Subject: [PATCH] mm/nvdimm: Add is_ioremap_addr and use that to check ioremap address

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Mon, 1 Jul 2019 19:10:38 +0530

Architectures like powerpc use different address range to map ioremap
and vmalloc range. The memunmap() check used by the nvdimm layer was
wrongly using is_vmalloc_addr() to check for ioremap range which fails for
ppc64. This result in ppc64 not freeing the ioremap mapping. The side effect
of this is an unbind failure during module unload with papr_scm nvdimm driver

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 arch/powerpc/include/asm/pgtable.h | 14 ++++++++++++++
 include/linux/mm.h                 |  5 +++++
 kernel/iomem.c                     |  2 +-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 3f53be60fb01..64145751b2fd 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -140,6 +140,20 @@ static inline void pte_frag_set(mm_context_t *ctx, void *p)
 }
 #endif
 
+#ifdef CONFIG_PPC64
+#define is_ioremap_addr is_ioremap_addr
+static inline bool is_ioremap_addr(const void *x)
+{
+#ifdef CONFIG_MMU
+	unsigned long addr = (unsigned long)x;
+
+	return addr >= IOREMAP_BASE && addr < IOREMAP_END;
+#else
+	return false;
+#endif
+}
+#endif /* CONFIG_PPC64 */
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_PGTABLE_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 973ebf71f7b6..65b2eb6c9f0a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -633,6 +633,11 @@ static inline bool is_vmalloc_addr(const void *x)
 	return false;
 #endif
 }
+
+#ifndef is_ioremap_addr
+#define is_ioremap_addr(x) is_vmalloc_addr(x)
+#endif
+
 #ifdef CONFIG_MMU
 extern int is_vmalloc_or_module_addr(const void *x);
 #else
diff --git a/kernel/iomem.c b/kernel/iomem.c
index 93c264444510..62c92e43aa0d 100644
--- a/kernel/iomem.c
+++ b/kernel/iomem.c
@@ -121,7 +121,7 @@ EXPORT_SYMBOL(memremap);
 
 void memunmap(void *addr)
 {
-	if (is_vmalloc_addr(addr))
+	if (is_ioremap_addr(addr))
 		iounmap((void __iomem *) addr);
 }
 EXPORT_SYMBOL(memunmap);
-- 
2.21.0