linux/arch/microblaze/kernel
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>
2026-04-05 13:53:01 -07:00
..
cpu microblaze: mb: Use str_yes_no() helper in show_cpuinfo() 2024-11-15 10:27:48 +01:00
syscalls rseq: Implement sys_rseq_slice_yield() 2026-01-22 11:11:17 +01:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
asm-offsets.c arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c 2025-09-25 09:57:15 +02:00
dma.c dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h> 2020-10-06 07:07:06 +02:00
entry.S microblaze: Add support for error injection 2022-09-26 14:13:29 +02:00
exceptions.c exit: Add and use make_task_dead. 2021-12-13 12:04:45 -06:00
ftrace.c ftrace: Cleanup ftrace_dyn_arch_init() 2021-10-08 19:41:39 -04:00
head.S arch, mm: consolidate empty_zero_page 2026-04-05 13:53:01 -07:00
hw_exception_handler.S microblaze: Remove noMMU code 2020-11-26 16:39:35 +01:00
irq.c irqchip/xilinx: Switch to GENERIC_IRQ_MULTI_HANDLER 2022-03-04 14:32:57 +00:00
kgdb.c microblaze: fix typos in comments 2022-05-02 08:36:10 +02:00
Makefile arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds 2025-06-07 14:38:07 +09:00
mcount.S
microblaze_ksyms.c arch, mm: consolidate empty_zero_page 2026-04-05 13:53:01 -07:00
misc.S microblaze: Add sync to tlb operations 2020-02-25 12:33:19 +01:00
module.c microblaze: Remove support for gcc < 4 2021-02-11 18:54:08 +01:00
process.c arch: copy_thread: pass clone_flags as u64 2025-09-01 15:31:34 +02:00
prom.c of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify 2024-10-29 15:32:45 -05:00
ptrace.c ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h 2022-03-10 13:35:08 -06:00
reset.c microblaze: Explicitly include correct DT includes 2023-07-17 08:22:42 +02:00
setup.c microblaze: Remove noMMU code 2020-11-26 16:39:35 +01:00
signal.c microblaze: allow pte_offset_map() to fail 2023-06-19 16:19:06 -07:00
stacktrace.c microblaze: add loglvl to microblaze_unwind() 2020-06-09 09:39:11 -07:00
sys_microblaze.c syscalls: mmap(): use unsigned offset type consistently 2024-06-25 15:57:38 +02:00
syscall_table.S microblaze: syscalls: switch to generic syscalltbl.sh 2021-03-02 13:21:22 +01:00
timer.c time/timecounter: Fix the lie that struct cyclecounter is const 2025-07-01 15:38:25 +02:00
traps.c arch: include linux/cpu.h for trap_init() prototype 2023-11-23 11:32:31 +01:00
unwind.c microblaze: Remove noMMU code 2020-11-26 16:39:35 +01:00
vmlinux.lds.S objtool/idle: Validate __cpuidle code as noinstr 2023-01-13 11:48:15 +01:00