lkml.org 
[lkml]   [2010]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] mm/nommu.c:Dynamic alloc/free percpu area for nommu
Date
From: Graff Yang <graff.yang@gmail.com>

This patch supports dynamic alloc/free percpu area for nommu arch like
blackfin.
It allocates contiguous pages in funtion pcpu_get_vm_areas() instead of
getting none contiguous pages then vmap it in mmu arch.
As we can not get the real page structure through vmalloc_to_page(), so
it also modified the nommu version vmalloc_to_page()/vmalloc_to_pfn().

Signed-off-by: Graff Yang <graff.yang@gmail.com>
---
mm/nommu.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 112 insertions(+), 2 deletions(-)
diff --git a/mm/nommu.c b/mm/nommu.c
index 605ace8..98bbdf4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -255,13 +255,15 @@ EXPORT_SYMBOL(vmalloc_user);

struct page *vmalloc_to_page(const void *addr)
{
- return virt_to_page(addr);
+ return (struct page *)
+ (virt_to_page(addr)->index) ? : virt_to_page(addr);
}
EXPORT_SYMBOL(vmalloc_to_page);

unsigned long vmalloc_to_pfn(const void *addr)
{
- return page_to_pfn(virt_to_page(addr));
+ return page_to_pfn((struct page *)
+ (virt_to_page(addr)->index) ? : virt_to_page(addr));
}
EXPORT_SYMBOL(vmalloc_to_pfn);

@@ -2000,3 +2002,111 @@ int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
up_write(&nommu_region_sem);
return 0;
}
+
+#ifdef CONFIG_SMP
+int map_kernel_range_noflush(unsigned long addr, unsigned long size,
+ pgprot_t prot, struct page **pages)
+{
+ int i, nr_page = size >> PAGE_SHIFT;
+ for (i = 0; i < nr_page; i++, addr += PAGE_SIZE)
+ virt_to_page(addr)->index = (pgoff_t)pages[i];
+ return size >> PAGE_SHIFT;
+}
+
+void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
+{
+ int i, nr_page = size >> PAGE_SHIFT;
+ for (i = 0; i < nr_page; i++, addr += PAGE_SIZE)
+ virt_to_page(addr)->index = 0;
+}
+
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+ const size_t *sizes, int nr_vms,
+ size_t align, gfp_t gfp_mask)
+{
+ struct vm_struct **vms;
+ int area, area2, first_area, last_area;
+ unsigned long start, end, first_start, last_end;
+ void *base;
+
+ gfp_mask &= GFP_RECLAIM_MASK;
+
+ /* verify parameters and allocate data structures */
+ BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
+ first_area = last_area = 0;
+ for (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));
+
+ if (end < offsets[first_area])
+ first_area = area;
+
+ /* 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);
+ }
+ }
+ first_start = offsets[first_area];
+ last_end = offsets[last_area] + sizes[last_area];
+
+ vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask);
+ if (!vms)
+ goto err_free;
+
+ for (area = 0; area < nr_vms; area++) {
+ vms[area] = kzalloc(sizeof(struct vm_struct), gfp_mask);
+ if (!vms[area])
+ goto err_free;
+ }
+
+ base = kmalloc(last_end - first_start, GFP_KERNEL | __GFP_COMP);
+ if (!base)
+ goto err_free;
+
+ for (area = 0; area < nr_vms; area++) {
+ struct vm_struct *vm = vms[area];
+
+ vm->flags = VM_ALLOC;
+ vm->addr = base + offsets[area];
+ vm->size = sizes[area];
+ vm->caller = NULL;
+ }
+ return vms;
+
+err_free:
+ for (area = 0; area < nr_vms; area++) {
+ if (vms)
+ kfree(vms[area]);
+ }
+ kfree(vms);
+ return NULL;
+}
+
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+ int area;
+ void *vaddr = (void *)(-1UL);
+ for (area = 0; area < nr_vms; area++)
+ if (vms[area]) {
+ if (vms[area]->addr < vaddr)
+ vaddr = vms[area]->addr;
+ kfree(vms[area]);
+ }
+ kfree(vms);
+ vfree(vaddr);
+}
+#endif
--
1.6.4.4


\
 
 \ /
  Last update: 2010-03-19 10:05    [from the cache]
©2003-2011 Jasper Spaans