--- /dev/null
+/*
+ * KVM guest address space mapping code
+ *
+ * Copyright IBM Corp. 2007, 2016
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/swapops.h>
+#include <linux/ksm.h>
+#include <linux/mman.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/gmap.h>
+#include <asm/tlb.h>
+
+/**
+ * gmap_alloc - allocate a guest address space
+ * @mm: pointer to the parent mm_struct
+ * @limit: maximum size of the gmap address space
+ *
+ * Returns a guest address space structure.
+ */
+struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit)
+{
+ struct gmap *gmap;
+ struct page *page;
+ unsigned long *table;
+ unsigned long etype, atype;
+
+ if (limit < (1UL << 31)) {
+ limit = (1UL << 31) - 1;
+ atype = _ASCE_TYPE_SEGMENT;
+ etype = _SEGMENT_ENTRY_EMPTY;
+ } else if (limit < (1UL << 42)) {
+ limit = (1UL << 42) - 1;
+ atype = _ASCE_TYPE_REGION3;
+ etype = _REGION3_ENTRY_EMPTY;
+ } else if (limit < (1UL << 53)) {
+ limit = (1UL << 53) - 1;
+ atype = _ASCE_TYPE_REGION2;
+ etype = _REGION2_ENTRY_EMPTY;
+ } else {
+ limit = -1UL;
+ atype = _ASCE_TYPE_REGION1;
+ etype = _REGION1_ENTRY_EMPTY;
+ }
+ gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
+ if (!gmap)
+ goto out;
+ INIT_LIST_HEAD(&gmap->crst_list);
+ INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
+ INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
+ spin_lock_init(&gmap->guest_table_lock);
+ gmap->mm = mm;
+ page = alloc_pages(GFP_KERNEL, 2);
+ if (!page)
+ goto out_free;
+ page->index = 0;
+ list_add(&page->lru, &gmap->crst_list);
+ table = (unsigned long *) page_to_phys(page);
+ crst_table_init(table, etype);
+ gmap->table = table;
+ gmap->asce = atype | _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS | __pa(table);
+ gmap->asce_end = limit;
+ down_write(&mm->mmap_sem);
+ list_add(&gmap->list, &mm->context.gmap_list);
+ up_write(&mm->mmap_sem);
+ return gmap;
+
+out_free:
+ kfree(gmap);
+out:
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(gmap_alloc);
+
+static void gmap_flush_tlb(struct gmap *gmap)
+{
+ if (MACHINE_HAS_IDTE)
+ __tlb_flush_asce(gmap->mm, gmap->asce);
+ else
+ __tlb_flush_global();
+}
+
+static void gmap_radix_tree_free(struct radix_tree_root *root)
+{
+ struct radix_tree_iter iter;
+ unsigned long indices[16];
+ unsigned long index;
+ void **slot;
+ int i, nr;
+
+ /* A radix tree is freed by deleting all of its entries */
+ index = 0;
+ do {
+ nr = 0;
+ radix_tree_for_each_slot(slot, root, &iter, index) {
+ indices[nr] = iter.index;
+ if (++nr == 16)
+ break;
+ }
+ for (i = 0; i < nr; i++) {
+ index = indices[i];
+ radix_tree_delete(root, index);
+ }
+ } while (nr > 0);
+}
+
+/**
+ * gmap_free - free a guest address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_free(struct gmap *gmap)
+{
+ struct page *page, *next;
+
+ /* Flush tlb. */
+ if (MACHINE_HAS_IDTE)
+ __tlb_flush_asce(gmap->mm, gmap->asce);
+ else
+ __tlb_flush_global();
+
+ /* Free all segment & region tables. */
+ list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
+ __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);
+ list_del(&gmap->list);
+ up_write(&gmap->mm->mmap_sem);
+ kfree(gmap);
+}
+EXPORT_SYMBOL_GPL(gmap_free);
+
+/**
+ * gmap_enable - switch primary space to the guest address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_enable(struct gmap *gmap)
+{
+ S390_lowcore.gmap = (unsigned long) gmap;
+}
+EXPORT_SYMBOL_GPL(gmap_enable);
+
+/**
+ * gmap_disable - switch back to the standard primary address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_disable(struct gmap *gmap)
+{
+ S390_lowcore.gmap = 0UL;
+}
+EXPORT_SYMBOL_GPL(gmap_disable);
+
+/*
+ * gmap_alloc_table is assumed to be called with mmap_sem held
+ */
+static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
+ unsigned long init, unsigned long gaddr)
+{
+ struct page *page;
+ unsigned long *new;
+
+ /* since we dont free the gmap table until gmap_free we can unlock */
+ page = alloc_pages(GFP_KERNEL, 2);
+ if (!page)
+ return -ENOMEM;
+ new = (unsigned long *) page_to_phys(page);
+ crst_table_init(new, init);
+ spin_lock(&gmap->mm->page_table_lock);
+ if (*table & _REGION_ENTRY_INVALID) {
+ list_add(&page->lru, &gmap->crst_list);
+ *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
+ (*table & _REGION_ENTRY_TYPE_MASK);
+ page->index = gaddr;
+ page = NULL;
+ }
+ spin_unlock(&gmap->mm->page_table_lock);
+ if (page)
+ __free_pages(page, 2);
+ return 0;
+}
+
+/**
+ * __gmap_segment_gaddr - find virtual address from segment pointer
+ * @entry: pointer to a segment table entry in the guest address space
+ *
+ * Returns the virtual address in the guest address space for the segment
+ */
+static unsigned long __gmap_segment_gaddr(unsigned long *entry)
+{
+ struct page *page;
+ unsigned long offset, mask;
+
+ offset = (unsigned long) entry / sizeof(unsigned long);
+ offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
+ mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
+ page = virt_to_page((void *)((unsigned long) entry & mask));
+ return page->index + offset;
+}
+
+/**
+ * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
+ * @gmap: pointer to the guest address space structure
+ * @vmaddr: address in the host process address space
+ *
+ * Returns 1 if a TLB flush is required
+ */
+static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
+{
+ unsigned long *entry;
+ int flush = 0;
+
+ spin_lock(&gmap->guest_table_lock);
+ entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
+ if (entry) {
+ flush = (*entry != _SEGMENT_ENTRY_INVALID);
+ *entry = _SEGMENT_ENTRY_INVALID;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ return flush;
+}
+
+/**
+ * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
+ * @gmap: pointer to the guest address space structure
+ * @gaddr: address in the guest address space
+ *
+ * Returns 1 if a TLB flush is required
+ */
+static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long vmaddr;
+
+ vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
+ gaddr >> PMD_SHIFT);
+ return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
+}
+
+/**
+ * gmap_unmap_segment - unmap segment from the guest address space
+ * @gmap: pointer to the guest address space structure
+ * @to: address in the guest address space
+ * @len: length of the memory area to unmap
+ *
+ * Returns 0 if the unmap succeeded, -EINVAL if not.
+ */
+int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
+{
+ unsigned long off;
+ int flush;
+
+ if ((to | len) & (PMD_SIZE - 1))
+ return -EINVAL;
+ if (len == 0 || to + len < to)
+ return -EINVAL;
+
+ flush = 0;
+ down_write(&gmap->mm->mmap_sem);
+ for (off = 0; off < len; off += PMD_SIZE)
+ flush |= __gmap_unmap_by_gaddr(gmap, to + off);
+ up_write(&gmap->mm->mmap_sem);
+ if (flush)
+ gmap_flush_tlb(gmap);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gmap_unmap_segment);
+
+/**
+ * gmap_map_segment - map a segment to the guest address space
+ * @gmap: pointer to the guest address space structure
+ * @from: source address in the parent address space
+ * @to: target address in the guest address space
+ * @len: length of the memory area to map
+ *
+ * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
+ */
+int gmap_map_segment(struct gmap *gmap, unsigned long from,
+ unsigned long to, unsigned long len)
+{
+ unsigned long off;
+ int flush;
+
+ if ((from | to | len) & (PMD_SIZE - 1))
+ return -EINVAL;
+ if (len == 0 || from + len < from || to + len < to ||
+ from + len > TASK_MAX_SIZE || to + len > gmap->asce_end)
+ return -EINVAL;
+
+ flush = 0;
+ down_write(&gmap->mm->mmap_sem);
+ for (off = 0; off < len; off += PMD_SIZE) {
+ /* Remove old translation */
+ flush |= __gmap_unmap_by_gaddr(gmap, to + off);
+ /* Store new translation */
+ if (radix_tree_insert(&gmap->guest_to_host,
+ (to + off) >> PMD_SHIFT,
+ (void *) from + off))
+ break;
+ }
+ up_write(&gmap->mm->mmap_sem);
+ if (flush)
+ gmap_flush_tlb(gmap);
+ if (off >= len)
+ return 0;
+ gmap_unmap_segment(gmap, to, len);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(gmap_map_segment);
+
+/**
+ * __gmap_translate - translate a guest address to a user space address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ *
+ * Returns user space address which corresponds to the guest address or
+ * -EFAULT if no such mapping exists.
+ * This function does not establish potentially missing page table entries.
+ * The mmap_sem of the mm that belongs to the address space must be held
+ * when this function gets called.
