Unverified Commit 82a1a1f3 authored by Qinglin Pan's avatar Qinglin Pan Committed by Palmer Dabbelt
Browse files

riscv: mm: support Svnapot in hugetlb page 



Svnapot can be used to support 64KB hugetlb page, so it can become a new
option when using hugetlbfs. Add a basic implementation of hugetlb page,
and support 64KB as a size in it by using Svnapot.

For test, boot kernel with command line contains "default_hugepagesz=64K
hugepagesz=64K hugepages=20" and run a simple test like this:

tools/testing/selftests/vm/map_hugetlb 1 16

And it should be passed.

Signed-off-by: default avatarQinglin Pan <panqinglin00@gmail.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230209131647.17245-3-panqinglin00@gmail.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 23ad288a

arch/riscv/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ config RISCV 
	select ARCH_USE_QUEUED_RWLOCKS

	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU

	select ARCH_WANT_FRAME_POINTERS

	select ARCH_WANT_GENERAL_HUGETLB

	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT

	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT

	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE

	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU

arch/riscv/include/asm/hugetlb.h

+33 −1
Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
#ifndef _ASM_RISCV_HUGETLB_H

#define _ASM_RISCV_HUGETLB_H



#include <asm-generic/hugetlb.h>

#include <asm/page.h>



static inline void arch_clear_hugepage_flags(struct page *page)
@@ -11,4 +10,37 @@ static inline void arch_clear_hugepage_flags(struct page *page) 
}

#define arch_clear_hugepage_flags arch_clear_hugepage_flags



#ifdef CONFIG_RISCV_ISA_SVNAPOT

#define __HAVE_ARCH_HUGE_PTE_CLEAR

void huge_pte_clear(struct mm_struct *mm, unsigned long addr,

		    pte_t *ptep, unsigned long sz);



#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT

void set_huge_pte_at(struct mm_struct *mm,

		     unsigned long addr, pte_t *ptep, pte_t pte);



#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR

pte_t huge_ptep_get_and_clear(struct mm_struct *mm,

			      unsigned long addr, pte_t *ptep);



#define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH

pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,

			    unsigned long addr, pte_t *ptep);



#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT

void huge_ptep_set_wrprotect(struct mm_struct *mm,

			     unsigned long addr, pte_t *ptep);



#define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS

int huge_ptep_set_access_flags(struct vm_area_struct *vma,

			       unsigned long addr, pte_t *ptep,

			       pte_t pte, int dirty);



pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);

#define arch_make_huge_pte arch_make_huge_pte



#endif /*CONFIG_RISCV_ISA_SVNAPOT*/



#include <asm-generic/hugetlb.h>



#endif /* _ASM_RISCV_HUGETLB_H */

arch/riscv/mm/hugetlbpage.c

+301 −0
Original line number Diff line number Diff line
@@ -2,6 +2,305 @@ 
#include <linux/hugetlb.h>

#include <linux/err.h>



#ifdef CONFIG_RISCV_ISA_SVNAPOT

pte_t *huge_pte_alloc(struct mm_struct *mm,

		      struct vm_area_struct *vma,

		      unsigned long addr,

		      unsigned long sz)

{

	unsigned long order;

	pte_t *pte = NULL;

	pgd_t *pgd;

	p4d_t *p4d;

	pud_t *pud;

	pmd_t *pmd;



	pgd = pgd_offset(mm, addr);

	p4d = p4d_alloc(mm, pgd, addr);

	if (!p4d)

		return NULL;



	pud = pud_alloc(mm, p4d, addr);

	if (!pud)

		return NULL;



	if (sz == PUD_SIZE) {

		pte = (pte_t *)pud;

		goto out;

	}



	if (sz == PMD_SIZE) {

		if (want_pmd_share(vma, addr) && pud_none(*pud))

			pte = huge_pmd_share(mm, vma, addr, pud);

		else

			pte = (pte_t *)pmd_alloc(mm, pud, addr);

		goto out;

	}



	pmd = pmd_alloc(mm, pud, addr);

	if (!pmd)

		return NULL;



	for_each_napot_order(order) {

		if (napot_cont_size(order) == sz) {

			pte = pte_alloc_map(mm, pmd, addr & napot_cont_mask(order));

			break;

		}

	}



out:

	WARN_ON_ONCE(pte && pte_present(*pte) && !pte_huge(*pte));

	return pte;

}



pte_t *huge_pte_offset(struct mm_struct *mm,

		       unsigned long addr,

		       unsigned long sz)

{

	unsigned long order;

	pte_t *pte = NULL;

	pgd_t *pgd;

	p4d_t *p4d;

	pud_t *pud;

	pmd_t *pmd;



	pgd = pgd_offset(mm, addr);

	if (!pgd_present(*pgd))

		return NULL;



	p4d = p4d_offset(pgd, addr);

	if (!p4d_present(*p4d))

		return NULL;



	pud = pud_offset(p4d, addr);

	if (sz == PUD_SIZE)

		/* must be pud huge, non-present or none */

		return (pte_t *)pud;



	if (!pud_present(*pud))

		return NULL;



	pmd = pmd_offset(pud, addr);

	if (sz == PMD_SIZE)

		/* must be pmd huge, non-present or none */

		return (pte_t *)pmd;



	if (!pmd_present(*pmd))

		return NULL;



	for_each_napot_order(order) {

		if (napot_cont_size(order) == sz) {

			pte = pte_offset_kernel(pmd, addr & napot_cont_mask(order));

			break;

		}

	}

	return pte;

