520 lines
13 KiB
C
520 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Page table allocation functions
|
|
*
|
|
* Copyright IBM Corp. 2016
|
|
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/sysctl.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mm.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/page-states.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/gmap.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
#ifdef CONFIG_PGSTE
|
|
|
|
int page_table_allocate_pgste = 0;
|
|
EXPORT_SYMBOL(page_table_allocate_pgste);
|
|
|
|
static struct ctl_table page_table_sysctl[] = {
|
|
{
|
|
.procname = "allocate_pgste",
|
|
.data = &page_table_allocate_pgste,
|
|
.maxlen = sizeof(int),
|
|
.mode = S_IRUGO | S_IWUSR,
|
|
.proc_handler = proc_dointvec_minmax,
|
|
.extra1 = SYSCTL_ZERO,
|
|
.extra2 = SYSCTL_ONE,
|
|
},
|
|
};
|
|
|
|
static int __init page_table_register_sysctl(void)
|
|
{
|
|
return register_sysctl("vm", page_table_sysctl) ? 0 : -ENOMEM;
|
|
}
|
|
__initcall(page_table_register_sysctl);
|
|
|
|
#endif /* CONFIG_PGSTE */
|
|
|
|
unsigned long *crst_table_alloc(struct mm_struct *mm)
|
|
{
|
|
struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
|
|
unsigned long *table;
|
|
|
|
if (!ptdesc)
|
|
return NULL;
|
|
table = ptdesc_to_virt(ptdesc);
|
|
__arch_set_page_dat(table, 1UL << CRST_ALLOC_ORDER);
|
|
return table;
|
|
}
|
|
|
|
void crst_table_free(struct mm_struct *mm, unsigned long *table)
|
|
{
|
|
pagetable_free(virt_to_ptdesc(table));
|
|
}
|
|
|
|
static void __crst_table_upgrade(void *arg)
|
|
{
|
|
struct mm_struct *mm = arg;
|
|
|
|
/* change all active ASCEs to avoid the creation of new TLBs */
|
|
if (current->active_mm == mm) {
|
|
S390_lowcore.user_asce.val = mm->context.asce;
|
|
local_ctl_load(7, &S390_lowcore.user_asce);
|
|
}
|
|
__tlb_flush_local();
|
|
}
|
|
|
|
int crst_table_upgrade(struct mm_struct *mm, unsigned long end)
|
|
{
|
|
unsigned long *pgd = NULL, *p4d = NULL, *__pgd;
|
|
unsigned long asce_limit = mm->context.asce_limit;
|
|
|
|
/* upgrade should only happen from 3 to 4, 3 to 5, or 4 to 5 levels */
|
|
VM_BUG_ON(asce_limit < _REGION2_SIZE);
|
|
|
|
if (end <= asce_limit)
|
|
return 0;
|
|
|
|
if (asce_limit == _REGION2_SIZE) {
|
|
p4d = crst_table_alloc(mm);
|
|
if (unlikely(!p4d))
|
|
goto err_p4d;
|
|
crst_table_init(p4d, _REGION2_ENTRY_EMPTY);
|
|
}
|
|
if (end > _REGION1_SIZE) {
|
|
pgd = crst_table_alloc(mm);
|
|
if (unlikely(!pgd))
|
|
goto err_pgd;
|
|
crst_table_init(pgd, _REGION1_ENTRY_EMPTY);
|
|
}
|
|
|
|
spin_lock_bh(&mm->page_table_lock);
|
|
|
|
/*
|
|
* This routine gets called with mmap_lock lock held and there is
|
|
* no reason to optimize for the case of otherwise. However, if
|
|
* that would ever change, the below check will let us know.
