---

yaml
---
r: 69582
b: refs/heads/master
c: 8f6aac4
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 540557b9439ec19668553830c90222f9fb0c2e95
+refs/heads/master: 8f6aac419bd590f535fb110875a51f7db2b62b5b

trunk/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.

trunk/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 */

trunk/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

trunk/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;
+}

trunk/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;
 }