Commit dce6098b authored by Huacai Chen's avatar Huacai Chen
Browse files

LoongArch: Add vDSO syscall __vdso_getcpu() 



We test 20 million times of getcpu(), the real syscall version take 25
seconds, while the vsyscall version take only 2.4 seconds.

Signed-off-by: default avatarRui Wang <wangrui@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 57fc7323

arch/loongarch/include/asm/vdso.h

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#ifndef __ASM_VDSO_H

#define __ASM_VDSO_H



#include <linux/mm.h>

#include <linux/mm_types.h>

#include <vdso/datapage.h>

arch/loongarch/include/asm/vdso/vdso.h

+14 −1
Original line number Diff line number Diff line
@@ -8,6 +8,18 @@ 


#include <asm/asm.h>

#include <asm/page.h>

#include <asm/vdso.h>



struct vdso_pcpu_data {

	u32 node;

} ____cacheline_aligned_in_smp;



struct loongarch_vdso_data {

	struct vdso_pcpu_data pdata[NR_CPUS];

	struct vdso_data data[CS_BASES]; /* Arch-independent data */

};



#define VDSO_DATA_SIZE PAGE_ALIGN(sizeof(struct loongarch_vdso_data))



static inline unsigned long get_vdso_base(void)

{
@@ -24,7 +36,8 @@ static inline unsigned long get_vdso_base(void) 


static inline const struct vdso_data *get_vdso_data(void)

{

	return (const struct vdso_data *)(get_vdso_base() - PAGE_SIZE);

	return (const struct vdso_data *)(get_vdso_base()

			- VDSO_DATA_SIZE + SMP_CACHE_BYTES * NR_CPUS);

}



#endif /* __ASSEMBLY__ */

arch/loongarch/kernel/vdso.c

+15 −10
Original line number Diff line number Diff line
@@ -25,12 +25,14 @@ 
extern char vdso_start[], vdso_end[];



/* Kernel-provided data used by the VDSO. */

static union loongarch_vdso_data {

	u8 page[PAGE_SIZE];

	struct vdso_data data[CS_BASES];

static union {

	u8 page[VDSO_DATA_SIZE];

	struct loongarch_vdso_data vdata;

} loongarch_vdso_data __page_aligned_data;

struct vdso_data *vdso_data = loongarch_vdso_data.data;



static struct page *vdso_pages[] = { NULL };

struct vdso_data *vdso_data = loongarch_vdso_data.vdata.data;

struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;



static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)

{
@@ -55,11 +57,14 @@ struct loongarch_vdso_info vdso_info = { 


static int __init init_vdso(void)

{

	unsigned long i, pfn;

	unsigned long i, cpu, pfn;



	BUG_ON(!PAGE_ALIGNED(vdso_info.vdso));

	BUG_ON(!PAGE_ALIGNED(vdso_info.size));



	for_each_possible_cpu(cpu)

		vdso_pdata[cpu].node = cpu_to_node(cpu);



	pfn = __phys_to_pfn(__pa_symbol(vdso_info.vdso));

	for (i = 0; i < vdso_info.size / PAGE_SIZE; i++)

		vdso_info.code_mapping.pages[i] = pfn_to_page(pfn + i);
@@ -93,9 +98,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 


	/*

	 * Determine total area size. This includes the VDSO data itself

	 * and the data page.

	 * and the data pages.

	 */

	vvar_size = PAGE_SIZE;

	vvar_size = VDSO_DATA_SIZE;

	size = vvar_size + info->size;



	data_addr = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
@@ -103,7 +108,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
		ret = data_addr;

		goto out;

	}

	vdso_addr = data_addr + PAGE_SIZE;

	vdso_addr = data_addr + VDSO_DATA_SIZE;



	vma = _install_special_mapping(mm, data_addr, vvar_size,

				       VM_READ | VM_MAYREAD,
@@ -115,8 +120,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 


	/* Map VDSO data page. */

	ret = remap_pfn_range(vma, data_addr,

			      virt_to_phys(vdso_data) >> PAGE_SHIFT,

			      PAGE_SIZE, PAGE_READONLY);

			      virt_to_phys(&loongarch_vdso_data) >> PAGE_SHIFT,

			      vvar_size, PAGE_READONLY);

	if (ret)

		goto out;

arch/loongarch/vdso/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
ARCH_REL_TYPE_ABS := R_LARCH_32|R_LARCH_64|R_LARCH_MARK_LA|R_LARCH_JUMP_SLOT

include $(srctree)/lib/vdso/Makefile



obj-vdso-y := elf.o vgettimeofday.o sigreturn.o

obj-vdso-y := elf.o vgetcpu.o vgettimeofday.o sigreturn.o



# Common compiler flags between ABIs.

ccflags-vdso := \

arch/loongarch/vdso/vdso.lds.S

+1 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ VERSION 
{

	LINUX_5.10 {

	global:

		__vdso_getcpu;

		__vdso_clock_getres;

		__vdso_clock_gettime;

		__vdso_gettimeofday;