|
|
*/
|
|
VM_BUG_ON(asce_limit != mm->context.asce_limit);
|
|
|
|
if (p4d) {
|
|
__pgd = (unsigned long *) mm->pgd;
|
|
p4d_populate(mm, (p4d_t *) p4d, (pud_t *) __pgd);
|
|
mm->pgd = (pgd_t *) p4d;
|
|
mm->context.asce_limit = _REGION1_SIZE;
|
|
mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
|
|
_ASCE_USER_BITS | _ASCE_TYPE_REGION2;
|
|
mm_inc_nr_puds(mm);
|
|
}
|
|
if (pgd) {
|
|
__pgd = (unsigned long *) mm->pgd;
|
|
pgd_populate(mm, (pgd_t *) pgd, (p4d_t *) __pgd);
|
|
mm->pgd = (pgd_t *) pgd;
|
|
mm->context.asce_limit = TASK_SIZE_MAX;
|
|
mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
|
|
_ASCE_USER_BITS | _ASCE_TYPE_REGION1;
|
|
}
|
|
|
|
spin_unlock_bh(&mm->page_table_lock);
|
|
|
|
on_each_cpu(__crst_table_upgrade, mm, 0);
|
|
|
|
return 0;
|
|
|
|
err_pgd:
|
|
crst_table_free(mm, p4d);
|
|
err_p4d:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
#ifdef CONFIG_PGSTE
|
|
|
|
struct ptdesc *page_table_alloc_pgste(struct mm_struct *mm)
|
|
{
|
|
struct ptdesc *ptdesc;
|
|
u64 *table;
|
|
|
|
ptdesc = pagetable_alloc(GFP_KERNEL, 0);
|
|
if (ptdesc) {
|
|
table = (u64 *)ptdesc_to_virt(ptdesc);
|
|
__arch_set_page_dat(table, 1);
|
|
memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
|
|
memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
|
|
}
|
|
return ptdesc;
|
|
}
|
|
|
|
void page_table_free_pgste(struct ptdesc *ptdesc)
|
|
{
|
|
pagetable_free(ptdesc);
|
|
}
|
|
|
|
#endif /* CONFIG_PGSTE */
|
|
|
|
unsigned long *page_table_alloc(struct mm_struct *mm)
|
|
{
|
|
struct ptdesc *ptdesc;
|
|
unsigned long *table;
|
|
|
|
ptdesc = pagetable_alloc(GFP_KERNEL, 0);
|
|
if (!ptdesc)
|
|
return NULL;
|
|
if (!pagetable_pte_ctor(ptdesc)) {
|
|
pagetable_free(ptdesc);
|
|
return NULL;
|
|
}
|
|
table = ptdesc_to_virt(ptdesc);
|
|
__arch_set_page_dat(table, 1);
|
|
/* pt_list is used by gmap only */
|
|
INIT_LIST_HEAD(&ptdesc->pt_list);
|
|
memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
|
|
memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
|
|
return table;
|
|
}
|
|
|
|
static void pagetable_pte_dtor_free(struct ptdesc *ptdesc)
|
|
{
|
|
pagetable_pte_dtor(ptdesc);
|
|
pagetable_free(ptdesc);
|
|
}
|
|
|
|
void page_table_free(struct mm_struct *mm, unsigned long *table)
|
|
{
|
|
struct ptdesc *ptdesc = virt_to_ptdesc(table);
|
|
|
|
pagetable_pte_dtor_free(ptdesc);
|
|
}
|
|
|
|
void __tlb_remove_table(void *table)
|
|
{
|
|
struct ptdesc *ptdesc = virt_to_ptdesc(table);
|
|
struct page *page = ptdesc_page(ptdesc);
|
|
|
|
if (compound_order(page) == CRST_ALLOC_ORDER) {
|
|
/* pmd, pud, or p4d */
|
|
pagetable_free(ptdesc);
|
|
return;
|
|
}
|
|
pagetable_pte_dtor_free(ptdesc);
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
static void pte_free_now(struct rcu_head *head)
|
|
{
|
|
struct ptdesc *ptdesc = container_of(head, struct ptdesc, pt_rcu_head);
|
|
|
|
pagetable_pte_dtor_free(ptdesc);
|
|
}
|
|
|
|
void pte_free_defer(struct mm_struct *mm, pgtable_t pgtable)
|
|
{
|
|
struct ptdesc *ptdesc = virt_to_ptdesc(pgtable);
|
|
|
|
call_rcu(&ptdesc->pt_rcu_head, pte_free_now);
|
|
/*
|
|
* THPs are not allowed for KVM guests. Warn if pgste ever reaches here.
