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[S390] Cleanup page table definitions.
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- De-confuse the defines for the address-space-control-elements
  and the segment/region table entries.
- Create out of line functions for page table allocation / freeing.
- Simplify get_shadow_xxx functions.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky committed Oct 22, 2007
1 parent e4aa402 commit 3610cce
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Showing 9 changed files with 305 additions and 328 deletions.
2 changes: 1 addition & 1 deletion arch/s390/mm/Makefile
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Expand Up @@ -2,6 +2,6 @@
# Makefile for the linux s390-specific parts of the memory manager.
#

obj-y := init.o fault.o extmem.o mmap.o vmem.o
obj-y := init.o fault.o extmem.o mmap.o vmem.o pgtable.o
obj-$(CONFIG_CMM) += cmm.o

28 changes: 12 additions & 16 deletions arch/s390/mm/init.c
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Expand Up @@ -103,32 +103,28 @@ static void __init setup_ro_region(void)
*/
void __init paging_init(void)
{
pgd_t *pg_dir;
int i;
unsigned long pgdir_k;
static const int ssm_mask = 0x04000000L;
unsigned long max_zone_pfns[MAX_NR_ZONES];
unsigned long pgd_type;

pg_dir = swapper_pg_dir;

init_mm.pgd = swapper_pg_dir;
S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
#ifdef CONFIG_64BIT
pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
for (i = 0; i < PTRS_PER_PGD; i++)
pgd_clear_kernel(pg_dir + i);
S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
pgd_type = _REGION3_ENTRY_EMPTY;
#else
pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
for (i = 0; i < PTRS_PER_PGD; i++)
pmd_clear_kernel((pmd_t *)(pg_dir + i));
S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
pgd_type = _SEGMENT_ENTRY_EMPTY;
#endif
clear_table((unsigned long *) init_mm.pgd, pgd_type,
sizeof(unsigned long)*2048);
vmem_map_init();
setup_ro_region();

S390_lowcore.kernel_asce = pgdir_k;

/* enable virtual mapping in kernel mode */
__ctl_load(pgdir_k, 1, 1);
__ctl_load(pgdir_k, 7, 7);
__ctl_load(pgdir_k, 13, 13);
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
__ctl_load(S390_lowcore.kernel_asce, 7, 7);
__ctl_load(S390_lowcore.kernel_asce, 13, 13);
__raw_local_irq_ssm(ssm_mask);

memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
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94 changes: 94 additions & 0 deletions arch/s390/mm/pgtable.c
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@@ -0,0 +1,94 @@
/*
* arch/s390/mm/pgtable.c
*
* Copyright IBM Corp. 2007
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/quicklist.h>

#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>

#ifndef CONFIG_64BIT
#define ALLOC_ORDER 1
#else
#define ALLOC_ORDER 2
#endif

unsigned long *crst_table_alloc(struct mm_struct *mm, int noexec)
{
struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);

if (!page)
return NULL;
page->index = 0;
if (noexec) {
struct page *shadow = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
if (!shadow) {
__free_pages(page, ALLOC_ORDER);
return NULL;
}
page->index = page_to_phys(shadow);
}
return (unsigned long *) page_to_phys(page);
}

void crst_table_free(unsigned long *table)
{
unsigned long *shadow = get_shadow_table(table);

if (shadow)
free_pages((unsigned long) shadow, ALLOC_ORDER);
free_pages((unsigned long) table, ALLOC_ORDER);
}

/*
* page table entry allocation/free routines.
*/
unsigned long *page_table_alloc(int noexec)
{
struct page *page = alloc_page(GFP_KERNEL);
unsigned long *table;

if (!page)
return NULL;
page->index = 0;
if (noexec) {
struct page *shadow = alloc_page(GFP_KERNEL);
if (!shadow) {
__free_page(page);
return NULL;
}
table = (unsigned long *) page_to_phys(shadow);
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
page->index = (addr_t) table;
}
table = (unsigned long *) page_to_phys(page);
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
return table;
}

void page_table_free(unsigned long *table)
{
unsigned long *shadow = get_shadow_pte(table);

if (shadow)
free_page((unsigned long) shadow);
free_page((unsigned long) table);

