text: /*
   * Based on arch/arm/include/asm/memory.h
   *
   * Copyright (C) 2000-2002 Russell King
   * Copyright (C) 2012 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/>.
   *
   * Note: this file should not be included by non-asm/.h files
   */
  #ifndef __ASM_MEMORY_H
  #define __ASM_MEMORY_H
  
  #include <linux/compiler.h>
  #include <linux/const.h>
  #include <linux/types.h>
  #include <asm/sizes.h>
  
  /*
   * Allow for constants defined here to be used from assembly code
   * by prepending the UL suffix only with actual C code compilation.
   */
  #define UL(x) _AC(x, UL)
  
  /*
   * Size of the PCI I/O space. This must remain a power of two so that
   * IO_SPACE_LIMIT acts as a mask for the low bits of I/O addresses.
   */
  #define PCI_IO_SIZE		SZ_16M
  
  /*
   * PAGE_OFFSET - the virtual address of the start of the kernel image (top
   *		 (VA_BITS - 1))
   * VA_BITS - the maximum number of bits for virtual addresses.
   * TASK_SIZE - the maximum size of a user space task.
   * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
   * The module space lives between the addresses given by TASK_SIZE
   * and PAGE_OFFSET - it must be within 128MB of the kernel text.
   */
  #define VA_BITS			(CONFIG_ARM64_VA_BITS)
  #define PAGE_OFFSET		(UL(0xffffffffffffffff) << (VA_BITS - 1))
  #define MODULES_END		(PAGE_OFFSET)
  #define MODULES_VADDR		(MODULES_END - SZ_64M)
  #define PCI_IO_END		(MODULES_VADDR - SZ_2M)
  #define PCI_IO_START		(PCI_IO_END - PCI_IO_SIZE)
  #define FIXADDR_TOP		(PCI_IO_START - SZ_2M)
  #define TASK_SIZE_64		(UL(1) << VA_BITS)
  
  #ifdef CONFIG_COMPAT
  #define TASK_SIZE_32		UL(0x100000000)
  #define TASK_SIZE		(test_thread_flag(TIF_32BIT) ? \
  				TASK_SIZE_32 : TASK_SIZE_64)
  #define TASK_SIZE_OF(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  				TASK_SIZE_32 : TASK_SIZE_64)
  #else
  #define TASK_SIZE		TASK_SIZE_64
  #endif /* CONFIG_COMPAT */
  
  #define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
  
  #if TASK_SIZE_64 > MODULES_VADDR
  #error Top of 64-bit user space clashes with start of module space
  #endif
  
  /*
   * Physical vs virtual RAM address space conversion.  These are
   * private definitions which should NOT be used outside memory.h
   * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
   */
  #define __virt_to_phys(x)	(((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
  #define __phys_to_virt(x)	((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
  
  /*
   * Convert a physical address to a Page Frame Number and back
   */
  #define	__phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT))
  #define	__pfn_to_phys(pfn)	((phys_addr_t)(pfn) << PAGE_SHIFT)
  
  /*
   * Convert a page to/from a physical address
   */
  #define page_to_phys(page)	(__pfn_to_phys(page_to_pfn(page)))
  #define phys_to_page(phys)	(pfn_to_page(__phys_to_pfn(phys)))
  
  /*
   * Memory types available.
   */
  #define MT_DEVICE_nGnRnE	0
  #define MT_DEVICE_nGnRE		1
  #define MT_DEVICE_GRE		2
  #define MT_NORMAL_NC		3
  #define MT_NORMAL		4
  
  /*
   * Memory types for Stage-2 translation
   */
  #define MT_S2_NORMAL		0xf
  #define MT_S2_DEVICE_nGnRE	0x1
  
  #ifndef __ASSEMBLY__
  
  extern phys_addr_t		memstart_addr;
  /* PHYS_OFFSET - the physical address of the start of memory. */
  #define PHYS_OFFSET		({ memstart_addr; })
  
  /*
   * The maximum physical address that the linear direct mapping
   * of system RAM can cover. (PAGE_OFFSET can be interpreted as
   * a 2's complement signed quantity and negated to derive the
   * maximum size of the linear mapping.)
   */
  #define MAX_MEMBLOCK_ADDR	({ memstart_addr - PAGE_OFFSET - 1; })
  
  /*
   * PFNs are used to describe any physical page; this means
   * PFN 0 == physical address 0.
   *
   * This is the PFN of the first RAM page in the kernel
   * direct-mapped view.  We assume this is the first page
   * of RAM in the mem_map as well.
   */
  #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
  
  /*
   * Note: Drivers should NOT use these.  They are the wrong
   * translation for translating DMA addresses.  Use the driver
   * DMA support - see dma-mapping.h.
   */
  #define virt_to_phys virt_to_phys
  static inline phys_addr_t virt_to_phys(const volatile void *x)
  {
  	return __virt_to_phys((unsigned long)(x));
  }
  
  #define phys_to_virt phys_to_virt
  static inline void *phys_to_virt(phys_addr_t x)
  {
  	return (void *)(__phys_to_virt(x));
  }
  
  /*
   * Drivers should NOT use these either.
   */
  #define __pa(x)			__virt_to_phys((unsigned long)(x))
  #define __va(x)			((void *)__phys_to_virt((phys_addr_t)(x)))
  #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
  #define virt_to_pfn(x)      __phys_to_pfn(__virt_to_phys(x))
  
  /*
   *  virt_to_page(k)	convert a _valid_ virtual address to struct page *
   *  virt_addr_valid(k)	indicates whether a virtual address is valid
   */
  #define ARCH_PFN_OFFSET		((unsigned long)PHYS_PFN_OFFSET)
  
  #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  #define	virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  
  #endif
  
  #include <asm-generic/memory_model.h>
  
  #endif
  