mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 02:23:16 +00:00
0944fe3f4a
The last remaining use for the storage key of the s390 architecture is reference counting. The alternative is to make page table entries invalid while they are old. On access the fault handler marks the pte/pmd as young which makes the pte/pmd valid if the access rights allow read access. The pte/pmd invalidations required for software managed reference bits cost a bit of performance, on the other hand the RRBE/RRBM instructions to read and reset the referenced bits are quite expensive as well. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
429 lines
9.6 KiB
C
429 lines
9.6 KiB
C
/*
|
|
* Copyright IBM Corp. 2006
|
|
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/bootmem.h>
|
|
#include <linux/pfn.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
#include <linux/list.h>
|
|
#include <linux/hugetlb.h>
|
|
#include <linux/slab.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sections.h>
|
|
|
|
static DEFINE_MUTEX(vmem_mutex);
|
|
|
|
struct memory_segment {
|
|
struct list_head list;
|
|
unsigned long start;
|
|
unsigned long size;
|
|
};
|
|
|
|
static LIST_HEAD(mem_segs);
|
|
|
|
static void __ref *vmem_alloc_pages(unsigned int order)
|
|
{
|
|
if (slab_is_available())
|
|
return (void *)__get_free_pages(GFP_KERNEL, order);
|
|
return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
|
|
}
|
|
|
|
static inline pud_t *vmem_pud_alloc(void)
|
|
{
|
|
pud_t *pud = NULL;
|
|
|
|
#ifdef CONFIG_64BIT
|
|
pud = vmem_alloc_pages(2);
|
|
if (!pud)
|
|
return NULL;
|
|
clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
|
|
#endif
|
|
return pud;
|
|
}
|
|
|
|
static inline pmd_t *vmem_pmd_alloc(void)
|
|
{
|
|
pmd_t *pmd = NULL;
|
|
|
|
#ifdef CONFIG_64BIT
|
|
pmd = vmem_alloc_pages(2);
|
|
if (!pmd)
|
|
return NULL;
|
|
clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
|
|
#endif
|
|
return pmd;
|
|
}
|
|
|
|
static pte_t __ref *vmem_pte_alloc(unsigned long address)
|
|
{
|
|
pte_t *pte;
|
|
|
|
if (slab_is_available())
|
|
pte = (pte_t *) page_table_alloc(&init_mm, address);
|
|
else
|
|
pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
|
|
if (!pte)
|
|
return NULL;
|
|
clear_table((unsigned long *) pte, _PAGE_INVALID,
|
|
PTRS_PER_PTE * sizeof(pte_t));
|
|
return pte;
|
|
}
|
|
|
|
/*
|
|
* Add a physical memory range to the 1:1 mapping.
|
|
*/
|
|
static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
|
|
{
|
|
unsigned long end = start + size;
|
|
unsigned long address = start;
|
|
pgd_t *pg_dir;
|
|
pud_t *pu_dir;
|
|
pmd_t *pm_dir;
|
|
pte_t *pt_dir;
|
|
int ret = -ENOMEM;
|
|
|
|
while (address < end) {
|
|
pg_dir = pgd_offset_k(address);
|
|
if (pgd_none(*pg_dir)) {
|
|
pu_dir = vmem_pud_alloc();
|
|
if (!pu_dir)
|
|
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)) {
|
|
pud_val(*pu_dir) = __pa(address) |
|
|
_REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE |
|
|
(ro ? _REGION_ENTRY_PROTECT : 0);
|
|
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);
|
|
}
|
|
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)) {
|
|
pmd_val(*pm_dir) = __pa(address) |
|
|
_SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
|
|
_SEGMENT_ENTRY_YOUNG |
|
|
(ro ? _SEGMENT_ENTRY_PROTECT : 0);
|
|
address += PMD_SIZE;
|
|
continue;
|
|
}
|
|
#endif
|
|
if (pmd_none(*pm_dir)) {
|
|
pt_dir = vmem_pte_alloc(address);
|
|
if (!pt_dir)
|
|
goto out;
|
|
pmd_populate(&init_mm, pm_dir, pt_dir);
|
|
}
|
|
|
|
pt_dir = pte_offset_kernel(pm_dir, address);
|
|
pte_val(*pt_dir) = __pa(address) |
|
|
pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
|
|
address += PAGE_SIZE;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
flush_tlb_kernel_range(start, end);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Remove a physical memory range from the 1:1 mapping.
|
|
* Currently only invalidates page table entries.