+ */
+unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long vmaddr;
+
+ vmaddr = (unsigned long)
+ radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
+ return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
+}
+EXPORT_SYMBOL_GPL(__gmap_translate);
+
+/**
+ * gmap_translate - translate a guest address to a user space address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ *
+ * Returns user space address which corresponds to the guest address or
+ * -EFAULT if no such mapping exists.
+ * This function does not establish potentially missing page table entries.
+ */
+unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long rc;
+
+ down_read(&gmap->mm->mmap_sem);
+ rc = __gmap_translate(gmap, gaddr);
+ up_read(&gmap->mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_translate);
+
+/**
+ * gmap_unlink - disconnect a page table from the gmap shadow tables
+ * @gmap: pointer to guest mapping meta data structure
+ * @table: pointer to the host page table
+ * @vmaddr: vm address associated with the host page table
+ */
+void gmap_unlink(struct mm_struct *mm, unsigned long *table,
+ unsigned long vmaddr)
+{
+ struct gmap *gmap;
+ int flush;
+
+ list_for_each_entry(gmap, &mm->context.gmap_list, list) {
+ flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
+ if (flush)
+ gmap_flush_tlb(gmap);
+ }
+}
+
+/**
+ * gmap_link - set up shadow page tables to connect a host to a guest address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ * @vmaddr: vm address
+ *
+ * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
+ * if the vm address is already mapped to a different guest segment.
+ * The mmap_sem of the mm that belongs to the address space must be held
+ * when this function gets called.
+ */
+int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
+{
+ struct mm_struct *mm;
+ unsigned long *table;
+ spinlock_t *ptl;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ int rc;
+
+ /* Create higher level tables in the gmap page table */
+ table = gmap->table;
+ if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
+ table += (gaddr >> 53) & 0x7ff;
+ if ((*table & _REGION_ENTRY_INVALID) &&
+ gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
+ gaddr & 0xffe0000000000000UL))
+ return -ENOMEM;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ }
+ if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
+ table += (gaddr >> 42) & 0x7ff;
+ if ((*table & _REGION_ENTRY_INVALID) &&
+ gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
+ gaddr & 0xfffffc0000000000UL))
+ return -ENOMEM;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ }
+ if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
+ table += (gaddr >> 31) & 0x7ff;
+ if ((*table & _REGION_ENTRY_INVALID) &&
+ gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
+ gaddr & 0xffffffff80000000UL))
+ return -ENOMEM;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ }
+ table += (gaddr >> 20) & 0x7ff;
+ /* Walk the parent mm page table */
+ mm = gmap->mm;
+ pgd = pgd_offset(mm, vmaddr);
+ VM_BUG_ON(pgd_none(*pgd));
+ pud = pud_offset(pgd, vmaddr);
+ VM_BUG_ON(pud_none(*pud));
+ pmd = pmd_offset(pud, vmaddr);
+ VM_BUG_ON(pmd_none(*pmd));
+ /* large pmds cannot yet be handled */
+ if (pmd_large(*pmd))
+ return -EFAULT;
+ /* Link gmap segment table entry location to page table. */
+ rc = radix_tree_preload(GFP_KERNEL);
+ if (rc)
+ return rc;
+ ptl = pmd_lock(mm, pmd);
+ spin_lock(&gmap->guest_table_lock);
+ if (*table == _SEGMENT_ENTRY_INVALID) {
+ rc = radix_tree_insert(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT, table);
+ if (!rc)
+ *table = pmd_val(*pmd);
+ } else
+ rc = 0;
+ spin_unlock(&gmap->guest_table_lock);
+ spin_unlock(ptl);
+ radix_tree_preload_end();
+ return rc;
+}
+
+/**
+ * gmap_fault - resolve a fault on a guest address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ * @fault_flags: flags to pass down to handle_mm_fault()
+ *
+ * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
+ * if the vm address is already mapped to a different guest segment.
+ */
+int gmap_fault(struct gmap *gmap, unsigned long gaddr,
+ unsigned int fault_flags)
+{
+ unsigned long vmaddr;
+ int rc;
+ bool unlocked;
+
+ down_read(&gmap->mm->mmap_sem);
+
+retry:
+ unlocked = false;
+ vmaddr = __gmap_translate(gmap, gaddr);
+ if (IS_ERR_VALUE(vmaddr)) {
+ rc = vmaddr;
+ goto out_up;
+ }
+ if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
+ &unlocked)) {
+ rc = -EFAULT;
+ goto out_up;
+ }
+ /*
+ * In the case that fixup_user_fault unlocked the mmap_sem during
+ * faultin redo __gmap_translate to not race with a map/unmap_segment.
+ */
+ if (unlocked)
+ goto retry;
+
+ rc = __gmap_link(gmap, gaddr, vmaddr);
+out_up:
+ up_read(&gmap->mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_fault);
+
+/*
+ * this function is assumed to be called with mmap_sem held
+ */
+void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long vmaddr;
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ /* Find the vm address for the guest address */
+ vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
+ gaddr >> PMD_SHIFT);
+ if (vmaddr) {
+ vmaddr |= gaddr & ~PMD_MASK;
+ /* Get pointer to the page table entry */
+ ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
+ if (likely(ptep))
+ ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
+ pte_unmap_unlock(ptep, ptl);
+ }
+}
+EXPORT_SYMBOL_GPL(__gmap_zap);
+
+void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
+{
+ unsigned long gaddr, vmaddr, size;
+ struct vm_area_struct *vma;
+
+ down_read(&gmap->mm->mmap_sem);
+ for (gaddr = from; gaddr < to;
+ gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
+ /* Find the vm address for the guest address */
+ vmaddr = (unsigned long)
+ radix_tree_lookup(&gmap->guest_to_host,
+ gaddr >> PMD_SHIFT);
+ if (!vmaddr)
+ continue;
+ vmaddr |= gaddr & ~PMD_MASK;
+ /* Find vma in the parent mm */
+ vma = find_vma(gmap->mm, vmaddr);
+ size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
+ zap_page_range(vma, vmaddr, size, NULL);
+ }
+ up_read(&gmap->mm->mmap_sem);
+}
+EXPORT_SYMBOL_GPL(gmap_discard);
+
+static LIST_HEAD(gmap_notifier_list);
+static DEFINE_SPINLOCK(gmap_notifier_lock);
+
+/**
+ * gmap_register_ipte_notifier - register a pte invalidation callback
+ * @nb: pointer to the gmap notifier block
+ */
+void gmap_register_ipte_notifier(struct gmap_notifier *nb)
+{
+ spin_lock(&gmap_notifier_lock);
+ list_add(&nb->list, &gmap_notifier_list);
+ spin_unlock(&gmap_notifier_lock);
+}
+EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier);
+
+/**
+ * gmap_unregister_ipte_notifier - remove a pte invalidation callback
+ * @nb: pointer to the gmap notifier block
+ */
+void gmap_unregister_ipte_notifier(struct gmap_notifier *nb)
+{
+ spin_lock(&gmap_notifier_lock);
+ list_del_init(&nb->list);
+ spin_unlock(&gmap_notifier_lock);
+}
+EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier);
+
+/**
+ * gmap_ipte_notify - mark a range of ptes for invalidation notification
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @len: size of area
+ *
+ * Returns 0 if for each page in the given range a gmap mapping exists and
+ * the invalidation notification could be set. If the gmap mapping is missing
+ * for one or more pages -EFAULT is returned. If no memory could be allocated
+ * -ENOMEM is returned. This function establishes missing page table entries.
+ */
+int gmap_ipte_notify(struct gmap *gmap, unsigned long gaddr, unsigned long len)
+{
+ unsigned long addr;
+ spinlock_t *ptl;
+ pte_t *ptep;
+ bool unlocked;
+ int rc = 0;
+
+ if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK))
+ return -EINVAL;
+ down_read(&gmap->mm->mmap_sem);
+ while (len) {
+ unlocked = false;
+ /* Convert gmap address and connect the page tables */
+ addr = __gmap_translate(gmap, gaddr);
+ if (IS_ERR_VALUE(addr)) {
+ rc = addr;
+ break;
+ }
+ /* Get the page mapped */
+ if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE,
+ &unlocked)) {
+ rc = -EFAULT;
+ break;
+ }
+ /* While trying to map mmap_sem got unlocked. Let us retry */
+ if (unlocked)
+ continue;
+ rc = __gmap_link(gmap, gaddr, addr);
+ if (rc)
+ break;
+ /* Walk the process page table, lock and get pte pointer */
+ ptep = get_locked_pte(gmap->mm, addr, &ptl);
+ VM_BUG_ON(!ptep);
+ /* Set notification bit in the pgste of the pte */
+ if ((pte_val(*ptep) & (_PAGE_INVALID | _PAGE_PROTECT)) == 0) {
+ ptep_set_notify(gmap->mm, addr, ptep);
+ gaddr += PAGE_SIZE;
+ len -= PAGE_SIZE;
+ }
+ pte_unmap_unlock(ptep, ptl);
+ }
+ up_read(&gmap->mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_ipte_notify);
+
+/**
+ * ptep_notify - call all invalidation callbacks for a specific pte.
