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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/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: Helge Deller <[email protected]>		[parisc]
Tested-by: Helge Deller <[email protected]>		[parisc]
Reviewed-by: Christophe Leroy (CS GROUP) <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Magnus Lindholm <[email protected]>	[alpha]
Acked-by: Dinh Nguyen <[email protected]>	[nios2]
Acked-by: Andreas Larsson <[email protected]>	[sparc]
Acked-by: David Hildenbrand (Arm) <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Cc: "Borislav Petkov (AMD)" <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: John Paul Adrian Glaubitz <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Russell King <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2026-04-05 13:53:01 -07:00

71 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Just a place holder.
*/
#ifndef _SPARC_SETUP_H
#define _SPARC_SETUP_H
#include <linux/interrupt.h>
#include <uapi/asm/setup.h>
extern char reboot_command[];
#ifdef CONFIG_SPARC32
/* The CPU that was used for booting
* Only sun4d + leon may have boot_cpu_id != 0
*/
extern unsigned char boot_cpu_id;
extern int serial_console;
static inline int con_is_present(void)
{
return serial_console ? 0 : 1;
}
/* from irq_32.c */
extern volatile unsigned char *fdc_status;
extern char *pdma_vaddr;
extern unsigned long pdma_size;
extern volatile int doing_pdma;
/* This is software state */
extern char *pdma_base;
extern unsigned long pdma_areasize;
int sparc_floppy_request_irq(unsigned int irq, irq_handler_t irq_handler);
/* setup_32.c */
extern unsigned long cmdline_memory_size;
/* devices.c */
void __init device_scan(void);
/* unaligned_32.c */
unsigned long safe_compute_effective_address(struct pt_regs *, unsigned int);
#endif
#ifdef CONFIG_SPARC64
void __init start_early_boot(void);
/* unaligned_64.c */
int handle_ldf_stq(u32 insn, struct pt_regs *regs);
void handle_ld_nf(u32 insn, struct pt_regs *regs);
/* init_64.c */
extern atomic_t dcpage_flushes;
extern atomic_t dcpage_flushes_xcall;
extern int sysctl_tsb_ratio;
#ifdef CONFIG_SERIAL_SUNHV
void sunhv_migrate_hvcons_irq(int cpu);
#endif
#endif
void sun_do_break(void);
extern int stop_a_enabled;
extern int scons_pwroff;
#endif /* _SPARC_SETUP_H */