mm/debug_vm_pgtable: use struct pgtable_debug_args in PGD and P4D modifying tests

This uses struct pgtable_debug_args in PGD/P4D modifying tests.  No
allocated huge page is used in these tests.  Besides, the unused variable
@saved_p4dp and @saved_pudp are dropped.

Link: https://lkml.kernel.org/r/20210809092631.1888748-11-gshan@redhat.comSigned-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/debug_vm_pgtable.c

@@ -518,27 +518,26 @@ static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
 #endif /* PAGETABLE_PUD_FOLDED */
 
 #ifndef __PAGETABLE_P4D_FOLDED
-static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
+static void __init p4d_clear_tests(struct pgtable_debug_args *args)
 {
-	p4d_t p4d = READ_ONCE(*p4dp);
+	p4d_t p4d = READ_ONCE(*args->p4dp);
 
-	if (mm_pud_folded(mm))
+	if (mm_pud_folded(args->mm))
 		return;
 
 	pr_debug("Validating P4D clear\n");
 	p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
-	WRITE_ONCE(*p4dp, p4d);
-	p4d_clear(p4dp);
-	p4d = READ_ONCE(*p4dp);
+	WRITE_ONCE(*args->p4dp, p4d);
+	p4d_clear(args->p4dp);
+	p4d = READ_ONCE(*args->p4dp);
 	WARN_ON(!p4d_none(p4d));
 }
 
-static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
-				      pud_t *pudp)
+static void __init p4d_populate_tests(struct pgtable_debug_args *args)
 {
 	p4d_t p4d;
 
-	if (mm_pud_folded(mm))
+	if (mm_pud_folded(args->mm))
 		return;
 
 	pr_debug("Validating P4D populate\n");
@@ -546,34 +545,33 @@ static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
 	 * This entry points to next level page table page.
 	 * Hence this must not qualify as p4d_bad().
 	 */
-	pud_clear(pudp);
-	p4d_clear(p4dp);
-	p4d_populate(mm, p4dp, pudp);
-	p4d = READ_ONCE(*p4dp);
+	pud_clear(args->pudp);
+	p4d_clear(args->p4dp);
+	p4d_populate(args->mm, args->p4dp, args->start_pudp);
+	p4d = READ_ONCE(*args->p4dp);
 	WARN_ON(p4d_bad(p4d));
 }
 
-static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
+static void __init pgd_clear_tests(struct pgtable_debug_args *args)
 {
-	pgd_t pgd = READ_ONCE(*pgdp);
+	pgd_t pgd = READ_ONCE(*(args->pgdp));
 
-	if (mm_p4d_folded(mm))
+	if (mm_p4d_folded(args->mm))
 		return;
 
 	pr_debug("Validating PGD clear\n");
 	pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
-	WRITE_ONCE(*pgdp, pgd);
-	pgd_clear(pgdp);
-	pgd = READ_ONCE(*pgdp);
+	WRITE_ONCE(*args->pgdp, pgd);
+	pgd_clear(args->pgdp);
+	pgd = READ_ONCE(*args->pgdp);
 	WARN_ON(!pgd_none(pgd));
 }
 
-static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
-				      p4d_t *p4dp)
+static void __init pgd_populate_tests(struct pgtable_debug_args *args)
 {
 	pgd_t pgd;
 
-	if (mm_p4d_folded(mm))
+	if (mm_p4d_folded(args->mm))
 		return;
 
 	pr_debug("Validating PGD populate\n");
@@ -581,23 +579,17 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
 	 * This entry points to next level page table page.
 	 * Hence this must not qualify as pgd_bad().
 	 */
-	p4d_clear(p4dp);
-	pgd_clear(pgdp);
-	pgd_populate(mm, pgdp, p4dp);
-	pgd = READ_ONCE(*pgdp);
+	p4d_clear(args->p4dp);
+	pgd_clear(args->pgdp);
+	pgd_populate(args->mm, args->pgdp, args->start_p4dp);
+	pgd = READ_ONCE(*args->pgdp);
 	WARN_ON(pgd_bad(pgd));
 }
 #else  /* !__PAGETABLE_P4D_FOLDED */
-static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
-static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
-static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
-				      pud_t *pudp)
-{
-}
-static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
-				      p4d_t *p4dp)
-{
-}
+static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
+static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
+static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
+static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
 #endif /* PAGETABLE_P4D_FOLDED */
 
 static void __init pte_clear_tests(struct pgtable_debug_args *args)
@@ -1200,8 +1192,8 @@ static int __init debug_vm_pgtable(void)
 	struct vm_area_struct *vma;
 	struct mm_struct *mm;
 	pgd_t *pgdp;
-	p4d_t *p4dp, *saved_p4dp;
-	pud_t *pudp, *saved_pudp;
+	p4d_t *p4dp;
+	pud_t *pudp;
 	pmd_t *pmdp, *saved_pmdp, pmd;
 	pgtable_t saved_ptep;
 	unsigned long vaddr;
@@ -1245,8 +1237,6 @@ static int __init debug_vm_pgtable(void)
 	 * page table pages.
 	 */
 	pmd = READ_ONCE(*pmdp);
-	saved_p4dp = p4d_offset(pgdp, 0UL);
-	saved_pudp = pud_offset(p4dp, 0UL);
 	saved_pmdp = pmd_offset(pudp, 0UL);
 	saved_ptep = pmd_pgtable(pmd);
 
@@ -1325,15 +1315,15 @@ static int __init debug_vm_pgtable(void)
 	pud_populate_tests(&args);
 	spin_unlock(ptl);
 
-	spin_lock(&mm->page_table_lock);
-	p4d_clear_tests(mm, p4dp);
-	pgd_clear_tests(mm, pgdp);
-	p4d_populate_tests(mm, p4dp, saved_pudp);
-	pgd_populate_tests(mm, pgdp, saved_p4dp);
-	spin_unlock(&mm->page_table_lock);
+	spin_lock(&(args.mm->page_table_lock));
+	p4d_clear_tests(&args);
+	pgd_clear_tests(&args);
+	p4d_populate_tests(&args);
+	pgd_populate_tests(&args);
+	spin_unlock(&(args.mm->page_table_lock));
 
-	p4d_free(mm, saved_p4dp);
-	pud_free(mm, saved_pudp);
+	p4d_free(mm, p4d_offset(pgdp, 0UL));
+	pud_free(mm, pud_offset(p4dp, 0UL));
 	pmd_free(mm, saved_pmdp);
 	pte_free(mm, saved_ptep);