+ * @mm: pointer to the process mm_struct
+ * @addr: virtual address in the process address space
+ * @pte: pointer to the page table entry
+ *
+ * This function is assumed to be called with the page table lock held
+ * for the pte to notify.
+ */
+void ptep_notify(struct mm_struct *mm, unsigned long vmaddr, pte_t *pte)
+{
+ unsigned long offset, gaddr;
+ unsigned long *table;
+ struct gmap_notifier *nb;
+ struct gmap *gmap;
+
+ offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
+ offset = offset * (4096 / sizeof(pte_t));
+ spin_lock(&gmap_notifier_lock);
+ list_for_each_entry(gmap, &mm->context.gmap_list, list) {
+ table = radix_tree_lookup(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (!table)
+ continue;
+ gaddr = __gmap_segment_gaddr(table) + offset;
+ list_for_each_entry(nb, &gmap_notifier_list, list)
+ nb->notifier_call(gmap, gaddr);
+ }
+ spin_unlock(&gmap_notifier_lock);
+}
+EXPORT_SYMBOL_GPL(ptep_notify);
+
+static inline void thp_split_mm(struct mm_struct *mm)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ struct vm_area_struct *vma;
+ unsigned long addr;
+
+ for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
+ for (addr = vma->vm_start;
+ addr < vma->vm_end;
+ addr += PAGE_SIZE)
+ follow_page(vma, addr, FOLL_SPLIT);
+ vma->vm_flags &= ~VM_HUGEPAGE;
+ vma->vm_flags |= VM_NOHUGEPAGE;
+ }
+ mm->def_flags |= VM_NOHUGEPAGE;
+#endif
+}
+
+/*
+ * switch on pgstes for its userspace process (for kvm)
+ */
+int s390_enable_sie(void)
+{
+ struct mm_struct *mm = current->mm;
+
+ /* Do we have pgstes? if yes, we are done */
+ if (mm_has_pgste(mm))
+ return 0;
+ /* Fail if the page tables are 2K */
+ if (!mm_alloc_pgste(mm))
+ return -EINVAL;
+ down_write(&mm->mmap_sem);
+ mm->context.has_pgste = 1;
+ /* split thp mappings and disable thp for future mappings */
+ thp_split_mm(mm);
+ up_write(&mm->mmap_sem);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s390_enable_sie);
+
+/*
+ * Enable storage key handling from now on and initialize the storage
+ * keys with the default key.
+ */
+static int __s390_enable_skey(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ /*
+ * Remove all zero page mappings,
+ * after establishing a policy to forbid zero page mappings
+ * following faults for that page will get fresh anonymous pages
+ */
+ if (is_zero_pfn(pte_pfn(*pte)))
+ ptep_xchg_direct(walk->mm, addr, pte, __pte(_PAGE_INVALID));
+ /* Clear storage key */
+ ptep_zap_key(walk->mm, addr, pte);
+ return 0;
+}
+
+int s390_enable_skey(void)
+{
+ struct mm_walk walk = { .pte_entry = __s390_enable_skey };
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int rc = 0;
+
+ down_write(&mm->mmap_sem);
+ if (mm_use_skey(mm))
+ goto out_up;
+
+ mm->context.use_skey = 1;
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
+ MADV_UNMERGEABLE, &vma->vm_flags)) {
+ mm->context.use_skey = 0;
+ rc = -ENOMEM;
+ goto out_up;
+ }
+ }
+ mm->def_flags &= ~VM_MERGEABLE;
+
+ walk.mm = mm;
+ walk_page_range(0, TASK_SIZE, &walk);
+
+out_up:
+ up_write(&mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(s390_enable_skey);
+
+/*
+ * Reset CMMA state, make all pages stable again.
+ */
+static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ ptep_zap_unused(walk->mm, addr, pte, 1);
+ return 0;
+}
+
+void s390_reset_cmma(struct mm_struct *mm)
+{
+ struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
+
+ down_write(&mm->mmap_sem);
+ walk.mm = mm;
+ walk_page_range(0, TASK_SIZE, &walk);
+ up_write(&mm->mmap_sem);
+}
+EXPORT_SYMBOL_GPL(s390_reset_cmma);
--- /dev/null
+/*
+ * Page table allocation functions
+ *
+ * Copyright IBM Corp. 2016
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/sysctl.h>
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+#include <asm/gmap.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+#ifdef CONFIG_PGSTE
+
+static int page_table_allocate_pgste_min = 0;
+static int page_table_allocate_pgste_max = 1;
+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,
+ .extra1 = &page_table_allocate_pgste_min,
+ .extra2 = &page_table_allocate_pgste_max,
+ },
+ { }
+};
+
+static struct ctl_table page_table_sysctl_dir[] = {
+ {
+ .procname = "vm",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = page_table_sysctl,
+ },
+ { }
+};
+
+static int __init page_table_register_sysctl(void)
+{
+ return register_sysctl_table(page_table_sysctl_dir) ? 0 : -ENOMEM;
+}
+__initcall(page_table_register_sysctl);
+
+#endif /* CONFIG_PGSTE */
+
+unsigned long *crst_table_alloc(struct mm_struct *mm)
+{
+ struct page *page = alloc_pages(GFP_KERNEL, 2);
+
+ if (!page)
+ return NULL;
+ return (unsigned long *) page_to_phys(page);
+}
+
+void crst_table_free(struct mm_struct *mm, unsigned long *table)
+{
+ free_pages((unsigned long) table, 2);
+}
+
+static void __crst_table_upgrade(void *arg)
+{
+ struct mm_struct *mm = arg;
+
+ if (current->active_mm == mm) {
+ clear_user_asce();
+ set_user_asce(mm);
+ }
+ __tlb_flush_local();
+}
+
+int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
+{
+ unsigned long *table, *pgd;
+ unsigned long entry;
+ int flush;
+
+ BUG_ON(limit > TASK_MAX_SIZE);
+ flush = 0;
+repeat:
+ table = crst_table_alloc(mm);
+ if (!table)
+ return -ENOMEM;
+ spin_lock_bh(&mm->page_table_lock);
+ if (mm->context.asce_limit < limit) {
+ pgd = (unsigned long *) mm->pgd;
+ if (mm->context.asce_limit <= (1UL << 31)) {
+ entry = _REGION3_ENTRY_EMPTY;
+ mm->context.asce_limit = 1UL << 42;
+ mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS |
+ _ASCE_TYPE_REGION3;
+ } else {
+ entry = _REGION2_ENTRY_EMPTY;
+ mm->context.asce_limit = 1UL << 53;
+ mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS |
+ _ASCE_TYPE_REGION2;
+ }
+ crst_table_init(table, entry);
+ pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
+ mm->pgd = (pgd_t *) table;
+ mm->task_size = mm->context.asce_limit;
+ table = NULL;
+ flush = 1;
+ }
+ spin_unlock_bh(&mm->page_table_lock);
+ if (table)
+ crst_table_free(mm, table);
+ if (mm->context.asce_limit < limit)
+ goto repeat;
+ if (flush)
+ on_each_cpu(__crst_table_upgrade, mm, 0);
+ return 0;
+}
+
+void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
+{
+ pgd_t *pgd;
+
+ if (current->active_mm == mm) {
+ clear_user_asce();
+ __tlb_flush_mm(mm);
+ }
+ while (mm->context.asce_limit > limit) {
+ pgd = mm->pgd;
+ switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
+ case _REGION_ENTRY_TYPE_R2:
+ mm->context.asce_limit = 1UL << 42;
+ mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS |
+ _ASCE_TYPE_REGION3;
+ break;
+ case _REGION_ENTRY_TYPE_R3:
+ mm->context.asce_limit = 1UL << 31;
+ mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS |
+ _ASCE_TYPE_SEGMENT;
+ break;
+ default:
+ BUG();
+ }
+ mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
+ mm->task_size = mm->context.asce_limit;
+ crst_table_free(mm, (unsigned long *) pgd);
+ }
+ if (current->active_mm == mm)
+ set_user_asce(mm);
+}
+
+static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
+{
+ unsigned int old, new;
+
+ do {
+ old = atomic_read(v);
+ new = old ^ bits;
+ } while (atomic_cmpxchg(v, old, new) != old);
+ return new;
+}
+
+/*
+ * page table entry allocation/free routines.
+ */
+unsigned long *page_table_alloc(struct mm_struct *mm)
+{
+ unsigned long *table;
+ struct page *page;
+ unsigned int mask, bit;
+
+ /* 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);
+ clear_table(table, _PAGE_INVALID, PAGE_SIZE);
+ spin_lock_bh(&mm->context.list_lock);
+ list_add(&page->lru, &mm->context.pgtable_list);
+ spin_unlock_bh(&mm->context.list_lock);
+ }
+ return table;
+}
+
+void page_table_free(struct mm_struct *mm, unsigned long *table)
+{
+ struct page *page;
+ unsigned int bit, mask;
+
+ page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
+ 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;
+ }
+
+ pgtable_page_dtor(page);
+ atomic_set(&page->_mapcount, -1);
+ __free_page(page);
+}
+
+void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
+ unsigned long vmaddr)
+{
+ struct mm_struct *mm;
+ struct page *page;
+ unsigned int bit, mask;
+
+ mm = tlb->mm;
+ page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
+ if (mm_alloc_pgste(mm)) {
+ gmap_unlink(mm, table, vmaddr);
+ table = (unsigned long *) (__pa(table) | 3);
+ tlb_remove_table(tlb, table);
+ return;
+ }
+ bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
+ spin_lock_bh(&mm->context.list_lock);
+ 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) | (1U << bit));
+ tlb_remove_table(tlb, table);
+}
+
+static void __tlb_remove_table(void *_table)
+{
+ 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)
+{
+ /* Simply deliver the interrupt */
+}
+
+static void tlb_remove_table_one(void *table)
+{
+ /*
+ * This isn't an RCU grace period and hence the page-tables cannot be
+ * assumed to be actually RCU-freed.
