diff options
author | 2015-08-04 12:17:53 -0700 | |
---|---|---|
committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/include/asm/pgtable-3level.h | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/include/asm/pgtable-3level.h')
-rw-r--r-- | kernel/arch/x86/include/asm/pgtable-3level.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/pgtable-3level.h b/kernel/arch/x86/include/asm/pgtable-3level.h new file mode 100644 index 000000000..cdaa58c9b --- /dev/null +++ b/kernel/arch/x86/include/asm/pgtable-3level.h @@ -0,0 +1,187 @@ +#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) +{ + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +#define pmd_read_atomic pmd_read_atomic +/* + * pte_offset_map_lock on 32bit PAE kernels was reading the pmd_t with + * a "*pmdp" dereference done by gcc. Problem is, in certain places + * where pte_offset_map_lock is called, concurrent page faults are + * allowed, if the mmap_sem is hold for reading. An example is mincore + * vs page faults vs MADV_DONTNEED. On the page fault side + * pmd_populate rightfully does a set_64bit, but if we're reading the + * pmd_t with a "*pmdp" on the mincore side, a SMP race can happen + * because gcc will not read the 64bit of the pmd atomically. To fix + * this all places running pmd_offset_map_lock() while holding the + * mmap_sem in read mode, shall read the pmdp pointer using this + * function to know if the pmd is null nor not, and in turn to know if + * they can run pmd_offset_map_lock or pmd_trans_huge or other pmd + * operations. + * + * Without THP if the mmap_sem is hold for reading, the pmd can only + * transition from null to not null while pmd_read_atomic runs. So + * we can always return atomic pmd values with this function. + * + * With THP if the mmap_sem is hold for reading, the pmd can become + * trans_huge or none or point to a pte (and in turn become "stable") + * at any time under pmd_read_atomic. We could read it really + * atomically here with a atomic64_read for the THP enabled case (and + * it would be a whole lot simpler), but to avoid using cmpxchg8b we + * only return an atomic pmdval if the low part of the pmdval is later + * found stable (i.e. pointing to a pte). And we're returning a none + * pmdval if the low part of the pmd is none. In some cases the high + * and low part of the pmdval returned may not be consistent if THP is + * enabled (the low part may point to previously mapped hugepage, + * while the high part may point to a more recently mapped hugepage), + * but pmd_none_or_trans_huge_or_clear_bad() only needs the low part + * of the pmd to be read atomically to decide if the pmd is unstable + * or not, with the only exception of when the low part of the pmd is + * zero in which case we return a none pmd. + */ +static inline pmd_t pmd_read_atomic(pmd_t *pmdp) +{ + pmdval_t ret; + u32 *tmp = (u32 *)pmdp; + + ret = (pmdval_t) (*tmp); + if (ret) { + /* + * If the low part is null, we must not read the high part + * or we can end up with a partial pmd. + */ + smp_rmb(); + ret |= ((pmdval_t)*(tmp + 1)) << 32; + } + + return (pmd_t) { ret }; +} + +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) +{ + 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) +{ + ptep->pte_low = 0; + smp_wmb(); + ptep->pte_high = 0; +} + +static inline void native_pmd_clear(pmd_t *pmd) +{ + u32 *tmp = (u32 *)pmd; + *tmp = 0; + smp_wmb(); + *(tmp + 1) = 0; +} + +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 res; + + /* xchg acts as a barrier before the setting of the high bits */ + res.pte_low = xchg(&ptep->pte_low, 0); + res.pte_high = ptep->pte_high; + ptep->pte_high = 0; + + return res; +} +#else +#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp) +#endif + +#ifdef CONFIG_SMP +union split_pmd { + struct { + u32 pmd_low; + u32 pmd_high; + }; + pmd_t pmd; +}; +static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp) +{ + union split_pmd res, *orig = (union split_pmd *)pmdp; + + /* xchg acts as a barrier before setting of the high bits */ + res.pmd_low = xchg(&orig->pmd_low, 0); + res.pmd_high = orig->pmd_high; + orig->pmd_high = 0; + + return res.pmd; +} +#else +#define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp) +#endif + +/* Encode and de-code a swap entry */ +#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5) +#define __swp_type(x) (((x).val) & 0x1f) +#define __swp_offset(x) ((x).val >> 5) +#define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << 5}) +#define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high }) +#define __swp_entry_to_pte(x) ((pte_t){ { .pte_high = (x).val } }) + +#endif /* _ASM_X86_PGTABLE_3LEVEL_H */ |