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-rw-r--r--mm/vmalloc.c1812
1 files changed, 1812 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
new file mode 100644
index 0000000..4172ce4
--- /dev/null
+++ b/mm/vmalloc.c
@@ -0,0 +1,1812 @@
+/*
+ * linux/mm/vmalloc.c
+ *
+ * Copyright (C) 1993 Linus Torvalds
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
+ * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
+ * Numa awareness, Christoph Lameter, SGI, June 2005
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/debugobjects.h>
+#include <linux/kallsyms.h>
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/radix-tree.h>
+#include <linux/rcupdate.h>
+#include <linux/bootmem.h>
+
+#include <asm/atomic.h>
+#include <asm/uaccess.h>
+#include <asm/tlbflush.h>
+
+
+/*** Page table manipulation functions ***/
+
+static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
+{
+ pte_t *pte;
+
+ pte = pte_offset_kernel(pmd, addr);
+ do {
+ pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
+ WARN_ON(!pte_none(ptent) && !pte_present(ptent));
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+}
+
+static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ vunmap_pte_range(pmd, addr, next);
+ } while (pmd++, addr = next, addr != end);
+}
+
+static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ vunmap_pmd_range(pud, addr, next);
+ } while (pud++, addr = next, addr != end);
+}
+
+static void vunmap_page_range(unsigned long addr, unsigned long end)
+{
+ pgd_t *pgd;
+ unsigned long next;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ vunmap_pud_range(pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+{
+ pte_t *pte;
+
+ /*
+ * nr is a running index into the array which helps higher level
+ * callers keep track of where we're up to.
+ */
+
+ pte = pte_alloc_kernel(pmd, addr);
+ if (!pte)
+ return -ENOMEM;
+ do {
+ struct page *page = pages[*nr];
+
+ if (WARN_ON(!pte_none(*pte)))
+ return -EBUSY;
+ if (WARN_ON(!page))
+ return -ENOMEM;
+ set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
+ (*nr)++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
+}
+
+static int vmap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_alloc(&init_mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_alloc(&init_mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+/*
+ * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
+ * will have pfns corresponding to the "pages" array.
+ *
+ * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
+ */
+static int vmap_page_range(unsigned long start, unsigned long end,
+ pgprot_t prot, struct page **pages)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long addr = start;
+ int err = 0;
+ int nr = 0;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+ flush_cache_vmap(start, end);
+
+ if (unlikely(err))
+ return err;
+ return nr;
+}
+
+static inline int is_vmalloc_or_module_addr(const void *x)
+{
+ /*
+ * ARM, x86-64 and sparc64 put modules in a special place,
+ * and fall back on vmalloc() if that fails. Others
+ * just put it in the vmalloc space.
+ */
+#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
+ unsigned long addr = (unsigned long)x;
+ if (addr >= MODULES_VADDR && addr < MODULES_END)
+ return 1;
+#endif
+ return is_vmalloc_addr(x);
+}
+
+/*
+ * Walk a vmap address to the struct page it maps.
+ */
+struct page *vmalloc_to_page(const void *vmalloc_addr)
+{
+ unsigned long addr = (unsigned long) vmalloc_addr;
+ struct page *page = NULL;
+ pgd_t *pgd = pgd_offset_k(addr);
+
+ /*
+ * XXX we might need to change this if we add VIRTUAL_BUG_ON for
+ * architectures that do not vmalloc module space
+ */
+ VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
+
+ if (!pgd_none(*pgd)) {
+ pud_t *pud = pud_offset(pgd, addr);
+ if (!pud_none(*pud)) {
+ pmd_t *pmd = pmd_offset(pud, addr);
+ if (!pmd_none(*pmd)) {
+ pte_t *ptep, pte;
+
+ ptep = pte_offset_map(pmd, addr);
+ pte = *ptep;
+ if (pte_present(pte))
+ page = pte_page(pte);
+ pte_unmap(ptep);
+ }
+ }
+ }
+ return page;
+}
+EXPORT_SYMBOL(vmalloc_to_page);
+
+/*
+ * Map a vmalloc()-space virtual address to the physical page frame number.
+ */
+unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
+{
+ return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+}
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
+
+/*** Global kva allocator ***/
+
+#define VM_LAZY_FREE 0x01
+#define VM_LAZY_FREEING 0x02
+#define VM_VM_AREA 0x04
+
+struct vmap_area {
+ unsigned long va_start;
+ unsigned long va_end;
+ unsigned long flags;
+ struct rb_node rb_node; /* address sorted rbtree */
+ struct list_head list; /* address sorted list */
+ struct list_head purge_list; /* "lazy purge" list */
+ void *private;
+ struct rcu_head rcu_head;
+};
+
+static DEFINE_SPINLOCK(vmap_area_lock);
+static struct rb_root vmap_area_root = RB_ROOT;
+static LIST_HEAD(vmap_area_list);
+
+static struct vmap_area *__find_vmap_area(unsigned long addr)
+{
+ struct rb_node *n = vmap_area_root.rb_node;
+
+ while (n) {
+ struct vmap_area *va;
+
+ va = rb_entry(n, struct vmap_area, rb_node);
+ if (addr < va->va_start)
+ n = n->rb_left;
+ else if (addr > va->va_start)
+ n = n->rb_right;
+ else
+ return va;
+ }
+
+ return NULL;
+}
+
+static void __insert_vmap_area(struct vmap_area *va)
+{
+ struct rb_node **p = &vmap_area_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct rb_node *tmp;
+
+ while (*p) {
+ struct vmap_area *tmp;
+
+ parent = *p;
+ tmp = rb_entry(parent, struct vmap_area, rb_node);
+ if (va->va_start < tmp->va_end)
+ p = &(*p)->rb_left;
+ else if (va->va_end > tmp->va_start)
+ p = &(*p)->rb_right;
+ else
+ BUG();
+ }
+
+ rb_link_node(&va->rb_node, parent, p);
+ rb_insert_color(&va->rb_node, &vmap_area_root);
+
+ /* address-sort this list so it is usable like the vmlist */
+ tmp = rb_prev(&va->rb_node);
+ if (tmp) {
+ struct vmap_area *prev;
+ prev = rb_entry(tmp, struct vmap_area, rb_node);
+ list_add_rcu(&va->list, &prev->list);
+ } else
+ list_add_rcu(&va->list, &vmap_area_list);
+}
+
+static void purge_vmap_area_lazy(void);
+
+/*
+ * Allocate a region of KVA of the specified size and alignment, within the
+ * vstart and vend.
