[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/mm/vmem.c b/arch/s390/mm/vmem.c
index 3ffc021..97bce6c 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -10,10 +10,12 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/list.h>
+#include <linux/hugetlb.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/tlbflush.h>
+#include <asm/sections.h>
static DEFINE_MUTEX(vmem_mutex);
@@ -113,7 +115,7 @@
/*
* Add a physical memory range to the 1:1 mapping.
*/
-static int vmem_add_range(unsigned long start, unsigned long size)
+static int vmem_add_range(unsigned long start, unsigned long size, int ro)
{
unsigned long address;
pgd_t *pg_dir;
@@ -140,7 +142,19 @@
pud_populate_kernel(&init_mm, pu_dir, pm_dir);
}
+ pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
pm_dir = pmd_offset(pu_dir, address);
+
+#ifdef __s390x__
+ if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
+ (address + HPAGE_SIZE <= start + size) &&
+ (address >= HPAGE_SIZE)) {
+ pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
+ pmd_val(*pm_dir) = pte_val(pte);
+ address += HPAGE_SIZE - PAGE_SIZE;
+ continue;
+ }
+#endif
if (pmd_none(*pm_dir)) {
pt_dir = vmem_pte_alloc();
if (!pt_dir)
@@ -149,7 +163,6 @@
}
pt_dir = pte_offset_kernel(pm_dir, address);
- pte = pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL);
*pt_dir = pte;
}
ret = 0;
@@ -180,6 +193,13 @@
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir))
continue;
+
+ if (pmd_huge(*pm_dir)) {
+ pmd_clear_kernel(pm_dir);
+ address += HPAGE_SIZE - PAGE_SIZE;
+ continue;
+ }
+
pt_dir = pte_offset_kernel(pm_dir, address);
*pt_dir = pte;
}
@@ -248,14 +268,14 @@
return ret;
}
-static int vmem_add_mem(unsigned long start, unsigned long size)
+static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
{
int ret;
ret = vmem_add_mem_map(start, size);
if (ret)
return ret;
- return vmem_add_range(start, size);
+ return vmem_add_range(start, size, ro);
}
/*
@@ -338,7 +358,7 @@
if (ret)
goto out_free;
- ret = vmem_add_mem(start, size);
+ ret = vmem_add_mem(start, size, 0);
if (ret)
goto out_remove;
@@ -374,14 +394,35 @@
*/
void __init vmem_map_init(void)
{
+ unsigned long ro_start, ro_end;
+ unsigned long start, end;
int i;
INIT_LIST_HEAD(&init_mm.context.crst_list);
INIT_LIST_HEAD(&init_mm.context.pgtable_list);
init_mm.context.noexec = 0;
NODE_DATA(0)->node_mem_map = VMEM_MAP;
- for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++)
- vmem_add_mem(memory_chunk[i].addr, memory_chunk[i].size);
+ ro_start = ((unsigned long)&_stext) & PAGE_MASK;
+ ro_end = PFN_ALIGN((unsigned long)&_eshared);
+ for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+ start = memory_chunk[i].addr;
+ end = memory_chunk[i].addr + memory_chunk[i].size;
+ if (start >= ro_end || end <= ro_start)
+ vmem_add_mem(start, end - start, 0);
+ else if (start >= ro_start && end <= ro_end)
+ vmem_add_mem(start, end - start, 1);
+ else if (start >= ro_start) {
+ vmem_add_mem(start, ro_end - start, 1);
+ vmem_add_mem(ro_end, end - ro_end, 0);
+ } else if (end < ro_end) {
+ vmem_add_mem(start, ro_start - start, 0);
+ vmem_add_mem(ro_start, end - ro_start, 1);
+ } else {
+ vmem_add_mem(start, ro_start - start, 0);
+ vmem_add_mem(ro_start, ro_end - ro_start, 1);
+ vmem_add_mem(ro_end, end - ro_end, 0);
+ }
+ }
}
/*