linux_dsm_epyc7002/arch/s390/mm/pageattr.c
Martin Schwidefsky b2fa47e6bf [S390] refactor page table functions for better pgste support
Rework the architecture page table functions to access the bits in the
page table extension array (pgste). There are a number of changes:
1) Fix missing pgste update if the attach_count for the mm is <= 1.
2) For every operation that affects the invalid bit in the pte or the
   rcp byte in the pgste the pcl lock needs to be acquired. The function
   pgste_get_lock gets the pcl lock and returns the current pgste value
   for a pte pointer. The function pgste_set_unlock stores the pgste
   and releases the lock. Between these two calls the bits in the pgste
   can be shuffled.
3) Define two software bits in the pte _PAGE_SWR and _PAGE_SWC to avoid
   calling SetPageDirty and SetPageReferenced from pgtable.h. If the
   host reference backup bit or the host change backup bit has been
   set the dirty/referenced state is transfered to the pte. The common
   code will pick up the state from the pte.
4) Add ptep_modify_prot_start and ptep_modify_prot_commit for mprotect.
5) Remove pgd_populate_kernel, pud_populate_kernel, pmd_populate_kernel
   pgd_clear_kernel, pud_clear_kernel, pmd_clear_kernel and ptep_invalidate.
6) Rename kvm_s390_test_and_clear_page_dirty to
   ptep_test_and_clear_user_dirty and add ptep_test_and_clear_user_young.
7) Define mm_exclusive() and mm_has_pgste() helper to improve readability.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23 10:24:31 +02:00

62 lines
1.2 KiB
C

/*
* Copyright IBM Corp. 2011
* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <asm/pgtable.h>
static void change_page_attr(unsigned long addr, int numpages,
pte_t (*set) (pte_t))
{
pte_t *ptep, pte;
pmd_t *pmdp;
pud_t *pudp;
pgd_t *pgdp;
int i;
for (i = 0; i < numpages; i++) {
pgdp = pgd_offset(&init_mm, addr);
pudp = pud_offset(pgdp, addr);
pmdp = pmd_offset(pudp, addr);
if (pmd_huge(*pmdp)) {
WARN_ON_ONCE(1);
continue;
}
ptep = pte_offset_kernel(pmdp, addr);
pte = *ptep;
pte = set(pte);
__ptep_ipte(addr, ptep);
*ptep = pte;
addr += PAGE_SIZE;
}
}
int set_memory_ro(unsigned long addr, int numpages)
{
change_page_attr(addr, numpages, pte_wrprotect);
return 0;
}
EXPORT_SYMBOL_GPL(set_memory_ro);
int set_memory_rw(unsigned long addr, int numpages)
{
change_page_attr(addr, numpages, pte_mkwrite);
return 0;
}
EXPORT_SYMBOL_GPL(set_memory_rw);
/* not possible */
int set_memory_nx(unsigned long addr, int numpages)
{
return 0;
}
EXPORT_SYMBOL_GPL(set_memory_nx);
int set_memory_x(unsigned long addr, int numpages)
{
return 0;
}