|
|
* Turn to the generic pte_free_defer() version once gmap is removed.
|
|
*/
|
|
WARN_ON_ONCE(mm_has_pgste(mm));
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
/*
|
|
* Base infrastructure required to generate basic asces, region, segment,
|
|
* and page tables that do not make use of enhanced features like EDAT1.
|
|
*/
|
|
|
|
static struct kmem_cache *base_pgt_cache;
|
|
|
|
static unsigned long *base_pgt_alloc(void)
|
|
{
|
|
unsigned long *table;
|
|
|
|
table = kmem_cache_alloc(base_pgt_cache, GFP_KERNEL);
|
|
if (table)
|
|
memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
|
|
return table;
|
|
}
|
|
|
|
static void base_pgt_free(unsigned long *table)
|
|
{
|
|
kmem_cache_free(base_pgt_cache, table);
|
|
}
|
|
|
|
static unsigned long *base_crst_alloc(unsigned long val)
|
|
{
|
|
unsigned long *table;
|
|
struct ptdesc *ptdesc;
|
|
|
|
ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
|
|
if (!ptdesc)
|
|
return NULL;
|
|
table = ptdesc_address(ptdesc);
|
|
crst_table_init(table, val);
|
|
return table;
|
|
}
|
|
|
|
static void base_crst_free(unsigned long *table)
|
|
{
|
|
pagetable_free(virt_to_ptdesc(table));
|
|
}
|
|
|
|
#define BASE_ADDR_END_FUNC(NAME, SIZE) \
|
|
static inline unsigned long base_##NAME##_addr_end(unsigned long addr, \
|
|
unsigned long end) \
|
|
{ \
|
|
unsigned long next = (addr + (SIZE)) & ~((SIZE) - 1); \
|
|
\
|
|
return (next - 1) < (end - 1) ? next : end; \
|
|
}
|
|
|
|
BASE_ADDR_END_FUNC(page, _PAGE_SIZE)
|
|
BASE_ADDR_END_FUNC(segment, _SEGMENT_SIZE)
|
|
BASE_ADDR_END_FUNC(region3, _REGION3_SIZE)
|
|
BASE_ADDR_END_FUNC(region2, _REGION2_SIZE)
|
|
BASE_ADDR_END_FUNC(region1, _REGION1_SIZE)
|
|
|
|
static inline unsigned long base_lra(unsigned long address)
|
|
{
|
|
unsigned long real;
|
|
|
|
asm volatile(
|
|
" lra %0,0(%1)\n"
|
|
: "=d" (real) : "a" (address) : "cc");
|
|
return real;
|
|
}
|
|
|
|
static int base_page_walk(unsigned long *origin, unsigned long addr,
|
|
unsigned long end, int alloc)
|
|
{
|
|
unsigned long *pte, next;
|
|
|
|
if (!alloc)
|
|
return 0;
|
|
pte = origin;
|
|
pte += (addr & _PAGE_INDEX) >> _PAGE_SHIFT;
|
|
do {
|
|
next = base_page_addr_end(addr, end);
|
|
*pte = base_lra(addr);
|
|
} while (pte++, addr = next, addr < end);
|
|
return 0;
|
|
}
|
|
|
|
static int base_segment_walk(unsigned long *origin, unsigned long addr,
|
|
unsigned long end, int alloc)
|
|
{
|
|
unsigned long *ste, next, *table;
|
|
int rc;
|
|
|
|
ste = origin;
|
|
ste += (addr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
|
|
do {
|
|
next = base_segment_addr_end(addr, end);
|
|
if (*ste & _SEGMENT_ENTRY_INVALID) {
|
|
if (!alloc)
|
|
continue;
|
|
table = base_pgt_alloc();
|
|
if (!table)
|
|
return -ENOMEM;
|
|
*ste = __pa(table) | _SEGMENT_ENTRY;
