diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h
index 30d8d33491dd..52226e14bd7d 100644
--- a/include/asm-generic/memory_model.h
+++ b/include/asm-generic/memory_model.h
@@ -46,6 +46,12 @@
__pgdat->node_start_pfn; \
})
+#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
+
+/* memmap is virtually contigious. */
+#define __pfn_to_page(pfn) (vmemmap + (pfn))
+#define __page_to_pfn(page) ((page) - vmemmap)
+
#elif defined(CONFIG_SPARSEMEM)
/*
* Note: section's mem_map is encorded to reflect its start_pfn.
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1692dd6cb915..d216abbd0574 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1218,5 +1218,11 @@ extern int randomize_va_space;
const char * arch_vma_name(struct vm_area_struct *vma);
+struct page *sparse_early_mem_map_populate(unsigned long pnum, int nid);
+int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
+int vmemmap_populate_pmd(pud_t *, unsigned long, unsigned long, int);
+void *vmemmap_alloc_block(unsigned long size, int node);
+void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
+
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */
diff --git a/mm/Makefile b/mm/Makefile
index 245e33ab00c4..d28f63e05b46 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
obj-$(CONFIG_HUGETLBFS) += hugetlb.o
obj-$(CONFIG_NUMA) += mempolicy.o
obj-$(CONFIG_SPARSEMEM) += sparse.o
+obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
obj-$(CONFIG_SHMEM) += shmem.o
obj-$(CONFIG_TMPFS_POSIX_ACL) += shmem_acl.o
obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
new file mode 100644
index 000000000000..7bb7a4b96d74
--- /dev/null
+++ b/mm/sparse-vmemmap.c
@@ -0,0 +1,181 @@
+/*
+ * Virtual Memory Map support
+ *
+ * (C) 2007 sgi. Christoph Lameter <clameter@sgi.com>.
+ *
+ * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
+ * virt_to_page, page_address() to be implemented as a base offset
+ * calculation without memory access.
+ *
+ * However, virtual mappings need a page table and TLBs. Many Linux
+ * architectures already map their physical space using 1-1 mappings
+ * via TLBs. For those arches the virtual memmory map is essentially
+ * for free if we use the same page size as the 1-1 mappings. In that
+ * case the overhead consists of a few additional pages that are
+ * allocated to create a view of memory for vmemmap.
+ *
+ * Special Kconfig settings:
+ *
+ * CONFIG_ARCH_POPULATES_SPARSEMEM_VMEMMAP
+ *
+ * The architecture has its own functions to populate the memory
+ * map and provides a vmemmap_populate function.
+ *
+ * CONFIG_ARCH_POPULATES_SPARSEMEM_VMEMMAP_PMD
+ *
+ * The architecture provides functions to populate the pmd level
+ * of the vmemmap mappings. Allowing mappings using large pages
+ * where available.
+ *
+ * If neither are set then PAGE_SIZE mappings are generated which
+ * require one PTE/TLB per PAGE_SIZE chunk of the virtual memory map.
+ */
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <asm/dma.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Allocate a block of memory to be used to back the virtual memory map
+ * or to back the page tables that are used to create the mapping.
+ * Uses the main allocators if they are available, else bootmem.