+ */
+static struct vmap_area *alloc_vmap_area(unsigned long size,
+ unsigned long align,
+ unsigned long vstart, unsigned long vend,
+ int node, gfp_t gfp_mask)
+{
+ struct vmap_area *va;
+ struct rb_node *n;
+ unsigned long addr;
+ int purged = 0;
+
+ BUG_ON(!size);
+ BUG_ON(size & ~PAGE_MASK);
+
+ va = kmalloc_node(sizeof(struct vmap_area),
+ gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!va))
+ return ERR_PTR(-ENOMEM);
+
+retry:
+ addr = ALIGN(vstart, align);
+
+ spin_lock(&vmap_area_lock);
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ /* XXX: could have a last_hole cache */
+ n = vmap_area_root.rb_node;
+ if (n) {
+ struct vmap_area *first = NULL;
+
+ do {
+ struct vmap_area *tmp;
+ tmp = rb_entry(n, struct vmap_area, rb_node);
+ if (tmp->va_end >= addr) {
+ if (!first && tmp->va_start < addr + size)
+ first = tmp;
+ n = n->rb_left;
+ } else {
+ first = tmp;
+ n = n->rb_right;
+ }
+ } while (n);
+
+ if (!first)
+ goto found;
+
+ if (first->va_end < addr) {
+ n = rb_next(&first->rb_node);
+ if (n)
+ first = rb_entry(n, struct vmap_area, rb_node);
+ else
+ goto found;
+ }
+
+ while (addr + size > first->va_start && addr + size <= vend) {
+ addr = ALIGN(first->va_end + PAGE_SIZE, align);
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ n = rb_next(&first->rb_node);
+ if (n)
+ first = rb_entry(n, struct vmap_area, rb_node);
+ else
+ goto found;
+ }
+ }
+found:
+ if (addr + size > vend) {
+overflow:
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = 1;
+ goto retry;
+ }
+ if (printk_ratelimit())
+ printk(KERN_WARNING "vmap allocation failed: "
+ "use vmalloc=<size> to increase size.\n");
+ return ERR_PTR(-EBUSY);
+ }
+
+ BUG_ON(addr & (align-1));
+
+ va->va_start = addr;
+ va->va_end = addr + size;
+ va->flags = 0;
+ __insert_vmap_area(va);
+ spin_unlock(&vmap_area_lock);
+
+ return va;
+}
+
+static void rcu_free_va(struct rcu_head *head)
+{
+ struct vmap_area *va = container_of(head, struct vmap_area, rcu_head);
+
+ kfree(va);
+}
+
+static void __free_vmap_area(struct vmap_area *va)
+{
+ BUG_ON(RB_EMPTY_NODE(&va->rb_node));
+ rb_erase(&va->rb_node, &vmap_area_root);
+ RB_CLEAR_NODE(&va->rb_node);
+ list_del_rcu(&va->list);
+
+ call_rcu(&va->rcu_head, rcu_free_va);
+}
+
+/*
+ * Free a region of KVA allocated by alloc_vmap_area
+ */
+static void free_vmap_area(struct vmap_area *va)
+{
+ spin_lock(&vmap_area_lock);
+ __free_vmap_area(va);
+ spin_unlock(&vmap_area_lock);
+}
+
+/*
+ * Clear the pagetable entries of a given vmap_area
+ */
+static void unmap_vmap_area(struct vmap_area *va)
+{
+ vunmap_page_range(va->va_start, va->va_end);
+}
+
+/*
+ * lazy_max_pages is the maximum amount of virtual address space we gather up
+ * before attempting to purge with a TLB flush.
+ *
+ * There is a tradeoff here: a larger number will cover more kernel page tables
+ * and take slightly longer to purge, but it will linearly reduce the number of
+ * global TLB flushes that must be performed. It would seem natural to scale
+ * this number up linearly with the number of CPUs (because vmapping activity
+ * could also scale linearly with the number of CPUs), however it is likely
+ * that in practice, workloads might be constrained in other ways that mean
+ * vmap activity will not scale linearly with CPUs. Also, I want to be
+ * conservative and not introduce a big latency on huge systems, so go with
+ * a less aggressive log scale. It will still be an improvement over the old
+ * code, and it will be simple to change the scale factor if we find that it
+ * becomes a problem on bigger systems.
+ */
+static unsigned long lazy_max_pages(void)
+{
+ unsigned int log;
+
+ log = fls(num_online_cpus());
+
+ return log * (32UL * 1024 * 1024 / PAGE_SIZE);
+}
+
+static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
+
+/*
+ * Purges all lazily-freed vmap areas.
+ *
+ * If sync is 0 then don't purge if there is already a purge in progress.
+ * If force_flush is 1, then flush kernel TLBs between *start and *end even
+ * if we found no lazy vmap areas to unmap (callers can use this to optimise
+ * their own TLB flushing).