}
19 changes: 7 additions & 12 deletions arch/s390/mm/vmem.c
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Expand Up @@ -75,29 +75,24 @@ static void __init_refok *vmem_alloc_pages(unsigned int order)

static inline pmd_t *vmem_pmd_alloc(void)
{
pmd_t *pmd;
int i;
pmd_t *pmd = NULL;

pmd = vmem_alloc_pages(PMD_ALLOC_ORDER);
#ifdef CONFIG_64BIT
pmd = vmem_alloc_pages(2);
if (!pmd)
return NULL;
for (i = 0; i < PTRS_PER_PMD; i++)
pmd_clear_kernel(pmd + i);
clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE*4);
#endif
return pmd;
}

static inline pte_t *vmem_pte_alloc(void)
{
pte_t *pte;
pte_t empty_pte;
int i;
pte_t *pte = vmem_alloc_pages(0);

pte = vmem_alloc_pages(PTE_ALLOC_ORDER);
if (!pte)
return NULL;
pte_val(empty_pte) = _PAGE_TYPE_EMPTY;
for (i = 0; i < PTRS_PER_PTE; i++)
pte[i] = empty_pte;
clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY, PAGE_SIZE);
return pte;
}

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50 changes: 24 additions & 26 deletions include/asm-s390/mmu_context.h
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Expand Up @@ -21,45 +21,43 @@

#ifndef __s390x__
#define LCTL_OPCODE "lctl"
#define PGTABLE_BITS (_SEGMENT_TABLE|USER_STD_MASK)
#else
#define LCTL_OPCODE "lctlg"
#define PGTABLE_BITS (_REGION_TABLE|USER_STD_MASK)
#endif

static inline void enter_lazy_tlb(struct mm_struct *mm,
struct task_struct *tsk)
static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
{
pgd_t *pgd = mm->pgd;
unsigned long asce_bits;

/* Calculate asce bits from the first pgd table entry. */
asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
#ifdef CONFIG_64BIT
asce_bits |= _ASCE_TYPE_REGION3;
#endif
S390_lowcore.user_asce = asce_bits | __pa(pgd);
if (switch_amode) {
/* Load primary space page table origin. */
pgd_t *shadow_pgd = get_shadow_table(pgd) ? : pgd;
S390_lowcore.user_exec_asce = asce_bits | __pa(shadow_pgd);
asm volatile(LCTL_OPCODE" 1,1,%0\n"
: : "m" (S390_lowcore.user_exec_asce) );
} else
/* Load home space page table origin. */
asm volatile(LCTL_OPCODE" 13,13,%0"
: : "m" (S390_lowcore.user_asce) );
}

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
pgd_t *shadow_pgd = get_shadow_pgd(next->pgd);

if (prev != next) {
S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
PGTABLE_BITS;
if (shadow_pgd) {
/* Load primary/secondary space page table origin. */
S390_lowcore.user_exec_asce =
(__pa(shadow_pgd) & PAGE_MASK) | PGTABLE_BITS;
asm volatile(LCTL_OPCODE" 1,1,%0\n"
LCTL_OPCODE" 7,7,%1"
: : "m" (S390_lowcore.user_exec_asce),
"m" (S390_lowcore.user_asce) );
} else if (switch_amode) {
/* Load primary space page table origin. */
asm volatile(LCTL_OPCODE" 1,1,%0"
: : "m" (S390_lowcore.user_asce) );
} else
/* Load home space page table origin. */
asm volatile(LCTL_OPCODE" 13,13,%0"
: : "m" (S390_lowcore.user_asce) );
}
if (unlikely(prev == next))
return;
cpu_set(smp_processor_id(), next->cpu_vm_mask);
update_mm(next, tsk);
}

#define enter_lazy_tlb(mm,tsk) do { } while (0)
#define deactivate_mm(tsk,mm) do { } while (0)

static inline void activate_mm(struct mm_struct *prev,
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