2 files changed, 47 insertions, 9 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 97fca4695e0b..ac45aab741a5 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -102,6 +102,9 @@ config HAVE_SETUP_PER_CPU_AREA
 config NEED_PER_CPU_EMBED_FIRST_CHUNK
         def_bool y if SPARC64
 
+config NEED_PER_CPU_PAGE_FIRST_CHUNK
+        def_bool y if SPARC64
+
 config GENERIC_HARDIRQS_NO__DO_IRQ
         bool
         def_bool y if SPARC64
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index ff68373ce6d6..aa36223497b9 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1420,7 +1420,7 @@ static void __init pcpu_free_bootmem(void *ptr, size_t size)
         free_bootmem(__pa(ptr), size);
 }
 
-static int pcpu_cpu_distance(unsigned int from, unsigned int to)
+static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
 {
         if (cpu_to_node(from) == cpu_to_node(to))
                 return LOCAL_DISTANCE;
@@ -1428,18 +1428,53 @@ static int pcpu_cpu_distance(unsigned int from, unsigned int to)
                 return REMOTE_DISTANCE;
 }
 
+static void __init pcpu_populate_pte(unsigned long addr)
+{
+        pgd_t *pgd = pgd_offset_k(addr);
+        pud_t *pud;
+        pmd_t *pmd;
+
+        pud = pud_offset(pgd, addr);
+        if (pud_none(*pud)) {
+                pmd_t *new;
+
+                new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
+                pud_populate(&init_mm, pud, new);
+        }
+
+        pmd = pmd_offset(pud, addr);
+        if (!pmd_present(*pmd)) {
+                pte_t *new;
+
+                new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
+                pmd_populate_kernel(&init_mm, pmd, new);
+        }
+}
+
 void __init setup_per_cpu_areas(void)
 {
         unsigned long delta;
         unsigned int cpu;
-        int rc;
-
-        rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
-                                    PERCPU_DYNAMIC_RESERVE, 4 << 20,
-                                    pcpu_cpu_distance, pcpu_alloc_bootmem,
-                                    pcpu_free_bootmem);
-        if (rc)
-                panic("failed to initialize first chunk (%d)", rc);
+        int rc = -EINVAL;
+
+        if (pcpu_chosen_fc != PCPU_FC_PAGE) {
+                rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
+                                            PERCPU_DYNAMIC_RESERVE, 4 << 20,
+                                            pcpu_cpu_distance,
+                                            pcpu_alloc_bootmem,
+                                            pcpu_free_bootmem);
+                if (rc)
+                        pr_warning("PERCPU: %s allocator failed (%d), "
+                                   "falling back to page size\n",
+                                   pcpu_fc_names[pcpu_chosen_fc], rc);
+        }
+        if (rc < 0)
+                rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE,
+                                           pcpu_alloc_bootmem,
+                                           pcpu_free_bootmem,
+                                           pcpu_populate_pte);
+        if (rc < 0)
+                panic("cannot initialize percpu area (err=%d)", rc);
 
         delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
         for_each_possible_cpu(cpu)