arm64: SMP: rework the SMP code to be enabling method agnostic (d329de3f) · Commits · EulixOS / Software / Kernel

arch/arm64/include/asm/smp.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -66,4 +66,14 @@ extern volatile unsigned long secondary_holding_pen_release;
		extern void arch_send_call_function_single_ipi(int cpu);
		extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);

		struct device_node;

		struct smp_enable_ops {
		const char *name;
		int (init_cpu)(struct device_node , int);
		int (*prepare_cpu)(int);
		};

		extern const struct smp_enable_ops smp_spin_table_ops;

		#endif /* ifndef __ASM_SMP_H */

arch/arm64/kernel/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -14,7 +14,7 @@ arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
		arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
		sys_compat.o
		arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o
		arm64-obj-$(CONFIG_SMP) += smp.o
		arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o
		arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
		arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
		arm64-obj-$(CONFIG_EARLY_PRINTK) += early_printk.o

arch/arm64/kernel/smp.c

+46 −22

Original line number	Diff line number	Diff line
		@@ -233,7 +233,27 @@ void __init smp_prepare_boot_cpu(void)
		}

		static void (smp_cross_call)(const struct cpumask , unsigned int);
		static phys_addr_t cpu_release_addr[NR_CPUS];

		static const struct smp_enable_ops *enable_ops[] __initconst = {
		&smp_spin_table_ops,
		NULL,
		};

		static const struct smp_enable_ops *smp_enable_ops[NR_CPUS];

		static const struct smp_enable_ops * __init smp_get_enable_ops(const char *name)
		{
		const struct smp_enable_ops *ops = enable_ops[0];

		while (ops) {
		if (!strcmp(name, ops->name))
		return ops;

		ops++;
		}

		return NULL;
		}

		/*
		* Enumerate the possible CPU set from the device tree.
		@@ -252,22 +272,22 @@ void __init smp_init_cpus(void)
		* We currently support only the "spin-table" enable-method.
		*/
		enable_method = of_get_property(dn, "enable-method", NULL);
		if (!enable_method \|\| strcmp(enable_method, "spin-table")) {
		pr_err("CPU %d: missing or invalid enable-method property: %s\n",
		cpu, enable_method);
		if (!enable_method) {
		pr_err("CPU %d: missing enable-method property\n", cpu);
		goto next;
		}

		/*
		* Determine the address from which the CPU is polling.
		*/
		if (of_property_read_u64(dn, "cpu-release-addr",
		&cpu_release_addr[cpu])) {
		pr_err("CPU %d: missing or invalid cpu-release-addr property\n",
		cpu);
		smp_enable_ops[cpu] = smp_get_enable_ops(enable_method);

		if (!smp_enable_ops[cpu]) {
		pr_err("CPU %d: invalid enable-method property: %s\n",
		cpu, enable_method);
		goto next;
		}

		if (smp_enable_ops[cpu]->init_cpu(dn, cpu))
		goto next;

		set_cpu_possible(cpu, true);
		next:
		cpu++;
		@@ -281,8 +301,7 @@ void __init smp_init_cpus(void)

		void __init smp_prepare_cpus(unsigned int max_cpus)
		{
		int cpu;
		void **release_addr;
		int cpu, err;
		unsigned int ncores = num_possible_cpus();

		/*
		@@ -291,30 +310,35 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
		if (max_cpus > ncores)
		max_cpus = ncores;

		/* Don't bother if we're effectively UP */
		if (max_cpus <= 1)
		return;

		/*
		* Initialise the present map (which describes the set of CPUs
		* actually populated at the present time) and release the
		* secondaries from the bootloader.
		*
		* Make sure we online at most (max_cpus - 1) additional CPUs.
		*/
		max_cpus--;
		for_each_possible_cpu(cpu) {
		if (max_cpus == 0)
		break;

		if (!cpu_release_addr[cpu])
		if (cpu == smp_processor_id())
		continue;

		release_addr = __va(cpu_release_addr[cpu]);
		release_addr[0] = (void *)__pa(secondary_holding_pen);
		__flush_dcache_area(release_addr, sizeof(release_addr[0]));
		if (!smp_enable_ops[cpu])
		continue;

		err = smp_enable_ops[cpu]->prepare_cpu(cpu);
		if (err)
		continue;

		set_cpu_present(cpu, true);
		max_cpus--;
		}

		/*
		* Send an event to wake up the secondaries.
		*/
		sev();
		}

arch/arm64/kernel/smp_spin_table.c

0 → 100644

+66 −0

Original line number	Diff line number	Diff line
		/*
		* Spin Table SMP initialisation
		*
		* Copyright (C) 2013 ARM Ltd.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 as
		* published by the Free Software Foundation.
		*
		* 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.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program. If not, see <http://www.gnu.org/licenses/>.
		*/

		#include <linux/init.h>
		#include <linux/of.h>
		#include <linux/smp.h>

		#include <asm/cacheflush.h>

		static phys_addr_t cpu_release_addr[NR_CPUS];

		static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu)
		{
		/*
		* Determine the address from which the CPU is polling.
		*/
		if (of_property_read_u64(dn, "cpu-release-addr",
		&cpu_release_addr[cpu])) {
		pr_err("CPU %d: missing or invalid cpu-release-addr property\n",
		cpu);

		return -1;
		}

		return 0;
		}

		static int __init smp_spin_table_prepare_cpu(int cpu)
		{
		void **release_addr;

		if (!cpu_release_addr[cpu])
		return -ENODEV;

		release_addr = __va(cpu_release_addr[cpu]);
		release_addr[0] = (void *)__pa(secondary_holding_pen);
		__flush_dcache_area(release_addr, sizeof(release_addr[0]));

		/*
		* Send an event to wake up the secondary CPU.
		*/
		sev();

		return 0;
		}

		const struct smp_enable_ops smp_spin_table_ops __initconst = {
		.name = "spin-table",
		.init_cpu = smp_spin_table_init_cpu,
		.prepare_cpu = smp_spin_table_prepare_cpu,
		};