tlb-pteaex.c

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/*
 * arch/sh/mm/tlb-pteaex.c
 *
 * TLB operations for SH-X3 CPUs featuring PTE ASID Extensions.
 *
 * Copyright (C) 2009 Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>

void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
{
    unsigned long flags, pteval, vpn;

    /*
     * Handle debugger faulting in for debugee.
     */
    if (vma && current->active_mm != vma->vm_mm)
        return;

    local_irq_save(flags);

    /* Set PTEH register */
    vpn = address & MMU_VPN_MASK;
    __raw_writel(vpn, MMU_PTEH);

    /* Set PTEAEX */
    __raw_writel(get_asid(), MMU_PTEAEX);

    pteval = pte.pte_low;

    /* Set PTEA register */
#ifdef CONFIG_X2TLB
    /*
     * For the extended mode TLB this is trivial, only the ESZ and
     * EPR bits need to be written out to PTEA, with the remainder of
     * the protection bits (with the exception of the compat-mode SZ
     * and PR bits, which are cleared) being written out in PTEL.
     */
    __raw_writel(pte.pte_high, MMU_PTEA);
#endif

    /* Set PTEL register */
    pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
#ifdef CONFIG_CACHE_WRITETHROUGH
    pteval |= _PAGE_WT;
#endif
    /* conveniently, we want all the software flags to be 0 anyway */
    __raw_writel(pteval, MMU_PTEL);

    /* Load the TLB */
    asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
    local_irq_restore(flags);
}

/*
 * While SH-X2 extended TLB mode splits out the memory-mapped I/UTLB
 * data arrays, SH-X3 cores with PTEAEX split out the memory-mapped
 * address arrays. In compat mode the second array is inaccessible, while
 * in extended mode, the legacy 8-bit ASID field in address array 1 has
 * undefined behaviour.
 */
void local_flush_tlb_one(unsigned long asid, unsigned long page)
{
    jump_to_uncached();
    __raw_writel(page, MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT);
    __raw_writel(asid, MMU_UTLB_ADDRESS_ARRAY2 | MMU_PAGE_ASSOC_BIT);
    __raw_writel(page, MMU_ITLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT);
    __raw_writel(asid, MMU_ITLB_ADDRESS_ARRAY2 | MMU_PAGE_ASSOC_BIT);
    back_to_cached();
}

void local_flush_tlb_all(void)
{
    unsigned long flags, status;
    int i;

    /*
     * Flush all the TLB.
     */
    local_irq_save(flags);
    jump_to_uncached();

    status = __raw_readl(MMUCR);
    status = ((status & MMUCR_URB) >> MMUCR_URB_SHIFT);

    if (status == 0)
        status = MMUCR_URB_NENTRIES;

    for (i = 0; i < status; i++)
        __raw_writel(0x0, MMU_UTLB_ADDRESS_ARRAY | (i << 8));

    for (i = 0; i < 4; i++)
        __raw_writel(0x0, MMU_ITLB_ADDRESS_ARRAY | (i << 8));

    back_to_cached();
    ctrl_barrier();
    local_irq_restore(flags);
}