[S390] Allocate and free cpu lowcores and stacks when needed/possible. (1cb6bb4b) · Commits · e / devices / android_kernel_xiaomi_markw

arch/s390/kernel/smp.c

+72 −34

Original line number	Original line	Diff line number	Diff line
	@@ -589,8 +589,72 @@ static void __init smp_create_idle(unsigned int cpu)
	spin_lock_init(&(&per_cpu(s390_idle, cpu))->lock);		spin_lock_init(&(&per_cpu(s390_idle, cpu))->lock);
	}		}

			static int __cpuinit smp_alloc_lowcore(int cpu)
			{
			unsigned long async_stack, panic_stack;
			struct _lowcore *lowcore;
			int lc_order;

			lc_order = sizeof(long) == 8 ? 1 : 0;
			lowcore = (void *) __get_free_pages(GFP_KERNEL \| GFP_DMA, lc_order);
			if (!lowcore)
			return -ENOMEM;
			async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
			if (!async_stack)
			goto out_async_stack;
			panic_stack = __get_free_page(GFP_KERNEL);
			if (!panic_stack)
			goto out_panic_stack;

			*lowcore = S390_lowcore;
			lowcore->async_stack = async_stack + ASYNC_SIZE;
			lowcore->panic_stack = panic_stack + PAGE_SIZE;

			#ifndef CONFIG_64BIT
			if (MACHINE_HAS_IEEE) {
			unsigned long save_area;

			save_area = get_zeroed_page(GFP_KERNEL);
			if (!save_area)
			goto out_save_area;
			lowcore->extended_save_area_addr = (u32) save_area;
			}
			#endif
			lowcore_ptr[cpu] = lowcore;
			return 0;

			#ifndef CONFIG_64BIT
			out_save_area:
			free_page(panic_stack);
			#endif
			out_panic_stack:
			free_pages(async_stack, ASYNC_ORDER);
			out_async_stack:
			free_pages((unsigned long) lowcore, lc_order);
			return -ENOMEM;
			}

			#ifdef CONFIG_HOTPLUG_CPU
			static void smp_free_lowcore(int cpu)
			{
			struct _lowcore *lowcore;
			int lc_order;

			lc_order = sizeof(long) == 8 ? 1 : 0;
			lowcore = lowcore_ptr[cpu];
			#ifndef CONFIG_64BIT
			if (MACHINE_HAS_IEEE)
			free_page((unsigned long) lowcore->extended_save_area_addr);
			#endif
			free_page(lowcore->panic_stack - PAGE_SIZE);
			free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
			free_pages((unsigned long) lowcore, lc_order);
			lowcore_ptr[cpu] = NULL;
			}
			#endif /* CONFIG_HOTPLUG_CPU */

	/* Upping and downing of CPUs */		/* Upping and downing of CPUs */
	int __cpu_up(unsigned int cpu)		int __cpuinit __cpu_up(unsigned int cpu)
	{		{
	struct task_struct *idle;		struct task_struct *idle;
	struct _lowcore *cpu_lowcore;		struct _lowcore *cpu_lowcore;
	@@ -599,6 +663,8 @@ int __cpu_up(unsigned int cpu)

	if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)		if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
	return -EIO;		return -EIO;
			if (smp_alloc_lowcore(cpu))
			return -ENOMEM;

	ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),		ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
	cpu, sigp_set_prefix);		cpu, sigp_set_prefix);
	@@ -613,6 +679,7 @@ int __cpu_up(unsigned int cpu)
	cpu_lowcore = lowcore_ptr[cpu];		cpu_lowcore = lowcore_ptr[cpu];
	cpu_lowcore->kernel_stack = (unsigned long)		cpu_lowcore->kernel_stack = (unsigned long)
	task_stack_page(idle) + THREAD_SIZE;		task_stack_page(idle) + THREAD_SIZE;
			cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
	sf = (struct stack_frame *) (cpu_lowcore->kernel_stack		sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
	- sizeof(struct pt_regs)		- sizeof(struct pt_regs)
	- sizeof(struct stack_frame));		- sizeof(struct stack_frame));
	@@ -626,6 +693,8 @@ int __cpu_up(unsigned int cpu)
	cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];		cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
	cpu_lowcore->current_task = (unsigned long) idle;		cpu_lowcore->current_task = (unsigned long) idle;
	cpu_lowcore->cpu_data.cpu_nr = cpu;		cpu_lowcore->cpu_data.cpu_nr = cpu;
			cpu_lowcore->softirq_pending = 0;
			cpu_lowcore->ext_call_fast = 0;
	eieio();		eieio();

	while (signal_processor(cpu, sigp_restart) == sigp_busy)		while (signal_processor(cpu, sigp_restart) == sigp_busy)
	@@ -686,6 +755,7 @@ void __cpu_die(unsigned int cpu)
	/* Wait until target cpu is down */		/* Wait until target cpu is down */
	while (!smp_cpu_not_running(cpu))		while (!smp_cpu_not_running(cpu))
	cpu_relax();		cpu_relax();
			smp_free_lowcore(cpu);
	printk(KERN_INFO "Processor %d spun down\n", cpu);		printk(KERN_INFO "Processor %d spun down\n", cpu);
	}		}

	@@ -699,15 +769,9 @@ void cpu_die(void)

	#endif /* CONFIG_HOTPLUG_CPU */		#endif /* CONFIG_HOTPLUG_CPU */

	/*
	* Cycle through the processors and setup structures.
	*/

	void __init smp_prepare_cpus(unsigned int max_cpus)		void __init smp_prepare_cpus(unsigned int max_cpus)
	{		{
	unsigned long stack;
	unsigned int cpu;		unsigned int cpu;
	int i;

	smp_detect_cpus();		smp_detect_cpus();

	@@ -715,35 +779,9 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
	if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)		if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
	panic("Couldn't request external interrupt 0x1201");		panic("Couldn't request external interrupt 0x1201");
	memset(lowcore_ptr, 0, sizeof(lowcore_ptr));		memset(lowcore_ptr, 0, sizeof(lowcore_ptr));
	/*
	* Initialize prefix pages and stacks for all possible cpus
	*/
	print_cpu_info(&S390_lowcore.cpu_data);		print_cpu_info(&S390_lowcore.cpu_data);
			smp_alloc_lowcore(smp_processor_id());

	for_each_possible_cpu(i) {
	lowcore_ptr[i] = (struct _lowcore *)
	__get_free_pages(GFP_KERNEL \| GFP_DMA,
	sizeof(void*) == 8 ? 1 : 0);
	stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
	if (!lowcore_ptr[i] \|\| !stack)
	panic("smp_boot_cpus failed to allocate memory\n");

	*(lowcore_ptr[i]) = S390_lowcore;
	lowcore_ptr[i]->async_stack = stack + ASYNC_SIZE;
	stack = __get_free_pages(GFP_KERNEL, 0);
	if (!stack)
	panic("smp_boot_cpus failed to allocate memory\n");
	lowcore_ptr[i]->panic_stack = stack + PAGE_SIZE;
	#ifndef CONFIG_64BIT
	if (MACHINE_HAS_IEEE) {
	lowcore_ptr[i]->extended_save_area_addr =
	(__u32) __get_free_pages(GFP_KERNEL, 0);
	if (!lowcore_ptr[i]->extended_save_area_addr)
	panic("smp_boot_cpus failed to "
	"allocate memory\n");
	}
	#endif
	}
	#ifndef CONFIG_64BIT		#ifndef CONFIG_64BIT
	if (MACHINE_HAS_IEEE)		if (MACHINE_HAS_IEEE)
	ctl_set_bit(14, 29); /* enable extended save area */		ctl_set_bit(14, 29); /* enable extended save area */