arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions

trans_pgd_* should be independent from mm context because the tables that
are created by this code are used when there are no mm context around, as
it is between kernels. Simply replace mm_init's with NULL.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20210125191923.1060122-7-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/mm/trans_pgd.c

@@ -67,7 +67,7 @@ static int copy_pte(struct trans_pgd_info *info, pmd_t *dst_pmdp,
 	dst_ptep = trans_alloc(info);
 	if (!dst_ptep)
 		return -ENOMEM;
-	pmd_populate_kernel(&init_mm, dst_pmdp, dst_ptep);
+	pmd_populate_kernel(NULL, dst_pmdp, dst_ptep);
 	dst_ptep = pte_offset_kernel(dst_pmdp, start);
 
 	src_ptep = pte_offset_kernel(src_pmdp, start);
@@ -90,7 +90,7 @@ static int copy_pmd(struct trans_pgd_info *info, pud_t *dst_pudp,
 		dst_pmdp = trans_alloc(info);
 		if (!dst_pmdp)
 			return -ENOMEM;
-		pud_populate(&init_mm, dst_pudp, dst_pmdp);
+		pud_populate(NULL, dst_pudp, dst_pmdp);
 	}
 	dst_pmdp = pmd_offset(dst_pudp, start);
 
@@ -126,7 +126,7 @@ static int copy_pud(struct trans_pgd_info *info, p4d_t *dst_p4dp,
 		dst_pudp = trans_alloc(info);
 		if (!dst_pudp)
 			return -ENOMEM;
-		p4d_populate(&init_mm, dst_p4dp, dst_pudp);
+		p4d_populate(NULL, dst_p4dp, dst_pudp);
 	}
 	dst_pudp = pud_offset(dst_p4dp, start);
 
@@ -241,31 +241,31 @@ int trans_pgd_map_page(struct trans_pgd_info *info, pgd_t *trans_pgd,
 		p4dp = trans_alloc(info);
 		if (!pgdp)
 			return -ENOMEM;
-		pgd_populate(&init_mm, pgdp, p4dp);
+		pgd_populate(NULL, pgdp, p4dp);
 	}
 
 	p4dp = p4d_offset(pgdp, dst_addr);
 	if (p4d_none(READ_ONCE(*p4dp))) {
 		pudp = trans_alloc(info);
 		if (!pudp)
 			return -ENOMEM;
-		p4d_populate(&init_mm, p4dp, pudp);
+		p4d_populate(NULL, p4dp, pudp);
 	}
 
 	pudp = pud_offset(p4dp, dst_addr);
 	if (pud_none(READ_ONCE(*pudp))) {
 		pmdp = trans_alloc(info);
 		if (!pmdp)
 			return -ENOMEM;
-		pud_populate(&init_mm, pudp, pmdp);
+		pud_populate(NULL, pudp, pmdp);
 	}
 
 	pmdp = pmd_offset(pudp, dst_addr);
 	if (pmd_none(READ_ONCE(*pmdp))) {
 		ptep = trans_alloc(info);
 		if (!ptep)
 			return -ENOMEM;
-		pmd_populate_kernel(&init_mm, pmdp, ptep);
+		pmd_populate_kernel(NULL, pmdp, ptep);
 	}
 
 	ptep = pte_offset_kernel(pmdp, dst_addr);