ia64: remove custom __early_pfn_to_nid()

The ia64 implementation of __early_pfn_to_nid() essentially relies on the
same data as the generic implementation.

The correspondence between memory ranges and nodes is set in memblock
during early memory initialization in register_active_ranges() function.

The initialization of sparsemem that requires early_pfn_to_nid() happens
later and it can use the memblock information like the other architectures.

Link: https://lkml.kernel.org/r/20201101170454.9567-3-rppt@kernel.orgSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
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>

arch/ia64/Kconfig

@@ -342,9 +342,6 @@ config HOLES_IN_ZONE
 	bool
 	default y if VIRTUAL_MEM_MAP
 
-config HAVE_ARCH_EARLY_PFN_TO_NID
-	def_bool NUMA && SPARSEMEM
-
 config HAVE_ARCH_NODEDATA_EXTENSION
 	def_bool y
 	depends on NUMA

arch/ia64/mm/numa.c

@@ -58,36 +58,6 @@ paddr_to_nid(unsigned long paddr)
 EXPORT_SYMBOL(paddr_to_nid);
 
 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
-/*
- * Because of holes evaluate on section limits.
- * If the section of memory exists, then return the node where the section
- * resides.  Otherwise return node 0 as the default.  This is used by
- * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
- * the section resides.
- */
-int __meminit __early_pfn_to_nid(unsigned long pfn,
-					struct mminit_pfnnid_cache *state)
-{
-	int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
-
-	if (section >= state->last_start && section < state->last_end)
-		return state->last_nid;
-
-	for (i = 0; i < num_node_memblks; i++) {
-		ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
-		esec = (node_memblk[i].start_paddr + node_memblk[i].size +
-			((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
-		if (section >= ssec && section < esec) {
-			state->last_start = ssec;
-			state->last_end = esec;
-			state->last_nid = node_memblk[i].nid;
-			return node_memblk[i].nid;
-		}
-	}
-
-	return -1;
-}
-
 void numa_clear_node(int cpu)
 {
 	unmap_cpu_from_node(cpu, NUMA_NO_NODE);

include/linux/mm.h

@@ -2434,9 +2434,6 @@ static inline int early_pfn_to_nid(unsigned long pfn)
 #else
 /* please see mm/page_alloc.c */
 extern int __meminit early_pfn_to_nid(unsigned long pfn);
-/* there is a per-arch backend function. */
-extern int __meminit __early_pfn_to_nid(unsigned long pfn,
-					struct mminit_pfnnid_cache *state);
 #endif
 
 extern void set_dma_reserve(unsigned long new_dma_reserve);

include/linux/mmzone.h

@@ -1428,17 +1428,6 @@ void sparse_init(void);
 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
 #endif /* CONFIG_SPARSEMEM */
 
-/*
- * During memory init memblocks map pfns to nids. The search is expensive and
- * this caches recent lookups. The implementation of __early_pfn_to_nid
- * may treat start/end as pfns or sections.
- */
-struct mminit_pfnnid_cache {
-	unsigned long last_start;
-	unsigned long last_end;
-	int last_nid;
-};
-
 /*
  * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
  * need to check pfn validity within that MAX_ORDER_NR_PAGES block.

mm/page_alloc.c

@@ -1559,14 +1559,23 @@ void __free_pages_core(struct page *page, unsigned int order)
 
 #ifdef CONFIG_NEED_MULTIPLE_NODES
 
-static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
+/*
+ * During memory init memblocks map pfns to nids. The search is expensive and
+ * this caches recent lookups. The implementation of __early_pfn_to_nid
+ * treats start/end as pfns.
+ */
+struct mminit_pfnnid_cache {
+	unsigned long last_start;
+	unsigned long last_end;
+	int last_nid;
+};
 
-#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
 
 /*
  * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
  */
-int __meminit __early_pfn_to_nid(unsigned long pfn,
+static int __meminit __early_pfn_to_nid(unsigned long pfn,
 					struct mminit_pfnnid_cache *state)
 {
 	unsigned long start_pfn, end_pfn;
@@ -1584,7 +1593,6 @@ int __meminit __early_pfn_to_nid(unsigned long pfn,
 
 	return nid;
 }
-#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
 
 int __meminit early_pfn_to_nid(unsigned long pfn)
 {