alistair23-linux/arch/arm/kernel/vmlinux.lds.S
Tejun Heo 0415b00d17 percpu: Always align percpu output section to PAGE_SIZE
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly.  The calculation of the
former depends on the alignment of percpu output section in the kernel
image.

The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.

This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE.  While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.

For um, this patch raises the alignment of percpu area.  As the area
is in .init, there shouldn't be any noticeable difference.

This problem was discovered by David Howells while debugging boot
failure on mn10300.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
2011-03-24 18:50:09 +01:00

288 lines
5.4 KiB
ArmAsm

/* ld script to make ARM Linux kernel
* taken from the i386 version by Russell King
* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
*/
#include <asm-generic/vmlinux.lds.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/page.h>
#define PROC_INFO \
VMLINUX_SYMBOL(__proc_info_begin) = .; \
*(.proc.info.init) \
VMLINUX_SYMBOL(__proc_info_end) = .;
#ifdef CONFIG_HOTPLUG_CPU
#define ARM_CPU_DISCARD(x)
#define ARM_CPU_KEEP(x) x
#else
#define ARM_CPU_DISCARD(x) x
#define ARM_CPU_KEEP(x)
#endif
#if defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)
#define ARM_EXIT_KEEP(x) x
#else
#define ARM_EXIT_KEEP(x)
#endif
OUTPUT_ARCH(arm)
ENTRY(stext)
#ifndef __ARMEB__
jiffies = jiffies_64;
#else
jiffies = jiffies_64 + 4;
#endif
SECTIONS
{
#ifdef CONFIG_XIP_KERNEL
. = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
#else
. = PAGE_OFFSET + TEXT_OFFSET;
#endif
.init : { /* Init code and data */
_stext = .;
_sinittext = .;
HEAD_TEXT
INIT_TEXT
ARM_EXIT_KEEP(EXIT_TEXT)
_einittext = .;
ARM_CPU_DISCARD(PROC_INFO)
__arch_info_begin = .;
*(.arch.info.init)
__arch_info_end = .;
__tagtable_begin = .;
*(.taglist.init)
__tagtable_end = .;
#ifdef CONFIG_SMP_ON_UP
__smpalt_begin = .;
*(.alt.smp.init)
__smpalt_end = .;
#endif
__pv_table_begin = .;
*(.pv_table)
__pv_table_end = .;
INIT_SETUP(16)
INIT_CALLS
CON_INITCALL
SECURITY_INITCALL
INIT_RAM_FS
#ifndef CONFIG_XIP_KERNEL
__init_begin = _stext;
INIT_DATA
ARM_EXIT_KEEP(EXIT_DATA)
#endif
}
PERCPU_SECTION(32)
#ifndef CONFIG_XIP_KERNEL
. = ALIGN(PAGE_SIZE);
__init_end = .;
#endif
/*
* unwind exit sections must be discarded before the rest of the
* unwind sections get included.
*/
/DISCARD/ : {
*(.ARM.exidx.exit.text)
*(.ARM.extab.exit.text)
ARM_CPU_DISCARD(*(.ARM.exidx.cpuexit.text))
ARM_CPU_DISCARD(*(.ARM.extab.cpuexit.text))
#ifndef CONFIG_HOTPLUG
*(.ARM.exidx.devexit.text)
*(.ARM.extab.devexit.text)
#endif
#ifndef CONFIG_MMU
*(.fixup)
*(__ex_table)
#endif
}
.text : { /* Real text segment */
_text = .; /* Text and read-only data */
__exception_text_start = .;
*(.exception.text)
__exception_text_end = .;
IRQENTRY_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
#ifdef CONFIG_MMU
*(.fixup)
