[IA64] fix show_mem for VIRTUAL_MEM_MAP+FLATMEM

contig.c (FLATMEM) requires the same optimization as in discontig.c for show_mem
when VIRTUAL_MEM_MAP is in use. Otherwise FLATMEM has softlockup timeouts.
This was boot tested for memory configuration: SPARSEMEM,
DISCONTIG+VIRTUAL_MEM_MAP, FLATMEM, FLATMEM+VIRTUAL_MEM_MAP and
FLATMEM+VIRTUAL_MEM_MAP with largest memory gap less than LARGE_GAP by
using boot parameter "mem=".

This was boot tested and "echo m >/proc/sysrq-trigger" output evaluated for
: FLATMEM, FLATMEM+VIRTUAL_MEM_MAP, DISCONTIGMEM+VIRTUAL_MEM_MAP and
SPARSEMEM.

Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

3 files changed, 66 insertions, 67 deletions

diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index 8919fed9666a..e004143ba86b 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -27,6 +27,7 @@
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
 static unsigned long num_dma_physpages;
+static unsigned long max_gap;
 #endif
 
 /**
@@ -45,9 +46,15 @@ show_mem (void)
 
         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
         i = max_mapnr;
-        while (i-- > 0) {
-                if (!pfn_valid(i))
+        for (i = 0; i < max_mapnr; i++) {
+                if (!pfn_valid(i)) {
+#ifdef CONFIG_VIRTUAL_MEM_MAP
+                        if (max_gap < LARGE_GAP)
+                                continue;
+                        i = vmemmap_find_next_valid_pfn(0, i) - 1;
+#endif
                         continue;
+                }
                 total++;
                 if (PageReserved(mem_map+i))
                         reserved++;
@@ -234,7 +241,6 @@ paging_init (void)
         unsigned long zones_size[MAX_NR_ZONES];
 #ifdef CONFIG_VIRTUAL_MEM_MAP
         unsigned long zholes_size[MAX_NR_ZONES];
-        unsigned long max_gap;
 #endif
 
         /* initialize mem_map[] */
@@ -266,7 +272,6 @@ paging_init (void)
                 }
         }
 
-        max_gap = 0;
         efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
         if (max_gap < LARGE_GAP) {
                 vmem_map = (struct page *) 0;
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index 8eeb669917fa..d260bffa01ab 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -534,68 +534,6 @@ void __cpuinit *per_cpu_init(void)
 }
 #endif /* CONFIG_SMP */
 
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-static inline int find_next_valid_pfn_for_pgdat(pg_data_t *pgdat, int i)
-{
-        unsigned long end_address, hole_next_pfn;
-        unsigned long stop_address;
-
-        end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
-        end_address = PAGE_ALIGN(end_address);
-
-        stop_address = (unsigned long) &vmem_map[
-                pgdat->node_start_pfn + pgdat->node_spanned_pages];
-
-        do {
-                pgd_t *pgd;
-                pud_t *pud;
-                pmd_t *pmd;
-                pte_t *pte;
-
-                pgd = pgd_offset_k(end_address);
-                if (pgd_none(*pgd)) {
-                        end_address += PGDIR_SIZE;
-                        continue;
-                }
-
-                pud = pud_offset(pgd, end_address);
-                if (pud_none(*pud)) {
-                        end_address += PUD_SIZE;
-                        continue;
-                }
-
-                pmd = pmd_offset(pud, end_address);
-                if (pmd_none(*pmd)) {
-                        end_address += PMD_SIZE;
-                        continue;
-                }
-
-                pte = pte_offset_kernel(pmd, end_address);
-retry_pte:
-                if (pte_none(*pte)) {
-                        end_address += PAGE_SIZE;
-                        pte++;
-                        if ((end_address < stop_address) &&
-                            (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
-                                goto retry_pte;
-                        continue;
-                }
-                /* Found next valid vmem_map page */
-                break;
-        } while (end_address < stop_address);
-
-        end_address = min(end_address, stop_address);
-        end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
-        hole_next_pfn = end_address / sizeof(struct page);
-        return hole_next_pfn - pgdat->node_start_pfn;
-}
-#else
-static inline int find_next_valid_pfn_for_pgdat(pg_data_t *pgdat, int i)
-{
-        return i + 1;
-}
-#endif
-
 /**
  * show_mem - give short summary of memory stats
  *
@@ -625,7 +563,8 @@ void show_mem(void)
                         if (pfn_valid(pgdat->node_start_pfn + i))
                                 page = pfn_to_page(pgdat->node_start_pfn + i);
                         else {
-                                i = find_next_valid_pfn_for_pgdat(pgdat, i) - 1;
+                                i = vmemmap_find_next_valid_pfn(pgdat->node_id,
+                                         i) - 1;
                                 continue;
                         }
                         if (PageReserved(page))
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 2f50c064513c..30617ccb4f7e 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -415,6 +415,61 @@ ia64_mmu_init (void *my_cpu_data)
 }
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
+int vmemmap_find_next_valid_pfn(int node, int i)
+{
+        unsigned long end_address, hole_next_pfn;
+        unsigned long stop_address;
+        pg_data_t *pgdat = NODE_DATA(node);
+
+        end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
+        end_address = PAGE_ALIGN(end_address);
+
+        stop_address = (unsigned long) &vmem_map[
+                pgdat->node_start_pfn + pgdat->node_spanned_pages];
+
+        do {
+                pgd_t *pgd;
+                pud_t *pud;
+                pmd_t *pmd;
+                pte_t *pte;
+
+                pgd = pgd_offset_k(end_address);
+                if (pgd_none(*pgd)) {
+                        end_address += PGDIR_SIZE;
+                        continue;
+                }
+
+                pud = pud_offset(pgd, end_address);
+                if (pud_none(*pud)) {
+                        end_address += PUD_SIZE;
+                        continue;
+                }
+
+                pmd = pmd_offset(pud, end_address);
+                if (pmd_none(*pmd)) {
+                        end_address += PMD_SIZE;
+                        continue;
+                }
+
+                pte = pte_offset_kernel(pmd, end_address);
+retry_pte:
+                if (pte_none(*pte)) {
+                        end_address += PAGE_SIZE;
+                        pte++;
+                        if ((end_address < stop_address) &&
+                            (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
+                                goto retry_pte;
+                        continue;
+                }
+                /* Found next valid vmem_map page */
+                break;
+        } while (end_address < stop_address);
+
+        end_address = min(end_address, stop_address);
+        end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
+        hole_next_pfn = end_address / sizeof(struct page);
+        return hole_next_pfn - pgdat->node_start_pfn;
+}
 
 int __init
 create_mem_map_page_table (u64 start, u64 end, void *arg)