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, 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 97 out_unlock: 98 up_read(&mm->mmap_sem); 99 return ret; 100 } 101 EXPORT_SYMBOL_GPL(copro_handle_mm_fault); 102 103 int 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 } 153 EXPORT_SYMBOL_GPL(copro_calculate_slb); 154 155 void 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 } 162 EXPORT_SYMBOL_GPL(copro_flush_all_slbs); 163