#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
-#include <linux/highmem.h>
-#include <linux/pagemap.h>
#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/quicklist.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/swapops.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
-#define ALLOC_ORDER 2
-#define FRAG_MASK 0x03
-
unsigned long *crst_table_alloc(struct mm_struct *mm)
{
- struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+ struct page *page = alloc_pages(GFP_KERNEL, 2);
if (!page)
return NULL;
void crst_table_free(struct mm_struct *mm, unsigned long *table)
{
- free_pages((unsigned long) table, ALLOC_ORDER);
+ free_pages((unsigned long) table, 2);
}
static void __crst_table_upgrade(void *arg)
INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
spin_lock_init(&gmap->guest_table_lock);
gmap->mm = mm;
- page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+ page = alloc_pages(GFP_KERNEL, 2);
if (!page)
goto out_free;
page->index = 0;
/* Free all segment & region tables. */
list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
- __free_pages(page, ALLOC_ORDER);
+ __free_pages(page, 2);
gmap_radix_tree_free(&gmap->guest_to_host);
gmap_radix_tree_free(&gmap->host_to_guest);
down_write(&gmap->mm->mmap_sem);
unsigned long *new;
/* since we dont free the gmap table until gmap_free we can unlock */
- page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+ page = alloc_pages(GFP_KERNEL, 2);
if (!page)
return -ENOMEM;
new = (unsigned long *) page_to_phys(page);
}
spin_unlock(&gmap->mm->page_table_lock);
if (page)
- __free_pages(page, ALLOC_ORDER);
+ __free_pages(page, 2);
return 0;
}
}
EXPORT_SYMBOL_GPL(gmap_do_ipte_notify);
-static inline int page_table_with_pgste(struct page *page)
-{
- return atomic_read(&page->_mapcount) == 0;
-}
-
-static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm)
-{
- struct page *page;
- unsigned long *table;
-
- page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
- if (!page)
- return NULL;
- if (!pgtable_page_ctor(page)) {
- __free_page(page);
- return NULL;
- }
- atomic_set(&page->_mapcount, 0);
- table = (unsigned long *) page_to_phys(page);
- clear_table(table, _PAGE_INVALID, PAGE_SIZE/2);
- clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2);
- return table;
-}
-
-static inline void page_table_free_pgste(unsigned long *table)
-{
- struct page *page;
-
- page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- pgtable_page_dtor(page);
- atomic_set(&page->_mapcount, -1);
- __free_page(page);
-}
-
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned long key, bool nq)
{
#else /* CONFIG_PGSTE */
-static inline int page_table_with_pgste(struct page *page)
-{
- return 0;
-}
-
-static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm)
-{
- return NULL;
-}
-
-static inline void page_table_free_pgste(unsigned long *table)
-{
-}
-
static inline void gmap_unlink(struct mm_struct *mm, unsigned long *table,
unsigned long vmaddr)
{
*/
unsigned long *page_table_alloc(struct mm_struct *mm)
{
- unsigned long *uninitialized_var(table);
- struct page *uninitialized_var(page);
+ unsigned long *table;
+ struct page *page;
unsigned int mask, bit;
- if (mm_alloc_pgste(mm))
- return page_table_alloc_pgste(mm);
- /* Allocate fragments of a 4K page as 1K/2K page table */
- spin_lock_bh(&mm->context.list_lock);
- mask = FRAG_MASK;
- if (!list_empty(&mm->context.pgtable_list)) {
- page = list_first_entry(&mm->context.pgtable_list,
- struct page, lru);
- table = (unsigned long *) page_to_phys(page);
- mask = atomic_read(&page->_mapcount);
- mask = mask | (mask >> 4);
- }
- if ((mask & FRAG_MASK) == FRAG_MASK) {
- spin_unlock_bh(&mm->context.list_lock);
- page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
- if (!page)
- return NULL;
- if (!pgtable_page_ctor(page)) {
- __free_page(page);
- return NULL;
+ /* Try to get a fragment of a 4K page as a 2K page table */
+ if (!mm_alloc_pgste(mm)) {
+ table = NULL;
+ spin_lock_bh(&mm->context.list_lock);
+ if (!list_empty(&mm->context.pgtable_list)) {
+ page = list_first_entry(&mm->context.pgtable_list,
+ struct page, lru);
+ mask = atomic_read(&page->_mapcount);
+ mask = (mask | (mask >> 4)) & 3;
+ if (mask != 3) {
+ table = (unsigned long *) page_to_phys(page);
+ bit = mask & 1; /* =1 -> second 2K */
+ if (bit)
+ table += PTRS_PER_PTE;
+ atomic_xor_bits(&page->_mapcount, 1U << bit);
+ list_del(&page->lru);
+ }
}
+ spin_unlock_bh(&mm->context.list_lock);
+ if (table)
+ return table;
+ }
+ /* Allocate a fresh page */
+ page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
