diff options
author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-02-09 18:24:37 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-02-09 18:24:41 +0100 |
commit | 6252d702c5311ce916caf75ed82e5c8245171c92 (patch) | |
tree | 3490f27b5f888ff2c1ec915d4e7201000f37a771 /arch/s390/mm/fault.c | |
parent | 5a216a20837c5f5fa1ca4b8ae8991ffd96b08e6f (diff) |
[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 <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/fault.c')
-rw-r--r-- | arch/s390/mm/fault.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 2456b52ed068..ed13d429a487 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -32,6 +32,7 @@ #include <asm/system.h> #include <asm/pgtable.h> #include <asm/s390_ext.h> +#include <asm/mmu_context.h> #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. |