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- // 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,
- };
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