+ *
+ * It is however sufficient for software page-table walkers that rely
+ * on IRQ disabling. See the comment near struct mmu_table_batch.
+ */
+ smp_call_function(tlb_remove_table_smp_sync, NULL, 1);
+ __tlb_remove_table(table);
+}
+
+static void tlb_remove_table_rcu(struct rcu_head *head)
+{
+ struct mmu_table_batch *batch;
+ int i;
+
+ batch = container_of(head, struct mmu_table_batch, rcu);
+
+ for (i = 0; i < batch->nr; i++)
+ __tlb_remove_table(batch->tables[i]);
+
+ free_page((unsigned long)batch);
+}
+
+void tlb_table_flush(struct mmu_gather *tlb)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ if (*batch) {
+ call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu);
+ *batch = NULL;
+ }
+}
+
+void tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ tlb->mm->context.flush_mm = 1;
+ if (*batch == NULL) {
+ *batch = (struct mmu_table_batch *)
+ __get_free_page(GFP_NOWAIT | __GFP_NOWARN);
+ if (*batch == NULL) {
+ __tlb_flush_mm_lazy(tlb->mm);
+ tlb_remove_table_one(table);
+ return;
+ }
+ (*batch)->nr = 0;
+ }
+ (*batch)->tables[(*batch)->nr++] = table;
+ if ((*batch)->nr == MAX_TABLE_BATCH)
+ tlb_flush_mmu(tlb);
+}
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
-unsigned long *crst_table_alloc(struct mm_struct *mm)
-{
- struct page *page = alloc_pages(GFP_KERNEL, 2);
-
- if (!page)
- return NULL;
- return (unsigned long *) page_to_phys(page);
-}
-
-void crst_table_free(struct mm_struct *mm, unsigned long *table)
-{
- free_pages((unsigned long) table, 2);
-}
-
-static void __crst_table_upgrade(void *arg)
-{
- struct mm_struct *mm = arg;
-
- if (current->active_mm == mm) {
- clear_user_asce();
- set_user_asce(mm);
- }
- __tlb_flush_local();
-}
-
-int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
-{
- unsigned long *table, *pgd;
- unsigned long entry;
- int flush;
-
- BUG_ON(limit > TASK_MAX_SIZE);
- flush = 0;
-repeat:
- table = crst_table_alloc(mm);
- if (!table)
- return -ENOMEM;
- spin_lock_bh(&mm->page_table_lock);
- if (mm->context.asce_limit < limit) {
- pgd = (unsigned long *) mm->pgd;
- if (mm->context.asce_limit <= (1UL << 31)) {
- entry = _REGION3_ENTRY_EMPTY;
- mm->context.asce_limit = 1UL << 42;
- mm->context.asce_bits = _ASCE_TABLE_LENGTH |
- _ASCE_USER_BITS |
- _ASCE_TYPE_REGION3;
- } else {
- entry = _REGION2_ENTRY_EMPTY;
- mm->context.asce_limit = 1UL << 53;
- mm->context.asce_bits = _ASCE_TABLE_LENGTH |
- _ASCE_USER_BITS |
- _ASCE_TYPE_REGION2;
- }
- crst_table_init(table, entry);
- pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
- mm->pgd = (pgd_t *) table;
- mm->task_size = mm->context.asce_limit;
- table = NULL;
- flush = 1;
- }
- spin_unlock_bh(&mm->page_table_lock);
- if (table)
- crst_table_free(mm, table);
- if (mm->context.asce_limit < limit)
- goto repeat;
- if (flush)
- on_each_cpu(__crst_table_upgrade, mm, 0);
- return 0;
-}
-
-void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
-{
- pgd_t *pgd;
-
- if (current->active_mm == mm) {
- clear_user_asce();
- __tlb_flush_mm(mm);
- }
- while (mm->context.asce_limit > limit) {
- pgd = mm->pgd;
- switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
- case _REGION_ENTRY_TYPE_R2:
- mm->context.asce_limit = 1UL << 42;
- mm->context.asce_bits = _ASCE_TABLE_LENGTH |
- _ASCE_USER_BITS |
- _ASCE_TYPE_REGION3;
- break;
- case _REGION_ENTRY_TYPE_R3:
- mm->context.asce_limit = 1UL << 31;
- mm->context.asce_bits = _ASCE_TABLE_LENGTH |
- _ASCE_USER_BITS |
- _ASCE_TYPE_SEGMENT;
- break;
- default:
- BUG();
- }
- mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
- mm->task_size = mm->context.asce_limit;
- crst_table_free(mm, (unsigned long *) pgd);
- }
- if (current->active_mm == mm)
- set_user_asce(mm);
-}
-
-#ifdef CONFIG_PGSTE
-
-/**
- * gmap_alloc - allocate a guest address space
- * @mm: pointer to the parent mm_struct
- * @limit: maximum address of the gmap address space
- *
- * Returns a guest address space structure.
- */
-struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit)
-{
- struct gmap *gmap;
- struct page *page;
- unsigned long *table;
- unsigned long etype, atype;
-
- if (limit < (1UL << 31)) {
- limit = (1UL << 31) - 1;
- atype = _ASCE_TYPE_SEGMENT;
- etype = _SEGMENT_ENTRY_EMPTY;
- } else if (limit < (1UL << 42)) {
- limit = (1UL << 42) - 1;
- atype = _ASCE_TYPE_REGION3;
- etype = _REGION3_ENTRY_EMPTY;
- } else if (limit < (1UL << 53)) {
- limit = (1UL << 53) - 1;
- atype = _ASCE_TYPE_REGION2;
- etype = _REGION2_ENTRY_EMPTY;
- } else {
- limit = -1UL;
- atype = _ASCE_TYPE_REGION1;
- etype = _REGION1_ENTRY_EMPTY;
- }
- gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
- if (!gmap)
- goto out;
- INIT_LIST_HEAD(&gmap->crst_list);
- INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
- INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
- spin_lock_init(&gmap->guest_table_lock);
- gmap->mm = mm;
- page = alloc_pages(GFP_KERNEL, 2);
- if (!page)
- goto out_free;
- page->index = 0;
- list_add(&page->lru, &gmap->crst_list);
- table = (unsigned long *) page_to_phys(page);
- crst_table_init(table, etype);
- gmap->table = table;
- gmap->asce = atype | _ASCE_TABLE_LENGTH |
- _ASCE_USER_BITS | __pa(table);
- gmap->asce_end = limit;
- down_write(&mm->mmap_sem);
- list_add(&gmap->list, &mm->context.gmap_list);
- up_write(&mm->mmap_sem);
- return gmap;
-
-out_free:
- kfree(gmap);
-out:
- return NULL;
-}
-EXPORT_SYMBOL_GPL(gmap_alloc);
-
-static void gmap_flush_tlb(struct gmap *gmap)
-{
- if (MACHINE_HAS_IDTE)
- __tlb_flush_asce(gmap->mm, gmap->asce);
- else
- __tlb_flush_global();
-}
-
-static void gmap_radix_tree_free(struct radix_tree_root *root)
-{
- struct radix_tree_iter iter;
- unsigned long indices[16];
- unsigned long index;
- void **slot;
- int i, nr;
-
- /* A radix tree is freed by deleting all of its entries */
- index = 0;
- do {
- nr = 0;
- radix_tree_for_each_slot(slot, root, &iter, index) {
- indices[nr] = iter.index;
- if (++nr == 16)
- break;
- }
- for (i = 0; i < nr; i++) {
- index = indices[i];
- radix_tree_delete(root, index);
- }
- } while (nr > 0);
-}
-
-/**
- * gmap_free - free a guest address space
- * @gmap: pointer to the guest address space structure
- */
-void gmap_free(struct gmap *gmap)
-{
- struct page *page, *next;
-
- /* Flush tlb. */
- if (MACHINE_HAS_IDTE)
- __tlb_flush_asce(gmap->mm, gmap->asce);
- else
- __tlb_flush_global();
-
- /* Free all segment & region tables. */
- list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
- __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);
- list_del(&gmap->list);
- up_write(&gmap->mm->mmap_sem);
- kfree(gmap);
-}
-EXPORT_SYMBOL_GPL(gmap_free);
-
-/**
- * gmap_enable - switch primary space to the guest address space
- * @gmap: pointer to the guest address space structure
- */
-void gmap_enable(struct gmap *gmap)
-{
- S390_lowcore.gmap = (unsigned long) gmap;
-}
-EXPORT_SYMBOL_GPL(gmap_enable);
-
-/**
- * gmap_disable - switch back to the standard primary address space
- * @gmap: pointer to the guest address space structure
- */
-void gmap_disable(struct gmap *gmap)
-{
- S390_lowcore.gmap = 0UL;
-}
-EXPORT_SYMBOL_GPL(gmap_disable);
-
-/*
- * gmap_alloc_table is assumed to be called with mmap_sem held
- */
-static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
- unsigned long init, unsigned long gaddr)
-{
- struct page *page;
- unsigned long *new;
-
- /* since we dont free the gmap table until gmap_free we can unlock */
- page = alloc_pages(GFP_KERNEL, 2);
- if (!page)
- return -ENOMEM;
- new = (unsigned long *) page_to_phys(page);
- crst_table_init(new, init);
- spin_lock(&gmap->mm->page_table_lock);
- if (*table & _REGION_ENTRY_INVALID) {
- list_add(&page->lru, &gmap->crst_list);
- *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
- (*table & _REGION_ENTRY_TYPE_MASK);
- page->index = gaddr;
- page = NULL;
- }
- spin_unlock(&gmap->mm->page_table_lock);
- if (page)
- __free_pages(page, 2);
- return 0;
-}
-
-/**
- * __gmap_segment_gaddr - find virtual address from segment pointer
- * @entry: pointer to a segment table entry in the guest address space
- *
- * Returns the virtual address in the guest address space for the segment
