forked from Minki/linux
8eda551420
Provide a new extended page flag, _PAGE_WIRED and an SH4 implementation for wiring TLB entries and use it in the fixmap code path so that we can wire the fixmap TLB entry. Signed-off-by: Matt Fleming <matt@console-pimps.org>
150 lines
3.5 KiB
C
150 lines
3.5 KiB
C
/*
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* arch/sh/mm/tlb-sh4.c
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*
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* SH-4 specific TLB operations
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*
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* Copyright (C) 1999 Niibe Yutaka
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* Copyright (C) 2002 - 2007 Paul Mundt
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*
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* Released under the terms of the GNU GPL v2.0.
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*/
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/io.h>
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#include <asm/system.h>
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#include <asm/mmu_context.h>
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#include <asm/cacheflush.h>
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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, pteval, vpn;
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/*
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* Handle debugger faulting in for debugee.
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*/
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if (vma && current->active_mm != vma->vm_mm)
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return;
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local_irq_save(flags);
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/* Set PTEH register */
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vpn = (address & MMU_VPN_MASK) | get_asid();
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ctrl_outl(vpn, MMU_PTEH);
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pteval = pte.pte_low;
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/* Set PTEA register */
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#ifdef CONFIG_X2TLB
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/*
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* For the extended mode TLB this is trivial, only the ESZ and
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* EPR bits need to be written out to PTEA, with the remainder of
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* the protection bits (with the exception of the compat-mode SZ
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* and PR bits, which are cleared) being written out in PTEL.
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*/
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ctrl_outl(pte.pte_high, MMU_PTEA);
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#else
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if (cpu_data->flags & CPU_HAS_PTEA) {
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/* The last 3 bits and the first one of pteval contains
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* the PTEA timing control and space attribute bits
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*/
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ctrl_outl(copy_ptea_attributes(pteval), MMU_PTEA);
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}
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#endif
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/* Set PTEL register */
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pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
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#ifdef CONFIG_CACHE_WRITETHROUGH
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pteval |= _PAGE_WT;
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#endif
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/* conveniently, we want all the software flags to be 0 anyway */
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ctrl_outl(pteval, MMU_PTEL);
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/* Load the TLB */
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asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
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local_irq_restore(flags);
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}
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void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
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unsigned long page)
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{
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unsigned long addr, data;
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/*
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* NOTE: PTEH.ASID should be set to this MM
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* _AND_ we need to write ASID to the array.
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*
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* It would be simple if we didn't need to set PTEH.ASID...
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*/
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addr = MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT;
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data = page | asid; /* VALID bit is off */
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jump_to_uncached();
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ctrl_outl(data, addr);
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back_to_cached();
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}
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/*
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* Load the entry for 'addr' into the TLB and wire the entry.
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*/
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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 status, flags;
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int urb;
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local_irq_save(flags);
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/* Load the entry into the TLB */
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__update_tlb(vma, addr, pte);
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/* ... and wire it up. */
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status = ctrl_inl(MMUCR);
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urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
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status &= ~MMUCR_URB;
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/*
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* Make sure we're not trying to wire the last TLB entry slot.
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*/
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BUG_ON(!--urb);
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urb = urb % MMUCR_URB_NENTRIES;
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status |= (urb << MMUCR_URB_SHIFT);
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ctrl_outl(status, MMUCR);
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ctrl_barrier();
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local_irq_restore(flags);
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}
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/*
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* Unwire the last wired TLB entry.
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*
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* It should also be noted that it is not possible to wire and unwire
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* TLB entries in an arbitrary order. If you wire TLB entry N, followed
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* by entry N+1, you must unwire entry N+1 first, then entry N. In this
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* respect, it works like a stack or LIFO queue.
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*/
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void tlb_unwire_entry(void)
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{
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unsigned long status, flags;
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int urb;
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local_irq_save(flags);
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status = ctrl_inl(MMUCR);
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urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
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status &= ~MMUCR_URB;
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/*
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* Make sure we're not trying to unwire a TLB entry when none
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* have been wired.
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*/
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BUG_ON(urb++ == MMUCR_URB_NENTRIES);
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urb = urb % MMUCR_URB_NENTRIES;
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status |= (urb << MMUCR_URB_SHIFT);
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ctrl_outl(status, MMUCR);
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ctrl_barrier();
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local_irq_restore(flags);
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}
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