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75b5b5e0a2
The Fixed Page Size TLB (FTLB) is a set-associative dual entry TLB. Its purpose is to reduce the number of TLB misses by increasing the effective TLB size and keep the implementation complexity to minimum levels. A supported core can have both VTLB and FTLB. Reviewed-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Signed-off-by: John Crispin <blogic@openwrt.org> Patchwork: http://patchwork.linux-mips.org/patch/6139/
468 lines
10 KiB
C
468 lines
10 KiB
C
/*
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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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* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
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* Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
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* Carsten Langgaard, carstenl@mips.com
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* Copyright (C) 2002 MIPS Technologies, Inc. All rights reserved.
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*/
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/module.h>
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#include <asm/cpu.h>
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#include <asm/cpu-type.h>
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#include <asm/bootinfo.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/tlb.h>
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#include <asm/tlbmisc.h>
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extern void build_tlb_refill_handler(void);
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/* Atomicity and interruptability */
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#ifdef CONFIG_MIPS_MT_SMTC
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#include <asm/smtc.h>
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#include <asm/mipsmtregs.h>
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#define ENTER_CRITICAL(flags) \
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{ \
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unsigned int mvpflags; \
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local_irq_save(flags);\
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mvpflags = dvpe()
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#define EXIT_CRITICAL(flags) \
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evpe(mvpflags); \
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local_irq_restore(flags); \
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}
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#else
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#define ENTER_CRITICAL(flags) local_irq_save(flags)
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#define EXIT_CRITICAL(flags) local_irq_restore(flags)
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#endif /* CONFIG_MIPS_MT_SMTC */
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/*
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* LOONGSON2 has a 4 entry itlb which is a subset of dtlb,
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* unfortrunately, itlb is not totally transparent to software.
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*/
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static inline void flush_itlb(void)
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{
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switch (current_cpu_type()) {
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case CPU_LOONGSON2:
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write_c0_diag(4);
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break;
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default:
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break;
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}
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}
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static inline void flush_itlb_vm(struct vm_area_struct *vma)
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{
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if (vma->vm_flags & VM_EXEC)
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flush_itlb();
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}
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void local_flush_tlb_all(void)
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{
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unsigned long flags;
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unsigned long old_ctx;
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int entry, ftlbhighset;
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ENTER_CRITICAL(flags);
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/* Save old context and create impossible VPN2 value */
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old_ctx = read_c0_entryhi();
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write_c0_entrylo0(0);
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write_c0_entrylo1(0);
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entry = read_c0_wired();
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/* Blast 'em all away. */
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if (cpu_has_tlbinv) {
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if (current_cpu_data.tlbsizevtlb) {
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write_c0_index(0);
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mtc0_tlbw_hazard();
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tlbinvf(); /* invalidate VTLB */
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}
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ftlbhighset = current_cpu_data.tlbsizevtlb +
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current_cpu_data.tlbsizeftlbsets;
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for (entry = current_cpu_data.tlbsizevtlb;
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entry < ftlbhighset;
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entry++) {
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write_c0_index(entry);
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mtc0_tlbw_hazard();
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tlbinvf(); /* invalidate one FTLB set */
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}
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} else {
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while (entry < current_cpu_data.tlbsize) {
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/* Make sure all entries differ. */
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write_c0_entryhi(UNIQUE_ENTRYHI(entry));
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write_c0_index(entry);
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mtc0_tlbw_hazard();
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tlb_write_indexed();
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entry++;
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}
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}
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tlbw_use_hazard();
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write_c0_entryhi(old_ctx);
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flush_itlb();
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EXIT_CRITICAL(flags);
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}
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EXPORT_SYMBOL(local_flush_tlb_all);
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/* All entries common to a mm share an asid. To effectively flush
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these entries, we just bump the asid. */
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void local_flush_tlb_mm(struct mm_struct *mm)
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{
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int cpu;
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preempt_disable();
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cpu = smp_processor_id();
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if (cpu_context(cpu, mm) != 0) {
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drop_mmu_context(mm, cpu);
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}
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preempt_enable();
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}
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void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
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unsigned long end)
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{
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struct mm_struct *mm = vma->vm_mm;
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int cpu = smp_processor_id();
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if (cpu_context(cpu, mm) != 0) {
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unsigned long size, flags;
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ENTER_CRITICAL(flags);
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start = round_down(start, PAGE_SIZE << 1);
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end = round_up(end, PAGE_SIZE << 1);
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size = (end - start) >> (PAGE_SHIFT + 1);
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if (size <= (current_cpu_data.tlbsizeftlbsets ?
