185 lines
4.6 KiB
C
185 lines
4.6 KiB
C
/*
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* arch/sh/mm/tlb-sh5.c
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*
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* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
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* Copyright (C) 2003 Richard Curnow <richard.curnow@superh.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <asm/page.h>
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#include <asm/tlb.h>
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#include <asm/mmu_context.h>
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/**
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* sh64_tlb_init - Perform initial setup for the DTLB and ITLB.
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*/
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int __init sh64_tlb_init(void)
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{
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/* Assign some sane DTLB defaults */
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cpu_data->dtlb.entries = 64;
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cpu_data->dtlb.step = 0x10;
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cpu_data->dtlb.first = DTLB_FIXED | cpu_data->dtlb.step;
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cpu_data->dtlb.next = cpu_data->dtlb.first;
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cpu_data->dtlb.last = DTLB_FIXED |
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((cpu_data->dtlb.entries - 1) *
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cpu_data->dtlb.step);
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/* And again for the ITLB */
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cpu_data->itlb.entries = 64;
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cpu_data->itlb.step = 0x10;
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cpu_data->itlb.first = ITLB_FIXED | cpu_data->itlb.step;
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cpu_data->itlb.next = cpu_data->itlb.first;
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cpu_data->itlb.last = ITLB_FIXED |
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((cpu_data->itlb.entries - 1) *
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cpu_data->itlb.step);
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return 0;
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}
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/**
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* sh64_next_free_dtlb_entry - Find the next available DTLB entry
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*/
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unsigned long long sh64_next_free_dtlb_entry(void)
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{
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return cpu_data->dtlb.next;
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}
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/**
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* sh64_get_wired_dtlb_entry - Allocate a wired (locked-in) entry in the DTLB
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*/
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unsigned long long sh64_get_wired_dtlb_entry(void)
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{
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unsigned long long entry = sh64_next_free_dtlb_entry();
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cpu_data->dtlb.first += cpu_data->dtlb.step;
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cpu_data->dtlb.next += cpu_data->dtlb.step;
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return entry;
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}
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/**
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* sh64_put_wired_dtlb_entry - Free a wired (locked-in) entry in the DTLB.
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*
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* @entry: Address of TLB slot.
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*
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* Works like a stack, last one to allocate must be first one to free.
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*/
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int sh64_put_wired_dtlb_entry(unsigned long long entry)
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{
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__flush_tlb_slot(entry);
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/*
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* We don't do any particularly useful tracking of wired entries,
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* so this approach works like a stack .. last one to be allocated
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* has to be the first one to be freed.
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*
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* We could potentially load wired entries into a list and work on
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* rebalancing the list periodically (which also entails moving the
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* contents of a TLB entry) .. though I have a feeling that this is
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* more trouble than it's worth.
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*/
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/*
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* Entry must be valid .. we don't want any ITLB addresses!
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*/
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if (entry <= DTLB_FIXED)
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return -EINVAL;
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/*
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* Next, check if we're within range to be freed. (ie, must be the
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* entry beneath the first 'free' entry!
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*/
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if (entry < (cpu_data->dtlb.first - cpu_data->dtlb.step))
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return -EINVAL;
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/* If we are, then bring this entry back into the list */
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cpu_data->dtlb.first -= cpu_data->dtlb.step;
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cpu_data->dtlb.next = entry;
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return 0;
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}
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/**
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* sh64_setup_tlb_slot - Load up a translation in a wired slot.
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*
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* @config_addr: Address of TLB slot.
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* @eaddr: Virtual address.
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* @asid: Address Space Identifier.
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* @paddr: Physical address.
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*
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* Load up a virtual<->physical translation for @eaddr<->@paddr in the
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* pre-allocated TLB slot @config_addr (see sh64_get_wired_dtlb_entry).
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*/
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void sh64_setup_tlb_slot(unsigned long long config_addr, unsigned long eaddr,
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unsigned long asid, unsigned long paddr)
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{
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unsigned long long pteh, ptel;
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pteh = neff_sign_extend(eaddr);
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pteh &= PAGE_MASK;
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pteh |= (asid << PTEH_ASID_SHIFT) | PTEH_VALID;
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ptel = neff_sign_extend(paddr);
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ptel &= PAGE_MASK;
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ptel |= (_PAGE_CACHABLE | _PAGE_READ | _PAGE_WRITE);
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asm volatile("putcfg %0, 1, %1\n\t"
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"putcfg %0, 0, %2\n"
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: : "r" (config_addr), "r" (ptel), "r" (pteh));
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}
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/**
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* sh64_teardown_tlb_slot - Teardown a translation.
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*
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* @config_addr: Address of TLB slot.
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*
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* Teardown any existing mapping in the TLB slot @config_addr.
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*/
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void sh64_teardown_tlb_slot(unsigned long long config_addr)
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__attribute__ ((alias("__flush_tlb_slot")));
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static int dtlb_entry;
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static unsigned long long dtlb_entries[64];
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void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
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{
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unsigned long long entry;
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unsigned long paddr, flags;
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BUG_ON(dtlb_entry == ARRAY_SIZE(dtlb_entries));
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local_irq_save(flags);
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entry = sh64_get_wired_dtlb_entry();
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dtlb_entries[dtlb_entry++] = entry;
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paddr = pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK;
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paddr &= ~PAGE_MASK;
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sh64_setup_tlb_slot(entry, addr, get_asid(), paddr);
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local_irq_restore(flags);
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}
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void tlb_unwire_entry(void)
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{
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unsigned long long entry;
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unsigned long flags;
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BUG_ON(!dtlb_entry);
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local_irq_save(flags);
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entry = dtlb_entries[dtlb_entry--];
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sh64_teardown_tlb_slot(entry);
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sh64_put_wired_dtlb_entry(entry);
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local_irq_restore(flags);
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}
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