SPARC64: SPARSEMEM_VMEMMAP support

[apw@shadowen.org: style fixups]
[apw@shadowen.org: vmemmap sparc64: convert to new config options]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index f0ab9aab308f..69538d1aa0ad 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -1645,6 +1645,58 @@ EXPORT_SYMBOL(_PAGE_E);
 unsigned long _PAGE_CACHE __read_mostly;
 EXPORT_SYMBOL(_PAGE_CACHE);
 
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+
+#define VMEMMAP_CHUNK_SHIFT     22
+#define VMEMMAP_CHUNK           (1UL << VMEMMAP_CHUNK_SHIFT)
+#define VMEMMAP_CHUNK_MASK      ~(VMEMMAP_CHUNK - 1UL)
+#define VMEMMAP_ALIGN(x)        (((x)+VMEMMAP_CHUNK-1UL)&VMEMMAP_CHUNK_MASK)
+
+#define VMEMMAP_SIZE    ((((1UL << MAX_PHYSADDR_BITS) >> PAGE_SHIFT) * \
+                          sizeof(struct page *)) >> VMEMMAP_CHUNK_SHIFT)
+unsigned long vmemmap_table[VMEMMAP_SIZE];
+
+int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
+{
+        unsigned long vstart = (unsigned long) start;
+        unsigned long vend = (unsigned long) (start + nr);
+        unsigned long phys_start = (vstart - VMEMMAP_BASE);
+        unsigned long phys_end = (vend - VMEMMAP_BASE);
+        unsigned long addr = phys_start & VMEMMAP_CHUNK_MASK;
+        unsigned long end = VMEMMAP_ALIGN(phys_end);
+        unsigned long pte_base;
+
+        pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4U |
+                    _PAGE_CP_4U | _PAGE_CV_4U |
+                    _PAGE_P_4U | _PAGE_W_4U);
+        if (tlb_type == hypervisor)
+                pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4V |
+                            _PAGE_CP_4V | _PAGE_CV_4V |
+                            _PAGE_P_4V | _PAGE_W_4V);
+
+        for (; addr < end; addr += VMEMMAP_CHUNK) {
+                unsigned long *vmem_pp =
+                        vmemmap_table + (addr >> VMEMMAP_CHUNK_SHIFT);
+                void *block;
+
+                if (!(*vmem_pp & _PAGE_VALID)) {
+                        block = vmemmap_alloc_block(1UL << 22, node);
+                        if (!block)
+                                return -ENOMEM;
+
+                        *vmem_pp = pte_base | __pa(block);
+
+                        printk(KERN_INFO "[%p-%p] page_structs=%lu "
+                               "node=%d entry=%lu/%lu\n", start, block, nr,
+                               node,
+                               addr >> VMEMMAP_CHUNK_SHIFT,
+                               VMEMMAP_SIZE >> VMEMMAP_CHUNK_SHIFT);
+                }
+        }
+        return 0;
+}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
 static void prot_init_common(unsigned long page_none,
                              unsigned long page_shared,
                              unsigned long page_copy,