Commit 200036a8 authored by Helge Deller's avatar Helge Deller
Browse files

parisc: Allow building 64-bit kernel without -mlong-calls compiler option 



A 64-bit kernel built without CONFIG_MLONGCALLS (-mlong-calls compiler
option) usually fails to link because of unreachable functions.  Try to
work around that linking issue by moving the *.init and *.exit text
segments closer to the main text segment. With that change those
segments now don't get freed at runtime any longer, but since we in most
cases run with huge-page enabled, we ignore the lost memory in
preference of better performance.

This change will not guarantee that every kernel config will now
sucessfully build with short calls and without linking issues.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 7a95aab5

arch/parisc/Kconfig

+2 −1
Original line number Diff line number Diff line
@@ -194,7 +194,8 @@ config PREFETCH 


config MLONGCALLS

	bool "Enable the -mlong-calls compiler option for big kernels"

	default y

	default y if !MODULES || UBSAN || FTRACE

	default n

	depends on PA8X00

	help

	  If you configure the kernel to include many drivers built-in instead

arch/parisc/kernel/vmlinux.lds.S

+14 −7
Original line number Diff line number Diff line
@@ -35,6 +35,15 @@ OUTPUT_FORMAT("elf64-hppa-linux") 
OUTPUT_ARCH(hppa:hppa2.0w)

#endif



#define EXIT_TEXT_SECTIONS()	.exit.text : { EXIT_TEXT }

#if !defined(CONFIG_64BIT) || defined(CONFIG_MLONGCALLS)

#define MLONGCALL_KEEP(x)

#define MLONGCALL_DISCARD(x)	x

#else

#define MLONGCALL_KEEP(x)	x

#define MLONGCALL_DISCARD(x)

#endif



ENTRY(parisc_kernel_start)

#ifndef CONFIG_64BIT

jiffies = jiffies_64 + 4;
@@ -47,15 +56,11 @@ SECTIONS 


	__init_begin = .;

	HEAD_TEXT_SECTION

	INIT_TEXT_SECTION(8)

	MLONGCALL_DISCARD(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

	}

	MLONGCALL_DISCARD(EXIT_TEXT_SECTIONS())

	.exit.data :

	{

		EXIT_DATA
@@ -73,11 +78,12 @@ SECTIONS 


	_text = .;		/* Text and read-only data */

	_stext = .;

	MLONGCALL_KEEP(INIT_TEXT_SECTION(8))

	.text ALIGN(PAGE_SIZE) : {

		TEXT_TEXT

		LOCK_TEXT

		SCHED_TEXT

		CPUIDLE_TEXT

		LOCK_TEXT

		KPROBES_TEXT

		IRQENTRY_TEXT

		SOFTIRQENTRY_TEXT
@@ -92,6 +98,7 @@ SECTIONS 
		*(.lock.text)		/* out-of-line lock text */

		*(.gnu.warning)

	}

	MLONGCALL_KEEP(EXIT_TEXT_SECTIONS())

	. = ALIGN(PAGE_SIZE);

	_etext = .;

	/* End of text section */

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