arm64/mm: Use phys_to_page() to access pgtable memory

The macros {pgd, pud, pmd}_page() retrieves the page struct of the
corresponding page frame, which is reserved as page table. There
is already a macro (phys_to_page), defined in memory.h as below,
to convert the physical address to the page struct. Also, the header
file (memory.h) has been included by pgtable.h.

   #define phys_to_page(phys)      (pfn_to_page(__phys_to_pfn(phys)))

So it's reasonable to use the macro in pgtable.h.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200427234655.111847-1-gshan@redhat.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/pgtable.h

@@ -508,7 +508,7 @@ static inline void pte_unmap(pte_t *pte) { }
 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
 
-#define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(__pmd_to_phys(pmd)))
+#define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
 
 /* use ONLY for statically allocated translation tables */
 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
@@ -566,7 +566,7 @@ static inline phys_addr_t pud_page_paddr(pud_t pud)
 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
 
-#define pud_page(pud)		pfn_to_page(__phys_to_pfn(__pud_to_phys(pud)))
+#define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
 
 /* use ONLY for statically allocated translation tables */
 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
@@ -624,7 +624,7 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
 #define pud_set_fixmap_offset(pgd, addr)	pud_set_fixmap(pud_offset_phys(pgd, addr))
 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
 
-#define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(__pgd_to_phys(pgd)))
+#define pgd_page(pgd)			phys_to_page(__pgd_to_phys(pgd))
 
 /* use ONLY for statically allocated translation tables */
 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))