+ * Returns with *start = min(*start, lowest purged address)
+ * *end = max(*end, highest purged address)
+ */
+static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
+ int sync, int force_flush)
+{
+ static DEFINE_SPINLOCK(purge_lock);
+ LIST_HEAD(valist);
+ struct vmap_area *va;
+ struct vmap_area *n_va;
+ int nr = 0;
+
+ /*
+ * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
+ * should not expect such behaviour. This just simplifies locking for
+ * the case that isn't actually used at the moment anyway.
+ */
+ if (!sync && !force_flush) {
+ if (!spin_trylock(&purge_lock))
+ return;
+ } else
+ spin_lock(&purge_lock);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(va, &vmap_area_list, list) {
+ if (va->flags & VM_LAZY_FREE) {
+ if (va->va_start < *start)
+ *start = va->va_start;
+ if (va->va_end > *end)
+ *end = va->va_end;
+ nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
+ unmap_vmap_area(va);
+ list_add_tail(&va->purge_list, &valist);
+ va->flags |= VM_LAZY_FREEING;
+ va->flags &= ~VM_LAZY_FREE;
+ }
+ }
+ rcu_read_unlock();
+
+ if (nr) {
+ BUG_ON(nr > atomic_read(&vmap_lazy_nr));
+ atomic_sub(nr, &vmap_lazy_nr);
+ }
+
+ if (nr || force_flush)
+ flush_tlb_kernel_range(*start, *end);
+
+ if (nr) {
+ spin_lock(&vmap_area_lock);
+ list_for_each_entry_safe(va, n_va, &valist, purge_list)
+ __free_vmap_area(va);
+ spin_unlock(&vmap_area_lock);
+ }
+ spin_unlock(&purge_lock);
+}
+
+/*
+ * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
+ * is already purging.
+ */
+static void try_purge_vmap_area_lazy(void)
+{
+ unsigned long start = ULONG_MAX, end = 0;
+
+ __purge_vmap_area_lazy(&start, &end, 0, 0);
+}
+
+/*
+ * Kick off a purge of the outstanding lazy areas.
+ */
+static void purge_vmap_area_lazy(void)
+{
+ unsigned long start = ULONG_MAX, end = 0;
+
+ __purge_vmap_area_lazy(&start, &end, 1, 0);
+}
+
+/*
+ * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
+ * called for the correct range previously.
+ */
+static void free_unmap_vmap_area_noflush(struct vmap_area *va)
+{
+ va->flags |= VM_LAZY_FREE;
+ atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
+ if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
+ try_purge_vmap_area_lazy();
+}
+
+/*
+ * Free and unmap a vmap area
+ */
+static void free_unmap_vmap_area(struct vmap_area *va)
+{
+ flush_cache_vunmap(va->va_start, va->va_end);
+ free_unmap_vmap_area_noflush(va);
+}
+
+static struct vmap_area *find_vmap_area(unsigned long addr)
+{
+ struct vmap_area *va;
+
+ spin_lock(&vmap_area_lock);
+ va = __find_vmap_area(addr);
+ spin_unlock(&vmap_area_lock);
+
+ return va;
+}
+
+static void free_unmap_vmap_area_addr(unsigned long addr)
+{
+ struct vmap_area *va;
+
+ va = find_vmap_area(addr);
+ BUG_ON(!va);
+ free_unmap_vmap_area(va);
+}
+
+
+/*** Per cpu kva allocator ***/
+
+/*
+ * vmap space is limited especially on 32 bit architectures. Ensure there is
+ * room for at least 16 percpu vmap blocks per CPU.
+ */
+/*
+ * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
+ * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
+ * instead (we just need a rough idea)
+ */
+#if BITS_PER_LONG == 32
+#define VMALLOC_SPACE (128UL*1024*1024)
+#else
+#define VMALLOC_SPACE (128UL*1024*1024*1024)
+#endif
+
+#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
+#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
+#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
+#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
+#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
+#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
+#define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
+ VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
+ VMALLOC_PAGES / NR_CPUS / 16))
+
+#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
+
+static bool vmap_initialized __read_mostly = false;
+
+struct vmap_block_queue {
+ spinlock_t lock;
+ struct list_head free;
+ struct list_head dirty;
+ unsigned int nr_dirty;
+};
+
+struct vmap_block {
+ spinlock_t lock;
+ struct vmap_area *va;
+ struct vmap_block_queue *vbq;
+ unsigned long free, dirty;
+ DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
+ DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
+ union {
+ struct {
+ struct list_head free_list;
+ struct list_head dirty_list;
+ };
+ struct rcu_head rcu_head;
+ };
+};
+
+/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
+static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
+
+/*
+ * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
+ * in the free path. Could get rid of this if we change the API to return a
+ * "cookie" from alloc, to be passed to free. But no big deal yet.
+ */
+static DEFINE_SPINLOCK(vmap_block_tree_lock);
+static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
+
+/*
+ * We should probably have a fallback mechanism to allocate virtual memory
+ * out of partially filled vmap blocks. However vmap block sizing should be
+ * fairly reasonable according to the vmalloc size, so it shouldn't be a
+ * big problem.
