Files
linux/arch/powerpc/include/asm/page_64.h
Lorenzo Stoakes (Oracle) 3a6455d56b mm: convert do_brk_flags() to use vma_flags_t
In order to be able to do this, we need to change VM_DATA_DEFAULT_FLAGS
and friends and update the architecture-specific definitions also.

We then have to update some KSM logic to handle VMA flags, and introduce
VMA_STACK_FLAGS to define the vma_flags_t equivalent of VM_STACK_FLAGS.

We also introduce two helper functions for use during the time we are
converting legacy flags to vma_flags_t values - vma_flags_to_legacy() and
legacy_to_vma_flags().

This enables us to iteratively make changes to break these changes up into
separate parts.

We use these explicitly here to keep VM_STACK_FLAGS around for certain
users which need to maintain the legacy vm_flags_t values for the time
being.

We are no longer able to rely on the simple VM_xxx being set to zero if
the feature is not enabled, so in the case of VM_DROPPABLE we introduce
VMA_DROPPABLE as the vma_flags_t equivalent, which is set to
EMPTY_VMA_FLAGS if the droppable flag is not available.

While we're here, we make the description of do_brk_flags() into a kdoc
comment, as it almost was already.

We use vma_flags_to_legacy() to not need to update the vm_get_page_prot()
logic as this time.

Note that in create_init_stack_vma() we have to replace the BUILD_BUG_ON()
with a VM_WARN_ON_ONCE() as the tested values are no longer build time
available.

We also update mprotect_fixup() to use VMA flags where possible, though we
have to live with a little duplication between vm_flags_t and vma_flags_t
values for the time being until further conversions are made.

While we're here, update VM_SPECIAL to be defined in terms of
VMA_SPECIAL_FLAGS now we have vma_flags_to_legacy().

Finally, we update the VMA tests to reflect these changes.

Link: https://lkml.kernel.org/r/d02e3e45d9a33d7904b149f5604904089fd640ae.1774034900.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>	[SELinux]
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05 13:53:40 -07:00

107 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ASM_POWERPC_PAGE_64_H
#define _ASM_POWERPC_PAGE_64_H
/*
* Copyright (C) 2001 PPC64 Team, IBM Corp
*/
#include <asm/asm-const.h>
/*
* We always define HW_PAGE_SHIFT to 12 as use of 64K pages remains Linux
* specific, every notion of page number shared with the firmware, TCEs,
* iommu, etc... still uses a page size of 4K.
*/
#define HW_PAGE_SHIFT 12
#define HW_PAGE_SIZE (ASM_CONST(1) << HW_PAGE_SHIFT)
#define HW_PAGE_MASK (~(HW_PAGE_SIZE-1))
/*
* PAGE_FACTOR is the number of bits factor between PAGE_SHIFT and
* HW_PAGE_SHIFT, that is 4K pages.
*/
#define PAGE_FACTOR (PAGE_SHIFT - HW_PAGE_SHIFT)
/* Segment size; normal 256M segments */
#define SID_SHIFT 28
#define SID_MASK ASM_CONST(0xfffffffff)
#define ESID_MASK 0xfffffffff0000000UL
#define GET_ESID(x) (((x) >> SID_SHIFT) & SID_MASK)
/* 1T segments */
#define SID_SHIFT_1T 40
#define SID_MASK_1T 0xffffffUL
#define ESID_MASK_1T 0xffffff0000000000UL
#define GET_ESID_1T(x) (((x) >> SID_SHIFT_1T) & SID_MASK_1T)
#ifndef __ASSEMBLER__
#include <asm/cache.h>
typedef unsigned long pte_basic_t;
static inline void clear_page(void *addr)
{
unsigned long iterations;
unsigned long onex, twox, fourx, eightx;
iterations = ppc64_caches.l1d.blocks_per_page / 8;
/*
* Some verisions of gcc use multiply instructions to
* calculate the offsets so lets give it a hand to
* do better.
*/
onex = ppc64_caches.l1d.block_size;
twox = onex << 1;
fourx = onex << 2;
eightx = onex << 3;
asm volatile(
"mtctr %1 # clear_page\n\
.balign 16\n\
1: dcbz 0,%0\n\
dcbz %3,%0\n\
dcbz %4,%0\n\
dcbz %5,%0\n\
dcbz %6,%0\n\
dcbz %7,%0\n\
dcbz %8,%0\n\
dcbz %9,%0\n\
add %0,%0,%10\n\
bdnz+ 1b"
: "=&r" (addr)
: "r" (iterations), "0" (addr), "b" (onex), "b" (twox),
"b" (twox+onex), "b" (fourx), "b" (fourx+onex),
"b" (twox+fourx), "b" (eightx-onex), "r" (eightx)
: "ctr", "memory");
}
extern void copy_page(void *to, void *from);
/* Log 2 of page table size */
extern u64 ppc64_pft_size;
#endif /* __ASSEMBLER__ */
#define VMA_DATA_DEFAULT_FLAGS \
(is_32bit_task() ? \
VMA_DATA_DEFAULT_FLAGS32 : VMA_DATA_DEFAULT_FLAGS64)
/*
* This is the default if a program doesn't have a PT_GNU_STACK
* program header entry. The PPC64 ELF ABI has a non executable stack
* stack by default, so in the absence of a PT_GNU_STACK program header
* we turn execute permission off.
*/
#define VMA_STACK_DEFAULT_FLAGS32 VMA_DATA_FLAGS_EXEC
#define VMA_STACK_DEFAULT_FLAGS64 VMA_DATA_FLAGS_NON_EXEC
#define VMA_STACK_DEFAULT_FLAGS \
(is_32bit_task() ? \
VMA_STACK_DEFAULT_FLAGS32 : VMA_STACK_DEFAULT_FLAGS64)
#include <asm-generic/getorder.h>
#endif /* _ASM_POWERPC_PAGE_64_H */