linux-kernel - [PATCH v2] powerpc: drop page_is_ram() and walk_system_ram

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Message-Id: <a14aac5408f98cf8ad8723ffa874764ccb42d4d4.1548978750.git.christophe.leroy@c-s.fr>
Date:   Fri,  1 Feb 2019 10:46:52 +0000 (UTC)
From:   Christophe Leroy <christophe.leroy@....fr>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v2] powerpc: drop page_is_ram() and walk_system_ram_range()

Since commit c40dd2f76644 ("powerpc: Add System RAM to /proc/iomem")
it is possible to use the generic walk_system_ram_range() and
the generic page_is_ram().

To enable the use of walk_system_ram_range() by the IBM EHEA
ethernet driver, the generic function has to be exported.

As powerpc was the only (last?) user of CONFIG_ARCH_HAS_WALK_MEMORY,
the #ifdef around the generic walk_system_ram_range() has become
useless and can be dropped.

Fixes: c40dd2f76644 ("powerpc: Add System RAM to /proc/iomem")
Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
---
 arch/powerpc/Kconfig            |  3 ---
 arch/powerpc/include/asm/page.h |  1 -
 arch/powerpc/mm/mem.c           | 33 ---------------------------------
 kernel/resource.c               |  5 +----
 4 files changed, 1 insertion(+), 41 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2890d36eb531..f92e6754edf1 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -478,9 +478,6 @@ config ARCH_CPU_PROBE_RELEASE
 config ARCH_ENABLE_MEMORY_HOTPLUG
 	def_bool y
 
-config ARCH_HAS_WALK_MEMORY
-	def_bool y
-
 config ARCH_ENABLE_MEMORY_HOTREMOVE
 	def_bool y
 
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 5c5ea2413413..aa4497175bd3 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -326,7 +326,6 @@ struct page;
 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 		struct page *p);
-extern int page_is_ram(unsigned long pfn);
 extern int devmem_is_allowed(unsigned long pfn);
 
 #ifdef CONFIG_PPC_SMLPAR
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 33cc6f676fa6..fa9916c2c662 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -80,11 +80,6 @@ static inline pte_t *virt_to_kpte(unsigned long vaddr)
 #define TOP_ZONE ZONE_NORMAL
 #endif
 
-int page_is_ram(unsigned long pfn)
-{
-	return memblock_is_memory(__pfn_to_phys(pfn));
-}
-
 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 			      unsigned long size, pgprot_t vma_prot)
 {
@@ -176,34 +171,6 @@ int __meminit arch_remove_memory(int nid, u64 start, u64 size,
 #endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
-/*
- * walk_memory_resource() needs to make sure there is no holes in a given
- * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
- * Instead it maintains it in memblock.memory structures.  Walk through the
- * memory regions, find holes and callback for contiguous regions.
- */
-int
-walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
-		void *arg, int (*func)(unsigned long, unsigned long, void *))
-{
-	struct memblock_region *reg;
-	unsigned long end_pfn = start_pfn + nr_pages;
-	unsigned long tstart, tend;
-	int ret = -1;
-
-	for_each_memblock(memory, reg) {
-		tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
-		tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
-		if (tstart >= tend)
-			continue;
-		ret = (*func)(tstart, tend - tstart, arg);
-		if (ret)
-			break;
-	}
-	return ret;
-}
-EXPORT_SYMBOL_GPL(walk_system_ram_range);
-
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 void __init mem_topology_setup(void)
 {
diff --git a/kernel/resource.c b/kernel/resource.c
index 915c02e8e5dd..2e1636041508 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -448,8 +448,6 @@ int walk_mem_res(u64 start, u64 end, void *arg,
 				     arg, func);
 }
 
-#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
-
 /*
  * This function calls the @func callback against all memory ranges of type
  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
@@ -480,8 +478,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 	}
 	return ret;
 }
-
-#endif
+EXPORT_SYMBOL_GPL(walk_system_ram_range);
 
 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 {
-- 
2.13.3