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-rw-r--r--mm/vmalloc.c588
1 files changed, 588 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
new file mode 100644
index 000000000000..c6182f6f1305
--- /dev/null
+++ b/mm/vmalloc.c
@@ -0,0 +1,588 @@
+/*
+ * 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
+ */
+
+#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/vmalloc.h>
+
+#include <asm/uaccess.h>
+#include <asm/tlbflush.h>
+
+
+DEFINE_RWLOCK(vmlist_lock);
+struct vm_struct *vmlist;
+
+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 inline 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 inline 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);
+}
+
+void unmap_vm_area(struct vm_struct *area)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long addr = (unsigned long) area->addr;
+ unsigned long end = addr + area->size;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset_k(addr);
+ flush_cache_vunmap(addr, end);
+ 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);
+ flush_tlb_kernel_range((unsigned long) area->addr, end);
+}
+
+static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page ***pages)
+{
+ pte_t *pte;
+
+ pte = pte_alloc_kernel(&init_mm, pmd, addr);
+ if (!pte)
+ return -ENOMEM;
+ do {
+ struct page *page = **pages;
+ WARN_ON(!pte_none(*pte));
+ if (!page)
+ return -ENOMEM;
+ set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
+ (*pages)++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
+}
+
+static inline int vmap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page ***pages)
+{
+ 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))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int vmap_pud_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page ***pages)
+{
+ 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))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long addr = (unsigned long) area->addr;
+ unsigned long end = addr + area->size - PAGE_SIZE;
+ int err;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset_k(addr);
+ spin_lock(&init_mm.page_table_lock);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = vmap_pud_range(pgd, addr, next, prot, pages);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+ spin_unlock(&init_mm.page_table_lock);
+ flush_cache_vmap((unsigned long) area->addr, end);
+ return err;
+}
+
+#define IOREMAP_MAX_ORDER (7 + PAGE_SHIFT) /* 128 pages */
+
+struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end)
+{
+ struct vm_struct **p, *tmp, *area;
+ unsigned long align = 1;
+ unsigned long addr;
+
+ 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;
+ }
+ addr = ALIGN(start, align);
+ size = PAGE_ALIGN(size);
+
+ area = kmalloc(sizeof(*area), GFP_KERNEL);
+ if (unlikely(!area))
+ return NULL;
+
+ if (unlikely(!size)) {
+ kfree (area);
+ return NULL;
+ }
+
+ /*
+ * We always allocate a guard page.
+ */
+ size += PAGE_SIZE;
+
+ write_lock(&vmlist_lock);
+ for (p = &vmlist; (tmp = *p) != NULL ;p = &tmp->next) {
+ if ((unsigned long)tmp->addr < addr) {
+ if((unsigned long)tmp->addr + tmp->size >= addr)
+ addr = ALIGN(tmp->size +
+ (unsigned long)tmp->addr, align);
+ continue;
+ }
+ if ((size + addr) < addr)
+ goto out;
+ if (size + addr <= (unsigned long)tmp->addr)
+ goto found;
+ addr = ALIGN(tmp->size + (unsigned long)tmp->addr, align);
+ if (addr > end - size)
+ goto out;
+ }
+
+found:
+ area->next = *p;
+ *p = area;
+
+ area->flags = flags;
+ area->addr = (void *)addr;
+ area->size = size;
+ area->pages = NULL;
+ area->nr_pages = 0;
+ area->phys_addr = 0;
+ write_unlock(&vmlist_lock);
+
+ return area;
+
+out:
+ write_unlock(&vmlist_lock);
+ kfree(area);
+ if (printk_ratelimit())
+ printk(KERN_WARNING "allocation failed: out of vmalloc space - use vmalloc=<size> to increase size.\n");
+ return NULL;
+}
+
+/**
+ * get_vm_area - reserve a contingous 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(size, flags, VMALLOC_START, VMALLOC_END);
+}
+
+/**
+ * remove_vm_area - find and remove a contingous 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.
