From 6252d702c5311ce916caf75ed82e5c8245171c92 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Sat, 9 Feb 2008 18:24:37 +0100 Subject: [S390] dynamic page tables. Add support for different number of page table levels dependent on the highest address used for a process. This will cause a 31 bit process to use a two level page table instead of the four level page table that is the default after the pud has been introduced. Likewise a normal 64 bit process will use three levels instead of four. Only if a process runs out of the 4 tera bytes which can be addressed with a three level page table the fourth level is dynamically added. Then the process can use up to 8 peta byte. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/fault.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'arch/s390/mm/fault.c') diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 2456b52..ed13d42 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -32,6 +32,7 @@ #include #include #include +#include #ifndef CONFIG_64BIT #define __FAIL_ADDR_MASK 0x7ffff000 @@ -444,6 +445,45 @@ void __kprobes do_dat_exception(struct pt_regs *regs, unsigned long error_code) do_exception(regs, error_code & 0xff, 0); } +#ifdef CONFIG_64BIT +void __kprobes do_asce_exception(struct pt_regs *regs, unsigned long error_code) +{ + struct mm_struct *mm; + struct vm_area_struct *vma; + unsigned long address; + int space; + + mm = current->mm; + address = S390_lowcore.trans_exc_code & __FAIL_ADDR_MASK; + space = check_space(current); + + if (unlikely(space == 0 || in_atomic() || !mm)) + goto no_context; + + local_irq_enable(); + + down_read(&mm->mmap_sem); + vma = find_vma(mm, address); + up_read(&mm->mmap_sem); + + if (vma) { + update_mm(mm, current); + return; + } + + /* User mode accesses just cause a SIGSEGV */ + if (regs->psw.mask & PSW_MASK_PSTATE) { + current->thread.prot_addr = address; + current->thread.trap_no = error_code; + do_sigsegv(regs, error_code, SEGV_MAPERR, address); + return; + } + +no_context: + do_no_context(regs, error_code, address); +} +#endif + #ifdef CONFIG_PFAULT /* * 'pfault' pseudo page faults routines. -- cgit v1.1