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current_cpu_data.tlbsize / 8 :
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current_cpu_data.tlbsize / 2)) {
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int oldpid = read_c0_entryhi();
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int newpid = cpu_asid(cpu, mm);
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while (start < end) {
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int idx;
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write_c0_entryhi(start | newpid);
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start += (PAGE_SIZE << 1);
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mtc0_tlbw_hazard();
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tlb_probe();
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tlb_probe_hazard();
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idx = read_c0_index();
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write_c0_entrylo0(0);
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write_c0_entrylo1(0);
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if (idx < 0)
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continue;
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/* Make sure all entries differ. */
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write_c0_entryhi(UNIQUE_ENTRYHI(idx));
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mtc0_tlbw_hazard();
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tlb_write_indexed();
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}
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tlbw_use_hazard();
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write_c0_entryhi(oldpid);
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} else {
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drop_mmu_context(mm, cpu);
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}
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flush_itlb();
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EXIT_CRITICAL(flags);
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}
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}
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void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
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{
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unsigned long size, flags;
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ENTER_CRITICAL(flags);
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size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
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size = (size + 1) >> 1;
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if (size <= (current_cpu_data.tlbsizeftlbsets ?
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current_cpu_data.tlbsize / 8 :
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current_cpu_data.tlbsize / 2)) {
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int pid = read_c0_entryhi();
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start &= (PAGE_MASK << 1);
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end += ((PAGE_SIZE << 1) - 1);
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end &= (PAGE_MASK << 1);
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while (start < end) {
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int idx;
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write_c0_entryhi(start);
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start += (PAGE_SIZE << 1);
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mtc0_tlbw_hazard();
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tlb_probe();
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tlb_probe_hazard();
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idx = read_c0_index();
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write_c0_entrylo0(0);
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write_c0_entrylo1(0);
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if (idx < 0)
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continue;
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/* Make sure all entries differ. */
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write_c0_entryhi(UNIQUE_ENTRYHI(idx));
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mtc0_tlbw_hazard();
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tlb_write_indexed();
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}
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tlbw_use_hazard();
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write_c0_entryhi(pid);
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} else {
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local_flush_tlb_all();
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}
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flush_itlb();
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EXIT_CRITICAL(flags);
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}
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void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
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{
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int cpu = smp_processor_id();
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if (cpu_context(cpu, vma->vm_mm) != 0) {
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unsigned long flags;
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int oldpid, newpid, idx;
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newpid = cpu_asid(cpu, vma->vm_mm);
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page &= (PAGE_MASK << 1);
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ENTER_CRITICAL(flags);
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oldpid = read_c0_entryhi();
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write_c0_entryhi(page | newpid);
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mtc0_tlbw_hazard();
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tlb_probe();
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tlb_probe_hazard();
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idx = read_c0_index();
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write_c0_entrylo0(0);
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write_c0_entrylo1(0);
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if (idx < 0)
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goto finish;
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/* Make sure all entries differ. */
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write_c0_entryhi(UNIQUE_ENTRYHI(idx));
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mtc0_tlbw_hazard();
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tlb_write_indexed();
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tlbw_use_hazard();
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finish:
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write_c0_entryhi(oldpid);
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flush_itlb_vm(vma);
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EXIT_CRITICAL(flags);
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}
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}
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/*
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* This one is only used for pages with the global bit set so we don't care
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* much about the ASID.
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*/
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void local_flush_tlb_one(unsigned long page)
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{
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unsigned long flags;
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int oldpid, idx;
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ENTER_CRITICAL(flags);
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oldpid = read_c0_entryhi();
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page &= (PAGE_MASK << 1);
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write_c0_entryhi(page);
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mtc0_tlbw_hazard();
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tlb_probe();
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tlb_probe_hazard();
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idx = read_c0_index();
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write_c0_entrylo0(0);
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write_c0_entrylo1(0);
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if (idx >= 0) {
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/* Make sure all entries differ. */
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write_c0_entryhi(UNIQUE_ENTRYHI(idx));
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mtc0_tlbw_hazard();
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tlb_write_indexed();
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tlbw_use_hazard();
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}
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write_c0_entryhi(oldpid);
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flush_itlb();
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EXIT_CRITICAL(flags);
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}
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/*
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* We will need multiple versions of update_mmu_cache(), one that just
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* updates the TLB with the new pte(s), and another which also checks
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* for the R4k "end of page" hardware bug and does the needy.
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*/
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void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
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{
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unsigned long flags;
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep;
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int idx, pid;
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/*
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* Handle debugger faulting in for debugee.
