[S390] System z large page support.

This adds hugetlbfs support on System z, using both hardware large page
support if available and software large page emulation on older hardware.
Shared (large) page tables are implemented in software emulation mode,
by using page->index of the first tail page from a compound large page
to store page table information.

Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 694c6546ce64..2bc70b6e876a 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -749,6 +749,9 @@ static void __init setup_hwcaps(void)
                         elf_hwcap |= 1UL << 6;
         }
 
+        if (MACHINE_HAS_HPAGE)
+                elf_hwcap |= 1UL << 7;
+
         switch (cpuinfo->cpu_id.machine) {
         case 0x9672:
 #if !defined(CONFIG_64BIT)
@@ -872,8 +875,9 @@ void __cpuinit print_cpu_info(struct cpuinfo_S390 *cpuinfo)
 
 static int show_cpuinfo(struct seq_file *m, void *v)
 {
-        static const char *hwcap_str[7] = {
-                "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp"
+        static const char *hwcap_str[8] = {
+                "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
+                "edat"
         };
         struct cpuinfo_S390 *cpuinfo;
         unsigned long n = (unsigned long) v - 1;
@@ -888,7 +892,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
                                num_online_cpus(), loops_per_jiffy/(500000/HZ),
                                (loops_per_jiffy/(5000/HZ))%100);
                 seq_puts(m, "features\t: ");
-                for (i = 0; i < 7; i++)
+                for (i = 0; i < 8; i++)
                         if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
                                 seq_printf(m, "%s ", hwcap_str[i]);
                 seq_puts(m, "\n");