x86, um: ... and asm-x86 move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 175 insertions, 0 deletions

diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
new file mode 100644
index 000000000000..75f4276b5ddb
--- /dev/null
+++ b/arch/x86/include/asm/pgtable-3level.h
@@ -0,0 +1,175 @@
+#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)							\
+	printk("%s:%d: bad pte %p(%08lx%08lx).\n",			\
+	       __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)
+#define pmd_ERROR(e)							\
+	printk("%s:%d: bad pmd %p(%016Lx).\n",				\
+	       __FILE__, __LINE__, &(e), pmd_val(e))
+#define pgd_ERROR(e)							\
+	printk("%s:%d: bad pgd %p(%016Lx).\n",				\
+	       __FILE__, __LINE__, &(e), pgd_val(e))
+
+static inline int pud_none(pud_t pud)
+{
+	return pud_val(pud) == 0;
+}
+
+static inline int pud_bad(pud_t pud)
+{
+	return (pud_val(pud) & ~(PTE_PFN_MASK | _KERNPG_TABLE | _PAGE_USER)) != 0;
+}
+
+static inline int pud_present(pud_t pud)
+{
+	return pud_val(pud) & _PAGE_PRESENT;
+}
+
+/* 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;
+}
+
+/*
+ * Since this is only called on user PTEs, and the page fault handler
+ * must handle the already racy situation of simultaneous page faults,
+ * we are justified in merely clearing the PTE present bit, followed
+ * by a set.  The ordering here is important.
+ */
+static inline void native_set_pte_present(struct mm_struct *mm,
+					  unsigned long addr,
+					  pte_t *ptep, pte_t pte)
+{
+	ptep->pte_low = 0;
+	smp_wmb();
+	ptep->pte_high = pte.pte_high;
+	smp_wmb();
+	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)
+{
+	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)
+{
+	unsigned long pgd;
+
+	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...
+	 *
+	 * Make sure the pud entry we're updating is within the
+	 * current pgd to avoid unnecessary TLB flushes.
+	 */
+	pgd = read_cr3();
+	if (__pa(pudp) >= pgd && __pa(pudp) <
+	    (pgd + sizeof(pgd_t)*PTRS_PER_PGD))
+		write_cr3(pgd);
+}
+
+#define pud_page(pud) ((struct page *) __va(pud_val(pud) & PTE_PFN_MASK))
+
+#define pud_page_vaddr(pud) ((unsigned long) __va(pud_val(pud) & PTE_PFN_MASK))
+
+
+/* Find an entry in the second-level page table.. */
+#define pmd_offset(pud, address) ((pmd_t *)pud_page(*(pud)) +	\
+				  pmd_index(address))
+
+#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
+
+#define __HAVE_ARCH_PTE_SAME
+static inline int pte_same(pte_t a, pte_t b)
+{
+	return a.pte_low == b.pte_low && a.pte_high == b.pte_high;
+}
+
+static inline int pte_none(pte_t pte)
+{
+	return !pte.pte_low && !pte.pte_high;
+}
+
+/*
+ * Bits 0, 6 and 7 are taken in the low part of the pte,
+ * put the 32 bits of offset into the high part.
+ */
+#define pte_to_pgoff(pte) ((pte).pte_high)
+#define pgoff_to_pte(off)						\
+	((pte_t) { { .pte_low = _PAGE_FILE, .pte_high = (off) } })
+#define PTE_FILE_MAX_BITS       32
+
+/* Encode and de-code a swap entry */
+#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 */