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-rw-r--r--mm/vmalloc.c2739
1 files changed, 2739 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
new file mode 100644
index 000000000..2faaa2976
--- /dev/null
+++ b/mm/vmalloc.c
@@ -0,0 +1,2739 @@
+/*
+ * 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/sched.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/pfn.h>
+#include <linux/kmemleak.h>
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/llist.h>
+#include <linux/bitops.h>
+
+#include <asm/uaccess.h>
+#include <asm/tlbflush.h>
+#include <asm/shmparam.h>
+
+struct vfree_deferred {
+ struct llist_head list;
+ struct work_struct wq;
+};
+static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
+
+static void __vunmap(const void *, int);
+
+static void free_work(struct work_struct *w)
+{
+ struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
+ struct llist_node *llnode = llist_del_all(&p->list);
+ while (llnode) {
+ void *p = llnode;
+ llnode = llist_next(llnode);
+ __vunmap(p, 1);
+ }
+}
+
+/*** 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_clear_huge(pmd))
+ continue;
+ 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_clear_huge(pud))
+ continue;
+ 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_noflush(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)
+ return err;
+ } while (pgd++, addr = next, addr != end);
+
+ return nr;
+}
+
+static int vmap_page_range(unsigned long start, unsigned long end,
+ pgprot_t prot, struct page **pages)
+{
+ int ret;
+
+ ret = vmap_page_range_noflush(start, end, prot, pages);
+ flush_cache_vmap(start, end);
+ return ret;
+}
+
+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
+
+static DEFINE_SPINLOCK(vmap_area_lock);
+/* Export for kexec only */
+LIST_HEAD(vmap_area_list);
+static struct rb_root vmap_area_root = RB_ROOT;
+
+/* The vmap cache globals are protected by vmap_area_lock */
+static struct rb_node *free_vmap_cache;
+static unsigned long cached_hole_size;
+static unsigned long cached_vstart;
+static unsigned long cached_align;
+
+static unsigned long vmap_area_pcpu_hole;
+
+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_end)
+ 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_va;
+
+ parent = *p;
+ tmp_va = rb_entry(parent, struct vmap_area, rb_node);
+ if (va->va_start < tmp_va->va_end)
+ p = &(*p)->rb_left;
+ else if (va->va_end > tmp_va->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 */
+ 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;
+ struct vmap_area *first;
+
+ BUG_ON(!size);
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(!is_power_of_2(align));
+
+ va = kmalloc_node(sizeof(struct vmap_area),
+ gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!va))
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Only scan the relevant parts containing pointers to other objects
+ * to avoid false negatives.
+ */
+ kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
+
+retry:
+ spin_lock(&vmap_area_lock);
+ /*
+ * Invalidate cache if we have more permissive parameters.
+ * cached_hole_size notes the largest hole noticed _below_
+ * the vmap_area cached in free_vmap_cache: if size fits
+ * into that hole, we want to scan from vstart to reuse
+ * the hole instead of allocating above free_vmap_cache.
+ * Note that __free_vmap_area may update free_vmap_cache
+ * without updating cached_hole_size or cached_align.
+ */
+ if (!free_vmap_cache ||
+ size < cached_hole_size ||
+ vstart < cached_vstart ||
+ align < cached_align) {
+nocache:
+ cached_hole_size = 0;
+ free_vmap_cache = NULL;
+ }
+ /* record if we encounter less permissive parameters */
+ cached_vstart = vstart;
+ cached_align = align;
+
+ /* find starting point for our search */
+ if (free_vmap_cache) {
+ first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ addr = ALIGN(first->va_end, align);
+ if (addr < vstart)
+ goto nocache;
+ if (addr + size < addr)
+ goto overflow;
+
+ } else {
+ addr = ALIGN(vstart, align);
+ if (addr + size < addr)
+ goto overflow;
+
+ n = vmap_area_root.rb_node;
+ first = NULL;
+
+ while (n) {
+ struct vmap_area *tmp;
+ tmp = rb_entry(n, struct vmap_area, rb_node);
+ if (tmp->va_end >= addr) {
+ first = tmp;
+ if (tmp->va_start <= addr)
+ break;
+ n = n->rb_left;
+ } else
+ n = n->rb_right;
+ }
+
+ if (!first)
+ goto found;
+ }
+
+ /* from the starting point, walk areas until a suitable hole is found */
+ while (addr + size > first->va_start && addr + size <= vend) {
+ if (addr + cached_hole_size < first->va_start)
+ cached_hole_size = first->va_start - addr;
+ addr = ALIGN(first->va_end, align);
+ if (addr + size < addr)
+ goto overflow;
+
+ if (list_is_last(&first->list, &vmap_area_list))
+ goto found;
+
+ first = list_entry(first->list.next,
+ struct vmap_area, list);
+ }
+
+found:
+ if (addr + size > vend)
+ goto overflow;
+
+ va->va_start = addr;
+ va->va_end = addr + size;
+ va->flags = 0;
+ __insert_vmap_area(va);
+ free_vmap_cache = &va->rb_node;
+ spin_unlock(&vmap_area_lock);
+
+ BUG_ON(va->va_start & (align-1));
+ BUG_ON(va->va_start < vstart);
+ BUG_ON(va->va_end > vend);
+
+ return va;
+
+overflow:
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = 1;
+ goto retry;
+ }
+ if (printk_ratelimit())
+ pr_warn("vmap allocation for size %lu failed: "
+ "use vmalloc=<size> to increase size.\n", size);
+ kfree(va);
+ return ERR_PTR(-EBUSY);
+}
+
+static void __free_vmap_area(struct vmap_area *va)
+{
+ BUG_ON(RB_EMPTY_NODE(&va->rb_node));
+
+ if (free_vmap_cache) {
+ if (va->va_end < cached_vstart) {
+ free_vmap_cache = NULL;
+ } else {
+ struct vmap_area *cache;
+ cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ if (va->va_start <= cache->va_start) {
+ free_vmap_cache = rb_prev(&va->rb_node);
+ /*
+ * We don't try to update cached_hole_size or
+ * cached_align, but it won't go very wrong.
