include/asm-x86/mach-xen/asm/mmu_context_32.h

   1 #ifndef __I386_SCHED_H
   2 #define __I386_SCHED_H
   3
   4 #include <asm/desc.h>
   5 #include <asm/atomic.h>
   6 #include <asm/pgalloc.h>
   7 #include <asm/tlbflush.h>
   8
   9 void arch_exit_mmap(struct mm_struct *mm);
  10 void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm);
  11
  12 void mm_pin(struct mm_struct *mm);
  13 void mm_unpin(struct mm_struct *mm);
  14 void mm_pin_all(void);
  15
  16 static inline void xen_activate_mm(struct mm_struct *prev,
  17                                    struct mm_struct *next)
  18 {
  19         if (!test_bit(PG_pinned, &virt_to_page(next->pgd)->flags))
  20                 mm_pin(next);
  21 }
  22
  23 /*
  24  * Used for LDT copy/destruction.
  25  */
  26 int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  27 void destroy_context(struct mm_struct *mm);
  28
  29
  30 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
  31 {
  32 #if 0 /* XEN: no lazy tlb */
  33         unsigned cpu = smp_processor_id();
  34         if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
  35                 per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_LAZY;
  36 #endif
  37 }
  38
  39 #define prepare_arch_switch(next)       __prepare_arch_switch()
  40
  41 static inline void __prepare_arch_switch(void)
  42 {
  43         /*
  44          * Save away %gs. No need to save %fs, as it was saved on the
  45          * stack on entry.  No need to save %es and %ds, as those are
  46          * always kernel segments while inside the kernel.
  47          */
  48         asm volatile ( "mov %%gs,%0"
  49                 : "=m" (current->thread.gs));
  50         asm volatile ( "movl %0,%%gs"
  51                 : : "r" (0) );
  52 }
  53
  54 void leave_mm(unsigned long cpu);
  55
  56 static inline void switch_mm(struct mm_struct *prev,
  57                              struct mm_struct *next,
  58                              struct task_struct *tsk)
  59 {
  60         int cpu = smp_processor_id();
  61         struct mmuext_op _op[2], *op = _op;
  62
  63         if (likely(prev != next)) {
  64                 BUG_ON(!xen_feature(XENFEAT_writable_page_tables) &&
  65                        !test_bit(PG_pinned, &virt_to_page(next->pgd)->flags));
  66
  67                 /* stop flush ipis for the previous mm */
  68                 cpu_clear(cpu, prev->cpu_vm_mask);
  69 #if 0 /* XEN: no lazy tlb */
  70                 per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
  71                 per_cpu(cpu_tlbstate, cpu).active_mm = next;
  72 #endif
  73                 cpu_set(cpu, next->cpu_vm_mask);
  74
  75                 /* Re-load page tables: load_cr3(next->pgd) */
  76                 op->cmd = MMUEXT_NEW_BASEPTR;
  77                 op->arg1.mfn = pfn_to_mfn(__pa(next->pgd) >> PAGE_SHIFT);
  78                 op++;
  79
  80                 /*
  81                  * load the LDT, if the LDT is different:
  82                  */
  83                 if (unlikely(prev->context.ldt != next->context.ldt)) {
  84                         /* load_LDT_nolock(&next->context, cpu) */
  85                         op->cmd = MMUEXT_SET_LDT;
  86                         op->arg1.linear_addr = (unsigned long)next->context.ldt;
  87                         op->arg2.nr_ents     = next->context.size;
  88                         op++;
  89                 }
  90
  91                 BUG_ON(HYPERVISOR_mmuext_op(_op, op-_op, NULL, DOMID_SELF));
  92         }
  93 #if 0 /* XEN: no lazy tlb */
  94         else {
  95                 per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
  96                 BUG_ON(per_cpu(cpu_tlbstate, cpu).active_mm != next);
  97
  98                 if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
  99                         /* We were in lazy tlb mode and leave_mm disabled
 100                          * tlb flush IPI delivery. We must reload %cr3.
 101                          */
 102                         load_cr3(next->pgd);
 103                         load_LDT_nolock(&next->context);
 104                 }
 105         }
 106 #endif
 107 }
 108
 109 #define deactivate_mm(tsk, mm)                  \
 110         asm("movl %0,%%gs": :"r" (0));
 111
 112 #define activate_mm(prev, next)                         \
 113         do {                                            \
 114                 xen_activate_mm(prev, next);            \
 115                 switch_mm((prev),(next),NULL);          \
 116         } while(0)
 117
 118 #endif