diff options
Diffstat (limited to 'arch/arm/mach-zynq/platsmp.c')
| -rw-r--r-- | arch/arm/mach-zynq/platsmp.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c new file mode 100644 index 000000000000..cdfd888ca783 --- /dev/null +++ b/arch/arm/mach-zynq/platsmp.c @@ -0,0 +1,149 @@ +/* + * 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 in __cpuinit section. + */ +static int ncores; + +/* Secondary CPU kernel startup is a 2 step process. The primary CPU + * starts the secondary CPU by giving it the address of the kernel and + * then sending it an event to wake it up. The secondary CPU then + * starts the kernel and tells the primary CPU it's up and running. + */ +static void __cpuinit zynq_secondary_init(unsigned int cpu) +{ + /* + * if any interrupts are already enabled for the primary + * core (e.g. timer irq), then they will not have been enabled + * for us: do so + */ + gic_secondary_init(0); +} + +int __cpuinit zynq_cpun_start(u32 address, int cpu) +{ + u32 trampoline_code_size = &zynq_secondary_trampoline_end - + &zynq_secondary_trampoline; + + if (cpu > ncores) { + pr_warn("CPU No. is not available in the system\n"); + return -1; + } + + /* 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 (__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 __cpuinit zynq_boot_secondary(unsigned int cpu, + struct task_struct *idle) +{ + return zynq_cpun_start(virt_to_phys(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) +{ + int i; + + /* + * Initialise the present map, which describes the set of CPUs + * actually populated at the present time. + */ + for (i = 0; i < max_cpus; i++) + set_cpu_present(i, true); + + scu_enable(zynq_scu_base); +} + +struct smp_operations zynq_smp_ops __initdata = { + .smp_init_cpus = zynq_smp_init_cpus, + .smp_prepare_cpus = zynq_smp_prepare_cpus, + .smp_secondary_init = zynq_secondary_init, + .smp_boot_secondary = zynq_boot_secondary, +}; |