+ */
+ }
+ }
+ }
+ rb_erase(&va->rb_node, &vmap_area_root);
+ RB_CLEAR_NODE(&va->rb_node);
+ list_del_rcu(&va->list);
+
+ /*
+ * Track the highest possible candidate for pcpu area
+ * allocation. Areas outside of vmalloc area can be returned
+ * here too, consider only end addresses which fall inside
+ * vmalloc area proper.
+ */
+ if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
+ vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
+
+ kfree_rcu(va, rcu_head);
+}
+
+/*
+ * 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);
+}
+
+static void vmap_debug_free_range(unsigned long start, unsigned long end)
+{
+ /*
+ * Unmap page tables and force a TLB flush immediately if
+ * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
+ * bugs similarly to those in linear kernel virtual address
+ * space after a page has been freed.
+ *
+ * All the lazy freeing logic is still retained, in order to
+ * minimise intrusiveness of this debugging feature.
+ *
+ * This is going to be *slow* (linear kernel virtual address
+ * debugging doesn't do a broadcast TLB flush so it is a lot
+ * faster).
+ */
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ vunmap_page_range(start, end);
+ flush_tlb_kernel_range(start, end);
+#endif
+}
+
+/*
+ * 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);
+
+/* for per-CPU blocks */
+static void purge_fragmented_blocks_allcpus(void);
+
+/*
+ * called before a call to iounmap() if the caller wants vm_area_struct's
+ * immediately freed.
+ */
+void set_iounmap_nonlazy(void)
+{
+ atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
+}
+
+/*
+ * 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);
+
+ if (sync)
+ purge_fragmented_blocks_allcpus();
+
+ 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;
+ list_add_tail(&va->purge_list, &valist);
+ va->flags |= VM_LAZY_FREEING;
+ va->flags &= ~VM_LAZY_FREE;
+ }
+ }
+ rcu_read_unlock();
+
+ if (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 a vmap area, caller ensuring that the area has been unmapped
+ * and flush_cache_vunmap had been called for the correct range
+ * previously.
+ */
+static void free_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, caller ensuring flush_cache_vunmap had been
+ * called for the correct range previously.
+ */
+static void free_unmap_vmap_area_noflush(struct vmap_area *va)
+{
+ unmap_vmap_area(va);
+ free_vmap_area_noflush(va);
+}
+
+/*
+ * 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 / roundup_pow_of_two(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 vmap_block {
+ spinlock_t lock;
+ struct vmap_area *va;
+ unsigned long free, dirty;
+ unsigned long dirty_min, dirty_max; /*< dirty range */
+ struct list_head free_list;
+ struct rcu_head rcu_head;
+ struct list_head purge;
+};
+
+/* 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 void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
+{
+ unsigned long addr;
+
+ addr = va_start + (pages_off << PAGE_SHIFT);
+ BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
+ return (void *)addr;
+}
+
+/**
+ * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
+ * block. Of course pages number can't exceed VMAP_BBMAP_BITS
+ * @order: how many 2^order pages should be occupied in newly allocated block
+ * @gfp_mask: flags for the page level allocator
+ *
+ * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
+ */
+static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
+{
+ struct vmap_block_queue *vbq;
+ struct vmap_block *vb;
+ struct vmap_area *va;
+ unsigned long vb_idx;
+ int node, err;
+ void *vaddr;
+
+ 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 (IS_ERR(va)) {
+ kfree(vb);
+ return ERR_CAST(va);
+ }
+
+ err = radix_tree_preload(gfp_mask);
+ if (unlikely(err)) {
+ kfree(vb);
+ free_vmap_area(va);
+ return ERR_PTR(err);
+ }
+
+ vaddr = vmap_block_vaddr(va->va_start, 0);
+ spin_lock_init(&vb->lock);
+ vb->va = va;
+ /* At least something should be left free */
+ BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
+ vb->free = VMAP_BBMAP_BITS - (1UL << order);
+ vb->dirty = 0;
+ vb->dirty_min = VMAP_BBMAP_BITS;
+ vb->dirty_max = 0;
+ INIT_LIST_HEAD(&vb->free_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);
+ spin_lock(&vbq->lock);
+ list_add_tail_rcu(&vb->free_list, &vbq->free);
+ spin_unlock(&vbq->lock);
+ put_cpu_var(vmap_block_queue);
+
+ return vaddr;
+}
+
+static void free_vmap_block(struct vmap_block *vb)
+{
+ struct vmap_block *tmp;
+ unsigned long vb_idx;
+
+ 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_vmap_area_noflush(vb->va);
+ kfree_rcu(vb, rcu_head);
+}
+
+static void purge_fragmented_blocks(int cpu)
+{
+ LIST_HEAD(purge);
+ struct vmap_block *vb;
+ struct vmap_block *n_vb;
+ struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+
+ if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
+ continue;
+
+ spin_lock(&vb->lock);
+ if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
+ vb->free = 0; /* prevent further allocs after releasing lock */
+ vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
+ vb->dirty_min = 0;
+ vb->dirty_max = VMAP_BBMAP_BITS;
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ spin_unlock(&vb->lock);
+ list_add_tail(&vb->purge, &purge);
+ } else
+ spin_unlock(&vb->lock);
+ }
+ rcu_read_unlock();
+
+ list_for_each_entry_safe(vb, n_vb, &purge, purge) {
+ list_del(&vb->purge);
+ free_vmap_block(vb);
+ }
+}
+
+static void purge_fragmented_blocks_allcpus(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ purge_fragmented_blocks(cpu);
+}
+
+static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
+{
+ struct vmap_block_queue *vbq;
+ struct vmap_block *vb;
+ void *vaddr = NULL;
+ unsigned int order;
+
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+ if (WARN_ON(size == 0)) {
+ /*
+ * Allocating 0 bytes isn't what caller wants since
+ * get_order(0) returns funny result. Just warn and terminate
+ * early.
