mm/debug_vm_pgtable/hugetlb: disable hugetlb test on ppc64

The seems to be missing quite a lot of details w.r.t allocating the
correct pgtable_t page (huge_pte_alloc()), holding the right lock
(huge_pte_lock()) etc.  The vma used is also not a hugetlb VMA.

ppc64 do have runtime checks within CONFIG_DEBUG_VM for most of these.
Hence disable the test on ppc64.

[anshuman.khandual@arm.com: drop hugetlb_advanced_tests()]
  Link: https://lore.kernel.org/lkml/289c3fdb-1394-c1af-bdc4-5542907089dc@linux.ibm.com/#t
  Link: https://lkml.kernel.org/r/1600914446-21890-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lkml.kernel.org/r/20200902114222.181353-13-aneesh.kumar@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/debug_vm_pgtable.c

@@ -808,57 +808,8 @@ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
 	WARN_ON(!pte_huge(pte_mkhuge(pte)));
 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
 }
-
-static void __init hugetlb_advanced_tests(struct mm_struct *mm,
-					  struct vm_area_struct *vma,
-					  pte_t *ptep, unsigned long pfn,
-					  unsigned long vaddr, pgprot_t prot)
-{
-	struct page *page = pfn_to_page(pfn);
-	pte_t pte = ptep_get(ptep);
-	unsigned long paddr = __pfn_to_phys(pfn) & PMD_MASK;
-
-	pr_debug("Validating HugeTLB advanced\n");
-	pte = pte_mkhuge(mk_pte(pfn_to_page(PHYS_PFN(paddr)), prot));
-	set_huge_pte_at(mm, vaddr, ptep, pte);
-	barrier();
-	WARN_ON(!pte_same(pte, huge_ptep_get(ptep)));
-	huge_pte_clear(mm, vaddr, ptep, PMD_SIZE);
-	pte = huge_ptep_get(ptep);
-	WARN_ON(!huge_pte_none(pte));
-
-	pte = mk_huge_pte(page, prot);
-	set_huge_pte_at(mm, vaddr, ptep, pte);
-	barrier();
-	huge_ptep_set_wrprotect(mm, vaddr, ptep);
-	pte = huge_ptep_get(ptep);
-	WARN_ON(huge_pte_write(pte));
-
-	pte = mk_huge_pte(page, prot);
-	set_huge_pte_at(mm, vaddr, ptep, pte);
-	barrier();
-	huge_ptep_get_and_clear(mm, vaddr, ptep);
-	pte = huge_ptep_get(ptep);
-	WARN_ON(!huge_pte_none(pte));
-
-	pte = mk_huge_pte(page, prot);
-	pte = huge_pte_wrprotect(pte);
-	set_huge_pte_at(mm, vaddr, ptep, pte);
-	barrier();
-	pte = huge_pte_mkwrite(pte);
-	pte = huge_pte_mkdirty(pte);
-	huge_ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
-	pte = huge_ptep_get(ptep);
-	WARN_ON(!(huge_pte_write(pte) && huge_pte_dirty(pte)));
-}
 #else  /* !CONFIG_HUGETLB_PAGE */
 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init hugetlb_advanced_tests(struct mm_struct *mm,
-					  struct vm_area_struct *vma,
-					  pte_t *ptep, unsigned long pfn,
-					  unsigned long vaddr, pgprot_t prot)
-{
-}
 #endif /* CONFIG_HUGETLB_PAGE */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -1063,8 +1014,6 @@ static int __init debug_vm_pgtable(void)
 	pud_populate_tests(mm, pudp, saved_pmdp);
 	spin_unlock(ptl);
 
-	hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
-
 	spin_lock(&mm->page_table_lock);
 	p4d_clear_tests(mm, p4dp);
 	pgd_clear_tests(mm, pgdp);