void __iomem *scu_base; > > + void __iomem *vectors_base; > > + > > + np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); > > + scu_base = of_iomap(np, 0); > > + of_node_put(np); > > + if (!scu_base) > > + return; > > + > > + np = of_find_compatible_node(NULL, NULL, "marvell,berlin-cpu-ctrl"); > > + cpu_ctrl = of_iomap(np, 0); > > + of_node_put(np); > > + if (!cpu_ctrl) > > + goto unmap_scu; > > + > > + vectors_base = ioremap(CONFIG_VECTORS_BASE, SZ_32K); > > + if (!vectors_base) > > + goto unmap_scu; > > + > > + scu_enable(scu_base); > > + flush_cache_all(); > > + > > + /* > > + * Write the first instruction the CPU will execute after being reseted > > + * in the reset exception register. > > + */ > > + writel(boot_inst, vectors_base + RESET_VECT); > > + > > + /* > > + * Write the secondary startup address into the SW reset address > > + * register. This is used by boot_inst. > > Maybe it would be better to call this the reset address vector instead > of address register. It is in the vector space after all. I don't have a strong opinion on this. I can update the 'reset exception register' as well then. Antoine -- Antoine Ténart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html