x86: use linker to offset symbols by __per_cpu_load

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / vmlinux_64.lds.S

/* ld script to make x86-64 Linux kernel
 * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>;
 */

#define LOAD_OFFSET __START_KERNEL_map

#include <asm-generic/vmlinux.lds.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>

#undef i386	/* in case the preprocessor is a 32bit one */

OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
OUTPUT_ARCH(i386:x86-64)
ENTRY(phys_startup_64)
jiffies_64 = jiffies;
PHDRS {
	text PT_LOAD FLAGS(5);	/* R_E */
	data PT_LOAD FLAGS(7);	/* RWE */
	user PT_LOAD FLAGS(7);	/* RWE */
	data.init PT_LOAD FLAGS(7);	/* RWE */
#ifdef CONFIG_SMP
	percpu PT_LOAD FLAGS(7);	/* RWE */
#endif
	data.init2 PT_LOAD FLAGS(7);	/* RWE */
	note PT_NOTE FLAGS(0);	/* ___ */
}
SECTIONS
{
  . = __START_KERNEL;
  phys_startup_64 = startup_64 - LOAD_OFFSET;
  _text = .;			/* Text and read-only data */
  .text :  AT(ADDR(.text) - LOAD_OFFSET) {
	/* First the code that has to be first for bootstrapping */
	*(.text.head)
	_stext = .;
	/* Then the rest */
	TEXT_TEXT
	SCHED_TEXT
	LOCK_TEXT
	KPROBES_TEXT
	IRQENTRY_TEXT
	*(.fixup)
	*(.gnu.warning)
	_etext = .;		/* End of text section */
  } :text = 0x9090

  NOTES :text :note

  . = ALIGN(16);		/* Exception table */
  __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
  	__start___ex_table = .;
	 *(__ex_table)
  	__stop___ex_table = .;
  } :text = 0x9090

  RODATA

  . = ALIGN(PAGE_SIZE);		/* Align data segment to page size boundary */
				/* Data */
  .data : AT(ADDR(.data) - LOAD_OFFSET) {
	DATA_DATA
	CONSTRUCTORS
	} :data

  _edata = .;			/* End of data section */

  . = ALIGN(PAGE_SIZE);
  . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
  .data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
	*(.data.cacheline_aligned)
  }
  . = ALIGN(CONFIG_X86_INTERNODE_CACHE_BYTES);
  .data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
  	*(.data.read_mostly)
  }

#define VSYSCALL_ADDR (-10*1024*1024)
#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.read_mostly) + SIZEOF(.data.read_mostly) + 4095) & ~(4095))
#define VSYSCALL_VIRT_ADDR ((ADDR(.data.read_mostly) + SIZEOF(.data.read_mostly) + 4095) & ~(4095))

#define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
#define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)

#define VVIRT_OFFSET (VSYSCALL_ADDR - VSYSCALL_VIRT_ADDR)
#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)

  . = VSYSCALL_ADDR;
  .vsyscall_0 :	 AT(VSYSCALL_PHYS_ADDR) { *(.vsyscall_0) } :user
  __vsyscall_0 = VSYSCALL_VIRT_ADDR;

  . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
  .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) }
  . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
  .vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data))
		{ *(.vsyscall_gtod_data) }
  vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data);
  .vsyscall_clock : AT(VLOAD(.vsyscall_clock))
		{ *(.vsyscall_clock) }
  vsyscall_clock = VVIRT(.vsyscall_clock);


  .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1))
		{ *(.vsyscall_1) }
  .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2))
		{ *(.vsyscall_2) }

  .vgetcpu_mode : AT(VLOAD(.vgetcpu_mode)) { *(.vgetcpu_mode) }
  vgetcpu_mode = VVIRT(.vgetcpu_mode);

  . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
  .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) }
  jiffies = VVIRT(.jiffies);

  .vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3))
		{ *(.vsyscall_3) }

  . = VSYSCALL_VIRT_ADDR + PAGE_SIZE;

