LXR linux/arch/powerpc/mm/copro

   1/*
   2 * CoProcessor (SPU/AFU) mm fault handler
   3 *
   4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
   5 *
   6 * Author: Arnd Bergmann <arndb@de.ibm.com>
   7 * Author: Jeremy Kerr <jk@ozlabs.org>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2, or (at your option)
  12 * any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23#include <linux/sched.h>
  24#include <linux/mm.h>
  25#include <linux/export.h>
  26#include <asm/reg.h>
  27#include <asm/copro.h>
  28#include <asm/spu.h>
  29#include <misc/cxl-base.h>
  30
  31/*
  32 * This ought to be kept in sync with the powerpc specific do_page_fault
  33 * function. Currently, there are a few corner cases that we haven't had
  34 * to handle fortunately.
  35 */
  36int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
  37                unsigned long dsisr, vm_fault_t *flt)
  38{
  39        struct vm_area_struct *vma;
  40        unsigned long is_write;
  41        int ret;
  42
  43        if (mm == NULL)
  44                return -EFAULT;
  45
  46        if (mm->pgd == NULL)
  47                return -EFAULT;
  48
  49        down_read(&mm->mmap_sem);
  50        ret = -EFAULT;
  51        vma = find_vma(mm, ea);
  52        if (!vma)
  53                goto out_unlock;
  54
  55        if (ea < vma->vm_start) {
  56                if (!(vma->vm_flags & VM_GROWSDOWN))
  57                        goto out_unlock;
  58                if (expand_stack(vma, ea))
  59                        goto out_unlock;
  60        }
  61
  62        is_write = dsisr & DSISR_ISSTORE;
  63        if (is_write) {
  64                if (!(vma->vm_flags & VM_WRITE))
  65                        goto out_unlock;
  66        } else {
  67                if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
  68                        goto out_unlock;
  69                /*
  70                 * PROT_NONE is covered by the VMA check above.
  71                 * and hash should get a NOHPTE fault instead of
  72                 * a PROTFAULT in case fixup is needed for things
  73                 * like autonuma.
  74                 */
  75                if (!radix_enabled())
  76                        WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
  77        }
  78
  79        ret = 0;
  80        *flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0);
  81        if (unlikely(*flt & VM_FAULT_ERROR)) {
  82                if (*flt & VM_FAULT_OOM) {
  83                        ret = -ENOMEM;
  84                        goto out_unlock;
  85                } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
  86                        ret = -EFAULT;
  87                        goto out_unlock;
  88                }
  89                BUG();
  90        }
  91
  92        if (*flt & VM_FAULT_MAJOR)
  93                current->maj_flt++;
  94        else
  95                current->min_flt++;
  96
  97out_unlock:
  98        up_read(&mm->mmap_sem);
  99        return ret;
 100}
 101EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
 102
 103int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
 104{
 105        u64 vsid, vsidkey;
 106        int psize, ssize;
 107
 108        switch (REGION_ID(ea)) {
 109        case USER_REGION_ID:
 110                pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
 111                if (mm == NULL)
 112                        return 1;
 113                psize = get_slice_psize(mm, ea);
 114                ssize = user_segment_size(ea);
 115                vsid = get_user_vsid(&mm->context, ea, ssize);
 116                vsidkey = SLB_VSID_USER;
 117                break;
 118        case VMALLOC_REGION_ID:
 119                pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
 120                if (ea < VMALLOC_END)
 121                        psize = mmu_vmalloc_psize;
 122                else
 123                        psize = mmu_io_psize;
 124                ssize = mmu_kernel_ssize;
 125                vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 126                vsidkey = SLB_VSID_KERNEL;
 127                break;
 128        case KERNEL_REGION_ID:
 129                pr_devel("%s: 0x%llx -- KERNEL_REGION_ID\n", __func__, ea);
 130                psize = mmu_linear_psize;
 131                ssize = mmu_kernel_ssize;
 132                vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 133                vsidkey = SLB_VSID_KERNEL;
 134                break;
 135        default:
 136                pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
 137                return 1;
 138        }
 139        /* Bad address */
 140        if (!vsid)
 141                return 1;
 142
 143        vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
 144
 145        vsid |= mmu_psize_defs[psize].sllp |
 146                ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
 147
 148        slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
 149        slb->vsid = vsid;
 150
 151        return 0;
 152}
 153EXPORT_SYMBOL_GPL(copro_calculate_slb);
 154
 155void copro_flush_all_slbs(struct mm_struct *mm)
 156{
 157#ifdef CONFIG_SPU_BASE
 158        spu_flush_all_slbs(mm);
 159#endif
 160        cxl_slbia(mm);
 161}
 162EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
 163