tlbflush.h

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#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 CONFIG_64BIT
    if (!MACHINE_HAS_CSP) {
        smp_ptlb_all();
        return;
    }
#endif /* CONFIG_64BIT */

    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()
#define __tlb_flush_global()    __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)
{
    if (mm->context.flush_mm) {
        __tlb_flush_mm(mm);
        mm->context.flush_mm = 0;
    }
}

/*
 * 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 */