#undef VSYSCALL_ADDR
#undef VSYSCALL_PHYS_ADDR
#undef VSYSCALL_VIRT_ADDR
#undef VLOAD_OFFSET
#undef VLOAD
#undef VVIRT_OFFSET
#undef VVIRT

  . = ALIGN(THREAD_SIZE);	/* init_task */
  .data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
	*(.data.init_task)
  }:data.init

  . = ALIGN(PAGE_SIZE);
  .data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
	*(.data.page_aligned)
  }

  /* might get freed after init */
  . = ALIGN(PAGE_SIZE);
  __smp_alt_begin = .;
  __smp_locks = .;
  .smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
	*(.smp_locks)
  }
  __smp_locks_end = .;
  . = ALIGN(PAGE_SIZE);
  __smp_alt_end = .;

  . = ALIGN(PAGE_SIZE);		/* Init code and data */
  __init_begin = .;
  .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
	_sinittext = .;
	INIT_TEXT
	_einittext = .;
  }
  .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
	__initdata_begin = .;
	INIT_DATA
	__initdata_end = .;
   }

  . = ALIGN(16);
  __setup_start = .;
  .init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) { *(.init.setup) }
  __setup_end = .;
  __initcall_start = .;
  .initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
	INITCALLS
  }
  __initcall_end = .;
  __con_initcall_start = .;
  .con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
	*(.con_initcall.init)
  }
  __con_initcall_end = .;
  __x86_cpu_dev_start = .;
  .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
	*(.x86_cpu_dev.init)
  }
  __x86_cpu_dev_end = .;
  SECURITY_INIT

  . = ALIGN(8);
  .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
  __parainstructions = .;
       *(.parainstructions)
  __parainstructions_end = .;
  }

  . = ALIGN(8);
  __alt_instructions = .;
  .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
	*(.altinstructions)
  }
  __alt_instructions_end = .;
  .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
	*(.altinstr_replacement)
  }
  /* .exit.text is discard at runtime, not link time, to deal with references
     from .altinstructions and .eh_frame */
  .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
	EXIT_TEXT
  }
  .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
	EXIT_DATA
  }

#ifdef CONFIG_BLK_DEV_INITRD
  . = ALIGN(PAGE_SIZE);
  __initramfs_start = .;
  .init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) { *(.init.ramfs) }
  __initramfs_end = .;
#endif

#ifdef CONFIG_SMP
  /*
   * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
   * output PHDR, so the next output section - __data_nosave - should
   * start another section data.init2.  Also, pda should be at the head of
   * percpu area.  Preallocate it and define the percpu offset symbol
   * so that it can be accessed as a percpu variable.
   */
  . = ALIGN(PAGE_SIZE);
  PERCPU_VADDR(0, :percpu)
#else
  PERCPU(PAGE_SIZE)
#endif

  . = ALIGN(PAGE_SIZE);
  __init_end = .;

  . = ALIGN(PAGE_SIZE);
  __nosave_begin = .;
  .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
      *(.data.nosave)
  } :data.init2 /* use another section data.init2, see PERCPU_VADDR() above */
  . = ALIGN(PAGE_SIZE);
  __nosave_end = .;

  __bss_start = .;		/* BSS */
  .bss : AT(ADDR(.bss) - LOAD_OFFSET) {
	*(.bss.page_aligned)
	*(.bss)
	}
  __bss_stop = .;

  _end = . ;

  /* Sections to be discarded */
  /DISCARD/ : {
	*(.exitcall.exit)
	*(.eh_frame)
	}

  STABS_DEBUG

  DWARF_DEBUG
}

 /*
  * Per-cpu symbols which need to be offset from __per_cpu_load
  * for the boot processor.
  */
#define INIT_PER_CPU(x) init_per_cpu__##x = per_cpu__##x + __per_cpu_load
INIT_PER_CPU(gdt_page);
INIT_PER_CPU(irq_stack_union);

/*
 * Build-time check on the image size:
 */
ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
	"kernel image bigger than KERNEL_IMAGE_SIZE")

#ifdef CONFIG_SMP
ASSERT((per_cpu__irq_stack_union == 0),
        "irq_stack_union is not at start of per-cpu area");
#endif