+ */
+ return NULL;
+ }
+ order = get_order(size);
+
+ rcu_read_lock();
+ vbq = &get_cpu_var(vmap_block_queue);
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ unsigned long pages_off;
+
+ spin_lock(&vb->lock);
+ if (vb->free < (1UL << order)) {
+ spin_unlock(&vb->lock);
+ continue;
+ }
+
+ pages_off = VMAP_BBMAP_BITS - vb->free;
+ vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
+ vb->free -= 1UL << order;
+ if (vb->free == 0) {
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ }
+
+ spin_unlock(&vb->lock);
+ break;
+ }
+
+ put_cpu_var(vmap_block_queue);
+ rcu_read_unlock();
+
+ /* Allocate new block if nothing was found */
+ if (!vaddr)
+ vaddr = new_vmap_block(order, gfp_mask);
+
+ return vaddr;
+}
+
+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);
+ offset >>= PAGE_SHIFT;
+
+ 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);
+
+ vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
+
+ spin_lock(&vb->lock);
+
+ /* Expand dirty range */
+ vb->dirty_min = min(vb->dirty_min, offset);
+ vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
+
+ vb->dirty += 1UL << order;
+ if (vb->dirty == VMAP_BBMAP_BITS) {
+ BUG_ON(vb->free);
+ 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) {
+ spin_lock(&vb->lock);
+ if (vb->dirty) {
+ unsigned long va_start = vb->va->va_start;
+ unsigned long s, e;
+
+ s = va_start + (vb->dirty_min << PAGE_SHIFT);
+ e = va_start + (vb->dirty_max << PAGE_SHIFT);
+
+ start = min(s, start);
+ end = max(e, end);
+
+ flush = 1;
+ }
+ 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);
+ vmap_debug_free_range(addr, addr+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
+ *
+ * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
+ * faster than vmap so it's good. But if you mix long-life and short-life
+ * objects with vm_map_ram(), it could consume lots of address space through
+ * fragmentation (especially on a 32bit machine). You could see failures in
+ * the end. Please use this function for short-lived objects.
+ *
+ * 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);
+
+static struct vm_struct *vmlist __initdata;
+/**
+ * vm_area_add_early - add vmap area early during boot
+ * @vm: vm_struct to add
+ *
+ * This function is used to add fixed kernel vm area to vmlist before
+ * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
+ * should contain proper values and the other fields should be zero.
+ *
+ * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
+ */
+void __init vm_area_add_early(struct vm_struct *vm)
+{
+ struct vm_struct *tmp, **p;
+
+ BUG_ON(vmap_initialized);
+ for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+ if (tmp->addr >= vm->addr) {
+ BUG_ON(tmp->addr < vm->addr + vm->size);
+ break;
+ } else
+ BUG_ON(tmp->addr + tmp->size > vm->addr);
+ }
+ vm->next = *p;
+ *p = vm;
+}
+
+/**
+ * vm_area_register_early - register vmap area early during boot
+ * @vm: vm_struct to register
+ * @align: requested alignment
+ *
+ * This function is used to register kernel vm area before
+ * vmalloc_init() is called. @vm->size and @vm->flags should contain
+ * proper values on entry and other fields should be zero. On return,
+ * vm->addr contains the allocated address.
+ *
+ * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
+ */
+void __init vm_area_register_early(struct vm_struct *vm, size_t align)
+{
+ static size_t vm_init_off __initdata;
+ unsigned long addr;
+
+ addr = ALIGN(VMALLOC_START + vm_init_off, align);
+ vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
+
+ vm->addr = (void *)addr;
+
+ vm_area_add_early(vm);
+}
+
+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;
+ struct vfree_deferred *p;
+
+ vbq = &per_cpu(vmap_block_queue, i);
+ spin_lock_init(&vbq->lock);
+ INIT_LIST_HEAD(&vbq->free);
+ p = &per_cpu(vfree_deferred, i);
+ init_llist_head(&p->list);
+ INIT_WORK(&p->wq, free_work);
+ }
+
+ /* Import existing vmlist entries. */
+ for (tmp = vmlist; tmp; tmp = tmp->next) {
+ va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
+ va->flags = VM_VM_AREA;
+ va->va_start = (unsigned long)tmp->addr;
+ va->va_end = va->va_start + tmp->size;
+ va->vm = tmp;
+ __insert_vmap_area(va);
+ }
+
+ vmap_area_pcpu_hole = VMALLOC_END;
+
+ vmap_initialized = true;
+}
+
+/**
+ * map_kernel_range_noflush - map kernel VM area with the specified pages
+ * @addr: start of the VM area to map
+ * @size: size of the VM area to map
+ * @prot: page protection flags to use
+ * @pages: pages to map
+ *
+ * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
+ * specify should have been allocated using get_vm_area() and its
+ * friends.
+ *
+ * NOTE:
+ * This function does NOT do any cache flushing. The caller is
+ * responsible for calling flush_cache_vmap() on to-be-mapped areas
+ * before calling this function.
+ *
+ * RETURNS:
+ * The number of pages mapped on success, -errno on failure.
+ */
+int map_kernel_range_noflush(unsigned long addr, unsigned long size,
+ pgprot_t prot, struct page **pages)
+{
+ return vmap_page_range_noflush(addr, addr + size, prot, pages);
+}
+
+/**
+ * unmap_kernel_range_noflush - unmap kernel VM area
+ * @addr: start of the VM area to unmap
+ * @size: size of the VM area to unmap
+ *
+ * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
+ * specify should have been allocated using get_vm_area() and its
+ * friends.
+ *
+ * NOTE:
+ * This function does NOT do any cache flushing. The caller is
+ * responsible for calling flush_cache_vunmap() on to-be-mapped areas
+ * before calling this function and flush_tlb_kernel_range() after.
