diff options
Diffstat (limited to 'kernel/arch/arm/mach-zynq/platsmp.c')
| -rw-r--r-- | kernel/arch/arm/mach-zynq/platsmp.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-zynq/platsmp.c b/kernel/arch/arm/mach-zynq/platsmp.c new file mode 100644 index 000000000..52d768ff7 --- /dev/null +++ b/kernel/arch/arm/mach-zynq/platsmp.c @@ -0,0 +1,170 @@ +/* + * This file contains Xilinx specific SMP code, used to start up + * the second processor. + * + * Copyright (C) 2011-2013 Xilinx + * + * based on linux/arch/arm/mach-realview/platsmp.c + * + * Copyright (C) 2002 ARM Ltd. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/export.h> +#include <linux/jiffies.h> +#include <linux/init.h> +#include <linux/io.h> +#include <asm/cacheflush.h> +#include <asm/smp_scu.h> +#include <linux/irqchip/arm-gic.h> +#include "common.h" + +/* + * Store number of cores in the system + * Because of scu_get_core_count() must be in __init section and can't + * be called from zynq_cpun_start() because it is not in __init section. + */ +static int ncores; + +int zynq_cpun_start(u32 address, int cpu) +{ + u32 trampoline_code_size = &zynq_secondary_trampoline_end - + &zynq_secondary_trampoline; + + /* MS: Expectation that SLCR are directly map and accessible */ + /* Not possible to jump to non aligned address */ + if (!(address & 3) && (!address || (address >= trampoline_code_size))) { + /* Store pointer to ioremap area which points to address 0x0 */ + static u8 __iomem *zero; + u32 trampoline_size = &zynq_secondary_trampoline_jump - + &zynq_secondary_trampoline; + + zynq_slcr_cpu_stop(cpu); + if (address) { + if (__pa(PAGE_OFFSET)) { + zero = ioremap(0, trampoline_code_size); + if (!zero) { + pr_warn("BOOTUP jump vectors not accessible\n"); + return -1; + } + } else { + zero = (__force u8 __iomem *)PAGE_OFFSET; + } + + /* + * This is elegant way how to jump to any address + * 0x0: Load address at 0x8 to r0 + * 0x4: Jump by mov instruction + * 0x8: Jumping address + */ + memcpy((__force void *)zero, &zynq_secondary_trampoline, + trampoline_size); + writel(address, zero + trampoline_size); + + flush_cache_all(); + outer_flush_range(0, trampoline_code_size); + smp_wmb(); + + if (__pa(PAGE_OFFSET)) + iounmap(zero); + } + zynq_slcr_cpu_start(cpu); + + return 0; + } + + pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address); + + return -1; +} +EXPORT_SYMBOL(zynq_cpun_start); + +static int zynq_boot_secondary(unsigned int cpu, + struct task_struct *idle) +{ + return zynq_cpun_start(virt_to_phys(zynq_secondary_startup), cpu); +} + +/* + * Initialise the CPU possible map early - this describes the CPUs + * which may be present or become present in the system. + */ +static void __init zynq_smp_init_cpus(void) +{ + int i; + + ncores = scu_get_core_count(zynq_scu_base); + + for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++) + set_cpu_possible(i, true); +} + +static void __init zynq_smp_prepare_cpus(unsigned int max_cpus) +{ + scu_enable(zynq_scu_base); +} + +/** + * zynq_secondary_init - Initialize secondary CPU cores + * @cpu: CPU that is initialized + * + * This function is in the hotplug path. Don't move it into the + * init section!! + */ +static void zynq_secondary_init(unsigned int cpu) +{ + zynq_core_pm_init(); +} + +#ifdef CONFIG_HOTPLUG_CPU +static int zynq_cpu_kill(unsigned cpu) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(50); + + while (zynq_slcr_cpu_state_read(cpu)) + if (time_after(jiffies, timeout)) + return 0; + + zynq_slcr_cpu_stop(cpu); + return 1; +} + +/** + * zynq_cpu_die - Let a CPU core die + * @cpu: Dying CPU + * + * Platform-specific code to shutdown a CPU. + * Called with IRQs disabled on the dying CPU. + */ +static void zynq_cpu_die(unsigned int cpu) +{ + zynq_slcr_cpu_state_write(cpu, true); + + /* + * there is no power-control hardware on this platform, so all + * we can do is put the core into WFI; this is safe as the calling + * code will have already disabled interrupts + */ + for (;;) + cpu_do_idle(); +} +#endif + +struct smp_operations zynq_smp_ops __initdata = { + .smp_init_cpus = zynq_smp_init_cpus, + .smp_prepare_cpus = zynq_smp_prepare_cpus, + .smp_boot_secondary = zynq_boot_secondary, + .smp_secondary_init = zynq_secondary_init, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = zynq_cpu_die, + .cpu_kill = zynq_cpu_kill, +#endif +}; |