On 26/05/14 04:57, Chen-Yu Tsai wrote: > On Mon, May 26, 2014 at 3:26 AM, Maxime Ripard > <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: >> On Fri, May 23, 2014 at 03:51:23PM +0800, Chen-Yu Tsai wrote: >>> The A23 is a dual Cortex-A7. Add the logic to use the IPs used to >>> control the CPU configuration and the CPU power so that we can >>> bring up secondary CPUs at boot. >>> >>> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx> >>> --- >>> arch/arm/mach-sunxi/platsmp.c | 69 +++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 69 insertions(+) >>> >>> diff --git a/arch/arm/mach-sunxi/platsmp.c b/arch/arm/mach-sunxi/platsmp.c >>> index c53077b..688faaf 100644 >>> --- a/arch/arm/mach-sunxi/platsmp.c >>> +++ b/arch/arm/mach-sunxi/platsmp.c >>> @@ -121,3 +121,72 @@ struct smp_operations sun6i_smp_ops __initdata = { >>> .smp_boot_secondary = sun6i_smp_boot_secondary, >>> }; >>> CPU_METHOD_OF_DECLARE(sun6i_smp, "allwinner,sun6i-a31", &sun6i_smp_ops); >>> + >>> +static void __init sun8i_smp_prepare_cpus(unsigned int max_cpus) >>> +{ >>> + struct device_node *node; >>> + >>> + node = of_find_compatible_node(NULL, NULL, "allwinner,sun8i-a23-prcm"); >>> + if (!node) { >>> + pr_err("Missing A23 PRCM node in the device tree\n"); >>> + return; >>> + } >>> + >>> + prcm_membase = of_iomap(node, 0); >>> + if (!prcm_membase) { >>> + pr_err("Couldn't map A23 PRCM registers\n"); >>> + return; >>> + } >>> + >>> + node = of_find_compatible_node(NULL, NULL, >>> + "allwinner,sun8i-a23-cpuconfig"); >>> + if (!node) { >>> + pr_err("Missing A23 CPU config node in the device tree\n"); >>> + return; >>> + } >>> + >>> + cpucfg_membase = of_iomap(node, 0); >>> + if (!cpucfg_membase) >>> + pr_err("Couldn't map A23 CPU config registers\n"); >>> + >>> +} >>> + >>> +static int sun8i_smp_boot_secondary(unsigned int cpu, >>> + struct task_struct *idle) >>> +{ >>> + u32 reg; >>> + >>> + if (!(prcm_membase && cpucfg_membase)) >>> + return -EFAULT; >>> + >>> + spin_lock(&cpu_lock); >>> + >>> + /* Set CPU boot address */ >>> + writel(virt_to_phys(secondary_startup), >>> + cpucfg_membase + CPUCFG_PRIVATE0_REG); >>> + >>> + /* Assert the CPU core in reset */ >>> + writel(0, cpucfg_membase + CPUCFG_CPU_RST_CTRL_REG(cpu)); >>> + >>> + /* Assert the L1 cache in reset */ >>> + reg = readl(cpucfg_membase + CPUCFG_GEN_CTRL_REG); >>> + writel(reg & ~BIT(cpu), cpucfg_membase + CPUCFG_GEN_CTRL_REG); >>> + >>> + /* Clear CPU power-off gating */ >>> + reg = readl(prcm_membase + PRCM_CPU_PWROFF_REG); >>> + writel(reg & ~BIT(cpu), prcm_membase + PRCM_CPU_PWROFF_REG); >>> + mdelay(1); >>> + >>> + /* Deassert the CPU core reset */ >>> + writel(3, cpucfg_membase + CPUCFG_CPU_RST_CTRL_REG(cpu)); >>> + >>> + spin_unlock(&cpu_lock); >>> + >>> + return 0; >>> +} >>> + >>> +struct smp_operations sun8i_smp_ops __initdata = { >>> + .smp_prepare_cpus = sun8i_smp_prepare_cpus, >>> + .smp_boot_secondary = sun8i_smp_boot_secondary, >>> +}; >>> +CPU_METHOD_OF_DECLARE(sun8i_smp, "allwinner,sun8i-a23", &sun8i_smp_ops); >> >> You forgot to document the new enable-method. > > I will add it. > >> Also, is there any plan to hae a working u-boot? I'd much prefer to >> use PSCI if possible. > > IIRC PSCI needs a secure SRAM block to store its program code. > Unfortunately the A23 doesn't have secure SRAM. I think it is > missing other security related features as well. > > Or could it just live in generic SRAM, and the kernel marks it > as reserved or something. > > Maybe Marc Zyngier (CCed) can shed some light on this? No secure SRAM is required. You can normal SRAM, or even a normal region of RAM that is accessed from secure mode. Not as nice as having proper SRAM as on sun7i, but still perfectly functional. Please consider having a proper PSCI implementation instead of always adding more code that will effectively lock people out of using the virtualization features the core has. Thanks, M. -- Jazz is not dead. It just smells funny... -- 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