+ */
+void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
+{
+ vunmap_page_range(addr, addr + size);
+}
+EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
+
+/**
+ * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
+ * @addr: start of the VM area to unmap
+ * @size: size of the VM area to unmap
+ *
+ * Similar to unmap_kernel_range_noflush() but flushes vcache before
+ * the unmapping and tlb after.
+ */
+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);
+}
+EXPORT_SYMBOL_GPL(unmap_kernel_range);
+
+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 + get_vm_area_size(area);
+ int err;
+
+ err = vmap_page_range(addr, end, prot, pages);
+
+ return err > 0 ? 0 : err;
+}
+EXPORT_SYMBOL_GPL(map_vm_area);
+
+static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+ unsigned long flags, const void *caller)
+{
+ spin_lock(&vmap_area_lock);
+ vm->flags = flags;
+ vm->addr = (void *)va->va_start;
+ vm->size = va->va_end - va->va_start;
+ vm->caller = caller;
+ va->vm = vm;
+ va->flags |= VM_VM_AREA;
+ spin_unlock(&vmap_area_lock);
+}
+
+static void clear_vm_uninitialized_flag(struct vm_struct *vm)
+{
+ /*
+ * Before removing VM_UNINITIALIZED,
+ * we should make sure that vm has proper values.
+ * Pair with smp_rmb() in show_numa_info().
+ */
+ smp_wmb();
+ vm->flags &= ~VM_UNINITIALIZED;
+}
+
+static struct vm_struct *__get_vm_area_node(unsigned long size,
+ unsigned long align, unsigned long flags, unsigned long start,
+ unsigned long end, int node, gfp_t gfp_mask, const void *caller)
+{
+ struct vmap_area *va;
+ struct vm_struct *area;
+
+ BUG_ON(in_interrupt());
+ if (flags & VM_IOREMAP)
+ align = 1ul << clamp_t(int, fls_long(size),
+ PAGE_SHIFT, IOREMAP_MAX_ORDER);
+
+ size = PAGE_ALIGN(size);
+ if (unlikely(!size))
+ return NULL;
+
+ area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!area))
+ return NULL;
+
+ if (!(flags & VM_NO_GUARD))
+ size += PAGE_SIZE;
+
+ va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
+ if (IS_ERR(va)) {
+ kfree(area);
+ return NULL;
+ }
+
+ setup_vmalloc_vm(area, va, flags, caller);
+
+ 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, 1, flags, start, end, NUMA_NO_NODE,
+ GFP_KERNEL, __builtin_return_address(0));
+}
+EXPORT_SYMBOL_GPL(__get_vm_area);
+
+struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end,
+ const void *caller)
+{
+ return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
+ GFP_KERNEL, caller);
+}
+
+/**
+ * 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, 1, flags, VMALLOC_START, VMALLOC_END,
+ NUMA_NO_NODE, GFP_KERNEL,
+ __builtin_return_address(0));
+}
+
+struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
+ const void *caller)
+{
+ return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
+ NUMA_NO_NODE, GFP_KERNEL, caller);
+}
+
+/**
+ * find_vm_area - find a continuous kernel virtual area
+ * @addr: base address
+ *
+ * Search for the kernel VM area starting at @addr, and return it.
+ * It is up to the caller to do all required locking to keep the returned
+ * pointer valid.
+ */
+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->vm;
+
+ 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->vm;
+
+ spin_lock(&vmap_area_lock);
+ va->vm = NULL;
+ va->flags &= ~VM_VM_AREA;
+ spin_unlock(&vmap_area_lock);
+
+ vmap_debug_free_range(va->va_start, va->va_end);
+ kasan_free_shadow(vm);
+ free_unmap_vmap_area(va);
+ vm->size -= PAGE_SIZE;
+
+ return vm;
+ }
+ return NULL;
+}
+
+static void __vunmap(const void *addr, int deallocate_pages)
+{
+ struct vm_struct *area;
+
+ if (!addr)
+ return;
+
+ if (WARN(!PAGE_ALIGNED(addr), "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 NMI context (strictly speaking, only if we don't
+ * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
+ * conventions for vfree() arch-depenedent would be a really bad idea)
+ *
+ * NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
+ */
+void vfree(const void *addr)
+{
+ BUG_ON(in_nmi());
+
+ kmemleak_free(addr);
+
+ if (!addr)
+ return;
+ if (unlikely(in_interrupt())) {
+ struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
+ if (llist_add((struct llist_node *)addr, &p->list))
+ schedule_work(&p->wq);
+ } else
+ __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());
+ might_sleep();
+ if (addr)
+ __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;
+
+ might_sleep();
+
+ if (count > totalram_pages)
+ 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, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, const void *caller);
+static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
+ pgprot_t prot, int node)
+{
+ const int order = 0;
+ struct page **pages;
+ unsigned int nr_pages, array_size, i;
+ const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
+ const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
+
+ nr_pages = get_vm_area_size(area) >> 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, 1, nested_gfp|__GFP_HIGHMEM,
+ PAGE_KERNEL, node, area->caller);
+ area->flags |= VM_VPAGES;
+ } else {
+ pages = kmalloc_node(array_size, nested_gfp, node);
+ }
+ area->pages = pages;
+ 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 == NUMA_NO_NODE)
+ page = alloc_page(alloc_mask);
+ else
+ page = alloc_pages_node(node, alloc_mask, order);
+
+ if (unlikely(!page)) {
+ /* Successfully allocated i pages, free them in __vunmap() */
+ area->nr_pages = i;
+ goto fail;
+ }
+ area->pages[i] = page;
+ if (gfp_mask & __GFP_WAIT)
+ cond_resched();
+ }
+
+ if (map_vm_area(area, prot, pages))
+ goto fail;
+ return area->addr;
+
+fail:
+ warn_alloc_failed(gfp_mask, order,
+ "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
+ (area->nr_pages*PAGE_SIZE), area->size);
+ vfree(area->addr);
+ return NULL;
+}
+
+/**
+ * __vmalloc_node_range - allocate virtually contiguous memory
+ * @size: allocation size
+ * @align: desired alignment
+ * @start: vm area range start
+ * @end: vm area range end
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
+ * @node: node to use for allocation or NUMA_NO_NODE
+ * @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.
