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 */ 36 int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea, 37 unsigned long dsisr, unsigned *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 * protfault should only happen due to us 71 * mapping a region readonly temporarily. PROT_NONE 72 * is also covered by the VMA check above. 73 */ 74 WARN_ON_ONCE(dsisr & DSISR_PROTFAULT); 75 } 76 77 ret = 0; 78 *flt = handle_mm_fault(mm, vma, ea, is_write ? FAULT_FLAG_WRITE : 0); 79 if (unlikely(*flt & VM_FAULT_ERROR)) { 80 if (*flt & VM_FAULT_OOM) { 81 ret = -ENOMEM; 82 goto out_unlock; 83 } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) { 84 ret = -EFAULT; 85 goto out_unlock; 86 } 87 BUG(); 88 } 89 90 if (*flt & VM_FAULT_MAJOR) 91 current->maj_flt++; 92 else 93 current->min_flt++; 94 95 out_unlock: 96 up_read(&mm->mmap_sem); 97 return ret; 98 } 99 EXPORT_SYMBOL_GPL(copro_handle_mm_fault); 100 101 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb) 102 { 103 u64 vsid, vsidkey; 104 int psize, ssize; 105 106 switch (REGION_ID(ea)) { 107 case USER_REGION_ID: 108 pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea); 109 psize = get_slice_psize(mm, ea); 110 ssize = user_segment_size(ea); 111 vsid = get_vsid(mm->context.id, ea, ssize); 112 vsidkey = SLB_VSID_USER; 113 break; 114 case VMALLOC_REGION_ID: 115 pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea); 116 if (ea < VMALLOC_END) 117 psize = mmu_vmalloc_psize; 118 else 119 psize = mmu_io_psize; 120 ssize = mmu_kernel_ssize; 121 vsid = get_kernel_vsid(ea, mmu_kernel_ssize); 122 vsidkey = SLB_VSID_KERNEL; 123 break; 124 case KERNEL_REGION_ID: 125 pr_devel("%s: 0x%llx -- KERNEL_REGION_ID\n", __func__, ea); 126 psize = mmu_linear_psize; 127 ssize = mmu_kernel_ssize; 128 vsid = get_kernel_vsid(ea, mmu_kernel_ssize); 129 vsidkey = SLB_VSID_KERNEL; 130 break; 131 default: 132 pr_debug("%s: invalid region access at %016llx\n", __func__, ea); 133 return 1; 134 } 135 136 vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey; 137 138 vsid |= mmu_psize_defs[psize].sllp | 139 ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0); 140 141 slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V; 142 slb->vsid = vsid; 143 144 return 0; 145 } 146 EXPORT_SYMBOL_GPL(copro_calculate_slb); 147 148 void copro_flush_all_slbs(struct mm_struct *mm) 149 { 150 #ifdef CONFIG_SPU_BASE 151 spu_flush_all_slbs(mm); 152 #endif 153 cxl_slbia(mm); 154 } 155 EXPORT_SYMBOL_GPL(copro_flush_all_slbs); 156