}



static pte_t get_clear_contig(struct mm_struct *mm,

			      unsigned long addr,

			      pte_t *ptep,

			      unsigned long pte_num)

{

	pte_t orig_pte = ptep_get(ptep);

	unsigned long i;



	for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) {

		pte_t pte = ptep_get_and_clear(mm, addr, ptep);



		if (pte_dirty(pte))

			orig_pte = pte_mkdirty(orig_pte);



		if (pte_young(pte))

			orig_pte = pte_mkyoung(orig_pte);

	}



	return orig_pte;

}



static pte_t get_clear_contig_flush(struct mm_struct *mm,

				    unsigned long addr,

				    pte_t *ptep,

				    unsigned long pte_num)

{

	pte_t orig_pte = get_clear_contig(mm, addr, ptep, pte_num);

	struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);

	bool valid = !pte_none(orig_pte);



	if (valid)

		flush_tlb_range(&vma, addr, addr + (PAGE_SIZE * pte_num));



	return orig_pte;

}



pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)

{

	unsigned long order;



	for_each_napot_order(order) {

		if (shift == napot_cont_shift(order)) {

			entry = pte_mknapot(entry, order);

			break;

		}

	}

	if (order == NAPOT_ORDER_MAX)

		entry = pte_mkhuge(entry);



	return entry;

}



void set_huge_pte_at(struct mm_struct *mm,

		     unsigned long addr,

		     pte_t *ptep,

		     pte_t pte)

{

	int i, pte_num;



	if (!pte_napot(pte)) {

		set_pte_at(mm, addr, ptep, pte);

		return;

	}



	pte_num = napot_pte_num(napot_cont_order(pte));

	for (i = 0; i < pte_num; i++, ptep++, addr += PAGE_SIZE)

		set_pte_at(mm, addr, ptep, pte);

}



int huge_ptep_set_access_flags(struct vm_area_struct *vma,

			       unsigned long addr,

			       pte_t *ptep,

			       pte_t pte,

			       int dirty)

{

	struct mm_struct *mm = vma->vm_mm;

	unsigned long order;

	pte_t orig_pte;

	int i, pte_num;



	if (!pte_napot(pte))

		return ptep_set_access_flags(vma, addr, ptep, pte, dirty);



	order = napot_cont_order(pte);

	pte_num = napot_pte_num(order);

	ptep = huge_pte_offset(mm, addr, napot_cont_size(order));

	orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);



	if (pte_dirty(orig_pte))

		pte = pte_mkdirty(pte);



	if (pte_young(orig_pte))

		pte = pte_mkyoung(pte);



	for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)

		set_pte_at(mm, addr, ptep, pte);



	return true;

}



pte_t huge_ptep_get_and_clear(struct mm_struct *mm,

			      unsigned long addr,

			      pte_t *ptep)

{

	pte_t orig_pte = ptep_get(ptep);

	int pte_num;



	if (!pte_napot(orig_pte))

		return ptep_get_and_clear(mm, addr, ptep);



	pte_num = napot_pte_num(napot_cont_order(orig_pte));



	return get_clear_contig(mm, addr, ptep, pte_num);

}



void huge_ptep_set_wrprotect(struct mm_struct *mm,

			     unsigned long addr,

			     pte_t *ptep)

{

	pte_t pte = ptep_get(ptep);

	unsigned long order;

	int i, pte_num;



	if (!pte_napot(pte)) {

		ptep_set_wrprotect(mm, addr, ptep);

		return;

	}



	order = napot_cont_order(pte);

	pte_num = napot_pte_num(order);

	ptep = huge_pte_offset(mm, addr, napot_cont_size(order));



	for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)

		ptep_set_wrprotect(mm, addr, ptep);

}



pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,

			    unsigned long addr,

			    pte_t *ptep)

{

	pte_t pte = ptep_get(ptep);

	int pte_num;



	if (!pte_napot(pte))

		return ptep_clear_flush(vma, addr, ptep);



	pte_num = napot_pte_num(napot_cont_order(pte));



	return get_clear_contig_flush(vma->vm_mm, addr, ptep, pte_num);

}



void huge_pte_clear(struct mm_struct *mm,

		    unsigned long addr,

		    pte_t *ptep,

		    unsigned long sz)

{

	pte_t pte = READ_ONCE(*ptep);

	int i, pte_num;



	if (!pte_napot(pte)) {

		pte_clear(mm, addr, ptep);

		return;

	}



	pte_num = napot_pte_num(napot_cont_order(pte));

	for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)

		pte_clear(mm, addr, ptep);

}



static __init bool is_napot_size(unsigned long size)

{

	unsigned long order;



	if (!has_svnapot())

		return false;



	for_each_napot_order(order) {

		if (size == napot_cont_size(order))

			return true;

	}

	return false;

}



static __init int napot_hugetlbpages_init(void)

{

	if (has_svnapot()) {

		unsigned long order;



		for_each_napot_order(order)

			hugetlb_add_hstate(order);

	}

	return 0;

}

arch_initcall(napot_hugetlbpages_init);



#else



static __init bool is_napot_size(unsigned long size)

{

	return false;

}



#endif /*CONFIG_RISCV_ISA_SVNAPOT*/



int pud_huge(pud_t pud)

{

	return pud_leaf(pud);
@@ -18,6 +317,8 @@ bool __init arch_hugetlb_valid_size(unsigned long size) 
		return true;

	else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)

		return true;

	else if (is_napot_size(size))

		return true;

	else

		return false;

}