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authorHelge Deller <deller@gmx.de>2013-11-30 22:07:51 +0100
committerHelge Deller <deller@gmx.de>2013-11-30 22:09:21 +0100
commit161bd3bf60ee2c5765455ad3e3da967d03449f4a (patch)
tree5287e2c53bdc876b7bf2660237dc926efcb50d9c /arch/parisc/kernel/vmlinux.lds.S
parentc790b41bac83512dc67da89b582daa6f4e1fab07 (diff)
downloadop-kernel-dev-161bd3bf60ee2c5765455ad3e3da967d03449f4a.zip
op-kernel-dev-161bd3bf60ee2c5765455ad3e3da967d03449f4a.tar.gz
parisc: fix kernel memory layout in vmlinux.ld.S
When building a 64bit kernel sometimes functions in the .init section were not able to reach the standard kernel function. Main reason for this problem is, that the linkage tables (.plt, .opd, .dlt) tend to become pretty huge and thus the distance gets too big for short calls. One option to avoid this is to use the -mlong-calls compiler option, but this increases the binary size and introduces a performance penalty. Instead, with this patch we just lay out the binary differently. Init code is stored first, followed by text, R/O and finally R/W data. This means, that init and text code is now much closer to each other, which is sufficient to reach each other by short calls. Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/kernel/vmlinux.lds.S')
-rw-r--r--arch/parisc/kernel/vmlinux.lds.S138
1 files changed, 60 insertions, 78 deletions
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index 4bb095a..0dacc5c 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -6,24 +6,19 @@
* Copyright (C) 2000 Michael Ang <mang with subcarrier.org>
* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
* Copyright (C) 2003 James Bottomley <jejb with parisc-linux.org>
- * Copyright (C) 2006 Helge Deller <deller@gmx.de>
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Copyright (C) 2006-2013 Helge Deller <deller@gmx.de>
+ */
+
+/*
+ * Put page table entries (swapper_pg_dir) as the first thing in .bss. This
+ * will ensure that it has .bss alignment (PAGE_SIZE).
*/
+#define BSS_FIRST_SECTIONS *(.data..vm0.pmd) \
+ *(.data..vm0.pgd) \
+ *(.data..vm0.pte)
+
#include <asm-generic/vmlinux.lds.h>
+
/* needed for the processor specific cache alignment size */
#include <asm/cache.h>
#include <asm/page.h>
@@ -39,7 +34,7 @@ OUTPUT_FORMAT("elf64-hppa-linux")
OUTPUT_ARCH(hppa:hppa2.0w)
#endif
-ENTRY(_stext)
+ENTRY(parisc_kernel_start)
#ifndef CONFIG_64BIT
jiffies = jiffies_64 + 4;
#else
@@ -49,11 +44,29 @@ SECTIONS
{
. = KERNEL_BINARY_TEXT_START;
+ __init_begin = .;
+ HEAD_TEXT_SECTION
+ INIT_TEXT_SECTION(8)
+
+ . = ALIGN(PAGE_SIZE);
+ INIT_DATA_SECTION(PAGE_SIZE)
+ /* we have to discard exit text and such at runtime, not link time */
+ .exit.text :
+ {
+ EXIT_TEXT
+ }
+ .exit.data :
+ {
+ EXIT_DATA
+ }
+ PERCPU_SECTION(8)
+ . = ALIGN(PAGE_SIZE);
+ __init_end = .;
+ /* freed after init ends here */
+
_text = .; /* Text and read-only data */
- .head ALIGN(16) : {
- HEAD_TEXT
- } = 0
- .text ALIGN(16) : {
+ _stext = .;
+ .text ALIGN(PAGE_SIZE) : {
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
@@ -68,21 +81,28 @@ SECTIONS
*(.lock.text) /* out-of-line lock text */
*(.gnu.warning)
}
- /* End of text section */
+ . = ALIGN(PAGE_SIZE);
_etext = .;
+ /* End of text section */
/* Start of data section */
_sdata = .;
- RODATA
+ RO_DATA_SECTION(8)
- /* writeable */
- /* Make sure this is page aligned so
- * that we can properly leave these
- * as writable
- */
- . = ALIGN(PAGE_SIZE);
- data_start = .;
+#ifdef CONFIG_64BIT
+ . = ALIGN(16);
+ /* Linkage tables */
+ .opd : {
+ *(.opd)
+ } PROVIDE (__gp = .);
+ .plt : {
+ *(.plt)
+ }
+ .dlt : {
+ *(.dlt)
+ }
+#endif
/* unwind info */
.PARISC.unwind : {
@@ -91,7 +111,15 @@ SECTIONS
__stop___unwind = .;
}
- EXCEPTION_TABLE(16)
+ /* writeable */
+ /* Make sure this is page aligned so
+ * that we can properly leave these
+ * as writable
+ */
+ . = ALIGN(PAGE_SIZE);
+ data_start = .;
+
+ EXCEPTION_TABLE(8)
NOTES
/* Data */
@@ -107,54 +135,8 @@ SECTIONS
_edata = .;
/* BSS */
- __bss_start = .;
- /* page table entries need to be PAGE_SIZE aligned */
- . = ALIGN(PAGE_SIZE);
- .data..vmpages : {
- *(.data..vm0.pmd)
- *(.data..vm0.pgd)
- *(.data..vm0.pte)
- }
- .bss : {
- *(.bss)
- *(COMMON)
- }
- __bss_stop = .;
-
-#ifdef CONFIG_64BIT
- . = ALIGN(16);
- /* Linkage tables */
- .opd : {
- *(.opd)
- } PROVIDE (__gp = .);
- .plt : {
- *(.plt)
- }
- .dlt : {
- *(.dlt)
- }
-#endif
+ BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 8)
- /* reserve space for interrupt stack by aligning __init* to 16k */
- . = ALIGN(16384);
- __init_begin = .;
- INIT_TEXT_SECTION(16384)
- . = ALIGN(PAGE_SIZE);
- INIT_DATA_SECTION(16)
- /* we have to discard exit text and such at runtime, not link time */
- .exit.text :
- {
- EXIT_TEXT
- }
- .exit.data :
- {
- EXIT_DATA
- }
-
- PERCPU_SECTION(L1_CACHE_BYTES)
- . = ALIGN(PAGE_SIZE);
- __init_end = .;
- /* freed after init ends here */
_end = . ;
STABS_DEBUG
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