Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/nds32/include/asm/cacheflush.h b/arch/nds32/include/asm/cacheflush.h
index d9ac7e6..caddded 100644
--- a/arch/nds32/include/asm/cacheflush.h
+++ b/arch/nds32/include/asm/cacheflush.h
@@ -9,7 +9,11 @@
 #define PG_dcache_dirty PG_arch_1
 
 void flush_icache_range(unsigned long start, unsigned long end);
+#define flush_icache_range flush_icache_range
+
 void flush_icache_page(struct vm_area_struct *vma, struct page *page);
+#define flush_icache_page flush_icache_page
+
 #ifdef CONFIG_CPU_CACHE_ALIASING
 void flush_cache_mm(struct mm_struct *mm);
 void flush_cache_dup_mm(struct mm_struct *mm);
@@ -40,12 +44,11 @@
 #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&(mapping)->i_pages)
 
 #else
-#include <asm-generic/cacheflush.h>
-#undef flush_icache_range
-#undef flush_icache_page
-#undef flush_icache_user_range
 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 	                     unsigned long addr, int len);
+#define flush_icache_user_range flush_icache_user_range
+
+#include <asm-generic/cacheflush.h>
 #endif
 
 #endif /* __NDS32_CACHEFLUSH_H__ */
diff --git a/arch/nds32/mm/cacheflush.c b/arch/nds32/mm/cacheflush.c
index 2547036..f34dc9b 100644
--- a/arch/nds32/mm/cacheflush.c
+++ b/arch/nds32/mm/cacheflush.c
@@ -239,7 +239,7 @@
 {
 	struct address_space *mapping;
 
-	mapping = page_mapping(page);
+	mapping = page_mapping_file(page);
 	if (mapping && !mapping_mapped(mapping))
 		set_bit(PG_dcache_dirty, &page->flags);
 	else {
diff --git a/arch/nds32/mm/mmap.c b/arch/nds32/mm/mmap.c
index c206b31..1bdf5e7 100644
--- a/arch/nds32/mm/mmap.c
+++ b/arch/nds32/mm/mmap.c
@@ -59,7 +59,7 @@
 
 		vma = find_vma(mm, addr);
 		if (TASK_SIZE - len >= addr &&
-		    (!vma || addr + len <= vma->vm_start))
+		    (!vma || addr + len <= vm_start_gap(vma)))
 			return addr;
 	}