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 */ 23 int 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 79 out_unlock: 80 mmap_read_unlock(mm); 81 return ret; 82 } 83 EXPORT_SYMBOL_GPL(copro_handle_mm_fault); 84 85 #ifdef CONFIG_PPC_64S_HASH_MMU 86 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb) 87 { 88 u64 vsid, vsidkey; 89 int psize, ssize; 90 91 switch (get_region_id(ea)) { 92 case USER_REGION_ID: 93 pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea); 94 if (mm == NULL) 95 return 1; 96 psize = get_slice_psize(mm, ea); 97 ssize = user_segment_size(ea); 98 vsid = get_user_vsid(&mm->context, ea, ssize); 99 vsidkey = SLB_VSID_USER; 100 break; 101 case VMALLOC_REGION_ID: 102 pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea); 103 psize = mmu_vmalloc_psize; 104 ssize = mmu_kernel_ssize; 105 vsid = get_kernel_vsid(ea, mmu_kernel_ssize); 106 vsidkey = SLB_VSID_KERNEL; 107 break; 108 case IO_REGION_ID: 109 pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea); 110 psize = mmu_io_psize; 111 ssize = mmu_kernel_ssize; 112 vsid = get_kernel_vsid(ea, mmu_kernel_ssize); 113 vsidkey = SLB_VSID_KERNEL; 114 break; 115 case LINEAR_MAP_REGION_ID: 116 pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea); 117 psize = mmu_linear_psize; 118 ssize = mmu_kernel_ssize; 119 vsid = get_kernel_vsid(ea, mmu_kernel_ssize); 120 vsidkey = SLB_VSID_KERNEL; 121 break; 122 default: 123 pr_debug("%s: invalid region access at %016llx\n", __func__, ea); 124 return 1; 125 } 126 /* Bad address */ 127 if (!vsid) 128 return 1; 129 130 vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey; 131 132 vsid |= mmu_psize_defs[psize].sllp | 133 ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0); 134 135 slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V; 136 slb->vsid = vsid; 137 138 return 0; 139 } 140 EXPORT_SYMBOL_GPL(copro_calculate_slb); 141 142 void copro_flush_all_slbs(struct mm_struct *mm) 143 { 144 #ifdef CONFIG_SPU_BASE 145 spu_flush_all_slbs(mm); 146 #endif 147 cxl_slbia(mm); 148 } 149 EXPORT_SYMBOL_GPL(copro_flush_all_slbs); 150 #endif 151