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Commit f074e48e authored by Mike Frysinger's avatar Mike Frysinger
Browse files

Blackfin: drop unused bad_page pages and move zero_page to the bss 



The empty_bad_page/empty_bad_page_table pages are unused, so punt them.
The zero_page is always allocated, so push it out to the bss to speed up
the booting process a bit and pack data nicer.

Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
parent 7a9b1492

arch/blackfin/include/asm/pgtable.h

+2 −1
Original line number Diff line number Diff line
@@ -80,7 +80,8 @@ PTE_BIT_FUNC(mkyoung, |= _PAGE_ACCESSED); 
 * ZERO_PAGE is a global shared page that is always zero: used

 * for zero-mapped memory areas etc..

 */

#define ZERO_PAGE(vaddr)	(virt_to_page(0))

#define ZERO_PAGE(vaddr)	virt_to_page(empty_zero_page)

extern char empty_zero_page[];



extern unsigned int kobjsize(const void *objp);

arch/blackfin/mm/init.c

+4 −25
Original line number Diff line number Diff line
@@ -15,23 +15,11 @@ 
#include "blackfin_sram.h"



/*

 * BAD_PAGE is the page that is used for page faults when linux

 * is out-of-memory. Older versions of linux just did a

 * do_exit(), but using this instead means there is less risk

 * for a process dying in kernel mode, possibly leaving a inode

 * unused etc..

 *

 * BAD_PAGETABLE is the accompanying page-table: it is initialized

 * to point to BAD_PAGE entries.

 *

 * ZERO_PAGE is a special page that is used for zero-initialized

 * data and COW.

 * ZERO_PAGE is a special page that is used for zero-initialized data and COW.

 * Let the bss do its zero-init magic so we don't have to do it ourselves.

 */

static unsigned long empty_bad_page_table;



static unsigned long empty_bad_page;



static unsigned long empty_zero_page;

char empty_zero_page[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));

EXPORT_SYMBOL(empty_zero_page);



#ifndef CONFIG_EXCEPTION_L1_SCRATCH

#if defined CONFIG_SYSCALL_TAB_L1
@@ -59,15 +47,6 @@ void __init paging_init(void) 


	pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);



	/*

	 * initialize the bad page table and bad page to point

	 * to a couple of allocated pages

	 */

	empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);

	empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);

	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);

	memset((void *)empty_zero_page, 0, PAGE_SIZE);



	/*

	 * Set up SFC/DFC registers (user data space)

	 */