#endif
*(.gnu.warning)
*(.rodata)
*(.rodata.*)
*(.glue_7)
*(.glue_7t)
. = ALIGN(4);
*(.got) /* Global offset table */
ARM_CPU_KEEP(PROC_INFO)
}
RO_DATA(PAGE_SIZE)
#ifdef CONFIG_ARM_UNWIND
/*
* Stack unwinding tables
*/
. = ALIGN(8);
.ARM.unwind_idx : {
__start_unwind_idx = .;
*(.ARM.exidx*)
__stop_unwind_idx = .;
}
.ARM.unwind_tab : {
__start_unwind_tab = .;
*(.ARM.extab*)
__stop_unwind_tab = .;
}
#endif
_etext = .; /* End of text and rodata section */
#ifdef CONFIG_XIP_KERNEL
__data_loc = ALIGN(4); /* location in binary */
. = PAGE_OFFSET + TEXT_OFFSET;
#else
. = ALIGN(THREAD_SIZE);
__data_loc = .;
#endif
.data : AT(__data_loc) {
_data = .; /* address in memory */
_sdata = .;
/*
* first, the init task union, aligned
* to an 8192 byte boundary.
*/
INIT_TASK_DATA(THREAD_SIZE)
#ifdef CONFIG_XIP_KERNEL
. = ALIGN(PAGE_SIZE);
__init_begin = .;
INIT_DATA
ARM_EXIT_KEEP(EXIT_DATA)
. = ALIGN(PAGE_SIZE);
__init_end = .;
#endif
NOSAVE_DATA
CACHELINE_ALIGNED_DATA(32)
READ_MOSTLY_DATA(32)
/*
* The exception fixup table (might need resorting at runtime)
*/
. = ALIGN(32);
__start___ex_table = .;
#ifdef CONFIG_MMU
*(__ex_table)
#endif
__stop___ex_table = .;
/*
* and the usual data section
*/
DATA_DATA
CONSTRUCTORS
_edata = .;
}
_edata_loc = __data_loc + SIZEOF(.data);
#ifdef CONFIG_HAVE_TCM
/*
* We align everything to a page boundary so we can
* free it after init has commenced and TCM contents have
* been copied to its destination.
*/
.tcm_start : {
. = ALIGN(PAGE_SIZE);
__tcm_start = .;
__itcm_start = .;
}
/*
* Link these to the ITCM RAM
* Put VMA to the TCM address and LMA to the common RAM
* and we'll upload the contents from RAM to TCM and free
* the used RAM after that.
*/
.text_itcm ITCM_OFFSET : AT(__itcm_start)
{
__sitcm_text = .;
*(.tcm.text)
*(.tcm.rodata)
. = ALIGN(4);
__eitcm_text = .;
}
/*
* Reset the dot pointer, this is needed to create the
* relative __dtcm_start below (to be used as extern in code).
*/
. = ADDR(.tcm_start) + SIZEOF(.tcm_start) + SIZEOF(.text_itcm);
.dtcm_start : {
__dtcm_start = .;
}
/* TODO: add remainder of ITCM as well, that can be used for data! */
.data_dtcm DTCM_OFFSET : AT(__dtcm_start)
{
. = ALIGN(4);
__sdtcm_data = .;
*(.tcm.data)
. = ALIGN(4);
__edtcm_data = .;
}
/* Reset the dot pointer or the linker gets confused */
. = ADDR(.dtcm_start) + SIZEOF(.data_dtcm);
/* End marker for freeing TCM copy in linked object */
.tcm_end : AT(ADDR(.dtcm_start) + SIZEOF(.data_dtcm)){
. = ALIGN(PAGE_SIZE);
__tcm_end = .;
}
#endif
NOTES
BSS_SECTION(0, 0, 0)
_end = .;
STABS_DEBUG
.comment 0 : { *(.comment) }
/* Default discards */
DISCARDS
#ifndef CONFIG_SMP_ON_UP
/DISCARD/ : {
*(.alt.smp.init)
}
#endif
}
/*
* These must never be empty
* If you have to comment these two assert statements out, your
* binutils is too old (for other reasons as well)
*/
ASSERT((__proc_info_end - __proc_info_begin), "missing CPU support")
ASSERT((__arch_info_end - __arch_info_begin), "no machine record defined")