[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>
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index bd188f6..d0e0968 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -268,6 +268,19 @@
s390_base_pgm_handler_fn = early_pgm_check_handler;
}
+static noinline __init void setup_hpage(void)
+{
+#ifndef CONFIG_DEBUG_PAGEALLOC
+ unsigned int facilities;
+
+ facilities = stfl();
+ if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
+ return;
+ machine_flags |= MACHINE_FLAG_HPAGE;
+ __ctl_set_bit(0, 23);
+#endif
+}
+
static __init void detect_mvpg(void)
{
#ifndef CONFIG_64BIT
@@ -360,6 +373,8 @@
facilities = stfl();
if (facilities & (1 << 28))
machine_flags |= MACHINE_FLAG_IDTE;
+ if (facilities & (1 << 23))
+ machine_flags |= MACHINE_FLAG_PFMF;
if (facilities & (1 << 4))
machine_flags |= MACHINE_FLAG_MVCOS;
#endif
@@ -388,6 +403,7 @@
detect_diag9c();
detect_diag44();
detect_machine_facilities();
+ setup_hpage();
sclp_read_info_early();
sclp_facilities_detect();
memsize = sclp_memory_detect();