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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PGTABLE_3LEVEL_H
#define _ASM_X86_PGTABLE_3LEVEL_H
/*
* Intel Physical Address Extension (PAE) Mode - three-level page
* tables on PPro+ CPUs.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*/
#define pte_ERROR(e) \
pr_err("%s:%d: bad pte %p(%08lx%08lx)\n", \
__FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)
#define pmd_ERROR(e) \
pr_err("%s:%d: bad pmd %p(%016Lx)\n", \
__FILE__, __LINE__, &(e), pmd_val(e))
#define pgd_ERROR(e) \
pr_err("%s:%d: bad pgd %p(%016Lx)\n", \
__FILE__, __LINE__, &(e), pgd_val(e))
/* Rules for using set_pte: the pte being assigned *must* be
* either not present or in a state where the hardware will
* not attempt to update the pte. In places where this is
* not possible, use pte_get_and_clear to obtain the old pte
* value and then use set_pte to update it. -ben
*/
static inline void native_set_pte(pte_t *ptep, pte_t pte)
{
WRITE_ONCE(ptep->pte_high, pte.pte_high);
smp_wmb();
WRITE_ONCE(ptep->pte_low, pte.pte_low);
}
static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
{
set_64bit((unsigned long long *)(ptep), native_pte_val(pte));
}
static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
{
set_64bit((unsigned long long *)(pmdp), native_pmd_val(pmd));
}
static inline void native_set_pud(pud_t *pudp, pud_t pud)
{
#ifdef CONFIG_PAGE_TABLE_ISOLATION
pud.p4d.pgd = pti_set_user_pgtbl(&pudp->p4d.pgd, pud.p4d.pgd);
#endif
set_64bit((unsigned long long *)(pudp), native_pud_val(pud));
}
/*
* For PTEs and PDEs, we must clear the P-bit first when clearing a page table
* entry, so clear the bottom half first and enforce ordering with a compiler
* barrier.
*/
static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
WRITE_ONCE(ptep->pte_low, 0);
smp_wmb();
WRITE_ONCE(ptep->pte_high, 0);
}
static inline void native_pmd_clear(pmd_t *pmdp)
{
WRITE_ONCE(pmdp->pmd_low, 0);
smp_wmb();
WRITE_ONCE(pmdp->pmd_high, 0);
}
static inline void native_pud_clear(pud_t *pudp)
{
}
static inline void pud_clear(pud_t *pudp)
{
set_pud(pudp, __pud(0));
/*
* According to Intel App note "TLBs, Paging-Structure Caches,
* and Their Invalidation", April 2007, document 317080-001,
* section 8.1: in PAE mode we explicitly have to flush the
* TLB via cr3 if the top-level pgd is changed...
*
* Currently all places where pud_clear() is called either have
* flush_tlb_mm() followed or don't need TLB flush (x86_64 code or
* pud_clear_bad()), so we don't need TLB flush here.
*/
}
#ifdef CONFIG_SMP
static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
{
pte_t old = *ptep;
do {
} while (!try_cmpxchg64(&ptep->pte, &old.pte, 0ULL));
return old;
}
#else
#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
#endif
#ifdef CONFIG_SMP
static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp)
{
pmd_t res;
/* xchg acts as a barrier before setting of the high bits */
res.pmd_low = xchg(&pmdp->pmd_low, 0);
res.pmd_high = READ_ONCE(pmdp->pmd_high);
WRITE_ONCE(pmdp->pmd_high, 0);
return res;
}
#else
#define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
#endif
#ifndef pmdp_establish
#define pmdp_establish pmdp_establish
static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp, pmd_t pmd)
{
pmd_t old;
/*
* If pmd has present bit cleared we can get away without expensive
* cmpxchg64: we can update pmdp half-by-half without racing with
* anybody.
*/
if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
/* xchg acts as a barrier before setting of the high bits */
old.pmd_low = xchg(&pmdp->pmd_low, pmd.pmd_low);
old.pmd_high = READ_ONCE(pmdp->pmd_high);
WRITE_ONCE(pmdp->pmd_high, pmd.pmd_high);
return old;
}
do {
old = *pmdp;
} while (cmpxchg64(&pmdp->pmd, old.pmd, pmd.pmd) != old.pmd);
return old;
}
#endif
#ifdef CONFIG_SMP
union split_pud {
struct {
u32 pud_low;
u32 pud_high;
};
pud_t pud;
};
static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
{
union split_pud res, *orig = (union split_pud *)pudp;
#ifdef CONFIG_PAGE_TABLE_ISOLATION
pti_set_user_pgtbl(&pudp->p4d.pgd, __pgd(0));
#endif
/* xchg acts as a barrier before setting of the high bits */
res.pud_low = xchg(&orig->pud_low, 0);
res.pud_high = orig->pud_high;
orig->pud_high = 0;
return res.pud;
}
#else
#define native_pudp_get_and_clear(xp) native_local_pudp_get_and_clear(xp)
#endif
/* Encode and de-code a swap entry */
#define SWP_TYPE_BITS 5
#define SWP_OFFSET_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
/* We always extract/encode the offset by shifting it all the way up, and then down again */
#define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT + SWP_TYPE_BITS)
#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
#define __swp_type(x) (((x).val) & ((1UL << SWP_TYPE_BITS) - 1))
#define __swp_offset(x) ((x).val >> SWP_TYPE_BITS)
#define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << SWP_TYPE_BITS})
/*
* Normally, __swp_entry() converts from arch-independent swp_entry_t to
* arch-dependent swp_entry_t, and __swp_entry_to_pte() just stores the result
* to pte. But here we have 32bit swp_entry_t and 64bit pte, and need to use the
* whole 64 bits. Thus, we shift the "real" arch-dependent conversion to
* __swp_entry_to_pte() through the following helper macro based on 64bit
* __swp_entry().
*/
#define __swp_pteval_entry(type, offset) ((pteval_t) { \
(~(pteval_t)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
| ((pteval_t)(type) << (64 - SWP_TYPE_BITS)) })
#define __swp_entry_to_pte(x) ((pte_t){ .pte = \
__swp_pteval_entry(__swp_type(x), __swp_offset(x)) })
/*
* Analogically, __pte_to_swp_entry() doesn't just extract the arch-dependent
* swp_entry_t, but also has to convert it from 64bit to the 32bit
* intermediate representation, using the following macros based on 64bit
* __swp_type() and __swp_offset().
*/
#define __pteval_swp_type(x) ((unsigned long)((x).pte >> (64 - SWP_TYPE_BITS)))
#define __pteval_swp_offset(x) ((unsigned long)(~((x).pte) << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT))
#define __pte_to_swp_entry(pte) (__swp_entry(__pteval_swp_type(pte), \
__pteval_swp_offset(pte)))
#include <asm/pgtable-invert.h>
#endif /* _ASM_X86_PGTABLE_3LEVEL_H */
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