mm: split altmap memory map allocation from normal case

No functional changes, just untangling the call chain and document
why the altmap is passed around the hotplug code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

arch/powerpc/mm/init_64.c

@@ -200,7 +200,10 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
 		if (vmemmap_populated(start, page_size))
 			continue;
 
-		p =  __vmemmap_alloc_block_buf(page_size, node, altmap);
+		if (altmap)
+			p = altmap_alloc_block_buf(page_size, altmap);
+		else
+			p = vmemmap_alloc_block_buf(page_size, node);
 		if (!p)
 			return -ENOMEM;
 

arch/x86/mm/init_64.c

@@ -1385,7 +1385,10 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start,
 		if (pmd_none(*pmd)) {
 			void *p;
 
-			p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
+			if (altmap)
+				p = altmap_alloc_block_buf(PMD_SIZE, altmap);
+			else
+				p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 			if (p) {
 				pte_t entry;
 

include/linux/mm.h

@@ -2547,13 +2547,8 @@ pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
 void *vmemmap_alloc_block(unsigned long size, int node);
 struct vmem_altmap;
-void *__vmemmap_alloc_block_buf(unsigned long size, int node,
-		struct vmem_altmap *altmap);
-static inline void *vmemmap_alloc_block_buf(unsigned long size, int node)
-{
-	return __vmemmap_alloc_block_buf(size, node, NULL);
-}
-
+void *vmemmap_alloc_block_buf(unsigned long size, int node);
+void *altmap_alloc_block_buf(unsigned long size, struct vmem_altmap *altmap);
 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
 int vmemmap_populate_basepages(unsigned long start, unsigned long end,
 			       int node);

mm/sparse-vmemmap.c

@@ -74,7 +74,7 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 }
 
 /* need to make sure size is all the same during early stage */
-static void * __meminit alloc_block_buf(unsigned long size, int node)
+void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
 {
 	void *ptr;
 
@@ -129,7 +129,7 @@ static unsigned long __meminit vmem_altmap_alloc(struct vmem_altmap *altmap,
 	return pfn + nr_align;
 }
 
-static void * __meminit altmap_alloc_block_buf(unsigned long size,
+void * __meminit altmap_alloc_block_buf(unsigned long size,
 		struct vmem_altmap *altmap)
 {
 	unsigned long pfn, nr_pfns;
@@ -153,15 +153,6 @@ static void * __meminit altmap_alloc_block_buf(unsigned long size,
 	return ptr;
 }
 
-/* need to make sure size is all the same during early stage */
-void * __meminit __vmemmap_alloc_block_buf(unsigned long size, int node,
-		struct vmem_altmap *altmap)
-{
-	if (altmap)
-		return altmap_alloc_block_buf(size, altmap);
-	return alloc_block_buf(size, node);
-}
-
 void __meminit vmemmap_verify(pte_t *pte, int node,
 				unsigned long start, unsigned long end)
 {
@@ -178,7 +169,7 @@ pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
 	pte_t *pte = pte_offset_kernel(pmd, addr);
 	if (pte_none(*pte)) {
 		pte_t entry;
-		void *p = alloc_block_buf(PAGE_SIZE, node);
+		void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
 		if (!p)
 			return NULL;
 		entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);