linux-kernel - [PATCH v2 3/4] mm: use VM_HIGH_ARCH

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Message-ID: <20250507131000.1204175-4-revest@chromium.org>
Date: Wed,  7 May 2025 15:09:59 +0200
From: Florent Revest <revest@...omium.org>
To: linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Cc: catalin.marinas@....com,
	will@...nel.org,
	tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de,
	dave.hansen@...ux.intel.com,
	x86@...nel.org,
	hpa@...or.com,
	akpm@...ux-foundation.org,
	broonie@...nel.org,
	thiago.bauermann@...aro.org,
	jackmanb@...gle.com,
	Florent Revest <revest@...omium.org>
Subject: [PATCH v2 3/4] mm: use VM_HIGH_ARCH_* macros consistently

Currently, some high vma flag bits are defined using VM_HIGH_ARCH_*
helper macros but others are not. Use the macros consistently so it's
easier to spot which ones are used/free.

To keep the VMA flags space easier to read and think about, VM_SEALED is
also shifted down from a very high bit (63rd) to a lower one (42nd).

Signed-off-by: Florent Revest <revest@...omium.org>
---
 include/linux/mm.h | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index da8f99a026deb..b12549f0a6dce 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -305,6 +305,10 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_HIGH_ARCH_BIT_4	36	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_BIT_5	37	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_BIT_6	38	/* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_7	39	/* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_8	40	/* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_9	41	/* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_10	42	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_0	BIT(VM_HIGH_ARCH_BIT_0)
 #define VM_HIGH_ARCH_1	BIT(VM_HIGH_ARCH_BIT_1)
 #define VM_HIGH_ARCH_2	BIT(VM_HIGH_ARCH_BIT_2)
@@ -312,6 +316,10 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_HIGH_ARCH_4	BIT(VM_HIGH_ARCH_BIT_4)
 #define VM_HIGH_ARCH_5	BIT(VM_HIGH_ARCH_BIT_5)
 #define VM_HIGH_ARCH_6	BIT(VM_HIGH_ARCH_BIT_6)
+#define VM_HIGH_ARCH_7	BIT(VM_HIGH_ARCH_BIT_7)
+#define VM_HIGH_ARCH_8	BIT(VM_HIGH_ARCH_BIT_8)
+#define VM_HIGH_ARCH_9	BIT(VM_HIGH_ARCH_BIT_9)
+#define VM_HIGH_ARCH_10	BIT(VM_HIGH_ARCH_BIT_10)
 #endif /* CONFIG_64BIT */
 
 #ifdef CONFIG_ARCH_HAS_PKEYS
@@ -385,8 +393,7 @@ extern unsigned int kobjsize(const void *objp);
 #endif
 
 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
-# define VM_UFFD_MINOR_BIT	41
-# define VM_UFFD_MINOR		BIT(VM_UFFD_MINOR_BIT)	/* UFFD minor faults */
+# define VM_UFFD_MINOR		VM_HIGH_ARCH_9	/* UFFD minor faults */
 #else /* !CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
 # define VM_UFFD_MINOR		VM_NONE
 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
@@ -399,15 +406,13 @@ extern unsigned int kobjsize(const void *objp);
  * if KVM does not lock down the memory type.
  */
 #ifdef CONFIG_64BIT
-#define VM_ALLOW_ANY_UNCACHED_BIT	39
-#define VM_ALLOW_ANY_UNCACHED		BIT(VM_ALLOW_ANY_UNCACHED_BIT)
+#define VM_ALLOW_ANY_UNCACHED		VM_HIGH_ARCH_7
 #else
 #define VM_ALLOW_ANY_UNCACHED		VM_NONE
 #endif
 
 #ifdef CONFIG_64BIT
-#define VM_DROPPABLE_BIT	40
-#define VM_DROPPABLE		BIT(VM_DROPPABLE_BIT)
+#define VM_DROPPABLE		VM_HIGH_ARCH_8
 #elif defined(CONFIG_PPC32)
 #define VM_DROPPABLE		VM_ARCH_1
 #else
@@ -416,7 +421,7 @@ extern unsigned int kobjsize(const void *objp);
 
 #ifdef CONFIG_64BIT
 /* VM is sealed, in vm_flags */
-#define VM_SEALED	_BITUL(63)
+#define VM_SEALED	VM_HIGH_ARCH_10
 #endif
 
 /* Bits set in the VMA until the stack is in its final location */
-- 
2.49.0.987.g0cc8ee98dc-goog