+ */
+
+static unsigned long addr_to_vb_idx(unsigned long addr)
+{
+ addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
+ addr /= VMAP_BLOCK_SIZE;
+ return addr;
+}
+
+static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
+{
+ struct vmap_block_queue *vbq;
+ struct vmap_block *vb;
+ struct vmap_area *va;
+ unsigned long vb_idx;
+ int node, err;
+
+ node = numa_node_id();
+
+ vb = kmalloc_node(sizeof(struct vmap_block),
+ gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!vb))
+ return ERR_PTR(-ENOMEM);
+
+ va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
+ VMALLOC_START, VMALLOC_END,
+ node, gfp_mask);
+ if (unlikely(IS_ERR(va))) {
+ kfree(vb);
+ return ERR_PTR(PTR_ERR(va));
+ }
+
+ err = radix_tree_preload(gfp_mask);
+ if (unlikely(err)) {
+ kfree(vb);
+ free_vmap_area(va);
+ return ERR_PTR(err);
+ }
+
+ spin_lock_init(&vb->lock);
+ vb->va = va;
+ vb->free = VMAP_BBMAP_BITS;
+ vb->dirty = 0;
+ bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
+ bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
+ INIT_LIST_HEAD(&vb->free_list);
+ INIT_LIST_HEAD(&vb->dirty_list);
+
+ vb_idx = addr_to_vb_idx(va->va_start);
+ spin_lock(&vmap_block_tree_lock);
+ err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
+ spin_unlock(&vmap_block_tree_lock);
+ BUG_ON(err);
+ radix_tree_preload_end();
+
+ vbq = &get_cpu_var(vmap_block_queue);
+ vb->vbq = vbq;
+ spin_lock(&vbq->lock);
+ list_add(&vb->free_list, &vbq->free);
+ spin_unlock(&vbq->lock);
+ put_cpu_var(vmap_cpu_blocks);
+
+ return vb;
+}
+
+static void rcu_free_vb(struct rcu_head *head)
+{
+ struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head);
+
+ kfree(vb);
+}
+
+static void free_vmap_block(struct vmap_block *vb)
+{
+ struct vmap_block *tmp;
+ unsigned long vb_idx;
+
+ spin_lock(&vb->vbq->lock);
+ if (!list_empty(&vb->free_list))
+ list_del(&vb->free_list);
+ if (!list_empty(&vb->dirty_list))
+ list_del(&vb->dirty_list);
+ spin_unlock(&vb->vbq->lock);
+
+ vb_idx = addr_to_vb_idx(vb->va->va_start);
+ spin_lock(&vmap_block_tree_lock);
+ tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
+ spin_unlock(&vmap_block_tree_lock);
+ BUG_ON(tmp != vb);
+
+ free_unmap_vmap_area_noflush(vb->va);
+ call_rcu(&vb->rcu_head, rcu_free_vb);
+}
+
+static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
+{
+ struct vmap_block_queue *vbq;
+ struct vmap_block *vb;
+ unsigned long addr = 0;
+ unsigned int order;
+
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+ order = get_order(size);
+
+again:
+ rcu_read_lock();
+ vbq = &get_cpu_var(vmap_block_queue);
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ int i;
+
+ spin_lock(&vb->lock);
+ i = bitmap_find_free_region(vb->alloc_map,
+ VMAP_BBMAP_BITS, order);
+
+ if (i >= 0) {
+ addr = vb->va->va_start + (i << PAGE_SHIFT);
+ BUG_ON(addr_to_vb_idx(addr) !=
+ addr_to_vb_idx(vb->va->va_start));
+ vb->free -= 1UL << order;
+ if (vb->free == 0) {
+ spin_lock(&vbq->lock);
+ list_del_init(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ }
+ spin_unlock(&vb->lock);
+ break;
+ }
+ spin_unlock(&vb->lock);
+ }
+ put_cpu_var(vmap_cpu_blocks);
+ rcu_read_unlock();
+
+ if (!addr) {
+ vb = new_vmap_block(gfp_mask);
+ if (IS_ERR(vb))
+ return vb;
+ goto again;
+ }
+
+ return (void *)addr;
+}
+
+static void vb_free(const void *addr, unsigned long size)
+{
+ unsigned long offset;
+ unsigned long vb_idx;
+ unsigned int order;
+ struct vmap_block *vb;
+
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+
+ flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
+
+ order = get_order(size);
+
+ offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
+
+ vb_idx = addr_to_vb_idx((unsigned long)addr);
+ rcu_read_lock();
+ vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
+ rcu_read_unlock();
+ BUG_ON(!vb);
+
+ spin_lock(&vb->lock);
+ bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order);
+ if (!vb->dirty) {
+ spin_lock(&vb->vbq->lock);
+ list_add(&vb->dirty_list, &vb->vbq->dirty);
+ spin_unlock(&vb->vbq->lock);
+ }
+ vb->dirty += 1UL << order;
+ if (vb->dirty == VMAP_BBMAP_BITS) {
+ BUG_ON(vb->free || !list_empty(&vb->free_list));
+ spin_unlock(&vb->lock);
+ free_vmap_block(vb);
+ } else
+ spin_unlock(&vb->lock);
+}
+
+/**
+ * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
+ *
+ * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
+ * to amortize TLB flushing overheads. What this means is that any page you
+ * have now, may, in a former life, have been mapped into kernel virtual
+ * address by the vmap layer and so there might be some CPUs with TLB entries
+ * still referencing that page (additional to the regular 1:1 kernel mapping).
+ *
+ * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
+ * be sure that none of the pages we have control over will have any aliases
+ * from the vmap layer.
