linux/arch/riscv
Mike Rapoport (Microsoft) 6215d9f447 arch, mm: consolidate empty_zero_page
Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of
ZERO_PAGE() to 4.

Every architecture defines empty_zero_page that way or another, but for the
most of them it is always a page aligned page in BSS and most definitions
of ZERO_PAGE do virt_to_page(empty_zero_page).

Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the
core MM and drop these definitions in architectures that do not implement
colored zero page (MIPS and s390).

ZERO_PAGE() remains a macro because turning it to a wrapper for a static
inline causes severe pain in header dependencies.

For the most part the change is mechanical, with these being noteworthy:

* alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot
  parameters. Switching to a generic empty_zero_page removes the aliasing
  and keeps ZERO_PGE for boot parameters only
* arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of
  ZERO_PAGE() is kept intact.
* m68k/parisc/um: allocated empty_zero_page from memblock,
  although they do not support zero page coloring and having it in BSS
  will work fine.
* sparc64 can have empty_zero_page in BSS rather allocate it, but it
  can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE()
  but instead of allocating it, make mem_map_zero point to
  empty_zero_page.
* sh: used empty_zero_page for boot parameters at the very early boot.
  Rename the parameters page to boot_params_page and let sh use the generic
  empty_zero_page.
* hexagon: had an amusing comment about empty_zero_page

	/* A handy thing to have if one has the RAM. Declared in head.S */

  that unfortunately had to go :)

Link: https://lkml.kernel.org/r/20260211103141.3215197-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>		[parisc]
Tested-by: Helge Deller <deller@gmx.de>		[parisc]
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Magnus Lindholm <linmag7@gmail.com>	[alpha]
Acked-by: Dinh Nguyen <dinguyen@kernel.org>	[nios2]
Acked-by: Andreas Larsson <andreas@gaisler.com>	[sparc]
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
History 2026-04-05 13:53:01 -07:00
..
boot RISC-V soc fixes for v7.0-rc1 2026-03-04 21:35:06 +01:00
configs RISC-V updates for v7.0 2026-02-12 19:17:44 -08:00
crypto lib/crypto: riscv/aes: Migrate optimized code into library 2026-01-12 11:39:58 -08:00
errata errata/sifive: remove unreliable warn_miss_errata 2026-01-25 21:09:04 -07:00
include arch, mm: consolidate empty_zero_page 2026-04-05 13:53:01 -07:00
kernel kbuild: Split .modinfo out from ELF_DETAILS 2026-02-26 11:50:19 -07:00
kvm KVM generic changes for 7.0 2026-03-11 18:01:55 +01:00
lib riscv: lib: optimize strlen loop efficiency 2026-02-09 15:27:33 -07:00
mm arch, mm: consolidate empty_zero_page 2026-04-05 13:53:01 -07:00
net Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
purgatory kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI 2025-09-24 14:29:14 -07:00
tools riscv: Stop considering R_RISCV_NONE as bad relocations 2025-07-16 08:13:55 -07:00
Kbuild riscv: migrate to the generic rule for built-in DTB 2025-03-18 13:30:13 +00:00
Kconfig RISC-V updates for v7.0 2026-02-12 19:17:44 -08:00
Kconfig.debug riscv: Add tests for riscv module loading 2023-11-07 14:59:32 -08:00
Kconfig.errata riscv: ERRATA_STARFIVE_JH7100: Fix missing dependency on new CONFIG_CACHEMAINT_FOR_DMA 2026-01-15 18:13:04 -07:00
Kconfig.socs Initial Anlogic Platform Support 2025-11-21 21:29:57 +01:00
Kconfig.vendor riscv: Add xmipsexectl as a vendor extension 2025-09-18 20:36:00 -06:00
Makefile arch/riscv: add dual vdso creation logic and select vdso based on hw 2026-01-29 02:38:40 -07:00
Makefile.postlink kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00