microblaze: simplify pte_alloc_one_kernel()

mainline inclusion
from mainline-v5.15-rc1
commit 22e78781
category: bugfix
bugzilla: 186414, https://gitee.com/openeuler/kernel/issues/I5K7IY
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=22e7878102f94a50e9a4c2c19f909a9a0898c4ce

--------------------------------

The microblaze's implementation of pte_alloc_one_kernel() used
memblock_alloc_try_nid_raw() along with clear_page() to allocated a zeroed
page during early setup.

Replace calls of these functions with a call to memblock_alloc_try_nid()
that already returns zeroed page and respects the same allocation limits
as memblock_alloc_try_nid_raw().

While on it drop early_get_page() wrapper that was only used in
pte_alloc_one_kernel().

Link: https://lkml.kernel.org/r/20210714123739.16493-3-rppt@kernel.orgSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Conflicts:
	arch/microblaze/mm/init.c
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/microblaze/include/asm/pgtable.h

@@ -486,8 +486,6 @@ extern int mem_init_done;
 
 asmlinkage void __init mmu_init(void);
 
-void __init *early_get_page(void);
-
 #endif /* __ASSEMBLY__ */
 #endif /* __KERNEL__ */
 

arch/microblaze/mm/init.c

@@ -318,18 +318,6 @@ asmlinkage void __init mmu_init(void)
 	dma_contiguous_reserve(memory_start + lowmem_size - 1);
 }
 
-/* This is only called until mem_init is done. */
-void __init *early_get_page(void)
-{
-	/*
-	 * Mem start + kernel_tlb -> here is limit
-	 * because of mem mapping from head.S
-	 */
-	return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
-				MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
-				NUMA_NO_NODE);
-}
-
 #endif /* CONFIG_MMU */
 
 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)

arch/microblaze/mm/pgtable.c

@@ -33,6 +33,7 @@
 #include <linux/init.h>
 #include <linux/mm_types.h>
 #include <linux/pgtable.h>
+#include <linux/memblock.h>
 
 #include <asm/pgalloc.h>
 #include <linux/io.h>
@@ -242,15 +243,13 @@ unsigned long iopa(unsigned long addr)
 
 __ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
 {
-	pte_t *pte;
-	if (mem_init_done) {
-		pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
-	} else {
-		pte = (pte_t *)early_get_page();
-		if (pte)
-			clear_page(pte);
-	}
-	return pte;
+	if (mem_init_done)
+		return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+	else
+		return memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE,
+					      MEMBLOCK_LOW_LIMIT,
+					      memory_start + kernel_tlb,
+					      NUMA_NO_NODE);
 }
 
 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)