+ */
+void *__vmalloc_node_range(unsigned long size, unsigned long align,
+ unsigned long start, unsigned long end, gfp_t gfp_mask,
+ pgprot_t prot, unsigned long vm_flags, int node,
+ const void *caller)
+{
+ struct vm_struct *area;
+ void *addr;
+ unsigned long real_size = size;
+
+ size = PAGE_ALIGN(size);
+ if (!size || (size >> PAGE_SHIFT) > totalram_pages)
+ goto fail;
+
+ area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
+ vm_flags, start, end, node, gfp_mask, caller);
+ if (!area)
+ goto fail;
+
+ addr = __vmalloc_area_node(area, gfp_mask, prot, node);
+ if (!addr)
+ return NULL;
+
+ /*
+ * In this function, newly allocated vm_struct has VM_UNINITIALIZED
+ * flag. It means that vm_struct is not fully initialized.
+ * Now, it is fully initialized, so remove this flag here.
+ */
+ clear_vm_uninitialized_flag(area);
+
+ /*
+ * A ref_count = 2 is needed because vm_struct allocated in
+ * __get_vm_area_node() contains a reference to the virtual address of
+ * the vmalloc'ed block.
+ */
+ kmemleak_alloc(addr, real_size, 2, gfp_mask);
+
+ return addr;
+
+fail:
+ warn_alloc_failed(gfp_mask, 0,
+ "vmalloc: allocation failure: %lu bytes\n",
+ real_size);
+ return NULL;
+}
+
+/**
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size: allocation size
+ * @align: desired alignment
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @node: node to use for allocation or NUMA_NO_NODE
+ * @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, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, const void *caller)
+{
+ return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
+ gfp_mask, prot, 0, node, caller);
+}
+
+void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
+{
+ return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__vmalloc);
+
+static inline void *__vmalloc_node_flags(unsigned long size,
+ int node, gfp_t flags)
+{
+ return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
+ node, __builtin_return_address(0));
+}
+
+/**
+ * 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_flags(size, NUMA_NO_NODE,
+ GFP_KERNEL | __GFP_HIGHMEM);
+}
+EXPORT_SYMBOL(vmalloc);
+
+/**
+ * vzalloc - allocate virtually contiguous memory with zero fill
+ * @size: allocation size
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vzalloc(unsigned long size)
+{
+ return __vmalloc_node_flags(size, NUMA_NO_NODE,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+EXPORT_SYMBOL(vzalloc);
+
+/**
+ * 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_node(size, SHMLBA,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ PAGE_KERNEL, NUMA_NO_NODE,
+ __builtin_return_address(0));
+ 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, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ node, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_node);
+
+/**
+ * vzalloc_node - allocate memory on a specific node with zero fill
+ * @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.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc_node() instead.
+ */
+void *vzalloc_node(unsigned long size, int node)
+{
+ return __vmalloc_node_flags(size, node,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+EXPORT_SYMBOL(vzalloc_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_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
+ NUMA_NO_NODE, __builtin_return_address(0));
+}
+
+#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_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
+ NUMA_NO_NODE, __builtin_return_address(0));
+}
+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_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+ NUMA_NO_NODE, __builtin_return_address(0));
+ if (ret) {
+ area = find_vm_area(ret);
+ area->flags |= VM_USERMAP;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_32_user);
+
+/*
+ * small helper routine , copy contents to buf from addr.
+ * If the page is not present, fill zero.
+ */
+
+static int aligned_vread(char *buf, char *addr, unsigned long count)
+{
+ struct page *p;
+ int copied = 0;
+
+ while (count) {
+ unsigned long offset, length;
+
+ offset = (unsigned long)addr & ~PAGE_MASK;
+ length = PAGE_SIZE - offset;
+ if (length > count)
+ length = count;
+ p = vmalloc_to_page(addr);
+ /*
+ * To do safe access to this _mapped_ area, we need
+ * lock. But adding lock here means that we need to add
+ * overhead of vmalloc()/vfree() calles for this _debug_
+ * interface, rarely used. Instead of that, we'll use
+ * kmap() and get small overhead in this access function.
+ */
+ if (p) {
+ /*
+ * we can expect USER0 is not used (see vread/vwrite's
+ * function description)
+ */
+ void *map = kmap_atomic(p);
+ memcpy(buf, map + offset, length);
+ kunmap_atomic(map);
+ } else
+ memset(buf, 0, length);
+
+ addr += length;
+ buf += length;
+ copied += length;
+ count -= length;
+ }
+ return copied;
+}
+
+static int aligned_vwrite(char *buf, char *addr, unsigned long count)
+{
+ struct page *p;
+ int copied = 0;
+
+ while (count) {
+ unsigned long offset, length;
+
+ offset = (unsigned long)addr & ~PAGE_MASK;
+ length = PAGE_SIZE - offset;
+ if (length > count)
+ length = count;
+ p = vmalloc_to_page(addr);
+ /*
+ * To do safe access to this _mapped_ area, we need
+ * lock. But adding lock here means that we need to add
+ * overhead of vmalloc()/vfree() calles for this _debug_
+ * interface, rarely used. Instead of that, we'll use
+ * kmap() and get small overhead in this access function.
+ */
+ if (p) {
+ /*
+ * we can expect USER0 is not used (see vread/vwrite's
+ * function description)
+ */
+ void *map = kmap_atomic(p);
+ memcpy(map + offset, buf, length);
+ kunmap_atomic(map);
+ }
+ addr += length;
+ buf += length;
+ copied += length;
+ count -= length;
+ }
+ return copied;
+}
+
+/**
+ * vread() - read vmalloc area in a safe way.
