diff options
| -rw-r--r-- | arch/s390/mm/pgtable.c | 225 |
1 files changed, 89 insertions, 136 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index b33f66110ca9..54ef3bc01b43 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -10,11 +10,7 @@ #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> @@ -28,12 +24,9 @@ #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; @@ -42,7 +35,7 @@ unsigned long *crst_table_alloc(struct mm_struct *mm) 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) @@ -176,7 +169,7 @@ struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit) 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; @@ -247,7 +240,7 @@ void gmap_free(struct gmap *gmap) /* 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); @@ -287,7 +280,7 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table, 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); @@ -302,7 +295,7 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table, } spin_unlock(&gmap->mm->page_table_lock); if (page) - __free_pages(page, ALLOC_ORDER); + __free_pages(page, 2); return 0; } @@ -795,40 +788,6 @@ void gmap_do_ipte_notify(struct mm_struct *mm, unsigned long vmaddr, pte_t *pte) } 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) { @@ -957,20 +916,6 @@ __initcall(page_table_register_sysctl); #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) { @@ -994,44 +939,55 @@ static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits) */ 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; } @@ -1041,37 +997,23 @@ void page_table_free(struct mm_struct *mm, unsigned long *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, @@ -1083,34 +1025,45 @@ 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) |