[S390] Fix section mismatch warnings.

This fixes the last remaining section mismatch warnings in s390
architecture code. It reveals also a real bug introduced by... me
with git commit 2069e978d5a6e7b45d58027e3de7f879b8c5e488
("[S390] sparsemem vmemmap: initialize memmap.")

Calling the generic vmemmap_alloc_block() function to get initialized
memory is a nice idea, however that function is __meminit annotated
and therefore the function might be gone if we try to call it later.
This can happen if a DCSS segment gets added.

So basically revert the patch and clear the memmap explicitly to fix
the original bug.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 14 insertions, 6 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 1f4228948dc4..42b1d12ebb10 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -1089,7 +1089,7 @@ out:
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-int smp_rescan_cpus(void)
+int __ref smp_rescan_cpus(void)
 {
         cpumask_t newcpus;
         int cpu;
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index ea2804808f39..f591188fa2c0 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -27,12 +27,19 @@ struct memory_segment {
 
 static LIST_HEAD(mem_segs);
 
-static pud_t *vmem_pud_alloc(void)
+static void __ref *vmem_alloc_pages(unsigned int order)
+{
+        if (slab_is_available())
+                return (void *)__get_free_pages(GFP_KERNEL, order);
+        return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
+}
+
+static inline pud_t *vmem_pud_alloc(void)
 {
         pud_t *pud = NULL;
 
 #ifdef CONFIG_64BIT
-        pud = vmemmap_alloc_block(PAGE_SIZE * 4, 0);
+        pud = vmem_alloc_pages(2);
         if (!pud)
                 return NULL;
         clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
@@ -40,12 +47,12 @@ static pud_t *vmem_pud_alloc(void)
         return pud;
 }
 
-static pmd_t *vmem_pmd_alloc(void)
+static inline pmd_t *vmem_pmd_alloc(void)
 {
         pmd_t *pmd = NULL;
 
 #ifdef CONFIG_64BIT
-        pmd = vmemmap_alloc_block(PAGE_SIZE * 4, 0);
+        pmd = vmem_alloc_pages(2);
         if (!pmd)
                 return NULL;
         clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
@@ -207,13 +214,14 @@ int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
                 if (pte_none(*pt_dir)) {
                         unsigned long new_page;
 
-                        new_page =__pa(vmemmap_alloc_block(PAGE_SIZE, 0));
+                        new_page =__pa(vmem_alloc_pages(0));
                         if (!new_page)
                                 goto out;
                         pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
                         *pt_dir = pte;
                 }
         }
+        memset(start, 0, nr * sizeof(struct page));
         ret = 0;
 out:
         flush_tlb_kernel_range(start_addr, end_addr);