- */
-static unsigned long __gmap_segment_gaddr(unsigned long *entry)
-{
- struct page *page;
- unsigned long offset, mask;
-
- offset = (unsigned long) entry / sizeof(unsigned long);
- offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
- mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
- page = virt_to_page((void *)((unsigned long) entry & mask));
- return page->index + offset;
-}
-
-/**
- * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
- * @gmap: pointer to the guest address space structure
- * @vmaddr: address in the host process address space
- *
- * Returns 1 if a TLB flush is required
- */
-static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
-{
- unsigned long *entry;
- int flush = 0;
-
- spin_lock(&gmap->guest_table_lock);
- entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
- if (entry) {
- flush = (*entry != _SEGMENT_ENTRY_INVALID);
- *entry = _SEGMENT_ENTRY_INVALID;
- }
- spin_unlock(&gmap->guest_table_lock);
- return flush;
-}
-
-/**
- * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
- * @gmap: pointer to the guest address space structure
- * @gaddr: address in the guest address space
- *
- * Returns 1 if a TLB flush is required
- */
-static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
-{
- unsigned long vmaddr;
-
- vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
- gaddr >> PMD_SHIFT);
- return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
-}
-
-/**
- * gmap_unmap_segment - unmap segment from the guest address space
- * @gmap: pointer to the guest address space structure
- * @to: address in the guest address space
- * @len: length of the memory area to unmap
- *
- * Returns 0 if the unmap succeeded, -EINVAL if not.
- */
-int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
-{
- unsigned long off;
- int flush;
-
- if ((to | len) & (PMD_SIZE - 1))
- return -EINVAL;
- if (len == 0 || to + len < to)
- return -EINVAL;
-
- flush = 0;
- down_write(&gmap->mm->mmap_sem);
- for (off = 0; off < len; off += PMD_SIZE)
- flush |= __gmap_unmap_by_gaddr(gmap, to + off);
- up_write(&gmap->mm->mmap_sem);
- if (flush)
- gmap_flush_tlb(gmap);
- return 0;
-}
-EXPORT_SYMBOL_GPL(gmap_unmap_segment);
-
-/**
- * gmap_mmap_segment - map a segment to the guest address space
- * @gmap: pointer to the guest address space structure
- * @from: source address in the parent address space
- * @to: target address in the guest address space
- * @len: length of the memory area to map
- *
- * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
- */
-int gmap_map_segment(struct gmap *gmap, unsigned long from,
- unsigned long to, unsigned long len)
-{
- unsigned long off;
- int flush;
-
- if ((from | to | len) & (PMD_SIZE - 1))
- return -EINVAL;
- if (len == 0 || from + len < from || to + len < to ||
- from + len - 1 > TASK_MAX_SIZE || to + len - 1 > gmap->asce_end)
- return -EINVAL;
-
- flush = 0;
- down_write(&gmap->mm->mmap_sem);
- for (off = 0; off < len; off += PMD_SIZE) {
- /* Remove old translation */
- flush |= __gmap_unmap_by_gaddr(gmap, to + off);
- /* Store new translation */
- if (radix_tree_insert(&gmap->guest_to_host,
- (to + off) >> PMD_SHIFT,
- (void *) from + off))
- break;
- }
- up_write(&gmap->mm->mmap_sem);
- if (flush)
- gmap_flush_tlb(gmap);
- if (off >= len)
- return 0;
- gmap_unmap_segment(gmap, to, len);
- return -ENOMEM;
-}
-EXPORT_SYMBOL_GPL(gmap_map_segment);
-
-/**
- * __gmap_translate - translate a guest address to a user space address
- * @gmap: pointer to guest mapping meta data structure
- * @gaddr: guest address
- *
- * Returns user space address which corresponds to the guest address or
- * -EFAULT if no such mapping exists.
- * This function does not establish potentially missing page table entries.
- * The mmap_sem of the mm that belongs to the address space must be held
- * when this function gets called.
- */
-unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
-{
- unsigned long vmaddr;
-
- vmaddr = (unsigned long)
- radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
- return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
-}
-EXPORT_SYMBOL_GPL(__gmap_translate);
-
-/**
- * gmap_translate - translate a guest address to a user space address
- * @gmap: pointer to guest mapping meta data structure
- * @gaddr: guest address
- *
- * Returns user space address which corresponds to the guest address or
- * -EFAULT if no such mapping exists.
- * This function does not establish potentially missing page table entries.
- */
-unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
-{
- unsigned long rc;
-
- down_read(&gmap->mm->mmap_sem);
- rc = __gmap_translate(gmap, gaddr);
- up_read(&gmap->mm->mmap_sem);
- return rc;
-}
-EXPORT_SYMBOL_GPL(gmap_translate);
-
-/**
- * gmap_unlink - disconnect a page table from the gmap shadow tables
- * @gmap: pointer to guest mapping meta data structure
- * @table: pointer to the host page table
- * @vmaddr: vm address associated with the host page table
- */
-static void gmap_unlink(struct mm_struct *mm, unsigned long *table,
- unsigned long vmaddr)
-{
- struct gmap *gmap;
- int flush;
-
- list_for_each_entry(gmap, &mm->context.gmap_list, list) {
- flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
- if (flush)
- gmap_flush_tlb(gmap);
- }
-}
-
-/**
- * gmap_link - set up shadow page tables to connect a host to a guest address
- * @gmap: pointer to guest mapping meta data structure
- * @gaddr: guest address
- * @vmaddr: vm address
- *
- * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
- * if the vm address is already mapped to a different guest segment.
- * The mmap_sem of the mm that belongs to the address space must be held
- * when this function gets called.
- */
-int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
-{
- struct mm_struct *mm;
- unsigned long *table;
- spinlock_t *ptl;
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- int rc;
-
- /* Create higher level tables in the gmap page table */
- table = gmap->table;
- if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
- table += (gaddr >> 53) & 0x7ff;
- if ((*table & _REGION_ENTRY_INVALID) &&
- gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
- gaddr & 0xffe0000000000000UL))
- return -ENOMEM;
- table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
- }
- if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
- table += (gaddr >> 42) & 0x7ff;
- if ((*table & _REGION_ENTRY_INVALID) &&
- gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
- gaddr & 0xfffffc0000000000UL))
- return -ENOMEM;
- table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
- }
- if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
- table += (gaddr >> 31) & 0x7ff;
- if ((*table & _REGION_ENTRY_INVALID) &&
- gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
- gaddr & 0xffffffff80000000UL))
- return -ENOMEM;
- table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
- }
- table += (gaddr >> 20) & 0x7ff;
- /* Walk the parent mm page table */
- mm = gmap->mm;
- pgd = pgd_offset(mm, vmaddr);
- VM_BUG_ON(pgd_none(*pgd));
- pud = pud_offset(pgd, vmaddr);
- VM_BUG_ON(pud_none(*pud));
- pmd = pmd_offset(pud, vmaddr);
- VM_BUG_ON(pmd_none(*pmd));
- /* large pmds cannot yet be handled */
- if (pmd_large(*pmd))
- return -EFAULT;
- /* Link gmap segment table entry location to page table. */
- rc = radix_tree_preload(GFP_KERNEL);
- if (rc)
- return rc;
- ptl = pmd_lock(mm, pmd);
- spin_lock(&gmap->guest_table_lock);
- if (*table == _SEGMENT_ENTRY_INVALID) {
- rc = radix_tree_insert(&gmap->host_to_guest,
- vmaddr >> PMD_SHIFT, table);
- if (!rc)
- *table = pmd_val(*pmd);
- } else
- rc = 0;
- spin_unlock(&gmap->guest_table_lock);
- spin_unlock(ptl);
- radix_tree_preload_end();
- return rc;
-}
-
-/**
- * gmap_fault - resolve a fault on a guest address
- * @gmap: pointer to guest mapping meta data structure
- * @gaddr: guest address
- * @fault_flags: flags to pass down to handle_mm_fault()
- *
- * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
- * if the vm address is already mapped to a different guest segment.
