mm/sparse-vmemmap: generalise vmemmap_populate_hugepages()

Generalise vmemmap_populate_hugepages() so ARM64 & X86 & LoongArch can
share its implementation.

Link: https://lkml.kernel.org/r/20221027125253.3458989-4-chenhuacai@loongson.cn
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Min Zhou <zhoumin@loongson.cn>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 32 insertions, 60 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index e8db4edd7cc9..a190aae8ceaf 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1492,72 +1492,44 @@ static long __meminitdata addr_start, addr_end;
 static void __meminitdata *p_start, *p_end;
 static int __meminitdata node_start;
 
-static int __meminit vmemmap_populate_hugepages(unsigned long start,
-		unsigned long end, int node, struct vmem_altmap *altmap)
+void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
+			       unsigned long addr, unsigned long next)
 {
-	unsigned long addr;
-	unsigned long next;
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
-
-	for (addr = start; addr < end; addr = next) {
-		next = pmd_addr_end(addr, end);
-
-		pgd = vmemmap_pgd_populate(addr, node);
-		if (!pgd)
-			return -ENOMEM;
-
-		p4d = vmemmap_p4d_populate(pgd, addr, node);
-		if (!p4d)
-			return -ENOMEM;
-
-		pud = vmemmap_pud_populate(p4d, addr, node);
-		if (!pud)
-			return -ENOMEM;
-
-		pmd = pmd_offset(pud, addr);
-		if (pmd_none(*pmd)) {
-			void *p;
-
-			p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
-			if (p) {
-				pte_t entry;
-
-				entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
-						PAGE_KERNEL_LARGE);
-				set_pmd(pmd, __pmd(pte_val(entry)));
+	pte_t entry;
+
+	entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
+			PAGE_KERNEL_LARGE);
+	set_pmd(pmd, __pmd(pte_val(entry)));
+
+	/* check to see if we have contiguous blocks */
+	if (p_end != p || node_start != node) {
+		if (p_start)
+			pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
+				addr_start, addr_end-1, p_start, p_end-1, node_start);
+		addr_start = addr;
+		node_start = node;
+		p_start = p;
+	}
 
-				/* check to see if we have contiguous blocks */
-				if (p_end != p || node_start != node) {
-					if (p_start)
-						pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
-						       addr_start, addr_end-1, p_start, p_end-1, node_start);
-					addr_start = addr;
-					node_start = node;
-					p_start = p;
-				}
+	addr_end = addr + PMD_SIZE;
+	p_end = p + PMD_SIZE;
 
-				addr_end = addr + PMD_SIZE;
-				p_end = p + PMD_SIZE;
+	if (!IS_ALIGNED(addr, PMD_SIZE) ||
+		!IS_ALIGNED(next, PMD_SIZE))
+		vmemmap_use_new_sub_pmd(addr, next);
+}
 
-				if (!IS_ALIGNED(addr, PMD_SIZE) ||
-				    !IS_ALIGNED(next, PMD_SIZE))
-					vmemmap_use_new_sub_pmd(addr, next);
+int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
+				unsigned long addr, unsigned long next)
+{
+	int large = pmd_large(*pmd);
 
-				continue;
-			} else if (altmap)
-				return -ENOMEM; /* no fallback */
-		} else if (pmd_large(*pmd)) {
-			vmemmap_verify((pte_t *)pmd, node, addr, next);
-			vmemmap_use_sub_pmd(addr, next);
-			continue;
-		}
-		if (vmemmap_populate_basepages(addr, next, node, NULL))
-			return -ENOMEM;
+	if (pmd_large(*pmd)) {
+		vmemmap_verify((pte_t *)pmd, node, addr, next);
+		vmemmap_use_sub_pmd(addr, next);
 	}
-	return 0;
+
+	return large;
 }
 
 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,