1
linux/arch/s390/include/asm/tlbflush.h
Martin Schwidefsky e5992f2e6c [S390] kvm guest address space mapping
Add code that allows KVM to control the virtual memory layout that
is seen by a guest. The guest address space uses a second page table
that shares the last level pte-tables with the process page table.
If a page is unmapped from the process page table it is automatically
unmapped from the guest page table as well.

The guest address space mapping starts out empty, KVM can map any
individual 1MB segments from the process virtual memory to any 1MB
aligned location in the guest virtual memory. If a target segment in
the process virtual memory does not exist or is unmapped while a
guest mapping exists the desired target address is stored as an
invalid segment table entry in the guest page table.
The population of the guest page table is fault driven.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 10:48:21 +02:00

140 lines
3.3 KiB
C

#ifndef _S390_TLBFLUSH_H
#define _S390_TLBFLUSH_H
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/processor.h>
#include <asm/pgalloc.h>
/*
* Flush all tlb entries on the local cpu.
*/
static inline void __tlb_flush_local(void)
{
asm volatile("ptlb" : : : "memory");
}
#ifdef CONFIG_SMP
/*
* Flush all tlb entries on all cpus.
*/
void smp_ptlb_all(void);
static inline void __tlb_flush_global(void)
{
register unsigned long reg2 asm("2");
register unsigned long reg3 asm("3");
register unsigned long reg4 asm("4");
long dummy;
#ifndef __s390x__
if (!MACHINE_HAS_CSP) {
smp_ptlb_all();
return;
}
#endif /* __s390x__ */
dummy = 0;
reg2 = reg3 = 0;
reg4 = ((unsigned long) &dummy) + 1;
asm volatile(
" csp %0,%2"
: : "d" (reg2), "d" (reg3), "d" (reg4), "m" (dummy) : "cc" );
}
static inline void __tlb_flush_full(struct mm_struct *mm)
{
cpumask_t local_cpumask;
preempt_disable();
/*
* If the process only ran on the local cpu, do a local flush.
*/
cpumask_copy(&local_cpumask, cpumask_of(smp_processor_id()));
if (cpumask_equal(mm_cpumask(mm), &local_cpumask))
__tlb_flush_local();
else
__tlb_flush_global();
preempt_enable();
}
#else
#define __tlb_flush_full(mm) __tlb_flush_local()
#endif
/*
* Flush all tlb entries of a page table on all cpus.
*/
static inline void __tlb_flush_idte(unsigned long asce)
{
asm volatile(
" .insn rrf,0xb98e0000,0,%0,%1,0"
: : "a" (2048), "a" (asce) : "cc" );
}
static inline void __tlb_flush_mm(struct mm_struct * mm)
{
if (unlikely(cpumask_empty(mm_cpumask(mm))))
return;
/*
* If the machine has IDTE we prefer to do a per mm flush
* on all cpus instead of doing a local flush if the mm
* only ran on the local cpu.
*/
if (MACHINE_HAS_IDTE && list_empty(&mm->context.gmap_list))
__tlb_flush_idte((unsigned long) mm->pgd |
mm->context.asce_bits);
else
__tlb_flush_full(mm);
}
static inline void __tlb_flush_mm_cond(struct mm_struct * mm)
{
spin_lock(&mm->page_table_lock);
if (mm->context.flush_mm) {
__tlb_flush_mm(mm);
mm->context.flush_mm = 0;
}
spin_unlock(&mm->page_table_lock);
}
/*
* TLB flushing:
* flush_tlb() - flushes the current mm struct TLBs
* flush_tlb_all() - flushes all processes TLBs
* flush_tlb_mm(mm) - flushes the specified mm context TLB's
* flush_tlb_page(vma, vmaddr) - flushes one page
* flush_tlb_range(vma, start, end) - flushes a range of pages
* flush_tlb_kernel_range(start, end) - flushes a range of kernel pages
*/
/*
* flush_tlb_mm goes together with ptep_set_wrprotect for the
* copy_page_range operation and flush_tlb_range is related to
* ptep_get_and_clear for change_protection. ptep_set_wrprotect and
* ptep_get_and_clear do not flush the TLBs directly if the mm has
* only one user. At the end of the update the flush_tlb_mm and
* flush_tlb_range functions need to do the flush.
*/
#define flush_tlb() do { } while (0)
#define flush_tlb_all() do { } while (0)
#define flush_tlb_page(vma, addr) do { } while (0)
static inline void flush_tlb_mm(struct mm_struct *mm)
{
__tlb_flush_mm_cond(mm);
}
static inline void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
__tlb_flush_mm_cond(vma->vm_mm);
}
static inline void flush_tlb_kernel_range(unsigned long start,
unsigned long end)
{
__tlb_flush_mm(&init_mm);
}
#endif /* _S390_TLBFLUSH_H */