kernel-ark/arch/sh64/kernel/vmlinux.lds.S
Fenghua Yu 5fb7dc37dc define new percpu interface for shared data
per cpu data section contains two types of data.  One set which is
exclusively accessed by the local cpu and the other set which is per cpu,
but also shared by remote cpus.  In the current kernel, these two sets are
not clearely separated out.  This can potentially cause the same data
cacheline shared between the two sets of data, which will result in
unnecessary bouncing of the cacheline between cpus.

One way to fix the problem is to cacheline align the remotely accessed per
cpu data, both at the beginning and at the end.  Because of the padding at
both ends, this will likely cause some memory wastage and also the
interface to achieve this is not clean.

This patch:

Moves the remotely accessed per cpu data (which is currently marked
as ____cacheline_aligned_in_smp) into a different section, where all the data
elements are cacheline aligned. And as such, this differentiates the local
only data and remotely accessed data cleanly.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00

182 lines
5.3 KiB
ArmAsm

/*
* 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.
*
* arch/sh5/vmlinux.lds.S
*
* ld script to make ST50 Linux kernel
*
* Copyright (C) 2000, 2001 Paolo Alberelli
*
* benedict.gaster@superh.com: 2nd May 2002
* Add definition of empty_zero_page to be the first page of kernel image.
*
* benedict.gaster@superh.com: 3rd May 2002
* Added support for ramdisk, removing statically linked romfs at the same time.
*
* lethal@linux-sh.org: 9th May 2003
* Kill off GLOBAL_NAME() usage and other CDC-isms.
*
* lethal@linux-sh.org: 19th May 2003
* Remove support for ancient toolchains.
*/
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/processor.h>
#include <asm/thread_info.h>
#define LOAD_OFFSET CONFIG_CACHED_MEMORY_OFFSET
#include <asm-generic/vmlinux.lds.h>
#ifdef NOTDEF
#ifdef CONFIG_LITTLE_ENDIAN
OUTPUT_FORMAT("elf32-sh64l-linux", "elf32-sh64l-linux", "elf32-sh64l-linux")
#else
OUTPUT_FORMAT("elf32-sh64", "elf32-sh64", "elf32-sh64")
#endif
#endif
OUTPUT_ARCH(sh:sh5)
#define C_PHYS(x) AT (ADDR(x) - LOAD_OFFSET)
ENTRY(__start)
SECTIONS
{
. = CONFIG_CACHED_MEMORY_OFFSET + CONFIG_MEMORY_START + PAGE_SIZE;
_text = .; /* Text and read-only data */
text = .; /* Text and read-only data */
.empty_zero_page : C_PHYS(.empty_zero_page) {
*(.empty_zero_page)
} = 0
.text : C_PHYS(.text) {
TEXT_TEXT
*(.text64)
*(.text..SHmedia32)
SCHED_TEXT
LOCK_TEXT
*(.fixup)
*(.gnu.warning)
#ifdef CONFIG_LITTLE_ENDIAN
} = 0x6ff0fff0
#else
} = 0xf0fff06f
#endif
/* We likely want __ex_table to be Cache Line aligned */
. = ALIGN(L1_CACHE_BYTES); /* Exception table */
__start___ex_table = .;
__ex_table : C_PHYS(__ex_table) { *(__ex_table) }
__stop___ex_table = .;
RODATA
_etext = .; /* End of text section */
.data : C_PHYS(.data) { /* Data */
DATA_DATA
CONSTRUCTORS
}
. = ALIGN(PAGE_SIZE);
.data.page_aligned : C_PHYS(.data.page_aligned) { *(.data.page_aligned) }
. = ALIGN(PAGE_SIZE);
__per_cpu_start = .;
.data.percpu : C_PHYS(.data.percpu) {
