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Subject[patch V2 01/16] x86/tlb: Uninline __get_current_cr3_fast()
cpu_tlbstate is exported because various TLB related functions need access
to it, but cpu_tlbstate is sensitive information which should only be
accessed by well contained kernel functions and not be directly exposed to
modules.

In preparation of unexporting cpu_tlbstate move __get_current_cr3_fast()
into the x86 TLB management code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/include/asm/mmu_context.h | 19 +------------------
arch/x86/mm/tlb.c | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+), 18 deletions(-)

--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -225,24 +225,7 @@ static inline bool arch_vma_access_permi
return __pkru_allows_pkey(vma_pkey(vma), write);
}

-/*
- * This can be used from process context to figure out what the value of
- * CR3 is without needing to do a (slow) __read_cr3().
- *
- * It's intended to be used for code like KVM that sneakily changes CR3
- * and needs to restore it. It needs to be used very carefully.
- */
-static inline unsigned long __get_current_cr3_fast(void)
-{
- unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
- this_cpu_read(cpu_tlbstate.loaded_mm_asid));
-
- /* For now, be very restrictive about when this can be called. */
- VM_WARN_ON(in_nmi() || preemptible());
-
- VM_BUG_ON(cr3 != __read_cr3());
- return cr3;
-}
+unsigned long __get_current_cr3_fast(void);

typedef struct {
struct mm_struct *mm;
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -844,6 +844,26 @@ void flush_tlb_kernel_range(unsigned lon
}

/*
+ * This can be used from process context to figure out what the value of
+ * CR3 is without needing to do a (slow) __read_cr3().
+ *
+ * It's intended to be used for code like KVM that sneakily changes CR3
+ * and needs to restore it. It needs to be used very carefully.
+ */
+unsigned long __get_current_cr3_fast(void)
+{
+ unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
+ this_cpu_read(cpu_tlbstate.loaded_mm_asid));
+
+ /* For now, be very restrictive about when this can be called. */
+ VM_WARN_ON(in_nmi() || preemptible());
+
+ VM_BUG_ON(cr3 != __read_cr3());
+ return cr3;
+}
+EXPORT_SYMBOL_GPL(__get_current_cr3_fast);
+
+/*
* arch_tlbbatch_flush() performs a full TLB flush regardless of the active mm.
* This means that the 'struct flush_tlb_info' that describes which mappings to
* flush is actually fixed. We therefore set a single fixed struct and use it in
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