On Fri, Apr 16, 2021 at 10:47:34AM +0530, Anshuman Khandual wrote:

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>.

Cc: Richard Henderson <redacted>
Cc: Vineet Gupta <redacted>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <redacted>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <redacted>
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 <redacted>
Cc: Paul Walmsley <redacted>
Cc: Palmer Dabbelt <palmer@dabbelt.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 <redacted>
Cc: Thomas Gleixner <redacted>
Cc: Chris Zankel <chris@zankel.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <redacted>
---
This applies on v5.12-rc7 and has been boot tested on arm64 platform.
But has been cross compiled on multiple other platforms.

Changes in V2:

- Dropped ARCH_HAS_FIRST_USER_ADDRESS construct

Changes in V1:

https://patchwork.kernel.org/project/linux-mm/patch/1618368899-20311-1-git-send-email-anshuman.khandual@arm.com/

 arch/alpha/include/asm/pgtable.h             | 1 -
 arch/arc/include/asm/pgtable.h               | 6 ------
 arch/arm64/include/asm/pgtable.h             | 2 --
 arch/csky/include/asm/pgtable.h              | 1 -
 arch/hexagon/include/asm/pgtable.h           | 3 ---
 arch/ia64/include/asm/pgtable.h              | 1 -
 arch/m68k/include/asm/pgtable_mm.h           | 1 -
 arch/microblaze/include/asm/pgtable.h        | 2 --
 arch/mips/include/asm/pgtable-32.h           | 1 -
 arch/mips/include/asm/pgtable-64.h           | 1 -
 arch/nios2/include/asm/pgtable.h             | 2 --
 arch/openrisc/include/asm/pgtable.h          | 1 -

Acked-by: Stafford Horne <shorne@gmail.com>

 arch/parisc/include/asm/pgtable.h            | 2 --
 arch/powerpc/include/asm/book3s/pgtable.h    | 1 -
 arch/powerpc/include/asm/nohash/32/pgtable.h | 1 -
 arch/powerpc/include/asm/nohash/64/pgtable.h | 2 --
 arch/riscv/include/asm/pgtable.h             | 2 --
 arch/s390/include/asm/pgtable.h              | 2 --
 arch/sh/include/asm/pgtable.h                | 2 --
 arch/sparc/include/asm/pgtable_32.h          | 1 -
 arch/sparc/include/asm/pgtable_64.h          | 3 ---
 arch/um/include/asm/pgtable-2level.h         | 1 -
 arch/um/include/asm/pgtable-3level.h         | 1 -
 arch/x86/include/asm/pgtable_types.h         | 2 --
 arch/xtensa/include/asm/pgtable.h            | 1 -
 include/linux/pgtable.h                      | 9 +++++++++
 26 files changed, 9 insertions(+), 43 deletions(-)

This all looks fine to me, will this be merged via the arm tree?  I guess you
have a means for that.

-Stafford