Commit fac7757e authored Jun 30, 2021 by Anshuman Khandual Committed by Linus Torvalds Jul 01, 2021

mm: define default value for FIRST_USER_ADDRESS

Currently most platforms define FIRST_USER_ADDRESS as 0UL duplication the
same code all over.  Instead just define a generic default value (i.e 0UL)
for FIRST_USER_ADDRESS and let the platforms override when required.  This
makes it much cleaner with reduced code.

The default FIRST_USER_ADDRESS here would be skipped in <linux/pgtable.h>
when the given platform overrides its value via <asm/pgtable.h>.

Link: https://lkml.kernel.org/r/1620615725-24623-1-git-send-email-anshuman.khandual@arm.com


Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Stafford Horne <shorne@gmail.com>		[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>	[RISC-V]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c4ffefd1

arch/alpha/include/asm/pgtable.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -46,7 +46,6 @@ struct vm_area_struct;
		#define PTRS_PER_PMD (1UL << (PAGE_SHIFT-3))
		#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-3))
		#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
		#define FIRST_USER_ADDRESS 0UL

		/* Number of pointers that fit on a page: this will go away. */
		#define PTRS_PER_PAGE (1UL << (PAGE_SHIFT-3))

arch/arc/include/asm/pgtable.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -222,12 +222,6 @@
		*/
		#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)

		/*
		* No special requirements for lowest virtual address we permit any user space
		* mapping to be mapped at.
		*/
		#define FIRST_USER_ADDRESS 0UL


		/****************************************************************
		* Bucket load of VM Helpers

arch/arm64/include/asm/pgtable.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -26,8 +26,6 @@

		#define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))

		#define FIRST_USER_ADDRESS 0UL

		#ifndef __ASSEMBLY__

		#include <asm/cmpxchg.h>

arch/csky/include/asm/pgtable.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -14,7 +14,6 @@
		#define PGDIR_MASK (~(PGDIR_SIZE-1))

		#define USER_PTRS_PER_PGD (PAGE_OFFSET/PGDIR_SIZE)
		#define FIRST_USER_ADDRESS 0UL

		/*
		* C-SKY is two-level paging structure:

arch/hexagon/include/asm/pgtable.h

+0 −3

Original line number	Diff line number	Diff line
		@@ -155,9 +155,6 @@ extern unsigned long _dflt_cache_att;

		extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* located in head.S */

		/* Seems to be zero even in architectures where the zero page is firewalled? */
		#define FIRST_USER_ADDRESS 0UL

		/* HUGETLB not working currently */
		#ifdef CONFIG_HUGETLB_PAGE
		#define pte_mkhuge(pte) __pte((pte_val(pte) & ~0x3) \| HVM_HUGEPAGE_SIZE)