[PATCH v2 07/14] mm/arm: Redefine pmd_huge() with pmd_leaf()

peterx
2024-03-18T20:04:20Z

Most of the archs already define these two APIs the same way. ARM is more
complicated in two aspects:

- For pXd_huge() it's always checking against !PXD_TABLE_BIT, while for
pXd_leaf() it's always checking against PXD_TYPE_SECT.

- SECT/TABLE bits are defined differently on 2-level v.s. 3-level ARM
pgtables, which makes the whole thing even harder to follow.

Luckily, the second complexity should be hidden by the pmd_leaf()
implementation against 2-level v.s. 3-level headers. Invoke pmd_leaf()
directly for pmd_huge(), to remove the first part of complexity. This
prepares to drop pXd_huge() API globally.

When at it, drop the obsolete comments - it's outdated.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Fabio Estevam <festevam@denx.de>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/arm/mm/hugetlbpage.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c
index dd7a0277c5c0..c2fa643f6bb5 100644
--- a/arch/arm/mm/hugetlbpage.c
+++ b/arch/arm/mm/hugetlbpage.c
@@ -18,11 +18,6 @@
#include <asm/tlb.h>
#include <asm/tlbflush.h>

-/*
- * On ARM, huge pages are backed by pmd's rather than pte's, so we do a lot
- * of type casting from pmd_t * to pte_t *.
- */
-
int pud_huge(pud_t pud)
{
return 0;
@@ -30,5 +25,5 @@ int pud_huge(pud_t pud)

int pmd_huge(pmd_t pmd)
{
- return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
+ return pmd_leaf(pmd);
}
--
2.44.0