+ * @buf: buffer for reading data
+ * @addr: vm address.
+ * @count: number of bytes to be read.
+ *
+ * Returns # of bytes which addr and buf should be increased.
+ * (same number to @count). Returns 0 if [addr...addr+count) doesn't
+ * includes any intersect with alive vmalloc area.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from that area to a given buffer. If the given memory range
+ * of [addr...addr+count) includes some valid address, data is copied to
+ * proper area of @buf. If there are memory holes, they'll be zero-filled.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
+ *
+ * Note: In usual ops, vread() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any informaion, as /dev/kmem.
+ *
+ */
+
+long vread(char *buf, char *addr, unsigned long count)
+{
+ struct vmap_area *va;
+ struct vm_struct *vm;
+ char *vaddr, *buf_start = buf;
+ unsigned long buflen = count;
+ unsigned long n;
+
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+
+ spin_lock(&vmap_area_lock);
+ list_for_each_entry(va, &vmap_area_list, list) {
+ if (!count)
+ break;
+
+ if (!(va->flags & VM_VM_AREA))
+ continue;
+
+ vm = va->vm;
+ vaddr = (char *) vm->addr;
+ if (addr >= vaddr + get_vm_area_size(vm))
+ continue;
+ while (addr < vaddr) {
+ if (count == 0)
+ goto finished;
+ *buf = '\0';
+ buf++;
+ addr++;
+ count--;
+ }
+ n = vaddr + get_vm_area_size(vm) - addr;
+ if (n > count)
+ n = count;
+ if (!(vm->flags & VM_IOREMAP))
+ aligned_vread(buf, addr, n);
+ else /* IOREMAP area is treated as memory hole */
+ memset(buf, 0, n);
+ buf += n;
+ addr += n;
+ count -= n;
+ }
+finished:
+ spin_unlock(&vmap_area_lock);
+
+ if (buf == buf_start)
+ return 0;
+ /* zero-fill memory holes */
+ if (buf != buf_start + buflen)
+ memset(buf, 0, buflen - (buf - buf_start));
+
+ return buflen;
+}
+
+/**
+ * vwrite() - write vmalloc area in a safe way.
+ * @buf: buffer for source data
+ * @addr: vm address.
+ * @count: number of bytes to be read.
+ *
+ * Returns # of bytes which addr and buf should be incresed.
+ * (same number to @count).
+ * If [addr...addr+count) doesn't includes any intersect with valid
+ * vmalloc area, returns 0.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from a buffer to the given addr. If specified range of
+ * [addr...addr+count) includes some valid address, data is copied from
+ * proper area of @buf. If there are memory holes, no copy to hole.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
+ *
+ * Note: In usual ops, vwrite() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any informaion, as /dev/kmem.
+ */
+
+long vwrite(char *buf, char *addr, unsigned long count)
+{
+ struct vmap_area *va;
+ struct vm_struct *vm;
+ char *vaddr;
+ unsigned long n, buflen;
+ int copied = 0;
+
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+ buflen = count;
+
+ spin_lock(&vmap_area_lock);
+ list_for_each_entry(va, &vmap_area_list, list) {
+ if (!count)
+ break;
+
+ if (!(va->flags & VM_VM_AREA))
+ continue;
+
+ vm = va->vm;
+ vaddr = (char *) vm->addr;
+ if (addr >= vaddr + get_vm_area_size(vm))
+ continue;
+ while (addr < vaddr) {
+ if (count == 0)
+ goto finished;
+ buf++;
+ addr++;
+ count--;
+ }
+ n = vaddr + get_vm_area_size(vm) - addr;
+ if (n > count)
+ n = count;
+ if (!(vm->flags & VM_IOREMAP)) {
+ aligned_vwrite(buf, addr, n);
+ copied++;
+ }
+ buf += n;
+ addr += n;
+ count -= n;
+ }
+finished:
+ spin_unlock(&vmap_area_lock);
+ if (!copied)
+ return 0;
+ return buflen;
+}
+
+/**
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma: vma to cover
+ * @uaddr: target user address to start at
+ * @kaddr: virtual address of vmalloc kernel memory
+ * @size: size of map area
+ *
+ * Returns: 0 for success, -Exxx on failure
+ *
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
+ void *kaddr, unsigned long size)
+{
+ struct vm_struct *area;
+
+ size = PAGE_ALIGN(size);
+
+ if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
+ return -EINVAL;
+
+ area = find_vm_area(kaddr);
+ if (!area)
+ return -EINVAL;
+
+ if (!(area->flags & VM_USERMAP))
+ return -EINVAL;
+
+ if (kaddr + size > area->addr + area->size)
+ return -EINVAL;
+
+ do {
+ struct page *page = vmalloc_to_page(kaddr);
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, page);
+ if (ret)
+ return ret;
+
+ uaddr += PAGE_SIZE;
+ kaddr += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ } while (size > 0);
+
+ vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+
+ return 0;
+}
+EXPORT_SYMBOL(remap_vmalloc_range_partial);
+
+/**
+ * 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)
+{
+ return remap_vmalloc_range_partial(vma, vma->vm_start,
+ addr + (pgoff << PAGE_SHIFT),
+ vma->vm_end - vma->vm_start);
+}
+EXPORT_SYMBOL(remap_vmalloc_range);
+
+/*
+ * Implement a stub for vmalloc_sync_all() if the architecture chose not to
+ * have one.
+ */
+void __weak vmalloc_sync_all(void)
+{
+}
+
+
+static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
+{
+ pte_t ***p = data;
+
+ if (p) {
+ *(*p) = pte;
+ (*p)++;
+ }
+ return 0;
+}
+
+/**
+ * alloc_vm_area - allocate a range of kernel address space
+ * @size: size of the area
+ * @ptes: returns the PTEs for the address space
+ *
+ * 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 @ptes is non-NULL, pointers to the PTEs (in init_mm)
+ * allocated for the VM area are returned.
