[PATCH 08/10] vmalloc: add un/map_kernel_range_noflush()

From: Tejun Heo
Date: Wed Feb 18 2009 - 07:07:07 EST


Impact: two more public map/unmap functions

Implement map_kernel_range_noflush() and unmap_kernel_range_noflush().
These functions respectively map and unmap address range in kernel VM
area but doesn't do any vcache or tlb flushing. These will be used by
new percpu allocator.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
include/linux/vmalloc.h | 3 ++
mm/vmalloc.c | 58 ++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index bbc0513..599ba79 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -91,6 +91,9 @@ extern struct vm_struct *remove_vm_area(const void *addr);

extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
struct page ***pages);
+extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
+ pgprot_t prot, struct page **pages);
+extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
extern void unmap_kernel_range(unsigned long addr, unsigned long size);

/* Allocate/destroy a 'vmalloc' VM area. */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d206261..e62c212 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -153,8 +153,8 @@ static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
*
* 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)
+static int vmap_page_range_noflush(unsigned long start, unsigned long end,
+ pgprot_t prot, struct page **pages)
{
pgd_t *pgd;
unsigned long next;
@@ -170,13 +170,22 @@ static int vmap_page_range(unsigned long start, unsigned long end,
if (err)
break;
} while (pgd++, addr = next, addr != end);
- flush_cache_vmap(start, end);

if (unlikely(err))
return err;
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;
+}
+
static inline int is_vmalloc_or_module_addr(const void *x)
{
/*
@@ -1033,6 +1042,49 @@ void __init vmalloc_init(void)
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. This function doesn't call flush_cache_vmap().
+ *
+ * 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. This function doesn't flush_cache_vunmap() or
+ * flush_tlb_kernel_range().
+ */
+void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
+{
+ vunmap_page_range(addr, addr + size);
+}
+
+/**
+ * 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;
--
1.6.0.2

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