+ */
+struct vm_struct *remove_vm_area(void *addr)
+{
+ struct vm_struct **p, *tmp;
+
+ write_lock(&vmlist_lock);
+ for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) {
+ if (tmp->addr == addr)
+ goto found;
+ }
+ write_unlock(&vmlist_lock);
+ return NULL;
+
+found:
+ unmap_vm_area(tmp);
+ *p = tmp->next;
+ write_unlock(&vmlist_lock);
+
+ /*
+ * Remove the guard page.
+ */
+ tmp->size -= PAGE_SIZE;
+ return tmp;
+}
+
+void __vunmap(void *addr, int deallocate_pages)
+{
+ struct vm_struct *area;
+
+ if (!addr)
+ return;
+
+ if ((PAGE_SIZE-1) & (unsigned long)addr) {
+ printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+ WARN_ON(1);
+ return;
+ }
+
+ area = remove_vm_area(addr);
+ if (unlikely(!area)) {
+ printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
+ addr);
+ WARN_ON(1);
+ return;
+ }
+
+ if (deallocate_pages) {
+ int i;
+
+ for (i = 0; i < area->nr_pages; i++) {
+ if (unlikely(!area->pages[i]))
+ BUG();
+ __free_page(area->pages[i]);
+ }
+
+ if (area->nr_pages > PAGE_SIZE/sizeof(struct page *))
+ vfree(area->pages);
+ else
+ kfree(area->pages);
+ }
+
+ kfree(area);
+ return;
+}
+
+/**
+ * vfree - release memory allocated by vmalloc()
+ *
+ * @addr: memory base address
+ *
+ * Free the virtually contiguous memory area starting at @addr, as
+ * obtained from vmalloc(), vmalloc_32() or __vmalloc().
+ *
+ * May not be called in interrupt context.
+ */
+void vfree(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().
+ *
+ * May not be called in interrupt context.
+ */
+void vunmap(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((count << PAGE_SHIFT), flags);
+ if (!area)
+ return NULL;
+ if (map_vm_area(area, prot, &pages)) {
+ vunmap(area->addr);
+ return NULL;
+ }
+
+ return area->addr;
+}
+
+EXPORT_SYMBOL(vmap);
+
+void *__vmalloc_area(struct vm_struct *area, unsigned int __nocast gfp_mask, pgprot_t prot)
+{
+ 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(array_size, gfp_mask, PAGE_KERNEL);
+ else
+ pages = kmalloc(array_size, (gfp_mask & ~__GFP_HIGHMEM));
+ area->pages = pages;
+ if (!area->pages) {
+ remove_vm_area(area->addr);
+ kfree(area);
+ return NULL;
+ }
+ memset(area->pages, 0, array_size);
+
+ for (i = 0; i < area->nr_pages; i++) {
+ area->pages[i] = alloc_page(gfp_mask);
+ if (unlikely(!area->pages[i])) {
+ /* Successfully allocated i pages, free them in __vunmap() */
+ area->nr_pages = i;
+ goto fail;
+ }
+ }
+
+ if (map_vm_area(area, prot, &pages))
+ goto fail;
+ return area->addr;
+
+fail:
+ vfree(area->addr);
+ return NULL;
+}
+
+/**
+ * __vmalloc - allocate virtually contiguous memory
+ *
+ * @size: allocation size
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ *
+ * 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(unsigned long size, unsigned int __nocast gfp_mask, pgprot_t prot)
+{
+ struct vm_struct *area;
+
+ size = PAGE_ALIGN(size);
+ if (!size || (size >> PAGE_SHIFT) > num_physpages)
+ return NULL;
+
+ area = get_vm_area(size, VM_ALLOC);
+ if (!area)
+ return NULL;
+
+ return __vmalloc_area(area, gfp_mask, prot);
+}
+
+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 cotrol over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
+}
+
+EXPORT_SYMBOL(vmalloc);
+
+/**
+ * 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 cotrol over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+
+#ifndef PAGE_KERNEL_EXEC
+# define PAGE_KERNEL_EXEC PAGE_KERNEL
+#endif
+
+void *vmalloc_exec(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC);
+}
+
+/**
+ * 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_KERNEL, PAGE_KERNEL);
+}
+
+EXPORT_SYMBOL(vmalloc_32);
+
+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;
+}
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