+ if (!page)
+ return NULL;
+ if (!pgtable_page_ctor(page)) {
+ __free_page(page);
+ return NULL;
+ }
+ /* Initialize page table */
+ table = (unsigned long *) page_to_phys(page);
+ if (mm_alloc_pgste(mm)) {
+ /* Return 4K page table with PGSTEs */
+ atomic_set(&page->_mapcount, 3);
+ clear_table(table, _PAGE_INVALID, PAGE_SIZE/2);
+ clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2);
+ } else {
+ /* Return the first 2K fragment of the page */
atomic_set(&page->_mapcount, 1);
- table = (unsigned long *) page_to_phys(page);
clear_table(table, _PAGE_INVALID, PAGE_SIZE);
spin_lock_bh(&mm->context.list_lock);
list_add(&page->lru, &mm->context.pgtable_list);
- } else {
- for (bit = 1; mask & bit; bit <<= 1)
- table += PTRS_PER_PTE;
- mask = atomic_xor_bits(&page->_mapcount, bit);
- if ((mask & FRAG_MASK) == FRAG_MASK)
- list_del(&page->lru);
+ spin_unlock_bh(&mm->context.list_lock);
}
- spin_unlock_bh(&mm->context.list_lock);
return table;
}
unsigned int bit, mask;
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- if (page_table_with_pgste(page))
- return page_table_free_pgste(table);
- /* Free 1K/2K page table fragment of a 4K page */
- bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t)));
- spin_lock_bh(&mm->context.list_lock);
- if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
- list_del(&page->lru);
- mask = atomic_xor_bits(&page->_mapcount, bit);
- if (mask & FRAG_MASK)
- list_add(&page->lru, &mm->context.pgtable_list);
- spin_unlock_bh(&mm->context.list_lock);
- if (mask == 0) {
- pgtable_page_dtor(page);
- atomic_set(&page->_mapcount, -1);
- __free_page(page);
+ if (!mm_alloc_pgste(mm)) {
+ /* Free 2K page table fragment of a 4K page */
+ bit = (__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
+ spin_lock_bh(&mm->context.list_lock);
+ mask = atomic_xor_bits(&page->_mapcount, 1U << bit);
+ if (mask & 3)
+ list_add(&page->lru, &mm->context.pgtable_list);
+ else
+ list_del(&page->lru);
+ spin_unlock_bh(&mm->context.list_lock);
+ if (mask != 0)
+ return;
}
-}
-
-static void __page_table_free_rcu(void *table, unsigned bit)
-{
- struct page *page;
- if (bit == FRAG_MASK)
- return page_table_free_pgste(table);
- /* Free 1K/2K page table fragment of a 4K page */
- page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- if (atomic_xor_bits(&page->_mapcount, bit) == 0) {
- pgtable_page_dtor(page);
- atomic_set(&page->_mapcount, -1);
- __free_page(page);
- }
+ pgtable_page_dtor(page);
+ atomic_set(&page->_mapcount, -1);
+ __free_page(page);
}
void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
mm = tlb->mm;
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- if (page_table_with_pgste(page)) {
+ if (mm_alloc_pgste(mm)) {
gmap_unlink(mm, table, vmaddr);
- table = (unsigned long *) (__pa(table) | FRAG_MASK);
+ table = (unsigned long *) (__pa(table) | 3);
tlb_remove_table(tlb, table);
return;
}
- bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t)));
+ bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
spin_lock_bh(&mm->context.list_lock);
- if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
- list_del(&page->lru);
- mask = atomic_xor_bits(&page->_mapcount, bit | (bit << 4));
- if (mask & FRAG_MASK)
+ mask = atomic_xor_bits(&page->_mapcount, 0x11U << bit);
+ if (mask & 3)
list_add_tail(&page->lru, &mm->context.pgtable_list);
+ else
+ list_del(&page->lru);
spin_unlock_bh(&mm->context.list_lock);
- table = (unsigned long *) (__pa(table) | (bit << 4));
+ table = (unsigned long *) (__pa(table) | (1U << bit));
tlb_remove_table(tlb, table);
}
static void __tlb_remove_table(void *_table)
{
- const unsigned long mask = (FRAG_MASK << 4) | FRAG_MASK;
- void *table = (void *)((unsigned long) _table & ~mask);
- unsigned type = (unsigned long) _table & mask;
-
- if (type)
- __page_table_free_rcu(table, type);
- else
- free_pages((unsigned long) table, ALLOC_ORDER);
+ unsigned int mask = (unsigned long) _table & 3;
+ void *table = (void *)((unsigned long) _table ^ mask);
+ struct page *page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
+
+ switch (mask) {
+ case 0: /* pmd or pud */
+ free_pages((unsigned long) table, 2);
+ break;
+ case 1: /* lower 2K of a 4K page table */
+ case 2: /* higher 2K of a 4K page table */
+ if (atomic_xor_bits(&page->_mapcount, mask << 4) != 0)
+ break;
+ /* fallthrough */
+ case 3: /* 4K page table with pgstes */
+ pgtable_page_dtor(page);
+ atomic_set(&page->_mapcount, -1);
+ __free_page(page);
+ break;
+ }
}
static void tlb_remove_table_smp_sync(void *arg)
Code Review / kvmfornfv.git / blobdiff