Commit 0921af6c authored by Bibo Mao's avatar Bibo Mao Committed by Huacai Chen
Browse files

LoongArch: Use static defined zero page rather than allocated 



On LoongArch system, there is only one page needed for zero page (no
cache synonyms), and there is no COLOR_ZERO_PAGE, so zero_page_mask is
useless and the macro __HAVE_COLOR_ZERO_PAGE is not necessary.

Like other popular architectures, It is simpler to define the zero page
in kernel BSS code segment rather than dynamically allocate.

Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 2bb20d29

arch/loongarch/include/asm/mmzone.h

+0 −2
Original line number Diff line number Diff line
@@ -13,6 +13,4 @@ extern struct pglist_data *node_data[]; 


#define NODE_DATA(nid)	(node_data[(nid)])



extern void setup_zero_pages(void);



#endif /* _ASM_MMZONE_H_ */

arch/loongarch/include/asm/pgtable.h

+2 −5
Original line number Diff line number Diff line
@@ -70,12 +70,9 @@ struct vm_area_struct; 
 * for zero-mapped memory areas etc..

 */



extern unsigned long empty_zero_page;

extern unsigned long zero_page_mask;

extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];



#define ZERO_PAGE(vaddr) \

	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))

#define __HAVE_COLOR_ZERO_PAGE

#define ZERO_PAGE(vaddr)	virt_to_page(empty_zero_page)



/*

 * TLB refill handlers may also map the vmalloc area into xkvrange.

arch/loongarch/kernel/numa.c

+0 −1
Original line number Diff line number Diff line
@@ -438,7 +438,6 @@ void __init mem_init(void) 
{

	high_memory = (void *) __va(get_num_physpages() << PAGE_SHIFT);

	memblock_free_all();

	setup_zero_pages();	/* This comes from node 0 */

}



int pcibus_to_node(struct pci_bus *bus)

arch/loongarch/mm/init.c

+1 −27
Original line number Diff line number Diff line
@@ -35,33 +35,8 @@ 
#include <asm/pgalloc.h>

#include <asm/tlb.h>



/*

 * We have up to 8 empty zeroed pages so we can map one of the right colour

 * when needed.	 Since page is never written to after the initialization we

 * don't have to care about aliases on other CPUs.

 */

unsigned long empty_zero_page, zero_page_mask;

unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;

EXPORT_SYMBOL(empty_zero_page);

EXPORT_SYMBOL(zero_page_mask);



void setup_zero_pages(void)

{

	unsigned int order, i;

	struct page *page;



	order = 0;



	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);

	if (!empty_zero_page)

		panic("Oh boy, that early out of memory?");



	page = virt_to_page((void *)empty_zero_page);

	split_page(page, order);

	for (i = 0; i < (1 << order); i++, page++)

		mark_page_reserved(page);



	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;

}



void copy_user_highpage(struct page *to, struct page *from,

	unsigned long vaddr, struct vm_area_struct *vma)
@@ -106,7 +81,6 @@ void __init mem_init(void) 
	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);



	memblock_free_all();

	setup_zero_pages();	/* Setup zeroed pages.  */

}

#endif /* !CONFIG_NUMA */