arch/sh/mm/tlb-pteaex.c

   1 /*
   2  * arch/sh/mm/tlb-pteaex.c
   3  *
   4  * TLB operations for SH-X3 CPUs featuring PTE ASID Extensions.
   5  *
   6  * Copyright (C) 2009 Paul Mundt
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/mm.h>
  14 #include <linux/io.h>
  15 #include <asm/system.h>
  16 #include <asm/mmu_context.h>
  17 #include <asm/cacheflush.h>
  18
  19 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
  20 {
  21         unsigned long flags, pteval, vpn;
  22
  23         /*
  24          * Handle debugger faulting in for debugee.
  25          */
  26         if (vma && current->active_mm != vma->vm_mm)
  27                 return;
  28
  29         local_irq_save(flags);
  30
  31         /* Set PTEH register */
  32         vpn = address & MMU_VPN_MASK;
  33         __raw_writel(vpn, MMU_PTEH);
  34
  35         /* Set PTEAEX */
  36         __raw_writel(get_asid(), MMU_PTEAEX);
  37
  38         pteval = pte.pte_low;
  39
  40         /* Set PTEA register */
  41 #ifdef CONFIG_X2TLB
  42         /*
  43          * For the extended mode TLB this is trivial, only the ESZ and
  44          * EPR bits need to be written out to PTEA, with the remainder of
  45          * the protection bits (with the exception of the compat-mode SZ
  46          * and PR bits, which are cleared) being written out in PTEL.
  47          */
  48         __raw_writel(pte.pte_high, MMU_PTEA);
  49 #endif
  50
  51         /* Set PTEL register */
  52         pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
  53 #ifdef CONFIG_CACHE_WRITETHROUGH
  54         pteval |= _PAGE_WT;
  55 #endif
  56         /* conveniently, we want all the software flags to be 0 anyway */
  57         __raw_writel(pteval, MMU_PTEL);
  58
  59         /* Load the TLB */
  60         asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
  61         local_irq_restore(flags);
  62 }
  63
  64 /*
  65  * While SH-X2 extended TLB mode splits out the memory-mapped I/UTLB
  66  * data arrays, SH-X3 cores with PTEAEX split out the memory-mapped
  67  * address arrays. In compat mode the second array is inaccessible, while
  68  * in extended mode, the legacy 8-bit ASID field in address array 1 has
  69  * undefined behaviour.
  70  */
  71 void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
  72                                                  unsigned long page)
  73 {
  74         jump_to_uncached();
  75         __raw_writel(page, MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT);
  76         __raw_writel(asid, MMU_UTLB_ADDRESS_ARRAY2 | MMU_PAGE_ASSOC_BIT);
  77         back_to_cached();
  78 }