+ */
+void vm_unmap_aliases(void)
+{
+ unsigned long start = ULONG_MAX, end = 0;
+ int cpu;
+ int flush = 0;
+
+ if (unlikely(!vmap_initialized))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+ struct vmap_block *vb;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ int i;
+
+ spin_lock(&vb->lock);
+ i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
+ while (i < VMAP_BBMAP_BITS) {
+ unsigned long s, e;
+ int j;
+ j = find_next_zero_bit(vb->dirty_map,
+ VMAP_BBMAP_BITS, i);
+
+ s = vb->va->va_start + (i << PAGE_SHIFT);
+ e = vb->va->va_start + (j << PAGE_SHIFT);
+ vunmap_page_range(s, e);
+ flush = 1;
+
+ if (s < start)
+ start = s;
+ if (e > end)
+ end = e;
+
+ i = j;
+ i = find_next_bit(vb->dirty_map,
+ VMAP_BBMAP_BITS, i);
+ }
+ spin_unlock(&vb->lock);
+ }
+ rcu_read_unlock();
+ }
+
+ __purge_vmap_area_lazy(&start, &end, 1, flush);
+}
+EXPORT_SYMBOL_GPL(vm_unmap_aliases);
+
+/**
+ * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
+ * @mem: the pointer returned by vm_map_ram
+ * @count: the count passed to that vm_map_ram call (cannot unmap partial)
+ */
+void vm_unmap_ram(const void *mem, unsigned int count)
+{
+ unsigned long size = count << PAGE_SHIFT;
+ unsigned long addr = (unsigned long)mem;
+
+ BUG_ON(!addr);
+ BUG_ON(addr < VMALLOC_START);
+ BUG_ON(addr > VMALLOC_END);
+ BUG_ON(addr & (PAGE_SIZE-1));
+
+ debug_check_no_locks_freed(mem, size);
+
+ if (likely(count <= VMAP_MAX_ALLOC))
+ vb_free(mem, size);
+ else
+ free_unmap_vmap_area_addr(addr);
+}
+EXPORT_SYMBOL(vm_unmap_ram);
+
+/**
+ * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
+ * @pages: an array of pointers to the pages to be mapped
+ * @count: number of pages
+ * @node: prefer to allocate data structures on this node
+ * @prot: memory protection to use. PAGE_KERNEL for regular RAM
+ *
+ * Returns: a pointer to the address that has been mapped, or %NULL on failure
+ */
+void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
+{
+ unsigned long size = count << PAGE_SHIFT;
+ unsigned long addr;
+ void *mem;
+
+ if (likely(count <= VMAP_MAX_ALLOC)) {
+ mem = vb_alloc(size, GFP_KERNEL);
+ if (IS_ERR(mem))
+ return NULL;
+ addr = (unsigned long)mem;
+ } else {
+ struct vmap_area *va;
+ va = alloc_vmap_area(size, PAGE_SIZE,
+ VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
+ if (IS_ERR(va))
+ return NULL;
+
+ addr = va->va_start;
+ mem = (void *)addr;
+ }
+ if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
+ vm_unmap_ram(mem, count);
+ return NULL;
+ }
+ return mem;
+}
+EXPORT_SYMBOL(vm_map_ram);
+
+void __init vmalloc_init(void)
+{
+ struct vmap_area *va;
+ struct vm_struct *tmp;
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct vmap_block_queue *vbq;
+
+ vbq = &per_cpu(vmap_block_queue, i);
+ spin_lock_init(&vbq->lock);
+ INIT_LIST_HEAD(&vbq->free);
+ INIT_LIST_HEAD(&vbq->dirty);
+ vbq->nr_dirty = 0;
+ }
+
+ /* Import existing vmlist entries. */
+ for (tmp = vmlist; tmp; tmp = tmp->next) {
+ va = alloc_bootmem(sizeof(struct vmap_area));
+ va->flags = tmp->flags | VM_VM_AREA;
+ va->va_start = (unsigned long)tmp->addr;
+ va->va_end = va->va_start + tmp->size;
+ __insert_vmap_area(va);
+ }
+ vmap_initialized = true;
+}
+
+void unmap_kernel_range(unsigned long addr, unsigned long size)
+{
+ unsigned long end = addr + size;
+
+ flush_cache_vunmap(addr, end);
+ vunmap_page_range(addr, end);
+ flush_tlb_kernel_range(addr, end);
+}
+
+int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
+{
+ unsigned long addr = (unsigned long)area->addr;
+ unsigned long end = addr + area->size - PAGE_SIZE;
+ int err;
+
+ err = vmap_page_range(addr, end, prot, *pages);
+ if (err > 0) {
+ *pages += err;
+ err = 0;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(map_vm_area);
+
+/*** Old vmalloc interfaces ***/
+DEFINE_RWLOCK(vmlist_lock);
+struct vm_struct *vmlist;
+
+static struct vm_struct *__get_vm_area_node(unsigned long size,
+ unsigned long flags, unsigned long start, unsigned long end,
+ int node, gfp_t gfp_mask, void *caller)
+{
+ static struct vmap_area *va;
+ struct vm_struct *area;
+ struct vm_struct *tmp, **p;
+ unsigned long align = 1;
+
+ BUG_ON(in_interrupt());
+ if (flags & VM_IOREMAP) {
+ int bit = fls(size);
+
+ if (bit > IOREMAP_MAX_ORDER)
+ bit = IOREMAP_MAX_ORDER;
+ else if (bit < PAGE_SHIFT)
+ bit = PAGE_SHIFT;
+
+ align = 1ul << bit;
+ }
+
+ size = PAGE_ALIGN(size);
+ if (unlikely(!size))
+ return NULL;
+
+ area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!area))
+ return NULL;
+
+ /*
+ * We always allocate a guard page.
