MIPS: Export pgd/pmd symbols for KVM

Export pmd_init(), invalid_pmd_table and tlbmiss_handler_setup_pgd to
GPL kernel modules so that MIPS KVM can use the inline page table
management functions and switch between page tables:

- pmd_init() will be used directly by KVM to initialise newly allocated
  pmd tables with invalid lower level table pointers.

- invalid_pmd_table is used by pud_present(), pud_none(), and
  pud_clear(), which KVM will use to test and clear pud entries.

- tlbmiss_handler_setup_pgd() will be called by KVM entry code to switch
  to the appropriate GVA page tables.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

arch/mips/mm/init.c

@@ -538,5 +538,6 @@ unsigned long pgd_current[NR_CPUS];
 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 #ifndef __PAGETABLE_PMD_FOLDED
 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
+EXPORT_SYMBOL_GPL(invalid_pmd_table);
 #endif
 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;

arch/mips/mm/pgtable-64.c

@@ -6,6 +6,7 @@
  * Copyright (C) 1999, 2000 by Silicon Graphics
  * Copyright (C) 2003 by Ralf Baechle
  */
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <asm/fixmap.h>
@@ -60,6 +61,7 @@ void pmd_init(unsigned long addr, unsigned long pagetable)
 		p[-1] = pagetable;
 	} while (p != end);
 }
+EXPORT_SYMBOL_GPL(pmd_init);
 #endif
 
 pmd_t mk_pmd(struct page *page, pgprot_t prot)

arch/mips/mm/tlbex.c

@@ -22,6 +22,7 @@
  */
 
 #include <linux/bug.h>
+#include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/smp.h>
@@ -1536,7 +1537,9 @@ static void build_loongson3_tlb_refill_handler(void)
 extern u32 handle_tlbl[], handle_tlbl_end[];
 extern u32 handle_tlbs[], handle_tlbs_end[];
 extern u32 handle_tlbm[], handle_tlbm_end[];
-extern u32 tlbmiss_handler_setup_pgd_start[], tlbmiss_handler_setup_pgd[];
+extern u32 tlbmiss_handler_setup_pgd_start[];
+extern u32 tlbmiss_handler_setup_pgd[];
+EXPORT_SYMBOL_GPL(tlbmiss_handler_setup_pgd);
 extern u32 tlbmiss_handler_setup_pgd_end[];
 
 static void build_setup_pgd(void)