|
|
}
|
|
table = __va(*ste & _SEGMENT_ENTRY_ORIGIN);
|
|
rc = base_page_walk(table, addr, next, alloc);
|
|
if (rc)
|
|
return rc;
|
|
if (!alloc)
|
|
base_pgt_free(table);
|
|
cond_resched();
|
|
} while (ste++, addr = next, addr < end);
|
|
return 0;
|
|
}
|
|
|
|
static int base_region3_walk(unsigned long *origin, unsigned long addr,
|
|
unsigned long end, int alloc)
|
|
{
|
|
unsigned long *rtte, next, *table;
|
|
int rc;
|
|
|
|
rtte = origin;
|
|
rtte += (addr & _REGION3_INDEX) >> _REGION3_SHIFT;
|
|
do {
|
|
next = base_region3_addr_end(addr, end);
|
|
if (*rtte & _REGION_ENTRY_INVALID) {
|
|
if (!alloc)
|
|
continue;
|
|
table = base_crst_alloc(_SEGMENT_ENTRY_EMPTY);
|
|
if (!table)
|
|
return -ENOMEM;
|
|
*rtte = __pa(table) | _REGION3_ENTRY;
|
|
}
|
|
table = __va(*rtte & _REGION_ENTRY_ORIGIN);
|
|
rc = base_segment_walk(table, addr, next, alloc);
|
|
if (rc)
|
|
return rc;
|
|
if (!alloc)
|
|
base_crst_free(table);
|
|
} while (rtte++, addr = next, addr < end);
|
|
return 0;
|
|
}
|
|
|
|
static int base_region2_walk(unsigned long *origin, unsigned long addr,
|
|
unsigned long end, int alloc)
|
|
{
|
|
unsigned long *rste, next, *table;
|
|
int rc;
|
|
|
|
rste = origin;
|
|
rste += (addr & _REGION2_INDEX) >> _REGION2_SHIFT;
|
|
do {
|
|
next = base_region2_addr_end(addr, end);
|
|
if (*rste & _REGION_ENTRY_INVALID) {
|
|
if (!alloc)
|
|
continue;
|
|
table = base_crst_alloc(_REGION3_ENTRY_EMPTY);
|
|
if (!table)
|
|
return -ENOMEM;
|
|
*rste = __pa(table) | _REGION2_ENTRY;
|
|
}
|
|
table = __va(*rste & _REGION_ENTRY_ORIGIN);
|
|
rc = base_region3_walk(table, addr, next, alloc);
|
|
if (rc)
|
|
return rc;
|
|
if (!alloc)
|
|
base_crst_free(table);
|
|
} while (rste++, addr = next, addr < end);
|
|
return 0;
|
|
}
|
|
|
|
static int base_region1_walk(unsigned long *origin, unsigned long addr,
|
|
unsigned long end, int alloc)
|
|
{
|
|
unsigned long *rfte, next, *table;
|
|
int rc;
|
|
|
|
rfte = origin;
|
|
rfte += (addr & _REGION1_INDEX) >> _REGION1_SHIFT;
|
|
do {
|
|
next = base_region1_addr_end(addr, end);
|
|
if (*rfte & _REGION_ENTRY_INVALID) {
|
|
if (!alloc)
|
|
continue;
|
|
table = base_crst_alloc(_REGION2_ENTRY_EMPTY);
|
|
if (!table)
|
|
return -ENOMEM;
|
|
*rfte = __pa(table) | _REGION1_ENTRY;
|
|
}
|
|
table = __va(*rfte & _REGION_ENTRY_ORIGIN);
|
|
rc = base_region2_walk(table, addr, next, alloc);
|
|
if (rc)
|
|
return rc;
|
|
if (!alloc)
|
|
base_crst_free(table);
|
|
} while (rfte++, addr = next, addr < end);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* base_asce_free - free asce and tables returned from base_asce_alloc()
|
|
* @asce: asce to be freed
|
|
*
|
|
* Frees all region, segment, and page tables that were allocated with a
|
|
* corresponding base_asce_alloc() call.