+ */
+ size += PAGE_SIZE;
+
+ va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
+ if (IS_ERR(va)) {
+ kfree(area);
+ return NULL;
+ }
+
+ area->flags = flags;
+ area->addr = (void *)va->va_start;
+ area->size = size;
+ area->pages = NULL;
+ area->nr_pages = 0;
+ area->phys_addr = 0;
+ area->caller = caller;
+ va->private = area;
+ va->flags |= VM_VM_AREA;
+
+ write_lock(&vmlist_lock);
+ for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+ if (tmp->addr >= area->addr)
+ break;
+ }
+ area->next = *p;
+ *p = area;
+ write_unlock(&vmlist_lock);
+
+ return area;
+}
+
+struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end)
+{
+ return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL_GPL(__get_vm_area);
+
+/**
+ * get_vm_area - reserve a contiguous kernel virtual area
+ * @size: size of the area
+ * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
+ *
+ * Search an area of @size in the kernel virtual mapping area,
+ * and reserved it for out purposes. Returns the area descriptor
+ * on success or %NULL on failure.
+ */
+struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
+{
+ return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+ -1, GFP_KERNEL, __builtin_return_address(0));
+}
+
+struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
+ void *caller)
+{
+ return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+ -1, GFP_KERNEL, caller);
+}
+
+struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
+ int node, gfp_t gfp_mask)
+{
+ return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
+ gfp_mask, __builtin_return_address(0));
+}
+
+static struct vm_struct *find_vm_area(const void *addr)
+{
+ struct vmap_area *va;
+
+ va = find_vmap_area((unsigned long)addr);
+ if (va && va->flags & VM_VM_AREA)
+ return va->private;
+
+ return NULL;
+}
+
+/**
+ * remove_vm_area - find and remove a continuous kernel virtual area
+ * @addr: base address
+ *
+ * Search for the kernel VM area starting at @addr, and remove it.
+ * This function returns the found VM area, but using it is NOT safe
+ * on SMP machines, except for its size or flags.
+ */
+struct vm_struct *remove_vm_area(const void *addr)
+{
+ struct vmap_area *va;
+
+ va = find_vmap_area((unsigned long)addr);
+ if (va && va->flags & VM_VM_AREA) {
+ struct vm_struct *vm = va->private;
+ struct vm_struct *tmp, **p;
+ free_unmap_vmap_area(va);
+ vm->size -= PAGE_SIZE;
+
+ write_lock(&vmlist_lock);
+ for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
+ ;
+ *p = tmp->next;
+ write_unlock(&vmlist_lock);
+
+ return vm;
+ }
+ return NULL;
+}
+
+static void __vunmap(const void *addr, int deallocate_pages)
+{
+ struct vm_struct *area;
+
+ if (!addr)
+ return;
+
+ if ((PAGE_SIZE-1) & (unsigned long)addr) {
+ WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+ return;
+ }
+
+ area = remove_vm_area(addr);
+ if (unlikely(!area)) {
+ WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
+ addr);
+ return;
+ }
+
+ debug_check_no_locks_freed(addr, area->size);
+ debug_check_no_obj_freed(addr, area->size);
+
+ if (deallocate_pages) {
+ int i;
+
+ for (i = 0; i < area->nr_pages; i++) {
+ struct page *page = area->pages[i];
+
+ BUG_ON(!page);
+ __free_page(page);
+ }
+
+ if (area->flags & VM_VPAGES)
+ vfree(area->pages);
+ else
+ kfree(area->pages);
+ }
+
+ kfree(area);
+ return;
+}
+
+/**
+ * vfree - release memory allocated by vmalloc()
+ * @addr: memory base address
+ *
+ * Free the virtually continuous memory area starting at @addr, as
+ * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
+ * NULL, no operation is performed.
+ *
+ * Must not be called in interrupt context.
+ */
+void vfree(const void *addr)
+{
+ BUG_ON(in_interrupt());
+ __vunmap(addr, 1);
+}
+EXPORT_SYMBOL(vfree);
+
+/**
+ * vunmap - release virtual mapping obtained by vmap()
+ * @addr: memory base address
+ *
+ * Free the virtually contiguous memory area starting at @addr,
+ * which was created from the page array passed to vmap().
+ *
+ * Must not be called in interrupt context.
+ */
+void vunmap(const void *addr)
+{
+ BUG_ON(in_interrupt());
+ __vunmap(addr, 0);
+}
+EXPORT_SYMBOL(vunmap);
+
+/**
+ * vmap - map an array of pages into virtually contiguous space
+ * @pages: array of page pointers
+ * @count: number of pages to map
+ * @flags: vm_area->flags
+ * @prot: page protection for the mapping
+ *
+ * Maps @count pages from @pages into contiguous kernel virtual
+ * space.
