|
|
@@ -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;
|
|
|
+}
|
Christoph Lameter