LXR linux/arch/powerpc/mm/copro

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * CoProcessor (SPU/AFU) mm fault handler
   4 *
   5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
   6 *
   7 * Author: Arnd Bergmann <arndb@de.ibm.com>
   8 * Author: Jeremy Kerr <jk@ozlabs.org>
   9 */
  10#include <linux/sched.h>
  11#include <linux/mm.h>
  12#include <linux/export.h>
  13#include <asm/reg.h>
  14#include <asm/copro.h>
  15#include <asm/spu.h>
  16#include <misc/cxl-base.h>
  17
  18/*
  19 * This ought to be kept in sync with the powerpc specific do_page_fault
  20 * function. Currently, there are a few corner cases that we haven't had
  21 * to handle fortunately.
  22 */
  23int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
  24                unsigned long dsisr, vm_fault_t *flt)
  25{
  26        struct vm_area_struct *vma;
  27        unsigned long is_write;
  28        int ret;
  29
  30        if (mm == NULL)
  31                return -EFAULT;
  32
  33        if (mm->pgd == NULL)
  34                return -EFAULT;
  35
  36        mmap_read_lock(mm);
  37        ret = -EFAULT;
  38        vma = find_vma(mm, ea);
  39        if (!vma)
  40                goto out_unlock;
  41
  42        if (ea < vma->vm_start) {
  43                if (!(vma->vm_flags & VM_GROWSDOWN))
  44                        goto out_unlock;
  45                if (expand_stack(vma, ea))
  46                        goto out_unlock;
  47        }
  48
  49        is_write = dsisr & DSISR_ISSTORE;
  50        if (is_write) {
  51                if (!(vma->vm_flags & VM_WRITE))
  52                        goto out_unlock;
  53        } else {
  54                if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
  55                        goto out_unlock;
  56                /*
  57                 * PROT_NONE is covered by the VMA check above.
  58                 * and hash should get a NOHPTE fault instead of
  59                 * a PROTFAULT in case fixup is needed for things
  60                 * like autonuma.
  61                 */
  62                if (!radix_enabled())
  63                        WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
  64        }
  65
  66        ret = 0;
  67        *flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL);
  68        if (unlikely(*flt & VM_FAULT_ERROR)) {
  69                if (*flt & VM_FAULT_OOM) {
  70                        ret = -ENOMEM;
  71                        goto out_unlock;
  72                } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
  73                        ret = -EFAULT;
  74                        goto out_unlock;
  75                }
  76                BUG();
  77        }
  78
  79out_unlock:
  80        mmap_read_unlock(mm);
  81        return ret;
  82}
  83EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
  84
  85int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
  86{
  87        u64 vsid, vsidkey;
  88        int psize, ssize;
  89
  90        switch (get_region_id(ea)) {
  91        case USER_REGION_ID:
  92                pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
  93                if (mm == NULL)
  94                        return 1;
  95                psize = get_slice_psize(mm, ea);
  96                ssize = user_segment_size(ea);
  97                vsid = get_user_vsid(&mm->context, ea, ssize);
  98                vsidkey = SLB_VSID_USER;
  99                break;
 100        case VMALLOC_REGION_ID:
 101                pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
 102                psize = mmu_vmalloc_psize;
 103                ssize = mmu_kernel_ssize;
 104                vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 105                vsidkey = SLB_VSID_KERNEL;
 106                break;
 107        case IO_REGION_ID:
 108                pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
 109                psize = mmu_io_psize;
 110                ssize = mmu_kernel_ssize;
 111                vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 112                vsidkey = SLB_VSID_KERNEL;
 113                break;
 114        case LINEAR_MAP_REGION_ID:
 115                pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
 116                psize = mmu_linear_psize;
 117                ssize = mmu_kernel_ssize;
 118                vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 119                vsidkey = SLB_VSID_KERNEL;
 120                break;
 121        default:
 122                pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
 123                return 1;
 124        }
 125        /* Bad address */
 126        if (!vsid)
 127                return 1;
 128
 129        vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
 130
 131        vsid |= mmu_psize_defs[psize].sllp |
 132                ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
 133
 134        slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
 135        slb->vsid = vsid;
 136
 137        return 0;
 138}
 139EXPORT_SYMBOL_GPL(copro_calculate_slb);
 140
 141void copro_flush_all_slbs(struct mm_struct *mm)
 142{
 143#ifdef CONFIG_SPU_BASE
 144        spu_flush_all_slbs(mm);
 145#endif
 146        cxl_slbia(mm);
 147}
 148EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
 149