- */
-int gmap_fault(struct gmap *gmap, unsigned long gaddr,
- unsigned int fault_flags)
-{
- unsigned long vmaddr;
- int rc;
- bool unlocked;
-
- down_read(&gmap->mm->mmap_sem);
-
-retry:
- unlocked = false;
- vmaddr = __gmap_translate(gmap, gaddr);
- if (IS_ERR_VALUE(vmaddr)) {
- rc = vmaddr;
- goto out_up;
- }
- if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
- &unlocked)) {
- rc = -EFAULT;
- goto out_up;
- }
- /*
- * In the case that fixup_user_fault unlocked the mmap_sem during
- * faultin redo __gmap_translate to not race with a map/unmap_segment.
- */
- if (unlocked)
- goto retry;
-
- rc = __gmap_link(gmap, gaddr, vmaddr);
-out_up:
- up_read(&gmap->mm->mmap_sem);
- return rc;
-}
-EXPORT_SYMBOL_GPL(gmap_fault);
-
-static void gmap_zap_swap_entry(swp_entry_t entry, struct mm_struct *mm)
-{
- if (!non_swap_entry(entry))
- dec_mm_counter(mm, MM_SWAPENTS);
- else if (is_migration_entry(entry)) {
- struct page *page = migration_entry_to_page(entry);
-
- dec_mm_counter(mm, mm_counter(page));
- }
- free_swap_and_cache(entry);
-}
-
-/*
- * this function is assumed to be called with mmap_sem held
- */
-void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
-{
- unsigned long vmaddr, ptev, pgstev;
- pte_t *ptep, pte;
- spinlock_t *ptl;
- pgste_t pgste;
-
- /* Find the vm address for the guest address */
- vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
- gaddr >> PMD_SHIFT);
- if (!vmaddr)
- return;
- vmaddr |= gaddr & ~PMD_MASK;
- /* Get pointer to the page table entry */
- ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
- if (unlikely(!ptep))
- return;
- pte = *ptep;
- if (!pte_swap(pte))
- goto out_pte;
- /* Zap unused and logically-zero pages */
- pgste = pgste_get_lock(ptep);
- pgstev = pgste_val(pgste);
- ptev = pte_val(pte);
- if (((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED) ||
- ((pgstev & _PGSTE_GPS_ZERO) && (ptev & _PAGE_INVALID))) {
- gmap_zap_swap_entry(pte_to_swp_entry(pte), gmap->mm);
- pte_clear(gmap->mm, vmaddr, ptep);
- }
- pgste_set_unlock(ptep, pgste);
-out_pte:
- pte_unmap_unlock(ptep, ptl);
-}
-EXPORT_SYMBOL_GPL(__gmap_zap);
-
-void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
-{
- unsigned long gaddr, vmaddr, size;
- struct vm_area_struct *vma;
-
- down_read(&gmap->mm->mmap_sem);
- for (gaddr = from; gaddr < to;
- gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
- /* Find the vm address for the guest address */
- vmaddr = (unsigned long)
- radix_tree_lookup(&gmap->guest_to_host,
- gaddr >> PMD_SHIFT);
- if (!vmaddr)
- continue;
- vmaddr |= gaddr & ~PMD_MASK;
- /* Find vma in the parent mm */
- vma = find_vma(gmap->mm, vmaddr);
- size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
- zap_page_range(vma, vmaddr, size, NULL);
- }
- up_read(&gmap->mm->mmap_sem);
-}
-EXPORT_SYMBOL_GPL(gmap_discard);
-
-static LIST_HEAD(gmap_notifier_list);
-static DEFINE_SPINLOCK(gmap_notifier_lock);
-
-/**
- * gmap_register_ipte_notifier - register a pte invalidation callback
- * @nb: pointer to the gmap notifier block
- */
-void gmap_register_ipte_notifier(struct gmap_notifier *nb)
-{
- spin_lock(&gmap_notifier_lock);
- list_add(&nb->list, &gmap_notifier_list);
- spin_unlock(&gmap_notifier_lock);
-}
-EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier);
-
-/**
- * gmap_unregister_ipte_notifier - remove a pte invalidation callback
- * @nb: pointer to the gmap notifier block
- */
-void gmap_unregister_ipte_notifier(struct gmap_notifier *nb)
-{
- spin_lock(&gmap_notifier_lock);
- list_del_init(&nb->list);
- spin_unlock(&gmap_notifier_lock);
-}
-EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier);
-
-/**
- * gmap_ipte_notify - mark a range of ptes for invalidation notification
- * @gmap: pointer to guest mapping meta data structure
- * @gaddr: virtual address in the guest address space
- * @len: size of area
- *
- * Returns 0 if for each page in the given range a gmap mapping exists and
- * the invalidation notification could be set. If the gmap mapping is missing
- * for one or more pages -EFAULT is returned. If no memory could be allocated
- * -ENOMEM is returned. This function establishes missing page table entries.
- */
-int gmap_ipte_notify(struct gmap *gmap, unsigned long gaddr, unsigned long len)
-{
- unsigned long addr;
- spinlock_t *ptl;
- pte_t *ptep, entry;
- pgste_t pgste;
- bool unlocked;
- int rc = 0;
-
- if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK))
- return -EINVAL;
- down_read(&gmap->mm->mmap_sem);
- while (len) {
- unlocked = false;
- /* Convert gmap address and connect the page tables */
- addr = __gmap_translate(gmap, gaddr);
- if (IS_ERR_VALUE(addr)) {
- rc = addr;
- break;
- }
- /* Get the page mapped */
- if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE,
- &unlocked)) {
- rc = -EFAULT;
- break;
- }
- /* While trying to map mmap_sem got unlocked. Let us retry */
- if (unlocked)
- continue;
- rc = __gmap_link(gmap, gaddr, addr);
- if (rc)
- break;
- /* Walk the process page table, lock and get pte pointer */
- ptep = get_locked_pte(gmap->mm, addr, &ptl);
- VM_BUG_ON(!ptep);
- /* Set notification bit in the pgste of the pte */
- entry = *ptep;
- if ((pte_val(entry) & (_PAGE_INVALID | _PAGE_PROTECT)) == 0) {
- pgste = pgste_get_lock(ptep);
- pgste_val(pgste) |= PGSTE_IN_BIT;
- pgste_set_unlock(ptep, pgste);
- gaddr += PAGE_SIZE;
- len -= PAGE_SIZE;
- }
- pte_unmap_unlock(ptep, ptl);
- }
- up_read(&gmap->mm->mmap_sem);
- return rc;
-}
-EXPORT_SYMBOL_GPL(gmap_ipte_notify);
-
-/**
- * ptep_ipte_notify - call all invalidation callbacks for a specific pte.
- * @mm: pointer to the process mm_struct
- * @addr: virtual address in the process address space
- * @pte: pointer to the page table entry
- *
- * This function is assumed to be called with the page table lock held
- * for the pte to notify.