+ */
+void * __meminit vmemmap_alloc_block(unsigned long size, int node)
+{
+ /* If the main allocator is up use that, fallback to bootmem. */
+ if (slab_is_available()) {
+ struct page *page = alloc_pages_node(node,
+ GFP_KERNEL | __GFP_ZERO, get_order(size));
+ if (page)
+ return page_address(page);
+ return NULL;
+ } else
+ return __alloc_bootmem_node(NODE_DATA(node), size, size,
+ __pa(MAX_DMA_ADDRESS));
+}
+
+#ifndef CONFIG_ARCH_POPULATES_SPARSEMEM_VMEMMAP
+void __meminit vmemmap_verify(pte_t *pte, int node,
+ unsigned long start, unsigned long end)
+{
+ unsigned long pfn = pte_pfn(*pte);
+ int actual_node = early_pfn_to_nid(pfn);
+
+ if (actual_node != node)
+ printk(KERN_WARNING "[%lx-%lx] potential offnode "
+ "page_structs\n", start, end - 1);
+}
+
+#ifndef CONFIG_ARCH_POPULATES_SPARSEMEM_VMEMMAP_PMD
+static int __meminit vmemmap_populate_pte(pmd_t *pmd, unsigned long addr,
+ unsigned long end, int node)
+{
+ pte_t *pte;
+
+ for (pte = pte_offset_kernel(pmd, addr); addr < end;
+ pte++, addr += PAGE_SIZE)
+ if (pte_none(*pte)) {
+ pte_t entry;
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return -ENOMEM;
+
+ entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
+ set_pte(pte, entry);
+
+ } else
+ vmemmap_verify(pte, node, addr + PAGE_SIZE, end);
+
+ return 0;
+}
+
+int __meminit vmemmap_populate_pmd(pud_t *pud, unsigned long addr,
+ unsigned long end, int node)
+{
+ pmd_t *pmd;
+ int error = 0;
+ unsigned long next;
+
+ for (pmd = pmd_offset(pud, addr); addr < end && !error;
+ pmd++, addr = next) {
+ if (pmd_none(*pmd)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return -ENOMEM;
+
+ pmd_populate_kernel(&init_mm, pmd, p);
+ } else
+ vmemmap_verify((pte_t *)pmd, node,
+ pmd_addr_end(addr, end), end);
+ next = pmd_addr_end(addr, end);
+ error = vmemmap_populate_pte(pmd, addr, next, node);
+ }
+ return error;
+}
+#endif /* CONFIG_ARCH_POPULATES_SPARSEMEM_VMEMMAP_PMD */
+
+static int __meminit vmemmap_populate_pud(pgd_t *pgd, unsigned long addr,
+ unsigned long end, int node)
+{
+ pud_t *pud;
+ int error = 0;
+ unsigned long next;
+
+ for (pud = pud_offset(pgd, addr); addr < end && !error;
+ pud++, addr = next) {
+ if (pud_none(*pud)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return -ENOMEM;
+
+ pud_populate(&init_mm, pud, p);
+ }
+ next = pud_addr_end(addr, end);
+ error = vmemmap_populate_pmd(pud, addr, next, node);
+ }
+ return error;
+}
+
+int __meminit vmemmap_populate(struct page *start_page,
+ unsigned long nr, int node)
+{
+ pgd_t *pgd;
+ unsigned long addr = (unsigned long)start_page;
+ unsigned long end = (unsigned long)(start_page + nr);
+ unsigned long next;
+ int error = 0;
+
+ printk(KERN_DEBUG "[%lx-%lx] Virtual memory section"
+ " (%ld pages) node %d\n", addr, end - 1, nr, node);
+
+ for (pgd = pgd_offset_k(addr); addr < end && !error;
+ pgd++, addr = next) {
+ if (pgd_none(*pgd)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return -ENOMEM;
+
+ pgd_populate(&init_mm, pgd, p);
+ }
+ next = pgd_addr_end(addr,end);
+ error = vmemmap_populate_pud(pgd, addr, next, node);
+ }
+ return error;
+}
+#endif /* !CONFIG_ARCH_POPULATES_SPARSEMEM_VMEMMAP */
+
+struct page __init *sparse_early_mem_map_populate(unsigned long pnum, int nid)
+{
+ struct page *map = pfn_to_page(pnum * PAGES_PER_SECTION);
+ int error = vmemmap_populate(map, PAGES_PER_SECTION, nid);
+ if (error)
+ return NULL;
+
+ return map;
+}
diff --git a/mm/sparse.c b/mm/sparse.c
index 54f3940406cb..52843a76feed 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -9,6 +9,8 @@
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <asm/dma.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
/*
* Permanent SPARSEMEM data:
@@ -222,11 +224,10 @@ void *alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size)
return NULL;
}
-static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+struct page __init *sparse_early_mem_map_populate(unsigned long pnum, int nid)
{
struct page *map;
- struct mem_section *ms = __nr_to_section(pnum);
- int nid = sparse_early_nid(ms);
map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
if (map)
@@ -239,10 +240,22 @@ static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
map = alloc_bootmem_node(NODE_DATA(nid),
sizeof(struct page) * PAGES_PER_SECTION);
+ return map;
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
+{
+ struct page *map;
+ struct mem_section *ms = __nr_to_section(pnum);
+ int nid = sparse_early_nid(ms);
+
+ map = sparse_early_mem_map_populate(pnum, nid);
if (map)
return map;
- printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
+ printk(KERN_ERR "%s: sparsemem memory map backing failed "
+ "some memory will not be available.\n", __FUNCTION__);
ms->section_mem_map = 0;
return NULL;
}