+ */
+void *vmap(struct page **pages, unsigned int count,
+ unsigned long flags, pgprot_t prot)
+{
+ struct vm_struct *area;
+
+ if (count > num_physpages)
+ return NULL;
+
+ area = get_vm_area_caller((count << PAGE_SHIFT), flags,
+ __builtin_return_address(0));
+ if (!area)
+ return NULL;
+
+ if (map_vm_area(area, prot, &pages)) {
+ vunmap(area->addr);
+ return NULL;
+ }
+
+ return area->addr;
+}
+EXPORT_SYMBOL(vmap);
+
+static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
+ int node, void *caller);
+static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
+ pgprot_t prot, int node, void *caller)
+{
+ struct page **pages;
+ unsigned int nr_pages, array_size, i;
+
+ nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
+ array_size = (nr_pages * sizeof(struct page *));
+
+ area->nr_pages = nr_pages;
+ /* Please note that the recursion is strictly bounded. */
+ if (array_size > PAGE_SIZE) {
+ pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
+ PAGE_KERNEL, node, caller);
+ area->flags |= VM_VPAGES;
+ } else {
+ pages = kmalloc_node(array_size,
+ (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO,
+ node);
+ }
+ area->pages = pages;
+ area->caller = caller;
+ if (!area->pages) {
+ remove_vm_area(area->addr);
+ kfree(area);
+ return NULL;
+ }
+
+ for (i = 0; i < area->nr_pages; i++) {
+ struct page *page;
+
+ if (node < 0)
+ page = alloc_page(gfp_mask);
+ else
+ page = alloc_pages_node(node, gfp_mask, 0);
+
+ if (unlikely(!page)) {
+ /* Successfully allocated i pages, free them in __vunmap() */
+ area->nr_pages = i;
+ goto fail;
+ }
+ area->pages[i] = page;
+ }
+
+ if (map_vm_area(area, prot, &pages))
+ goto fail;
+ return area->addr;
+
+fail:
+ vfree(area->addr);
+ return NULL;
+}
+
+void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
+{
+ return __vmalloc_area_node(area, gfp_mask, prot, -1,
+ __builtin_return_address(0));
+}
+
+/**
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size: allocation size
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @node: node to use for allocation or -1
+ * @caller: caller's return address
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags. Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
+ */
+static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
+ int node, void *caller)
+{
+ struct vm_struct *area;
+
+ size = PAGE_ALIGN(size);
+ if (!size || (size >> PAGE_SHIFT) > num_physpages)
+ return NULL;
+
+ area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
+ node, gfp_mask, caller);
+
+ if (!area)
+ return NULL;
+
+ return __vmalloc_area_node(area, gfp_mask, prot, node, caller);
+}
+
+void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
+{
+ return __vmalloc_node(size, gfp_mask, prot, -1,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__vmalloc);
+
+/**
+ * vmalloc - allocate virtually contiguous memory
+ * @size: allocation size
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc(unsigned long size)
+{
+ return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ -1, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc);
+
+/**
+ * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
+ * @size: allocation size
+ *
+ * The resulting memory area is zeroed so it can be mapped to userspace
+ * without leaking data.
+ */
+void *vmalloc_user(unsigned long size)
+{
+ struct vm_struct *area;
+ void *ret;
+
+ ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
+ if (ret) {
+ area = find_vm_area(ret);
+ area->flags |= VM_USERMAP;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_user);
+
+/**
+ * vmalloc_node - allocate memory on a specific node
+ * @size: allocation size
+ * @node: numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc_node(unsigned long size, int node)
+{
+ return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ node, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_node);
+
+#ifndef PAGE_KERNEL_EXEC
+# define PAGE_KERNEL_EXEC PAGE_KERNEL
+#endif
+
+/**
+ * vmalloc_exec - allocate virtually contiguous, executable memory
+ * @size: allocation size
+ *
+ * Kernel-internal function to allocate enough pages to cover @size
+ * the page level allocator and map them into contiguous and
+ * executable kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+
+void *vmalloc_exec(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC);
+}
+
+#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
+#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
+#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
+#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
+#else
+#define GFP_VMALLOC32 GFP_KERNEL
+#endif
+
+/**
+ * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
+ * @size: allocation size
+ *
+ * Allocate enough 32bit PA addressable pages to cover @size from the
+ * page level allocator and map them into contiguous kernel virtual space.
+ */
+void *vmalloc_32(unsigned long size)
+{
+ return __vmalloc(size, GFP_VMALLOC32, PAGE_KERNEL);
+}
+EXPORT_SYMBOL(vmalloc_32);
+
+/**
+ * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
+ * @size: allocation size
+ *
+ * The resulting memory area is 32bit addressable and zeroed so it can be
+ * mapped to userspace without leaking data.
+ */
+void *vmalloc_32_user(unsigned long size)
+{
+ struct vm_struct *area;
+ void *ret;
+
+ ret = __vmalloc(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL);
+ if (ret) {
+ area = find_vm_area(ret);
+ area->flags |= VM_USERMAP;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_32_user);
+
+long vread(char *buf, char *addr, unsigned long count)
+{
+ struct vm_struct *tmp;
+ char *vaddr, *buf_start = buf;
+ unsigned long n;
+
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+
+ read_lock(&vmlist_lock);
+ for (tmp = vmlist; tmp; tmp = tmp->next) {
+ vaddr = (char *) tmp->addr;
+ if (addr >= vaddr + tmp->size - PAGE_SIZE)
+ continue;
+ while (addr < vaddr) {
+ if (count == 0)
+ goto finished;
+ *buf = '\0';
+ buf++;
+ addr++;
+ count--;
+ }
+ n = vaddr + tmp->size - PAGE_SIZE - addr;
+ do {
+ if (count == 0)
+ goto finished;
+ *buf = *addr;
+ buf++;
+ addr++;
+ count--;
+ } while (--n > 0);
+ }
+finished:
+ read_unlock(&vmlist_lock);
+ return buf - buf_start;
+}
+
+long vwrite(char *buf, char *addr, unsigned long count)
+{
+ struct vm_struct *tmp;
+ char *vaddr, *buf_start = buf;
+ unsigned long n;
+
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+
+ read_lock(&vmlist_lock);
+ for (tmp = vmlist; tmp; tmp = tmp->next) {
+ vaddr = (char *) tmp->addr;
+ if (addr >= vaddr + tmp->size - PAGE_SIZE)
+ continue;
+ while (addr < vaddr) {
+ if (count == 0)
+ goto finished;
+ buf++;
+ addr++;
+ count--;
+ }
+ n = vaddr + tmp->size - PAGE_SIZE - addr;
+ do {
+ if (count == 0)
+ goto finished;
+ *addr = *buf;
+ buf++;
+ addr++;
+ count--;
+ } while (--n > 0);
+ }
+finished:
+ read_unlock(&vmlist_lock);
+ return buf - buf_start;
+}
+
+/**
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma: vma to cover (map full range of vma)
+ * @addr: vmalloc memory
+ * @pgoff: number of pages into addr before first page to map
+ *
+ * Returns: 0 for success, -Exxx on failure
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+ unsigned long pgoff)
+{
+ struct vm_struct *area;
+ unsigned long uaddr = vma->vm_start;
+ unsigned long usize = vma->vm_end - vma->vm_start;
+
+ if ((PAGE_SIZE-1) & (unsigned long)addr)
+ return -EINVAL;
+
+ area = find_vm_area(addr);
+ if (!area)
+ return -EINVAL;
+
+ if (!(area->flags & VM_USERMAP))
+ return -EINVAL;
+
+ if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
+ return -EINVAL;
+
+ addr += pgoff << PAGE_SHIFT;
+ do {
+ struct page *page = vmalloc_to_page(addr);
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, page);
+ if (ret)
+ return ret;
+
+ uaddr += PAGE_SIZE;
+ addr += PAGE_SIZE;
+ usize -= PAGE_SIZE;
+ } while (usize > 0);
+
+ /* Prevent "things" like memory migration? VM_flags need a cleanup... */
+ vma->vm_flags |= VM_RESERVED;
+
+ return 0;
+}
+EXPORT_SYMBOL(remap_vmalloc_range);
+
+/*
+ * Implement a stub for vmalloc_sync_all() if the architecture chose not to
+ * have one.
