kernel_optimize_test/arch/xtensa/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

273 lines
7.0 KiB
ArmAsm

/*
* arch/xtensa/kernel/vmlinux.lds.S
*
* Xtensa linker script
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
* Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
*/
#include <asm-generic/vmlinux.lds.h>
#include <asm/page.h>
#include <asm/thread_info.h>
#include <variant/core.h>
#include <platform/hardware.h>
OUTPUT_ARCH(xtensa)
ENTRY(_start)
#ifdef __XTENSA_EB__
jiffies = jiffies_64 + 4;
#else
jiffies = jiffies_64;
#endif
#ifndef KERNELOFFSET
#define KERNELOFFSET 0xd0001000
#endif
/* Note: In the following macros, it would be nice to specify only the
vector name and section kind and construct "sym" and "section" using
CPP concatenation, but that does not work reliably. Concatenating a
string with "." produces an invalid token. CPP will not print a
warning because it thinks this is an assembly file, but it leaves
them as multiple tokens and there may or may not be whitespace
between them. */
/* Macro for a relocation entry */
#define RELOCATE_ENTRY(sym, section) \
LONG(sym ## _start); \
LONG(sym ## _end); \
LONG(LOADADDR(section))
/* Macro to define a section for a vector.
*
* Use of the MIN function catches the types of errors illustrated in
* the following example:
*
* Assume the section .DoubleExceptionVector.literal is completely
* full. Then a programmer adds code to .DoubleExceptionVector.text
* that produces another literal. The final literal position will
* overlay onto the first word of the adjacent code section
* .DoubleExceptionVector.text. (In practice, the literals will
* overwrite the code, and the first few instructions will be
* garbage.)
*/
#define SECTION_VECTOR(sym, section, addr, max_prevsec_size, prevsec) \
section addr : AT((MIN(LOADADDR(prevsec) + max_prevsec_size, \
LOADADDR(prevsec) + SIZEOF(prevsec)) + 3) & ~ 3) \
{ \
. = ALIGN(4); \
sym ## _start = ABSOLUTE(.); \
*(section) \
sym ## _end = ABSOLUTE(.); \
}
/*
* Mapping of input sections to output sections when linking.
*/
SECTIONS
{
. = KERNELOFFSET;
/* .text section */
_text = .;
_stext = .;
_ftext = .;
.text :
{
/* The HEAD_TEXT section must be the first section! */
HEAD_TEXT
TEXT_TEXT
VMLINUX_SYMBOL(__sched_text_start) = .;
*(.sched.literal .sched.text)
VMLINUX_SYMBOL(__sched_text_end) = .;
VMLINUX_SYMBOL(__lock_text_start) = .;
*(.spinlock.literal .spinlock.text)
VMLINUX_SYMBOL(__lock_text_end) = .;
}
_etext = .;
PROVIDE (etext = .);
. = ALIGN(16);
RODATA
/* Relocation table */
.fixup : { *(.fixup) }
EXCEPTION_TABLE(16)
/* Data section */
_fdata = .;
RW_DATA_SECTION(XCHAL_ICACHE_LINESIZE, PAGE_SIZE, THREAD_SIZE)
_edata = .;
/* Initialization code and data: */
. = ALIGN(PAGE_SIZE);
__init_begin = .;
INIT_TEXT_SECTION(PAGE_SIZE)
.init.data :
{
INIT_DATA
. = ALIGN(0x4);
__tagtable_begin = .;
*(.taglist)
__tagtable_end = .;
. = ALIGN(16);
__boot_reloc_table_start = ABSOLUTE(.);
RELOCATE_ENTRY(_WindowVectors_text,
.WindowVectors.text);
RELOCATE_ENTRY(_KernelExceptionVector_text,
.KernelExceptionVector.text);
RELOCATE_ENTRY(_UserExceptionVector_text,
.UserExceptionVector.text);