|
|
*/
|
|
static void vmem_remove_range(unsigned long start, unsigned long size)
|
|
{
|
|
unsigned long end = start + size;
|
|
unsigned long address = start;
|
|
pgd_t *pg_dir;
|
|
pud_t *pu_dir;
|
|
pmd_t *pm_dir;
|
|
pte_t *pt_dir;
|
|
pte_t pte;
|
|
|
|
pte_val(pte) = _PAGE_INVALID;
|
|
while (address < end) {
|
|
pg_dir = pgd_offset_k(address);
|
|
if (pgd_none(*pg_dir)) {
|
|
address += PGDIR_SIZE;
|
|
continue;
|
|
}
|
|
pu_dir = pud_offset(pg_dir, address);
|
|
if (pud_none(*pu_dir)) {
|
|
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;
|
|
continue;
|
|
}
|
|
if (pmd_large(*pm_dir)) {
|
|
pmd_clear(pm_dir);
|
|
address += PMD_SIZE;
|
|
continue;
|
|
}
|
|
pt_dir = pte_offset_kernel(pm_dir, address);
|
|
*pt_dir = pte;
|
|
address += PAGE_SIZE;
|
|
}
|
|
flush_tlb_kernel_range(start, end);
|
|
}
|
|
|
|
/*
|
|
* Add a backed mem_map array to the virtual mem_map array.
|
|
*/
|
|
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
|
|
{
|
|
unsigned long address = start;
|
|
pgd_t *pg_dir;
|
|
pud_t *pu_dir;
|
|
pmd_t *pm_dir;
|
|
pte_t *pt_dir;
|
|
int ret = -ENOMEM;
|
|
|
|
for (address = start; address < end;) {
|
|
pg_dir = pgd_offset_k(address);
|
|
if (pgd_none(*pg_dir)) {
|
|
pu_dir = vmem_pud_alloc();
|
|
if (!pu_dir)
|
|
goto out;
|
|
pgd_populate(&init_mm, pg_dir, pu_dir);
|
|
}
|
|
|
|
pu_dir = pud_offset(pg_dir, address);
|
|
if (pud_none(*pu_dir)) {
|
|
pm_dir = vmem_pmd_alloc();
|
|
if (!pm_dir)
|
|
goto out;
|
|
pud_populate(&init_mm, pu_dir, pm_dir);
|
|
}
|
|
|
|
pm_dir = pmd_offset(pu_dir, address);
|
|
if (pmd_none(*pm_dir)) {
|
|
#ifdef CONFIG_64BIT
|
|
/* Use 1MB frames for vmemmap if available. We always
|
|
* use large frames even if they are only partially
|
|
* used.
|
|
* Otherwise we would have also page tables since
|
|
* vmemmap_populate gets called for each section
|
|
* separately. */
|
|
if (MACHINE_HAS_EDAT1) {
|
|
void *new_page;
|
|
|
|
new_page = vmemmap_alloc_block(PMD_SIZE, node);
|
|
if (!new_page)
|
|
goto out;
|
|
pmd_val(*pm_dir) = __pa(new_page) |
|
|
_SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
|
|
_SEGMENT_ENTRY_CO;
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
continue;
|
|
}
|
|
#endif
|
|
pt_dir = vmem_pte_alloc(address);
|
|
if (!pt_dir)
|
|
goto out;
|
|
pmd_populate(&init_mm, pm_dir, pt_dir);
|
|
} else if (pmd_large(*pm_dir)) {
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
continue;
|
|
}
|
|
|
|
pt_dir = pte_offset_kernel(pm_dir, address);
|
|
if (pte_none(*pt_dir)) {
|
|
unsigned long new_page;
|
|
|
|
new_page =__pa(vmem_alloc_pages(0));
|
|
if (!new_page)
|
|
goto out;
|
|
pte_val(*pt_dir) =
|
|
__pa(new_page) | pgprot_val(PAGE_KERNEL);
|
|
}
|
|
address += PAGE_SIZE;
|
|
}
|
|
memset((void *)start, 0, end - start);
|
|
ret = 0;
|
|
out:
|
|
flush_tlb_kernel_range(start, end);
|
|
return ret;
|
|
}
|
|
|
|
void vmemmap_free(unsigned long start, unsigned long end)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* Add memory segment to the segment list if it doesn't overlap with
|
|
* an already present segment.
|
|
*/
|
|
static int insert_memory_segment(struct memory_segment *seg)
|
|
{
|
|
struct memory_segment *tmp;
|
|
|
|
if (seg->start + seg->size > VMEM_MAX_PHYS ||
|
|
seg->start + seg->size < seg->start)
|
|
return -ERANGE;
|
|
|
|
list_for_each_entry(tmp, &mem_segs, list) {
|
|
if (seg->start >= tmp->start + tmp->size)
|
|
continue;
|
|
if (seg->start + seg->size <= tmp->start)
|
|
continue;
|
|
return -ENOSPC;
|
|
}
|
|
list_add(&seg->list, &mem_segs);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Remove memory segment from the segment list.