- */
-void ptep_ipte_notify(struct mm_struct *mm, unsigned long vmaddr, pte_t *pte)
-{
- unsigned long offset, gaddr;
- unsigned long *table;
- struct gmap_notifier *nb;
- struct gmap *gmap;
-
- offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
- offset = offset * (4096 / sizeof(pte_t));
- spin_lock(&gmap_notifier_lock);
- list_for_each_entry(gmap, &mm->context.gmap_list, list) {
- table = radix_tree_lookup(&gmap->host_to_guest,
- vmaddr >> PMD_SHIFT);
- if (!table)
- continue;
- gaddr = __gmap_segment_gaddr(table) + offset;
- list_for_each_entry(nb, &gmap_notifier_list, list)
- nb->notifier_call(gmap, gaddr);
- }
- spin_unlock(&gmap_notifier_lock);
-}
-EXPORT_SYMBOL_GPL(ptep_ipte_notify);
-
-int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
- unsigned long key, bool nq)
-{
- spinlock_t *ptl;
- pgste_t old, new;
- pte_t *ptep;
-
- down_read(&mm->mmap_sem);
- ptep = get_locked_pte(mm, addr, &ptl);
- if (unlikely(!ptep)) {
- up_read(&mm->mmap_sem);
- return -EFAULT;
- }
-
- new = old = pgste_get_lock(ptep);
- pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
- PGSTE_ACC_BITS | PGSTE_FP_BIT);
- pgste_val(new) |= (key & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
- pgste_val(new) |= (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
- if (!(pte_val(*ptep) & _PAGE_INVALID)) {
- unsigned long address, bits, skey;
-
- address = pte_val(*ptep) & PAGE_MASK;
- skey = (unsigned long) page_get_storage_key(address);
- bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
- skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
- /* Set storage key ACC and FP */
- page_set_storage_key(address, skey, !nq);
- /* Merge host changed & referenced into pgste */
- pgste_val(new) |= bits << 52;
- }
- /* changing the guest storage key is considered a change of the page */
- if ((pgste_val(new) ^ pgste_val(old)) &
- (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
- pgste_val(new) |= PGSTE_UC_BIT;
-
- pgste_set_unlock(ptep, new);
- pte_unmap_unlock(ptep, ptl);
- up_read(&mm->mmap_sem);
- return 0;
-}
-EXPORT_SYMBOL(set_guest_storage_key);
-
-unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
-{
- spinlock_t *ptl;
- pgste_t pgste;
- pte_t *ptep;
- uint64_t physaddr;
- unsigned long key = 0;
-
- down_read(&mm->mmap_sem);
- ptep = get_locked_pte(mm, addr, &ptl);
- if (unlikely(!ptep)) {
- up_read(&mm->mmap_sem);
- return -EFAULT;
- }
- pgste = pgste_get_lock(ptep);
-
- if (pte_val(*ptep) & _PAGE_INVALID) {
- key |= (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56;
- key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56;
- key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48;
- key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48;
- } else {
- physaddr = pte_val(*ptep) & PAGE_MASK;
- key = page_get_storage_key(physaddr);
-
- /* Reflect guest's logical view, not physical */
- if (pgste_val(pgste) & PGSTE_GR_BIT)
- key |= _PAGE_REFERENCED;
- if (pgste_val(pgste) & PGSTE_GC_BIT)
- key |= _PAGE_CHANGED;
- }
-
- pgste_set_unlock(ptep, pgste);
- pte_unmap_unlock(ptep, ptl);
- up_read(&mm->mmap_sem);
- return key;
-}
-EXPORT_SYMBOL(get_guest_storage_key);
-
-static int page_table_allocate_pgste_min = 0;
-static int page_table_allocate_pgste_max = 1;
-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,
- .extra1 = &page_table_allocate_pgste_min,
- .extra2 = &page_table_allocate_pgste_max,
- },
- { }
-};
-
-static struct ctl_table page_table_sysctl_dir[] = {
- {
- .procname = "vm",
- .maxlen = 0,
- .mode = 0555,
- .child = page_table_sysctl,
- },
- { }
-};
-
-static int __init page_table_register_sysctl(void)
-{
- return register_sysctl_table(page_table_sysctl_dir) ? 0 : -ENOMEM;
-}
-__initcall(page_table_register_sysctl);
-
-#else /* CONFIG_PGSTE */
-
-static inline void gmap_unlink(struct mm_struct *mm, unsigned long *table,
- unsigned long vmaddr)
-{
-}
-
-#endif /* CONFIG_PGSTE */
-
-static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
-{
- unsigned int old, new;
-
- do {
- old = atomic_read(v);
- new = old ^ bits;
- } while (atomic_cmpxchg(v, old, new) != old);
- return new;
-}
-
-/*
- * page table entry allocation/free routines.
- */
-unsigned long *page_table_alloc(struct mm_struct *mm)
-{
- unsigned long *table;
- struct page *page;
- unsigned int mask, bit;
-
- /* 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);
- clear_table(table, _PAGE_INVALID, PAGE_SIZE);
- spin_lock_bh(&mm->context.list_lock);
- list_add(&page->lru, &mm->context.pgtable_list);
- spin_unlock_bh(&mm->context.list_lock);
- }
- return table;
-}
-
-void page_table_free(struct mm_struct *mm, unsigned long *table)
-{
- struct page *page;
- unsigned int bit, mask;
-
- page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- 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;
- }
-
- pgtable_page_dtor(page);
- atomic_set(&page->_mapcount, -1);
- __free_page(page);
-}
-
-void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
- unsigned long vmaddr)
-{
- struct mm_struct *mm;
- struct page *page;
- unsigned int bit, mask;
-
- mm = tlb->mm;
- page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- if (mm_alloc_pgste(mm)) {
- gmap_unlink(mm, table, vmaddr);
- table = (unsigned long *) (__pa(table) | 3);
- tlb_remove_table(tlb, table);
- return;
- }
- bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
- spin_lock_bh(&mm->context.list_lock);
- 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) | (1U << bit));
- tlb_remove_table(tlb, table);
-}
-
-static void __tlb_remove_table(void *_table)
-{
- 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)
-{
- /* Simply deliver the interrupt */
-}
-
-static void tlb_remove_table_one(void *table)
-{
- /*
- * This isn't an RCU grace period and hence the page-tables cannot be
- * assumed to be actually RCU-freed.
- *
- * It is however sufficient for software page-table walkers that rely
- * on IRQ disabling. See the comment near struct mmu_table_batch.
- */
- smp_call_function(tlb_remove_table_smp_sync, NULL, 1);
- __tlb_remove_table(table);
-}
-
-static void tlb_remove_table_rcu(struct rcu_head *head)
-{
- struct mmu_table_batch *batch;
- int i;
-
- batch = container_of(head, struct mmu_table_batch, rcu);
-
- for (i = 0; i < batch->nr; i++)
- __tlb_remove_table(batch->tables[i]);
-
- free_page((unsigned long)batch);
-}
-
-void tlb_table_flush(struct mmu_gather *tlb)
-{
- struct mmu_table_batch **batch = &tlb->batch;
-
- if (*batch) {
- call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu);
- *batch = NULL;
- }
-}
-
-void tlb_remove_table(struct mmu_gather *tlb, void *table)
-{
- struct mmu_table_batch **batch = &tlb->batch;
-
- tlb->mm->context.flush_mm = 1;
- if (*batch == NULL) {
- *batch = (struct mmu_table_batch *)
- __get_free_page(GFP_NOWAIT | __GFP_NOWARN);
- if (*batch == NULL) {
- __tlb_flush_mm_lazy(tlb->mm);
- tlb_remove_table_one(table);
- return;
- }
- (*batch)->nr = 0;
- }
- (*batch)->tables[(*batch)->nr++] = table;
- if ((*batch)->nr == MAX_TABLE_BATCH)
- tlb_flush_mmu(tlb);
-}
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static inline void thp_split_vma(struct vm_area_struct *vma)
-{
- unsigned long addr;
-
- for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE)
- follow_page(vma, addr, FOLL_SPLIT);
-}
-
-static inline void thp_split_mm(struct mm_struct *mm)
-{
- struct vm_area_struct *vma;
-
- for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
- thp_split_vma(vma);
- vma->vm_flags &= ~VM_HUGEPAGE;
- vma->vm_flags |= VM_NOHUGEPAGE;
- }
- mm->def_flags |= VM_NOHUGEPAGE;
-}
-#else
-static inline void thp_split_mm(struct mm_struct *mm)
-{
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
static inline pte_t ptep_flush_direct(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
return old;
}
+static inline pgste_t pgste_get_lock(pte_t *ptep)
+{
+ unsigned long new = 0;
+#ifdef CONFIG_PGSTE
+ unsigned long old;
+
+ preempt_disable();
+ asm(
+ " lg %0,%2\n"
+ "0: lgr %1,%0\n"
+ " nihh %0,0xff7f\n" /* clear PCL bit in old */
+ " oihh %1,0x0080\n" /* set PCL bit in new */
+ " csg %0,%1,%2\n"
+ " jl 0b\n"
+ : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
+ : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
+#endif
+ return __pgste(new);
+}
+
+static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
+{
+#ifdef CONFIG_PGSTE
+ asm(
+ " nihh %1,0xff7f\n" /* clear PCL bit */
+ " stg %1,%0\n"
+ : "=Q" (ptep[PTRS_PER_PTE])
+ : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
+ : "cc", "memory");
+ preempt_enable();
+#endif
+}
+
+static inline pgste_t pgste_get(pte_t *ptep)
+{
+ unsigned long pgste = 0;
+#ifdef CONFIG_PGSTE
+ pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
+#endif
+ return __pgste(pgste);
+}
+
+static inline void pgste_set(pte_t *ptep, pgste_t pgste)
+{
+#ifdef CONFIG_PGSTE
+ *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
+#endif
+}
+
static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
struct mm_struct *mm)
{
#ifdef CONFIG_PGSTE
if (pgste_val(pgste) & PGSTE_IN_BIT) {
pgste_val(pgste) &= ~PGSTE_IN_BIT;
- ptep_ipte_notify(mm, addr, ptep);
+ ptep_notify(mm, addr, ptep);
}
#endif
return pgste;
}
-#ifdef CONFIG_PGSTE
-/*
- * Test and reset if a guest page is dirty
- */
-bool pgste_test_and_clear_dirty(struct mm_struct *mm, unsigned long addr)
-{
- spinlock_t *ptl;
- pgste_t pgste;
- pte_t *ptep;
- pte_t pte;
- bool dirty;
-
- ptep = get_locked_pte(mm, addr, &ptl);
- if (unlikely(!ptep))
- return false;
-
- pgste = pgste_get_lock(ptep);
- dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
- pgste_val(pgste) &= ~PGSTE_UC_BIT;
- pte = *ptep;
- if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
- pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
- __ptep_ipte(addr, ptep);
- if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
- pte_val(pte) |= _PAGE_PROTECT;
- else
- pte_val(pte) |= _PAGE_INVALID;
- *ptep = pte;
- }
- pgste_set_unlock(ptep, pgste);
-
- spin_unlock(ptl);
- return dirty;
-}
-EXPORT_SYMBOL_GPL(pgste_test_and_clear_dirty);
-
-void set_pte_pgste_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t entry)
-{
- pgste_t pgste;
-
- /* the mm_has_pgste() check is done in set_pte_at() */
- pgste = pgste_get_lock(ptep);
- pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
- pgste_set_key(ptep, pgste, entry, mm);
- pgste = pgste_set_pte(ptep, pgste, entry);
- pgste_set_unlock(ptep, pgste);
-}
-EXPORT_SYMBOL(set_pte_pgste_at);
-#endif
-
static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
}
EXPORT_SYMBOL(pmdp_xchg_lazy);
-/*
- * switch on pgstes for its userspace process (for kvm)
- */
-int s390_enable_sie(void)
-{
- struct mm_struct *mm = current->mm;
-
- /* Do we have pgstes? if yes, we are done */
- if (mm_has_pgste(mm))
- return 0;
- /* Fail if the page tables are 2K */
- if (!mm_alloc_pgste(mm))
- return -EINVAL;
- down_write(&mm->mmap_sem);
- mm->context.has_pgste = 1;
- /* split thp mappings and disable thp for future mappings */
- thp_split_mm(mm);
- up_write(&mm->mmap_sem);
- return 0;
-}
-EXPORT_SYMBOL_GPL(s390_enable_sie);
-
-/*
- * Enable storage key handling from now on and initialize the storage
- * keys with the default key.