RELOCATE_ENTRY(_DoubleExceptionVector_literal,
.DoubleExceptionVector.literal);
RELOCATE_ENTRY(_DoubleExceptionVector_text,
.DoubleExceptionVector.text);
RELOCATE_ENTRY(_DebugInterruptVector_text,
.DebugInterruptVector.text);
__boot_reloc_table_end = ABSOLUTE(.) ;
INIT_SETUP(XCHAL_ICACHE_LINESIZE)
INIT_CALLS
CON_INITCALL
SECURITY_INITCALL
INIT_RAM_FS
}
PERCPU_SECTION(XCHAL_ICACHE_LINESIZE)
/* We need this dummy segment here */
. = ALIGN(4);
.dummy : { LONG(0) }
/* The vectors are relocated to the real position at startup time */
SECTION_VECTOR (_WindowVectors_text,
.WindowVectors.text,
XCHAL_WINDOW_VECTORS_VADDR, 4,
.dummy)
SECTION_VECTOR (_DebugInterruptVector_literal,
.DebugInterruptVector.literal,
XCHAL_DEBUG_VECTOR_VADDR - 4,
SIZEOF(.WindowVectors.text),
.WindowVectors.text)
SECTION_VECTOR (_DebugInterruptVector_text,
.DebugInterruptVector.text,
XCHAL_DEBUG_VECTOR_VADDR,
4,
.DebugInterruptVector.literal)
SECTION_VECTOR (_KernelExceptionVector_literal,
.KernelExceptionVector.literal,
XCHAL_KERNEL_VECTOR_VADDR - 4,
SIZEOF(.DebugInterruptVector.text),
.DebugInterruptVector.text)
SECTION_VECTOR (_KernelExceptionVector_text,
.KernelExceptionVector.text,
XCHAL_KERNEL_VECTOR_VADDR,
4,
.KernelExceptionVector.literal)
SECTION_VECTOR (_UserExceptionVector_literal,
.UserExceptionVector.literal,
XCHAL_USER_VECTOR_VADDR - 4,
SIZEOF(.KernelExceptionVector.text),
.KernelExceptionVector.text)
SECTION_VECTOR (_UserExceptionVector_text,
.UserExceptionVector.text,
XCHAL_USER_VECTOR_VADDR,
4,
.UserExceptionVector.literal)
SECTION_VECTOR (_DoubleExceptionVector_literal,
.DoubleExceptionVector.literal,
XCHAL_DOUBLEEXC_VECTOR_VADDR - 16,
SIZEOF(.UserExceptionVector.text),
.UserExceptionVector.text)
SECTION_VECTOR (_DoubleExceptionVector_text,
.DoubleExceptionVector.text,
XCHAL_DOUBLEEXC_VECTOR_VADDR,
32,
.DoubleExceptionVector.literal)
. = (LOADADDR( .DoubleExceptionVector.text ) + SIZEOF( .DoubleExceptionVector.text ) + 3) & ~ 3;
. = ALIGN(PAGE_SIZE);
__init_end = .;
BSS_SECTION(0, 8192, 0)
_end = .;
/* only used by the boot loader */
. = ALIGN(0x10);
.bootstrap : { *(.bootstrap.literal .bootstrap.text .bootstrap.data) }
. = ALIGN(0x1000);
__initrd_start = .;
.initrd : { *(.initrd) }
__initrd_end = .;
.ResetVector.text XCHAL_RESET_VECTOR_VADDR :
{
*(.ResetVector.text)
}
.xt.lit : { *(.xt.lit) }
.xt.prop : { *(.xt.prop) }
.debug 0 : { *(.debug) }
.line 0 : { *(.line) }
.debug_srcinfo 0 : { *(.debug_srcinfo) }
.debug_sfnames 0 : { *(.debug_sfnames) }
.debug_aranges 0 : { *(.debug_aranges) }
.debug_pubnames 0 : { *(.debug_pubnames) }
.debug_info 0 : { *(.debug_info) }
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_line 0 : { *(.debug_line) }
.debug_frame 0 : { *(.debug_frame) }
.debug_str 0 : { *(.debug_str) }
.debug_loc 0 : { *(.debug_loc) }
.debug_macinfo 0 : { *(.debug_macinfo) }
.debug_weaknames 0 : { *(.debug_weaknames) }
.debug_funcnames 0 : { *(.debug_funcnames) }
.debug_typenames 0 : { *(.debug_typenames) }
.debug_varnames 0 : { *(.debug_varnames) }
.xt.insn 0 :
{
*(.xt.insn)
*(.gnu.linkonce.x*)
}
.xt.lit 0 :
{
*(.xt.lit)
*(.gnu.linkonce.p*)
}
/* Sections to be discarded */
DISCARDS
/DISCARD/ : { *(.exit.literal) }
}