+ */
+void __attribute__((weak)) vmalloc_sync_all(void)
+{
+}
+
+
+static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
+{
+ /* apply_to_page_range() does all the hard work. */
+ return 0;
+}
+
+/**
+ * alloc_vm_area - allocate a range of kernel address space
+ * @size: size of the area
+ *
+ * Returns: NULL on failure, vm_struct on success
+ *
+ * This function reserves a range of kernel address space, and
+ * allocates pagetables to map that range. No actual mappings
+ * are created. If the kernel address space is not shared
+ * between processes, it syncs the pagetable across all
+ * processes.
+ */
+struct vm_struct *alloc_vm_area(size_t size)
+{
+ struct vm_struct *area;
+
+ area = get_vm_area_caller(size, VM_IOREMAP,
+ __builtin_return_address(0));
+ if (area == NULL)
+ return NULL;
+
+ /*
+ * This ensures that page tables are constructed for this region
+ * of kernel virtual address space and mapped into init_mm.
+ */
+ if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
+ area->size, f, NULL)) {
+ free_vm_area(area);
+ return NULL;
+ }
+
+ /* Make sure the pagetables are constructed in process kernel
+ mappings */
+ vmalloc_sync_all();
+
+ return area;
+}
+EXPORT_SYMBOL_GPL(alloc_vm_area);
+
+void free_vm_area(struct vm_struct *area)
+{
+ struct vm_struct *ret;
+ ret = remove_vm_area(area->addr);
+ BUG_ON(ret != area);
+ kfree(area);
+}
+EXPORT_SYMBOL_GPL(free_vm_area);
+
+
+#ifdef CONFIG_PROC_FS
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+ struct vm_struct *v;
+
+ read_lock(&vmlist_lock);
+ v = vmlist;
+ while (n > 0 && v) {
+ n--;
+ v = v->next;
+ }
+ if (!n)
+ return v;
+
+ return NULL;
+
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct vm_struct *v = p;
+
+ ++*pos;
+ return v->next;
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+ read_unlock(&vmlist_lock);
+}
+
+static void show_numa_info(struct seq_file *m, struct vm_struct *v)
+{
+ if (NUMA_BUILD) {
+ unsigned int nr, *counters = m->private;
+
+ if (!counters)
+ return;
+
+ memset(counters, 0, nr_node_ids * sizeof(unsigned int));
+
+ for (nr = 0; nr < v->nr_pages; nr++)
+ counters[page_to_nid(v->pages[nr])]++;
+
+ for_each_node_state(nr, N_HIGH_MEMORY)
+ if (counters[nr])
+ seq_printf(m, " N%u=%u", nr, counters[nr]);
+ }
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ struct vm_struct *v = p;
+
+ seq_printf(m, "0x%p-0x%p %7ld",
+ v->addr, v->addr + v->size, v->size);
+
+ if (v->caller) {
+ char buff[KSYM_SYMBOL_LEN];
+
+ seq_putc(m, ' ');
+ sprint_symbol(buff, (unsigned long)v->caller);
+ seq_puts(m, buff);
+ }
+
+ if (v->nr_pages)
+ seq_printf(m, " pages=%d", v->nr_pages);
+
+ if (v->phys_addr)
+ seq_printf(m, " phys=%lx", v->phys_addr);
+
+ if (v->flags & VM_IOREMAP)
+ seq_printf(m, " ioremap");
+
+ if (v->flags & VM_ALLOC)
+ seq_printf(m, " vmalloc");
+
+ if (v->flags & VM_MAP)
+ seq_printf(m, " vmap");
+
+ if (v->flags & VM_USERMAP)
+ seq_printf(m, " user");
+
+ if (v->flags & VM_VPAGES)
+ seq_printf(m, " vpages");
+
+ show_numa_info(m, v);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static const struct seq_operations vmalloc_op = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+static int vmalloc_open(struct inode *inode, struct file *file)
+{
+ unsigned int *ptr = NULL;
+ int ret;
+
+ if (NUMA_BUILD)
+ ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
+ ret = seq_open(file, &vmalloc_op);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = ptr;
+ } else
+ kfree(ptr);
+ return ret;
+}
+
+static const struct file_operations proc_vmalloc_operations = {
+ .open = vmalloc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static int __init proc_vmalloc_init(void)
+{
+ proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
+ return 0;
+}
+module_init(proc_vmalloc_init);
+#endif
+
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