arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK]

SECTION_[SHIFT|SIZE|MASK] are essentially PMD_[SHIFT|SIZE|MASK]. But these
create confusion being similar to generic sparsemem memory sections, which
are derived from SECTION_SIZE_BITS. Section references have always implied
PMD level block mapping. Instead just use all PMD level macros which would
make it explicit and also remove confusion with sparsmem memory sections.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1623658706-7182-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/kernel-pgtable.h

@@ -91,8 +91,8 @@
 
 /* Initial memory map size */
 #if ARM64_SWAPPER_USES_SECTION_MAPS
-#define SWAPPER_BLOCK_SHIFT	SECTION_SHIFT
-#define SWAPPER_BLOCK_SIZE	SECTION_SIZE
+#define SWAPPER_BLOCK_SHIFT	PMD_SHIFT
+#define SWAPPER_BLOCK_SIZE	PMD_SIZE
 #define SWAPPER_TABLE_SHIFT	PUD_SHIFT
 #else
 #define SWAPPER_BLOCK_SHIFT	PAGE_SHIFT

arch/arm64/include/asm/pgtable-hwdef.h

@@ -71,13 +71,6 @@
 #define PGDIR_MASK		(~(PGDIR_SIZE-1))
 #define PTRS_PER_PGD		(1 << (VA_BITS - PGDIR_SHIFT))
 
-/*
- * Section address mask and size definitions.
- */
-#define SECTION_SHIFT		PMD_SHIFT
-#define SECTION_SIZE		(_AC(1, UL) << SECTION_SHIFT)
-#define SECTION_MASK		(~(SECTION_SIZE-1))
-
 /*
  * Contiguous page definitions.
  */

arch/arm64/mm/mmu.c

@@ -228,7 +228,7 @@ static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end,
 		next = pmd_addr_end(addr, end);
 
 		/* try section mapping first */
-		if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
+		if (((addr | next | phys) & ~PMD_MASK) == 0 &&
 		    (flags & NO_BLOCK_MAPPINGS) == 0) {
 			pmd_set_huge(pmdp, phys, prot);