linux_dsm_epyc7002/arch/mips/mm/pgtable-64.c
David Daney f59a2d22a0 MIPS: Optimize pgd_init and pmd_init
On a dual issue processor GCC generates code that saves a couple of
clock cycles per loop if we rearrange things slightly.  Checking for
p != end saves a SLTU per loop, moving the increment to the middle can
let it dual issue on multi-issue processors.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4249/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-10-11 11:04:35 +02:00

81 lines
1.6 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999, 2000 by Silicon Graphics
* Copyright (C) 2003 by Ralf Baechle
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <asm/fixmap.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
void pgd_init(unsigned long page)
{
unsigned long *p, *end;
unsigned long entry;
#ifdef __PAGETABLE_PMD_FOLDED
entry = (unsigned long)invalid_pte_table;
#else
entry = (unsigned long)invalid_pmd_table;
#endif
p = (unsigned long *) page;
end = p + PTRS_PER_PGD;
do {
p[0] = entry;
p[1] = entry;
p[2] = entry;
p[3] = entry;
p[4] = entry;
p += 8;
p[-3] = entry;
p[-2] = entry;
p[-1] = entry;
} while (p != end);
}
#ifndef __PAGETABLE_PMD_FOLDED
void pmd_init(unsigned long addr, unsigned long pagetable)
{
unsigned long *p, *end;
p = (unsigned long *) addr;
end = p + PTRS_PER_PMD;
do {
p[0] = pagetable;
p[1] = pagetable;
p[2] = pagetable;
p[3] = pagetable;
p[4] = pagetable;
p += 8;
p[-3] = pagetable;
p[-2] = pagetable;
p[-1] = pagetable;
} while (p != end);
}
#endif
void __init pagetable_init(void)
{
unsigned long vaddr;
pgd_t *pgd_base;
/* Initialize the entire pgd. */
pgd_init((unsigned long)swapper_pg_dir);
#ifndef __PAGETABLE_PMD_FOLDED
pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
#endif
pgd_base = swapper_pg_dir;
/*
* Fixed mappings:
*/
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
fixrange_init(vaddr, vaddr + FIXADDR_SIZE, pgd_base);
}