[PATCH v2 15/34] x86: Convert various functions to use ptdescs

Vishal Moola (Oracle)
2023-05-01T19:29:59Z

In order to split struct ptdesc from struct page, convert various
functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use ptdesc_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
arch/x86/mm/pgtable.c | 46 +++++++++++++++++++++++++------------------
1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index afab0bc7862b..9b6f81c8eb32 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -52,7 +52,7 @@ early_param("userpte", setup_userpte);

void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
{
- pgtable_pte_page_dtor(pte);
+ ptdesc_pte_dtor(page_ptdesc(pte));
paravirt_release_pte(page_to_pfn(pte));
paravirt_tlb_remove_table(tlb, pte);
}
@@ -60,7 +60,7 @@ void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
#if CONFIG_PGTABLE_LEVELS > 2
void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
{
- struct page *page = virt_to_page(pmd);
+ struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT);
/*
* NOTE! For PAE, any changes to the top page-directory-pointer-table
@@ -69,8 +69,8 @@ void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
#ifdef CONFIG_X86_PAE
tlb->need_flush_all = 1;
#endif
- pgtable_pmd_page_dtor(page);
- paravirt_tlb_remove_table(tlb, page);
+ ptdesc_pmd_dtor(ptdesc);
+ paravirt_tlb_remove_table(tlb, ptdesc_page(ptdesc));
}

#if CONFIG_PGTABLE_LEVELS > 3
@@ -92,16 +92,16 @@ void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d)

static inline void pgd_list_add(pgd_t *pgd)
{
- struct page *page = virt_to_page(pgd);
+ struct ptdesc *ptdesc = virt_to_ptdesc(pgd);

- list_add(&page->lru, &pgd_list);
+ list_add(&ptdesc->pt_list, &pgd_list);
}

static inline void pgd_list_del(pgd_t *pgd)
{
- struct page *page = virt_to_page(pgd);
+ struct ptdesc *ptdesc = virt_to_ptdesc(pgd);

- list_del(&page->lru);
+ list_del(&ptdesc->pt_list);
}

#define UNSHARED_PTRS_PER_PGD \
@@ -112,12 +112,12 @@ static inline void pgd_list_del(pgd_t *pgd)

static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
{
- virt_to_page(pgd)->pt_mm = mm;
+ virt_to_ptdesc(pgd)->pt_mm = mm;
}

struct mm_struct *pgd_page_get_mm(struct page *page)
{
- return page->pt_mm;
+ return page_ptdesc(page)->pt_mm;
}

static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
@@ -213,11 +213,14 @@ void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd)
static void free_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
{
int i;
+ struct ptdesc *ptdesc;

for (i = 0; i < count; i++)
if (pmds[i]) {
- pgtable_pmd_page_dtor(virt_to_page(pmds[i]));
- free_page((unsigned long)pmds[i]);
+ ptdesc = virt_to_ptdesc(pmds[i]);
+
+ ptdesc_pmd_dtor(ptdesc);
+ ptdesc_free(ptdesc);
mm_dec_nr_pmds(mm);
}
}
@@ -232,16 +235,21 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
gfp &= ~__GFP_ACCOUNT;

for (i = 0; i < count; i++) {
- pmd_t *pmd = (pmd_t *)__get_free_page(gfp);
- if (!pmd)
+ pmd_t *pmd = NULL;
+ struct ptdesc *ptdesc = ptdesc_alloc(gfp, 0);
+
+ if (!ptdesc)
failed = true;
- if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {
- free_page((unsigned long)pmd);
- pmd = NULL;
+ if (ptdesc && !ptdesc_pmd_ctor(ptdesc)) {
+ ptdesc_free(ptdesc);
+ ptdesc = NULL;
failed = true;
}
- if (pmd)
+ if (ptdesc) {
mm_inc_nr_pmds(mm);
+ pmd = (pmd_t *)ptdesc_address(ptdesc);
+ }
+
pmds[i] = pmd;
}

@@ -838,7 +846,7 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr)

free_page((unsigned long)pmd_sv);

- pgtable_pmd_page_dtor(virt_to_page(pmd));
+ ptdesc_pmd_dtor(virt_to_ptdesc(pmd));
free_page((unsigned long)pmd);

return 1;
--
2.39.2