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s390/mm,vmem: use 2GB frames for identity mapping

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Use 2GB frames for indentity mapping if EDAT2 is
available to reduce TLB pressure.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2012-10-08 09:18:26 +02:00 committed by Martin Schwidefsky
parent 26d29d06ea
commit 18da236908
4 changed files with 33 additions and 6 deletions
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10
arch/s390/include/asm/pgtable.h
View File

@ -345,6 +345,8 @@ extern unsigned long MODULES_END;
#define _REGION3_ENTRY (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH)
#define _REGION3_ENTRY_EMPTY (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INV)
#define _REGION3_ENTRY_LARGE 0x400 /* RTTE-format control, large page */
/* Bits in the segment table entry */
#define _SEGMENT_ENTRY_ORIGIN ~0x7ffUL/* segment table origin */
#define _SEGMENT_ENTRY_RO 0x200 /* page protection bit */
@ -444,6 +446,7 @@ static inline int pgd_bad(pgd_t pgd) { return 0; }
static inline int pud_present(pud_t pud) { return 1; }
static inline int pud_none(pud_t pud) { return 0; }
static inline int pud_large(pud_t pud) { return 0; }
static inline int pud_bad(pud_t pud) { return 0; }
#else /* CONFIG_64BIT */
@ -489,6 +492,13 @@ static inline int pud_none(pud_t pud)
return (pud_val(pud) & _REGION_ENTRY_INV) != 0UL;
}
static inline int pud_large(pud_t pud)
{
if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) != _REGION_ENTRY_TYPE_R3)
return 0;
return !!(pud_val(pud) & _REGION3_ENTRY_LARGE);
}
static inline int pud_bad(pud_t pud)
{
/*

7
arch/s390/mm/dump_pagetables.c
View File

@ -150,6 +150,7 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st,
static void walk_pud_level(struct seq_file *m, struct pg_state *st,
pgd_t *pgd, unsigned long addr)
{
unsigned int prot;
pud_t *pud;
int i;
@ -157,7 +158,11 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st,
st->current_address = addr;
pud = pud_offset(pgd, addr);
if (!pud_none(*pud))
walk_pmd_level(m, st, pud, addr);
if (pud_large(*pud)) {
prot = pud_val(*pud) & _PAGE_RO;
note_page(m, st, prot, 2);
} else
walk_pmd_level(m, st, pud, addr);
else
note_page(m, st, _PAGE_INVALID, 2);
addr += PUD_SIZE;

2
arch/s390/mm/pageattr.c
View File

@ -19,7 +19,7 @@ static pte_t *walk_page_table(unsigned long addr)
if (pgd_none(*pgdp))
return NULL;
pudp = pud_offset(pgdp, addr);
if (pud_none(*pudp))
if (pud_none(*pudp) || pud_large(*pudp))
return NULL;
pmdp = pmd_offset(pudp, addr);
if (pmd_none(*pmdp) || pmd_large(*pmdp))

20
arch/s390/mm/vmem.c
View File

@ -89,6 +89,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
int ret = -ENOMEM;
while (address < end) {
pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
@ -96,18 +97,24 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
goto out;
pgd_populate(&init_mm, pg_dir, pu_dir);
}
pu_dir = pud_offset(pg_dir, address);
#if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
!(address & ~PUD_MASK) && (address + PUD_SIZE <= end)) {
pte_val(pte) |= _REGION3_ENTRY_LARGE;
pte_val(pte) |= _REGION_ENTRY_TYPE_R3;
pud_val(*pu_dir) = pte_val(pte);
address += PUD_SIZE;
continue;
}
#endif
if (pud_none(*pu_dir)) {
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
pud_populate(&init_mm, pu_dir, pm_dir);
}
pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
pm_dir = pmd_offset(pu_dir, address);
#if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
!(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) {
@ -160,6 +167,11 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
address += PUD_SIZE;
continue;
}
if (pud_large(*pu_dir)) {
pud_clear(pu_dir);
address += PUD_SIZE;
continue;
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
address += PMD_SIZE;