|
|
*/
|
|
void base_asce_free(unsigned long asce)
|
|
{
|
|
unsigned long *table = __va(asce & _ASCE_ORIGIN);
|
|
|
|
if (!asce)
|
|
return;
|
|
switch (asce & _ASCE_TYPE_MASK) {
|
|
case _ASCE_TYPE_SEGMENT:
|
|
base_segment_walk(table, 0, _REGION3_SIZE, 0);
|
|
break;
|
|
case _ASCE_TYPE_REGION3:
|
|
base_region3_walk(table, 0, _REGION2_SIZE, 0);
|
|
break;
|
|
case _ASCE_TYPE_REGION2:
|
|
base_region2_walk(table, 0, _REGION1_SIZE, 0);
|
|
break;
|
|
case _ASCE_TYPE_REGION1:
|
|
base_region1_walk(table, 0, TASK_SIZE_MAX, 0);
|
|
break;
|
|
}
|
|
base_crst_free(table);
|
|
}
|
|
|
|
static int base_pgt_cache_init(void)
|
|
{
|
|
static DEFINE_MUTEX(base_pgt_cache_mutex);
|
|
unsigned long sz = _PAGE_TABLE_SIZE;
|
|
|
|
if (base_pgt_cache)
|
|
return 0;
|
|
mutex_lock(&base_pgt_cache_mutex);
|
|
if (!base_pgt_cache)
|
|
base_pgt_cache = kmem_cache_create("base_pgt", sz, sz, 0, NULL);
|
|
mutex_unlock(&base_pgt_cache_mutex);
|
|
return base_pgt_cache ? 0 : -ENOMEM;
|
|
}
|
|
|
|
/**
|
|
* base_asce_alloc - create kernel mapping without enhanced DAT features
|
|
* @addr: virtual start address of kernel mapping
|
|
* @num_pages: number of consecutive pages
|
|
*
|
|
* Generate an asce, including all required region, segment and page tables,
|
|
* that can be used to access the virtual kernel mapping. The difference is
|
|
* that the returned asce does not make use of any enhanced DAT features like
|
|
* e.g. large pages. This is required for some I/O functions that pass an
|
|
* asce, like e.g. some service call requests.
|
|
*
|
|
* Note: the returned asce may NEVER be attached to any cpu. It may only be
|
|
* used for I/O requests. tlb entries that might result because the
|
|
* asce was attached to a cpu won't be cleared.
|
|
*/
|
|
unsigned long base_asce_alloc(unsigned long addr, unsigned long num_pages)
|
|
{
|
|
unsigned long asce, *table, end;
|
|
int rc;
|
|
|
|
if (base_pgt_cache_init())
|
|
return 0;
|
|
end = addr + num_pages * PAGE_SIZE;
|
|
if (end <= _REGION3_SIZE) {
|
|
table = base_crst_alloc(_SEGMENT_ENTRY_EMPTY);
|
|
if (!table)
|
|
return 0;
|
|
rc = base_segment_walk(table, addr, end, 1);
|
|
asce = __pa(table) | _ASCE_TYPE_SEGMENT | _ASCE_TABLE_LENGTH;
|
|
} else if (end <= _REGION2_SIZE) {
|
|
table = base_crst_alloc(_REGION3_ENTRY_EMPTY);
|
|
if (!table)
|
|
return 0;
|
|
rc = base_region3_walk(table, addr, end, 1);
|
|
asce = __pa(table) | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
|
|
} else if (end <= _REGION1_SIZE) {
|
|
table = base_crst_alloc(_REGION2_ENTRY_EMPTY);
|
|
if (!table)
|
|
return 0;
|
|
rc = base_region2_walk(table, addr, end, 1);
|
|
asce = __pa(table) | _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
|
|
} else {
|
|
table = base_crst_alloc(_REGION1_ENTRY_EMPTY);
|
|
if (!table)
|
|
return 0;
|
|
rc = base_region1_walk(table, addr, end, 1);
|
|
asce = __pa(table) | _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH;
|
|
}
|
|
if (rc) {
|
|
base_asce_free(asce);
|
|
asce = 0;
|
|
}
|
|
return asce;
|
|
}
|