- */
-static int __s390_enable_skey(pte_t *pte, unsigned long addr,
- unsigned long next, struct mm_walk *walk)
-{
- unsigned long ptev;
- pgste_t pgste;
-
- /*
- * Remove all zero page mappings,
- * after establishing a policy to forbid zero page mappings
- * following faults for that page will get fresh anonymous pages
- */
- if (is_zero_pfn(pte_pfn(*pte)))
- ptep_xchg_direct(walk->mm, addr, pte, __pte(_PAGE_INVALID));
- /* Clear storage key */
- pgste = pgste_get_lock(pte);
- pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
- PGSTE_GR_BIT | PGSTE_GC_BIT);
- ptev = pte_val(*pte);
- if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
- page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
- pgste_set_unlock(pte, pgste);
- return 0;
-}
-
-int s390_enable_skey(void)
-{
- struct mm_walk walk = { .pte_entry = __s390_enable_skey };
- struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
- int rc = 0;
-
- down_write(&mm->mmap_sem);
- if (mm_use_skey(mm))
- goto out_up;
-
- mm->context.use_skey = 1;
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
- MADV_UNMERGEABLE, &vma->vm_flags)) {
- mm->context.use_skey = 0;
- rc = -ENOMEM;
- goto out_up;
- }
- }
- mm->def_flags &= ~VM_MERGEABLE;
-
- walk.mm = mm;
- walk_page_range(0, TASK_SIZE, &walk);
-
-out_up:
- up_write(&mm->mmap_sem);
- return rc;
-}
-EXPORT_SYMBOL_GPL(s390_enable_skey);
-
-/*
- * Reset CMMA state, make all pages stable again.
- */
-static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
- unsigned long next, struct mm_walk *walk)
-{
- pgste_t pgste;
-
- pgste = pgste_get_lock(pte);
- pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
- pgste_set_unlock(pte, pgste);
- return 0;
-}
-
-void s390_reset_cmma(struct mm_struct *mm)
-{
- struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
-
- down_write(&mm->mmap_sem);
- walk.mm = mm;
- walk_page_range(0, TASK_SIZE, &walk);
- up_write(&mm->mmap_sem);
-}
-EXPORT_SYMBOL_GPL(s390_reset_cmma);
-
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable)
return pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_PGSTE
+void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t entry)
+{
+ pgste_t pgste;
+
+ /* the mm_has_pgste() check is done in set_pte_at() */
+ pgste = pgste_get_lock(ptep);
+ pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
+ pgste_set_key(ptep, pgste, entry, mm);
+ pgste = pgste_set_pte(ptep, pgste, entry);
+ pgste_set_unlock(ptep, pgste);
+}
+
+void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ pgste_t pgste;
+
+ pgste = pgste_get_lock(ptep);
+ pgste_val(pgste) |= PGSTE_IN_BIT;
+ pgste_set_unlock(ptep, pgste);
+}
+
+static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
+{
+ if (!non_swap_entry(entry))
+ dec_mm_counter(mm, MM_SWAPENTS);
+ else if (is_migration_entry(entry)) {
+ struct page *page = migration_entry_to_page(entry);
+
+ dec_mm_counter(mm, mm_counter(page));
+ }
+ free_swap_and_cache(entry);
+}
+
+void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, int reset)
+{
+ unsigned long pgstev;
+ pgste_t pgste;
+ pte_t pte;
+
+ /* Zap unused and logically-zero pages */
+ pgste = pgste_get_lock(ptep);
+ pgstev = pgste_val(pgste);
+ pte = *ptep;
+ if (pte_swap(pte) &&
+ ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
+ (pgstev & _PGSTE_GPS_ZERO))) {
+ ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
+ pte_clear(mm, addr, ptep);
+ }
+ if (reset)
+ pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
+ pgste_set_unlock(ptep, pgste);
+}
+
+void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ unsigned long ptev;
+ pgste_t pgste;
+
+ /* Clear storage key */
+ pgste = pgste_get_lock(ptep);
+ pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
+ PGSTE_GR_BIT | PGSTE_GC_BIT);
+ ptev = pte_val(*ptep);
+ if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
+ page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
+ pgste_set_unlock(ptep, pgste);
+}
+
+/*
+ * Test and reset if a guest page is dirty
+ */
+bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr)
+{
+ spinlock_t *ptl;
+ pgste_t pgste;
+ pte_t *ptep;
+ pte_t pte;
+ bool dirty;
+
+ ptep = get_locked_pte(mm, addr, &ptl);
+ if (unlikely(!ptep))
+ return false;
+
+ pgste = pgste_get_lock(ptep);
+ dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
+ pgste_val(pgste) &= ~PGSTE_UC_BIT;
+ pte = *ptep;
+ if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
+ pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
+ __ptep_ipte(addr, ptep);
+ if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
+ pte_val(pte) |= _PAGE_PROTECT;
+ else
+ pte_val(pte) |= _PAGE_INVALID;
+ *ptep = pte;
+ }
+ pgste_set_unlock(ptep, pgste);
+
+ spin_unlock(ptl);
+ return dirty;
+}
+EXPORT_SYMBOL_GPL(test_and_clear_guest_dirty);
+
+int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char key, bool nq)
+{
+ unsigned long keyul;
+ spinlock_t *ptl;
+ pgste_t old, new;
+ pte_t *ptep;
+
+ down_read(&mm->mmap_sem);
+ ptep = get_locked_pte(mm, addr, &ptl);
+ if (unlikely(!ptep)) {
+ up_read(&mm->mmap_sem);
+ return -EFAULT;
+ }
+
+ new = old = pgste_get_lock(ptep);
+ pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
+ PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ keyul = (unsigned long) key;
+ pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
+ pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ unsigned long address, bits, skey;
+
+ address = pte_val(*ptep) & PAGE_MASK;
+ skey = (unsigned long) page_get_storage_key(address);
+ bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
+ skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
+ /* Set storage key ACC and FP */
+ page_set_storage_key(address, skey, !nq);
+ /* Merge host changed & referenced into pgste */
+ pgste_val(new) |= bits << 52;
+ }
+ /* changing the guest storage key is considered a change of the page */
+ if ((pgste_val(new) ^ pgste_val(old)) &
+ (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
+ pgste_val(new) |= PGSTE_UC_BIT;
+
+ pgste_set_unlock(ptep, new);
+ pte_unmap_unlock(ptep, ptl);
+ up_read(&mm->mmap_sem);
+ return 0;
+}
+EXPORT_SYMBOL(set_guest_storage_key);
+
+unsigned char get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
+{
+ unsigned char key;
+ spinlock_t *ptl;
+ pgste_t pgste;
+ pte_t *ptep;
+
+ down_read(&mm->mmap_sem);
+ ptep = get_locked_pte(mm, addr, &ptl);
+ if (unlikely(!ptep)) {
+ up_read(&mm->mmap_sem);
+ return -EFAULT;
+ }
+ pgste = pgste_get_lock(ptep);
+
+ if (pte_val(*ptep) & _PAGE_INVALID) {
+ key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56;
+ key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56;
+ key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48;
+ key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48;
+ } else {
+ key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
+
+ /* Reflect guest's logical view, not physical */
+ if (pgste_val(pgste) & PGSTE_GR_BIT)
+ key |= _PAGE_REFERENCED;
+ if (pgste_val(pgste) & PGSTE_GC_BIT)
+ key |= _PAGE_CHANGED;
+ }
+
+ pgste_set_unlock(ptep, pgste);
+ pte_unmap_unlock(ptep, ptl);
+ up_read(&mm->mmap_sem);
+ return key;
+}
+EXPORT_SYMBOL(get_guest_storage_key);
+#endif
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff