hugetlbpage-book3e.c

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/*
 * PPC Huge TLB Page Support for Book3E MMU
 *
 * Copyright (C) 2009 David Gibson, IBM Corporation.
 * Copyright (C) 2011 Becky Bruce, Freescale Semiconductor
 *
 */
#include <linux/mm.h>
#include <linux/hugetlb.h>

static inline int mmu_get_tsize(int psize)
{
    return mmu_psize_defs[psize].enc;
}

static inline int book3e_tlb_exists(unsigned long ea, unsigned long pid)
{
    int found = 0;

    mtspr(SPRN_MAS6, pid << 16);
    if (mmu_has_feature(MMU_FTR_USE_TLBRSRV)) {
        asm volatile(
            "li %0,0\n"
            "tlbsx. 0,%1\n"
            "bne    1f\n"
            "li %0,1\n"
            "1:\n"
            : "=&r"(found) : "r"(ea));
    } else {
        asm volatile(
            "tlbsx  0,%1\n"
            "mfspr  %0,0x271\n"
            "srwi   %0,%0,31\n"
            : "=&r"(found) : "r"(ea));
    }

    return found;
}

void book3e_hugetlb_preload(struct vm_area_struct *vma, unsigned long ea,
                pte_t pte)
{
    unsigned long mas1, mas2;
    u64 mas7_3;
    unsigned long psize, tsize, shift;
    unsigned long flags;
    struct mm_struct *mm;

#ifdef CONFIG_PPC_FSL_BOOK3E
    int index, ncams;
#endif

    if (unlikely(is_kernel_addr(ea)))
        return;

    mm = vma->vm_mm;

#ifdef CONFIG_PPC_MM_SLICES
    psize = get_slice_psize(mm, ea);
    tsize = mmu_get_tsize(psize);
    shift = mmu_psize_defs[psize].shift;
#else
    psize = vma_mmu_pagesize(vma);
    shift = __ilog2(psize);
    tsize = shift - 10;
#endif

    /*
     * We can't be interrupted while we're setting up the MAS
     * regusters or after we've confirmed that no tlb exists.
     */
    local_irq_save(flags);

    if (unlikely(book3e_tlb_exists(ea, mm->context.id))) {
        local_irq_restore(flags);
        return;
    }

#ifdef CONFIG_PPC_FSL_BOOK3E
    ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;

    /* We have to use the CAM(TLB1) on FSL parts for hugepages */
    index = __get_cpu_var(next_tlbcam_idx);
    mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));

    /* Just round-robin the entries and wrap when we hit the end */
    if (unlikely(index == ncams - 1))
        __get_cpu_var(next_tlbcam_idx) = tlbcam_index;
    else
        __get_cpu_var(next_tlbcam_idx)++;
#endif
    mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
    mas2 = ea & ~((1UL << shift) - 1);
    mas2 |= (pte_val(pte) >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
    mas7_3 = (u64)pte_pfn(pte) << PAGE_SHIFT;
    mas7_3 |= (pte_val(pte) >> PTE_BAP_SHIFT) & MAS3_BAP_MASK;
    if (!pte_dirty(pte))
        mas7_3 &= ~(MAS3_SW|MAS3_UW);

    mtspr(SPRN_MAS1, mas1);
    mtspr(SPRN_MAS2, mas2);

    if (mmu_has_feature(MMU_FTR_USE_PAIRED_MAS)) {
        mtspr(SPRN_MAS7_MAS3, mas7_3);
    } else {
        mtspr(SPRN_MAS7, upper_32_bits(mas7_3));
        mtspr(SPRN_MAS3, lower_32_bits(mas7_3));
    }

    asm volatile ("tlbwe");

    local_irq_restore(flags);
}

void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
    struct hstate *hstate = hstate_file(vma->vm_file);
    unsigned long tsize = huge_page_shift(hstate) - 10;

    __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, tsize, 0);

}