|
|
*/
|
|
static void remove_memory_segment(struct memory_segment *seg)
|
|
{
|
|
list_del(&seg->list);
|
|
}
|
|
|
|
static void __remove_shared_memory(struct memory_segment *seg)
|
|
{
|
|
remove_memory_segment(seg);
|
|
vmem_remove_range(seg->start, seg->size);
|
|
}
|
|
|
|
int vmem_remove_mapping(unsigned long start, unsigned long size)
|
|
{
|
|
struct memory_segment *seg;
|
|
int ret;
|
|
|
|
mutex_lock(&vmem_mutex);
|
|
|
|
ret = -ENOENT;
|
|
list_for_each_entry(seg, &mem_segs, list) {
|
|
if (seg->start == start && seg->size == size)
|
|
break;
|
|
}
|
|
|
|
if (seg->start != start || seg->size != size)
|
|
goto out;
|
|
|
|
ret = 0;
|
|
__remove_shared_memory(seg);
|
|
kfree(seg);
|
|
out:
|
|
mutex_unlock(&vmem_mutex);
|
|
return ret;
|
|
}
|
|
|
|
int vmem_add_mapping(unsigned long start, unsigned long size)
|
|
{
|
|
struct memory_segment *seg;
|
|
int ret;
|
|
|
|
mutex_lock(&vmem_mutex);
|
|
ret = -ENOMEM;
|
|
seg = kzalloc(sizeof(*seg), GFP_KERNEL);
|
|
if (!seg)
|
|
goto out;
|
|
seg->start = start;
|
|
seg->size = size;
|
|
|
|
ret = insert_memory_segment(seg);
|
|
if (ret)
|
|
goto out_free;
|
|
|
|
ret = vmem_add_mem(start, size, 0);
|
|
if (ret)
|
|
goto out_remove;
|
|
goto out;
|
|
|
|
out_remove:
|
|
__remove_shared_memory(seg);
|
|
out_free:
|
|
kfree(seg);
|
|
out:
|
|
mutex_unlock(&vmem_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* map whole physical memory to virtual memory (identity mapping)
|
|
* we reserve enough space in the vmalloc area for vmemmap to hotplug
|
|
* additional memory segments.
|
|
*/
|
|
void __init vmem_map_init(void)
|
|
{
|
|
unsigned long ro_start, ro_end;
|
|
unsigned long start, end;
|
|
int i;
|
|
|
|
ro_start = PFN_ALIGN((unsigned long)&_stext);
|
|
ro_end = (unsigned long)&_eshared & PAGE_MASK;
|
|
for (i = 0; i < MEMORY_CHUNKS; i++) {
|
|
if (!memory_chunk[i].size)
|
|
continue;
|
|
start = memory_chunk[i].addr;
|
|
end = memory_chunk[i].addr + memory_chunk[i].size;
|
|
if (start >= ro_end || end <= ro_start)
|
|
vmem_add_mem(start, end - start, 0);
|
|
else if (start >= ro_start && end <= ro_end)
|
|
vmem_add_mem(start, end - start, 1);
|
|
else if (start >= ro_start) {
|
|
vmem_add_mem(start, ro_end - start, 1);
|
|
vmem_add_mem(ro_end, end - ro_end, 0);
|
|
} else if (end < ro_end) {
|
|
vmem_add_mem(start, ro_start - start, 0);
|
|
vmem_add_mem(ro_start, end - ro_start, 1);
|
|
} else {
|
|
vmem_add_mem(start, ro_start - start, 0);
|
|
vmem_add_mem(ro_start, ro_end - ro_start, 1);
|
|
vmem_add_mem(ro_end, end - ro_end, 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Convert memory chunk array to a memory segment list so there is a single
|
|
* list that contains both r/w memory and shared memory segments.
|
|
*/
|
|
static int __init vmem_convert_memory_chunk(void)
|
|
{
|
|
struct memory_segment *seg;
|
|
int i;
|
|
|
|
mutex_lock(&vmem_mutex);
|
|
for (i = 0; i < MEMORY_CHUNKS; i++) {
|
|
if (!memory_chunk[i].size)
|
|
continue;
|
|
seg = kzalloc(sizeof(*seg), GFP_KERNEL);
|
|
if (!seg)
|
|
panic("Out of memory...\n");
|
|
seg->start = memory_chunk[i].addr;
|
|
seg->size = memory_chunk[i].size;
|
|
insert_memory_segment(seg);
|
|
}
|
|
mutex_unlock(&vmem_mutex);
|
|
return 0;
|
|
}
|
|
|
|
core_initcall(vmem_convert_memory_chunk);
|