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linux/arch/m68k/mm/sun3mmu.c
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

101 lines
2.8 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/m68k/mm/sun3mmu.c
*
* Implementations of mm routines specific to the sun3 MMU.
*
* Moved here 8/20/1999 Sam Creasey
*
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <asm/setup.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include "../sun3/sun3.h"
const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
extern unsigned long num_pages;
/* For the sun3 we try to follow the i386 paging_init() more closely */
/* start_mem and end_mem have PAGE_OFFSET added already */
/* now sets up tables using sun3 PTEs rather than i386 as before. --m */
void __init paging_init(void)
{
pgd_t * pg_dir;
pte_t * pg_table;
int i;
unsigned long address;
unsigned long next_pgtable;
unsigned long bootmem_end;
unsigned long size;
address = PAGE_OFFSET;
pg_dir = swapper_pg_dir;
memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
memset (kernel_pg_dir, 0, sizeof (kernel_pg_dir));
size = num_pages * sizeof(pte_t);
size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
next_pgtable = (unsigned long)memblock_alloc_or_panic(size, PAGE_SIZE);
bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
/* Map whole memory from PAGE_OFFSET (0x0E000000) */
pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
while (address < (unsigned long)high_memory) {
pg_table = (pte_t *) __pa (next_pgtable);
next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
pgd_val(*pg_dir) = (unsigned long) pg_table;
pg_dir++;
/* now change pg_table to kernel virtual addresses */
pg_table = (pte_t *) __va ((unsigned long) pg_table);
for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
pte_t pte = pfn_pte(virt_to_pfn((void *)address), PAGE_INIT);
if (address >= (unsigned long)high_memory)
pte_val (pte) = 0;
set_pte (pg_table, pte);
address += PAGE_SIZE;
}
}
mmu_emu_init(bootmem_end);
current->mm = NULL;
}
static const pgprot_t protection_map[16] = {
[VM_NONE] = PAGE_NONE,
[VM_READ] = PAGE_READONLY,
[VM_WRITE] = PAGE_COPY,
[VM_WRITE | VM_READ] = PAGE_COPY,
[VM_EXEC] = PAGE_READONLY,
[VM_EXEC | VM_READ] = PAGE_READONLY,
[VM_EXEC | VM_WRITE] = PAGE_COPY,
[VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY,
[VM_SHARED] = PAGE_NONE,
[VM_SHARED | VM_READ] = PAGE_READONLY,
[VM_SHARED | VM_WRITE] = PAGE_SHARED,
[VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
[VM_SHARED | VM_EXEC] = PAGE_READONLY,
[VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY,
[VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED
};
DECLARE_VM_GET_PAGE_PROT
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