+ */
+struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
+{
+ 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,
+ size, f, ptes ? &ptes : NULL)) {
+ free_vm_area(area);
+ return NULL;
+ }
+
+ 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_SMP
+static struct vmap_area *node_to_va(struct rb_node *n)
+{
+ return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
+}
+
+/**
+ * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
+ * @end: target address
+ * @pnext: out arg for the next vmap_area
+ * @pprev: out arg for the previous vmap_area
+ *
+ * Returns: %true if either or both of next and prev are found,
+ * %false if no vmap_area exists
+ *
+ * Find vmap_areas end addresses of which enclose @end. ie. if not
+ * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
+ */
+static bool pvm_find_next_prev(unsigned long end,
+ struct vmap_area **pnext,
+ struct vmap_area **pprev)
+{
+ struct rb_node *n = vmap_area_root.rb_node;
+ struct vmap_area *va = NULL;
+
+ while (n) {
+ va = rb_entry(n, struct vmap_area, rb_node);
+ if (end < va->va_end)
+ n = n->rb_left;
+ else if (end > va->va_end)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ if (!va)
+ return false;
+
+ if (va->va_end > end) {
+ *pnext = va;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ } else {
+ *pprev = va;
+ *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
+ }
+ return true;
+}
+
+/**
+ * pvm_determine_end - find the highest aligned address between two vmap_areas
+ * @pnext: in/out arg for the next vmap_area
+ * @pprev: in/out arg for the previous vmap_area
+ * @align: alignment
+ *
+ * Returns: determined end address
+ *
+ * Find the highest aligned address between *@pnext and *@pprev below
+ * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
+ * down address is between the end addresses of the two vmap_areas.
+ *
+ * Please note that the address returned by this function may fall
+ * inside *@pnext vmap_area. The caller is responsible for checking
+ * that.
+ */
+static unsigned long pvm_determine_end(struct vmap_area **pnext,
+ struct vmap_area **pprev,
+ unsigned long align)
+{
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ unsigned long addr;
+
+ if (*pnext)
+ addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
+ else
+ addr = vmalloc_end;
+
+ while (*pprev && (*pprev)->va_end > addr) {
+ *pnext = *pprev;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ }
+
+ return addr;
+}
+
+/**
+ * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
+ * @offsets: array containing offset of each area
+ * @sizes: array containing size of each area
+ * @nr_vms: the number of areas to allocate
+ * @align: alignment, all entries in @offsets and @sizes must be aligned to this
+ *
+ * Returns: kmalloc'd vm_struct pointer array pointing to allocated
+ * vm_structs on success, %NULL on failure
+ *
+ * Percpu allocator wants to use congruent vm areas so that it can
+ * maintain the offsets among percpu areas. This function allocates
+ * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
+ * be scattered pretty far, distance between two areas easily going up
+ * to gigabytes. To avoid interacting with regular vmallocs, these
+ * areas are allocated from top.
+ *
+ * Despite its complicated look, this allocator is rather simple. It
+ * does everything top-down and scans areas from the end looking for
+ * matching slot. While scanning, if any of the areas overlaps with
+ * existing vmap_area, the base address is pulled down to fit the
+ * area. Scanning is repeated till all the areas fit and then all
+ * necessary data structres are inserted and the result is returned.
+ */
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+ const size_t *sizes, int nr_vms,
+ size_t align)
+{
+ const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ struct vmap_area **vas, *prev, *next;
+ struct vm_struct **vms;
+ int area, area2, last_area, term_area;
+ unsigned long base, start, end, last_end;
+ bool purged = false;
+
+ /* verify parameters and allocate data structures */
+ BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
+ for (last_area = 0, area = 0; area < nr_vms; area++) {
+ start = offsets[area];
+ end = start + sizes[area];
+
+ /* is everything aligned properly? */
+ BUG_ON(!IS_ALIGNED(offsets[area], align));
+ BUG_ON(!IS_ALIGNED(sizes[area], align));
+
+ /* detect the area with the highest address */
+ if (start > offsets[last_area])
+ last_area = area;
+
+ for (area2 = 0; area2 < nr_vms; area2++) {
+ unsigned long start2 = offsets[area2];
+ unsigned long end2 = start2 + sizes[area2];
+
+ if (area2 == area)
+ continue;
+
+ BUG_ON(start2 >= start && start2 < end);
+ BUG_ON(end2 <= end && end2 > start);
+ }
+ }
+ last_end = offsets[last_area] + sizes[last_area];
+
+ if (vmalloc_end - vmalloc_start < last_end) {
+ WARN_ON(true);
+ return NULL;
+ }
+
+ vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
+ vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
+ if (!vas || !vms)
+ goto err_free2;
+
+ for (area = 0; area < nr_vms; area++) {
+ vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
+ vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
+ if (!vas[area] || !vms[area])
+ goto err_free;
+ }
+retry:
+ spin_lock(&vmap_area_lock);
+
+ /* start scanning - we scan from the top, begin with the last area */
+ area = term_area = last_area;
+ start = offsets[area];
+ end = start + sizes[area];
+
+ if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
+ base = vmalloc_end - last_end;
+ goto found;
+ }
+ base = pvm_determine_end(&next, &prev, align) - end;
+
+ while (true) {
+ BUG_ON(next && next->va_end <= base + end);
+ BUG_ON(prev && prev->va_end > base + end);
+
+ /*
+ * base might have underflowed, add last_end before
+ * comparing.
+ */
+ if (base + last_end < vmalloc_start + last_end) {
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = true;
+ goto retry;
+ }
+ goto err_free;
+ }
+
+ /*
+ * If next overlaps, move base downwards so that it's
+ * right below next and then recheck.
