diff options
Diffstat (limited to 'arch/arm/mach-sti/platsmp.c')
-rw-r--r-- | arch/arm/mach-sti/platsmp.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c new file mode 100644 index 000000000..e2ba04b56 --- /dev/null +++ b/arch/arm/mach-sti/platsmp.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * arch/arm/mach-sti/platsmp.c + * + * Copyright (C) 2013 STMicroelectronics (R&D) Limited. + * http://www.st.com + * + * Cloned from linux/arch/arm/mach-vexpress/platsmp.c + * + * Copyright (C) 2002 ARM Ltd. + * All Rights Reserved + */ +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/smp.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/memblock.h> + +#include <asm/cacheflush.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> + +#include "smp.h" + +static u32 __iomem *cpu_strt_ptr; + +static int sti_boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + unsigned long entry_pa = __pa_symbol(secondary_startup); + + /* + * Secondary CPU is initialised and started by a U-BOOTROM firmware. + * Secondary CPU is spinning and waiting for a write at cpu_strt_ptr. + * Writing secondary_startup address at cpu_strt_ptr makes it to + * jump directly to secondary_startup(). + */ + __raw_writel(entry_pa, cpu_strt_ptr); + + /* wmb so that data is actually written before cache flush is done */ + smp_wmb(); + sync_cache_w(cpu_strt_ptr); + + return 0; +} + +static void __init sti_smp_prepare_cpus(unsigned int max_cpus) +{ + struct device_node *np; + void __iomem *scu_base; + u32 release_phys; + int cpu; + + np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); + + if (np) { + scu_base = of_iomap(np, 0); + scu_enable(scu_base); + of_node_put(np); + } + + if (max_cpus <= 1) + return; + + for_each_possible_cpu(cpu) { + + np = of_get_cpu_node(cpu, NULL); + + if (!np) + continue; + + if (of_property_read_u32(np, "cpu-release-addr", + &release_phys)) { + pr_err("CPU %d: missing or invalid cpu-release-addr " + "property\n", cpu); + continue; + } + + /* + * cpu-release-addr is usually configured in SBC DMEM but can + * also be in RAM. + */ + + if (!memblock_is_memory(release_phys)) + cpu_strt_ptr = + ioremap(release_phys, sizeof(release_phys)); + else + cpu_strt_ptr = + (u32 __iomem *)phys_to_virt(release_phys); + + set_cpu_possible(cpu, true); + } +} + +const struct smp_operations sti_smp_ops __initconst = { + .smp_prepare_cpus = sti_smp_prepare_cpus, + .smp_boot_secondary = sti_boot_secondary, +}; |