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From:   Joerg Roedel <joro@8bytes.org>
To:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>
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Subject: [PATCH 20/35] x86/pgtable: Move two more functions from pgtable_64.h to pgtable.h
Date:   Mon, 16 Apr 2018 17:25:08 +0200
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From: Joerg Roedel <jroedel@suse.de>

These two functions are required for PTI on 32 bit:

	* pgdp_maps_userspace()
	* pgd_large()

Also re-implement pgdp_maps_userspace() so that it will work
on 64 and 32 bit kernels.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/include/asm/pgtable-2level_types.h |  3 +++
 arch/x86/include/asm/pgtable-3level_types.h |  1 +
 arch/x86/include/asm/pgtable.h              | 15 +++++++++++++++
 arch/x86/include/asm/pgtable_32.h           |  2 --
 arch/x86/include/asm/pgtable_64.h           | 15 ---------------
 arch/x86/include/asm/pgtable_64_types.h     |  2 ++
 6 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/pgtable-2level_types.h b/arch/x86/include/asm/pgtable-2level_types.h
index f982ef8..6deb6cd 100644
--- a/arch/x86/include/asm/pgtable-2level_types.h
+++ b/arch/x86/include/asm/pgtable-2level_types.h
@@ -35,4 +35,7 @@ typedef union {
 
 #define PTRS_PER_PTE	1024
 
+/* This covers all VMSPLIT_* and VMSPLIT_*_OPT variants */
+#define PGD_KERNEL_START	(CONFIG_PAGE_OFFSET >> PGDIR_SHIFT)
+
 #endif /* _ASM_X86_PGTABLE_2LEVEL_DEFS_H */
diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h
index 78038e0..858358a 100644
--- a/arch/x86/include/asm/pgtable-3level_types.h
+++ b/arch/x86/include/asm/pgtable-3level_types.h
@@ -46,5 +46,6 @@ typedef union {
 #define PTRS_PER_PTE	512
 
 #define MAX_POSSIBLE_PHYSMEM_BITS	36
+#define PGD_KERNEL_START	(CONFIG_PAGE_OFFSET >> PGDIR_SHIFT)
 
 #endif /* _ASM_X86_PGTABLE_3LEVEL_DEFS_H */
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 557ddf8..55c236e 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1172,6 +1172,21 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 	}
 }
 #endif
+/*
+ * Page table pages are page-aligned.  The lower half of the top
+ * level is used for userspace and the top half for the kernel.
+ *
+ * Returns true for parts of the PGD that map userspace and
+ * false for the parts that map the kernel.
+ */
+static inline bool pgdp_maps_userspace(void *__ptr)
+{
+	unsigned long ptr = (unsigned long)__ptr;
+
+	return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START);
+}
+
+static inline int pgd_large(pgd_t pgd) { return 0; }
 
 #ifdef CONFIG_PAGE_TABLE_ISOLATION
 /*
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index 88a056b..b3ec519 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -34,8 +34,6 @@ static inline void check_pgt_cache(void) { }
 void paging_init(void);
 void sync_initial_page_table(void);
 
-static inline int pgd_large(pgd_t pgd) { return 0; }
-
 /*
  * Define this if things work differently on an i386 and an i486:
  * it will (on an i486) warn about kernel memory accesses that are
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 6dd2eb6..84a5eb0 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -132,20 +132,6 @@ static inline pud_t native_pudp_get_and_clear(pud_t *xp)
 #endif
 }
 
-/*
- * Page table pages are page-aligned.  The lower half of the top
- * level is used for userspace and the top half for the kernel.
- *
- * Returns true for parts of the PGD that map userspace and
- * false for the parts that map the kernel.
- */
-static inline bool pgdp_maps_userspace(void *__ptr)
-{
-	unsigned long ptr = (unsigned long)__ptr;
-
-	return (ptr & ~PAGE_MASK) < (PAGE_SIZE / 2);
-}
-
 static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
 {
 	pgd_t pgd;
@@ -185,7 +171,6 @@ extern void sync_global_pgds(unsigned long start, unsigned long end);
 /*
  * Level 4 access.
  */
-static inline int pgd_large(pgd_t pgd) { return 0; }
 #define mk_kernel_pgd(address) __pgd((address) | _KERNPG_TABLE)
 
 /* PUD - Level3 access */
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index d5c21a3..355b488 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -142,4 +142,6 @@ extern unsigned int ptrs_per_p4d;
 
 #define EARLY_DYNAMIC_PAGE_TABLES	64
 
+#define PGD_KERNEL_START	((PAGE_SIZE / 2) / sizeof(pgd_t))
+
 #endif /* _ASM_X86_PGTABLE_64_DEFS_H */
-- 
2.7.4