[PATCH] arm64: decouple check whether pfn is normal memory from pfn_valid()

[Mike Rapoport]

The intended semantics of pfn_valid() is to verify whether there is a
struct page for the pfn in question and nothing else.

Yet, on arm64 it is used to distinguish memory areas that are mapped in the
linear map vs those that require ioremap() to access them.

Introduce a dedicated pfn_is_memory() to perform such check and use it
where appropriate.

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
 arch/arm64/include/asm/memory.h | 2 +-
 arch/arm64/include/asm/page.h   | 1 +
 arch/arm64/kvm/mmu.c            | 2 +-
 arch/arm64/mm/init.c            | 6 ++++++
 arch/arm64/mm/ioremap.c         | 4 ++--
 arch/arm64/mm/mmu.c             | 2 +-
 6 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index c759faf7a1ff..778dbfe95d0e 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -346,7 +346,7 @@ static inline void *phys_to_virt(phys_addr_t x)
 
 #define virt_addr_valid(addr)	({					\
 	__typeof__(addr) __addr = __tag_reset(addr);			\
-	__is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr));	\
+	__is_lm_address(__addr) && pfn_is_memory(virt_to_pfn(__addr));	\
 })
 
 void dump_mem_limit(void);
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 012cffc574e8..32b485bcc6ff 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -38,6 +38,7 @@ void copy_highpage(struct page *to, struct page *from);
 typedef struct page *pgtable_t;
 
 extern int pfn_valid(unsigned long);
+extern int pfn_is_memory(unsigned long);
 
 #include <asm/memory.h>
 
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 77cb2d28f2a4..a60069604361 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -85,7 +85,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
 
 static bool kvm_is_device_pfn(unsigned long pfn)
 {
-	return !pfn_valid(pfn);
+	return !pfn_is_memory(pfn);
 }
 
 /*
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 0ace5e68efba..77c08853bafc 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -235,6 +235,12 @@ int pfn_valid(unsigned long pfn)
 }
 EXPORT_SYMBOL(pfn_valid);
 
+int pfn_is_memory(unsigned long pfn)
+{
+	return memblock_is_map_memory(PFN_PHYS(pfn));
+}
+EXPORT_SYMBOL(pfn_is_memory);
+
 static phys_addr_t memory_limit = PHYS_ADDR_MAX;
 
 /*
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index b5e83c46b23e..82a369b22ef5 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -43,7 +43,7 @@ static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
 	/*
 	 * Don't allow RAM to be mapped.
 	 */
-	if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
+	if (WARN_ON(pfn_is_memory(__phys_to_pfn(phys_addr))))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
@@ -84,7 +84,7 @@ EXPORT_SYMBOL(iounmap);
 void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
 {
 	/* For normal memory we already have a cacheable mapping. */
-	if (pfn_valid(__phys_to_pfn(phys_addr)))
+	if (pfn_is_memory(__phys_to_pfn(phys_addr)))
 		return (void __iomem *)__phys_to_virt(phys_addr);
 
 	return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 3802cfbdd20d..ee66f2f21b6f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -81,7 +81,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 			      unsigned long size, pgprot_t vma_prot)
 {
-	if (!pfn_valid(pfn))
+	if (!pfn_is_memory(pfn))
 		return pgprot_noncached(vma_prot);
 	else if (file->f_flags & O_SYNC)
 		return pgprot_writecombine(vma_prot);
-- 
2.28.0


-- 
Sincerely yours,
Mike.