From 53492b1de46a7576170e865062ffcfc93bb5650b Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Wed, 30 Apr 2008 13:38:46 +0200 Subject: [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 Signed-off-by: Martin Schwidefsky --- arch/s390/mm/vmem.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 48 insertions(+), 7 deletions(-) (limited to 'arch/s390/mm/vmem.c') diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index 3ffc0211dc85..97bce6c97574 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -10,10 +10,12 @@ #include #include #include +#include #include #include #include #include +#include static DEFINE_MUTEX(vmem_mutex); @@ -113,7 +115,7 @@ static pte_t __init_refok *vmem_pte_alloc(void) /* * 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 @@ static int vmem_add_range(unsigned long start, unsigned long size) 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 @@ static int vmem_add_range(unsigned long start, unsigned long size) } 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 @@ static void vmem_remove_range(unsigned long start, unsigned long size) 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 @@ out: 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 @@ int add_shared_memory(unsigned long start, unsigned long size) 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 @@ out: */ 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); + } + } } /* -- cgit v1.2.3