mm/mmap: build protect protection_map[] with __P000

Patch series "mm/mmap: Drop __SXXX/__PXXX macros from across platforms",
v7.

__SXXX/__PXXX macros are unnecessary abstraction layer in creating the
generic protection_map[] array which is used for vm_get_page_prot().  This
abstraction layer can be avoided, if the platforms just define the array
protection_map[] for all possible vm_flags access permission combinations
and also export vm_get_page_prot() implementation.

This series drops __SXXX/__PXXX macros from across platforms in the tree. 
First it build protects generic protection_map[] array with '#ifdef
__P000' and moves it inside platforms which enable
ARCH_HAS_VM_GET_PAGE_PROT.  Later this build protects same array with
'#ifdef ARCH_HAS_VM_GET_PAGE_PROT' and moves inside remaining platforms
while enabling ARCH_HAS_VM_GET_PAGE_PROT.  This adds a new macro
DECLARE_VM_GET_PAGE_PROT defining the current generic vm_get_page_prot(),
in order for it to be reused on platforms that do not require custom
implementation.  Finally, ARCH_HAS_VM_GET_PAGE_PROT can just be dropped,
as all platforms now define and export vm_get_page_prot(), via looking up
a private and static protection_map[] array.  protection_map[] data type
has been changed as 'static const' on all platforms that do not change it
during boot.


This patch (of 26):

Build protect generic protection_map[] array with __P000, so that it can
be moved inside all the platforms one after the other.  Otherwise there
will be build failures during this process. 
CONFIG_ARCH_HAS_VM_GET_PAGE_PROT cannot be used for this purpose as only
certain platforms enable this config now.

Link: https://lkml.kernel.org/r/20220711070600.2378316-1-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/20220711070600.2378316-2-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.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: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Anshuman Khandual 2022-07-11 12:35:35 +05:30 committed by akpm
parent 9330723c26
commit 840532711d
2 changed files with 4 additions and 0 deletions

View File

@ -425,7 +425,9 @@ extern unsigned int kobjsize(const void *objp);
* mapping from the currently active vm_flags protection bits (the * mapping from the currently active vm_flags protection bits (the
* low four bits) to a page protection mask.. * low four bits) to a page protection mask..
*/ */
#ifdef __P000
extern pgprot_t protection_map[16]; extern pgprot_t protection_map[16];
#endif
/* /*
* The default fault flags that should be used by most of the * The default fault flags that should be used by most of the

View File

@ -101,6 +101,7 @@ static void unmap_region(struct mm_struct *mm,
* w: (no) no * w: (no) no
* x: (yes) yes * x: (yes) yes
*/ */
#ifdef __P000
pgprot_t protection_map[16] __ro_after_init = { pgprot_t protection_map[16] __ro_after_init = {
[VM_NONE] = __P000, [VM_NONE] = __P000,
[VM_READ] = __P001, [VM_READ] = __P001,
@ -119,6 +120,7 @@ pgprot_t protection_map[16] __ro_after_init = {
[VM_SHARED | VM_EXEC | VM_WRITE] = __S110, [VM_SHARED | VM_EXEC | VM_WRITE] = __S110,
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __S111 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __S111
}; };
#endif
#ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT #ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT
pgprot_t vm_get_page_prot(unsigned long vm_flags) pgprot_t vm_get_page_prot(unsigned long vm_flags)