arm64: Add vmap_stack header file

// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2017 Arm Ltd.

#ifndef __ASM_VMAP_STACK_H

#define __ASM_VMAP_STACK_H

#include <linux/bug.h>

#include <linux/gfp.h>

#include <linux/kconfig.h>

#include <linux/vmalloc.h>

#include <asm/memory.h>

#include <asm/pgtable.h>

#include <asm/thread_info.h>

/*

 * To ensure that VMAP'd stack overflow detection works correctly, all VMAP'd

 * stacks need to have the same alignment.

 */

static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int node)

{

	BUILD_BUG_ON(!IS_ENABLED(CONFIG_VMAP_STACK));

	return __vmalloc_node_range(stack_size, THREAD_ALIGN,

				    VMALLOC_START, VMALLOC_END,

				    THREADINFO_GFP, PAGE_KERNEL, 0, node,

				    __builtin_return_address(0));

}

#endif /* __ASM_VMAP_STACK_H */

#include <linux/irqchip.h>

#include <linux/seq_file.h>

#include <linux/vmalloc.h>

#include <asm/vmap_stack.h>

unsigned long irq_err_count;

	unsigned long *p;

	for_each_possible_cpu(cpu) {

		/*

		* To ensure that VMAP'd stack overflow detection works

		* correctly, the IRQ stacks need to have the same

		* alignment as other stacks.

		*/

		p = __vmalloc_node_range(IRQ_STACK_SIZE, THREAD_ALIGN,

					 VMALLOC_START, VMALLOC_END,

					 THREADINFO_GFP, PAGE_KERNEL,

					 0, cpu_to_node(cpu),

					 __builtin_return_address(0));

		p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));

		per_cpu(irq_stack_ptr, cpu) = p;

	}

}