+ */
+ if (next && next->va_start < base + end) {
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * If prev overlaps, shift down next and prev and move
+ * base so that it's right below new next and then
+ * recheck.
+ */
+ if (prev && prev->va_end > base + start) {
+ next = prev;
+ prev = node_to_va(rb_prev(&next->rb_node));
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * This area fits, move on to the previous one. If
+ * the previous one is the terminal one, we're done.
+ */
+ area = (area + nr_vms - 1) % nr_vms;
+ if (area == term_area)
+ break;
+ start = offsets[area];
+ end = start + sizes[area];
+ pvm_find_next_prev(base + end, &next, &prev);
+ }
+found:
+ /* we've found a fitting base, insert all va's */
+ for (area = 0; area < nr_vms; area++) {
+ struct vmap_area *va = vas[area];
+
+ va->va_start = base + offsets[area];
+ va->va_end = va->va_start + sizes[area];
+ __insert_vmap_area(va);
+ }
+
+ vmap_area_pcpu_hole = base + offsets[last_area];
+
+ spin_unlock(&vmap_area_lock);
+
+ /* insert all vm's */
+ for (area = 0; area < nr_vms; area++)
+ setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);
+
+ kfree(vas);
+ return vms;
+
+err_free:
+ for (area = 0; area < nr_vms; area++) {
+ kfree(vas[area]);
+ kfree(vms[area]);
+ }
+err_free2:
+ kfree(vas);
+ kfree(vms);
+ return NULL;
+}
+
+/**
+ * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
+ * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
+ * @nr_vms: the number of allocated areas
+ *
+ * Free vm_structs and the array allocated by pcpu_get_vm_areas().
+ */
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+ int i;
+
+ for (i = 0; i < nr_vms; i++)
+ free_vm_area(vms[i]);
+ kfree(vms);
+}
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PROC_FS
+static void *s_start(struct seq_file *m, loff_t *pos)
+ __acquires(&vmap_area_lock)
+{
+ loff_t n = *pos;
+ struct vmap_area *va;
+
+ spin_lock(&vmap_area_lock);
+ va = list_entry((&vmap_area_list)->next, typeof(*va), list);
+ while (n > 0 && &va->list != &vmap_area_list) {
+ n--;
+ va = list_entry(va->list.next, typeof(*va), list);
+ }
+ if (!n && &va->list != &vmap_area_list)
+ return va;
+
+ return NULL;
+
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct vmap_area *va = p, *next;
+
+ ++*pos;
+ next = list_entry(va->list.next, typeof(*va), list);
+ if (&next->list != &vmap_area_list)
+ return next;
+
+ return NULL;
+}
+
+static void s_stop(struct seq_file *m, void *p)
+ __releases(&vmap_area_lock)
+{
+ spin_unlock(&vmap_area_lock);
+}
+
+static void show_numa_info(struct seq_file *m, struct vm_struct *v)
+{
+ if (IS_ENABLED(CONFIG_NUMA)) {
+ unsigned int nr, *counters = m->private;
+
+ if (!counters)
+ return;
+
+ if (v->flags & VM_UNINITIALIZED)
+ return;
+ /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+ smp_rmb();
+
+ 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 vmap_area *va = p;
+ struct vm_struct *v;
+
+ /*
+ * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
+ * behalf of vmap area is being tear down or vm_map_ram allocation.
+ */
+ if (!(va->flags & VM_VM_AREA))
+ return 0;
+
+ v = va->vm;
+
+ seq_printf(m, "0x%pK-0x%pK %7ld",
+ v->addr, v->addr + v->size, v->size);
+
+ if (v->caller)
+ seq_printf(m, " %pS", v->caller);
+
+ if (v->nr_pages)
+ seq_printf(m, " pages=%d", v->nr_pages);
+
+ if (v->phys_addr)
+ seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
+
+ if (v->flags & VM_IOREMAP)
+ seq_puts(m, " ioremap");
+
+ if (v->flags & VM_ALLOC)
+ seq_puts(m, " vmalloc");
+
+ if (v->flags & VM_MAP)
+ seq_puts(m, " vmap");
+
+ if (v->flags & VM_USERMAP)
+ seq_puts(m, " user");
+
+ if (v->flags & VM_VPAGES)
+ seq_puts(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)
+{
+ if (IS_ENABLED(CONFIG_NUMA))
+ return seq_open_private(file, &vmalloc_op,
+ nr_node_ids * sizeof(unsigned int));
+ else
+ return seq_open(file, &vmalloc_op);
+}
+
+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);
+
+void get_vmalloc_info(struct vmalloc_info *vmi)
+{
+ struct vmap_area *va;
+ unsigned long free_area_size;
+ unsigned long prev_end;
+
+ vmi->used = 0;
+ vmi->largest_chunk = 0;
+
+ prev_end = VMALLOC_START;
+
+ rcu_read_lock();
+
+ if (list_empty(&vmap_area_list)) {
+ vmi->largest_chunk = VMALLOC_TOTAL;
+ goto out;
+ }
+
+ list_for_each_entry_rcu(va, &vmap_area_list, list) {
+ unsigned long addr = va->va_start;
+
+ /*
+ * Some archs keep another range for modules in vmalloc space
+ */
+ if (addr < VMALLOC_START)
+ continue;
+ if (addr >= VMALLOC_END)
+ break;
+
+ if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING))
+ continue;
+
+ vmi->used += (va->va_end - va->va_start);
+
+ free_area_size = addr - prev_end;
+ if (vmi->largest_chunk < free_area_size)
+ vmi->largest_chunk = free_area_size;
+
+ prev_end = va->va_end;
+ }
+
+ if (VMALLOC_END - prev_end > vmi->largest_chunk)
+ vmi->largest_chunk = VMALLOC_END - prev_end;
+
+out:
+ rcu_read_unlock();
+}
+#endif
+
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-16 15:18:00 +0000