Re: [PATCH V2] mm: Define default value for FIRST_USER_ADDRESS

From: Anshuman Khandual
Date: Sun Apr 25 2021 - 20:06:04 EST




On 4/16/21 10:47 AM, 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 <rth@xxxxxxxxxxx>
> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Guo Ren <guoren@xxxxxxxxxx>
> Cc: Brian Cain <bcain@xxxxxxxxxxxxxx>
> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Cc: Michal Simek <monstr@xxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Ley Foon Tan <ley.foon.tan@xxxxxxxxx>
> Cc: Jonas Bonn <jonas@xxxxxxxxxxxx>
> Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx>
> Cc: Stafford Horne <shorne@xxxxxxxxx>
> Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Jeff Dike <jdike@xxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Chris Zankel <chris@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: linux-arch@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> 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

Gentle ping. Any updates on this ?

- Anshuman