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*/
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if (current->active_mm != vma->vm_mm)
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return;
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ENTER_CRITICAL(flags);
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pid = read_c0_entryhi() & ASID_MASK;
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address &= (PAGE_MASK << 1);
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write_c0_entryhi(address | pid);
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pgdp = pgd_offset(vma->vm_mm, address);
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mtc0_tlbw_hazard();
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tlb_probe();
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tlb_probe_hazard();
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pudp = pud_offset(pgdp, address);
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pmdp = pmd_offset(pudp, address);
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idx = read_c0_index();
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#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
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/* this could be a huge page */
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if (pmd_huge(*pmdp)) {
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unsigned long lo;
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write_c0_pagemask(PM_HUGE_MASK);
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ptep = (pte_t *)pmdp;
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lo = pte_to_entrylo(pte_val(*ptep));
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write_c0_entrylo0(lo);
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write_c0_entrylo1(lo + (HPAGE_SIZE >> 7));
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mtc0_tlbw_hazard();
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if (idx < 0)
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tlb_write_random();
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else
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tlb_write_indexed();
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tlbw_use_hazard();
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write_c0_pagemask(PM_DEFAULT_MASK);
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} else
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#endif
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{
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ptep = pte_offset_map(pmdp, address);
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#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
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write_c0_entrylo0(ptep->pte_high);
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ptep++;
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write_c0_entrylo1(ptep->pte_high);
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#else
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write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
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write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
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#endif
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mtc0_tlbw_hazard();
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if (idx < 0)
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tlb_write_random();
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else
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tlb_write_indexed();
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}
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tlbw_use_hazard();
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flush_itlb_vm(vma);
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EXIT_CRITICAL(flags);
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}
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void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
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unsigned long entryhi, unsigned long pagemask)
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{
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unsigned long flags;
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unsigned long wired;
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unsigned long old_pagemask;
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unsigned long old_ctx;
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ENTER_CRITICAL(flags);
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/* Save old context and create impossible VPN2 value */
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old_ctx = read_c0_entryhi();
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old_pagemask = read_c0_pagemask();
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wired = read_c0_wired();
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write_c0_wired(wired + 1);
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write_c0_index(wired);
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tlbw_use_hazard(); /* What is the hazard here? */
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write_c0_pagemask(pagemask);
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write_c0_entryhi(entryhi);
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write_c0_entrylo0(entrylo0);
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write_c0_entrylo1(entrylo1);
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mtc0_tlbw_hazard();
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tlb_write_indexed();
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tlbw_use_hazard();
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write_c0_entryhi(old_ctx);
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tlbw_use_hazard(); /* What is the hazard here? */
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write_c0_pagemask(old_pagemask);
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local_flush_tlb_all();
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EXIT_CRITICAL(flags);
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}
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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int __init has_transparent_hugepage(void)
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{
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unsigned int mask;
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unsigned long flags;
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ENTER_CRITICAL(flags);
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write_c0_pagemask(PM_HUGE_MASK);
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back_to_back_c0_hazard();
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mask = read_c0_pagemask();
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write_c0_pagemask(PM_DEFAULT_MASK);
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EXIT_CRITICAL(flags);
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return mask == PM_HUGE_MASK;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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static int ntlb;
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static int __init set_ntlb(char *str)
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{
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get_option(&str, &ntlb);
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return 1;
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}
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__setup("ntlb=", set_ntlb);
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void tlb_init(void)
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{
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/*
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* You should never change this register:
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* - On R4600 1.7 the tlbp never hits for pages smaller than
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* the value in the c0_pagemask register.
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* - The entire mm handling assumes the c0_pagemask register to
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* be set to fixed-size pages.
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*/
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write_c0_pagemask(PM_DEFAULT_MASK);
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write_c0_wired(0);
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if (current_cpu_type() == CPU_R10000 ||
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current_cpu_type() == CPU_R12000 ||
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current_cpu_type() == CPU_R14000)
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write_c0_framemask(0);
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if (cpu_has_rixi) {
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/*
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* Enable the no read, no exec bits, and enable large virtual
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* address.
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*/
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u32 pg = PG_RIE | PG_XIE;
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#ifdef CONFIG_64BIT
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pg |= PG_ELPA;
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#endif
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write_c0_pagegrain(pg);
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}
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/* From this point on the ARC firmware is dead. */
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local_flush_tlb_all();
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/* Did I tell you that ARC SUCKS? */
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if (ntlb) {
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if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
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int wired = current_cpu_data.tlbsize - ntlb;
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write_c0_wired(wired);
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write_c0_index(wired-1);
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printk("Restricting TLB to %d entries\n", ntlb);
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} else
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printk("Ignoring invalid argument ntlb=%d\n", ntlb);
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}
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build_tlb_refill_handler();
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}
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