4539282dbc
Presently the TLB wiring code depends on MMUCR.URB for working out where to place the wired entry, but fails to take the replacment counter in to consideration. This fixes up the wiring logic and ensures that wired entries remain so. Signed-off-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
94 lines
2 KiB
C
94 lines
2 KiB
C
/*
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* arch/sh/mm/tlb-urb.c
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*
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* TLB entry wiring helpers for URB-equipped parts.
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*
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* Copyright (C) 2010 Matt Fleming
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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/io.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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* 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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status = __raw_readl(MMUCR);
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urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
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status &= ~MMUCR_URC;
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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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/*
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* Insert this entry into the highest non-wired TLB slot (via
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* the URC field).
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*/
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status |= (urb << MMUCR_URC_SHIFT);
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__raw_writel(status, MMUCR);
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ctrl_barrier();
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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 = __raw_readl(MMUCR);
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status &= ~MMUCR_URB;
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status |= (urb << MMUCR_URB_SHIFT);
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__raw_writel(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 = __raw_readl(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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__raw_writel(status, MMUCR);
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ctrl_barrier();
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local_irq_restore(flags);
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}
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