*(.data.percpu)
*(.data.percpu.shared_aligned)
}
__per_cpu_end = . ;
.data.cacheline_aligned : C_PHYS(.data.cacheline_aligned) { *(.data.cacheline_aligned) }
_edata = .; /* End of data section */
. = ALIGN(THREAD_SIZE); /* init_task: structure size aligned */
.data.init_task : C_PHYS(.data.init_task) { *(.data.init_task) }
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
_sinittext = .;
.init.text : C_PHYS(.init.text) { *(.init.text) }
_einittext = .;
.init.data : C_PHYS(.init.data) { *(.init.data) }
. = ALIGN(L1_CACHE_BYTES); /* Better if Cache Line aligned */
__setup_start = .;
.init.setup : C_PHYS(.init.setup) { *(.init.setup) }
__setup_end = .;
__initcall_start = .;
.initcall.init : C_PHYS(.initcall.init) {
INITCALLS
}
__initcall_end = .;
__con_initcall_start = .;
.con_initcall.init : C_PHYS(.con_initcall.init) { *(.con_initcall.init) }
__con_initcall_end = .;
SECURITY_INIT
#ifdef CONFIG_BLK_DEV_INITRD
__initramfs_start = .;
.init.ramfs : C_PHYS(.init.ramfs) { *(.init.ramfs) }
__initramfs_end = .;
#endif
. = ALIGN(PAGE_SIZE);
__init_end = .;
/* Align to the biggest single data representation, head and tail */
. = ALIGN(8);
__bss_start = .; /* BSS */
.bss : C_PHYS(.bss) {
*(.bss)
}
. = ALIGN(8);
_end = . ;
/* Sections to be discarded */
/DISCARD/ : {
*(.exit.text)
*(.exit.data)
*(.exitcall.exit)
}
/* Stabs debugging sections. */
.stab 0 : C_PHYS(.stab) { *(.stab) }
.stabstr 0 : C_PHYS(.stabstr) { *(.stabstr) }
.stab.excl 0 : C_PHYS(.stab.excl) { *(.stab.excl) }
.stab.exclstr 0 : C_PHYS(.stab.exclstr) { *(.stab.exclstr) }
.stab.index 0 : C_PHYS(.stab.index) { *(.stab.index) }
.stab.indexstr 0 : C_PHYS(.stab.indexstr) { *(.stab.indexstr) }
.comment 0 : C_PHYS(.comment) { *(.comment) }
/* DWARF debug sections.
Symbols in the DWARF debugging section are relative to the beginning
of the section so we begin .debug at 0. */
/* DWARF 1 */
.debug 0 : C_PHYS(.debug) { *(.debug) }
.line 0 : C_PHYS(.line) { *(.line) }
/* GNU DWARF 1 extensions */
.debug_srcinfo 0 : C_PHYS(.debug_srcinfo) { *(.debug_srcinfo) }
.debug_sfnames 0 : C_PHYS(.debug_sfnames) { *(.debug_sfnames) }
/* DWARF 1.1 and DWARF 2 */
.debug_aranges 0 : C_PHYS(.debug_aranges) { *(.debug_aranges) }
.debug_pubnames 0 : C_PHYS(.debug_pubnames) { *(.debug_pubnames) }
/* DWARF 2 */
.debug_info 0 : C_PHYS(.debug_info) { *(.debug_info) }
.debug_abbrev 0 : C_PHYS(.debug_abbrev) { *(.debug_abbrev) }
.debug_line 0 : C_PHYS(.debug_line) { *(.debug_line) }
.debug_frame 0 : C_PHYS(.debug_frame) { *(.debug_frame) }
.debug_str 0 : C_PHYS(.debug_str) { *(.debug_str) }
.debug_loc 0 : C_PHYS(.debug_loc) { *(.debug_loc) }
.debug_macinfo 0 : C_PHYS(.debug_macinfo) { *(.debug_macinfo) }
/* SGI/MIPS DWARF 2 extensions */
.debug_weaknames 0 : C_PHYS(.debug_weaknames) { *(.debug_weaknames) }
.debug_funcnames 0 : C_PHYS(.debug_funcnames) { *(.debug_funcnames) }
.debug_typenames 0 : C_PHYS(.debug_typenames) { *(.debug_typenames) }
.debug_varnames 0 : C_PHYS(.debug_varnames) { *(.debug_varnames) }
/* These must appear regardless of . */
}