powerpc/mm/copro_fault.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * CoProcessor (SPU/AFU) mm fault handler
0004  *
0005  * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
0006  *
0007  * Author: Arnd Bergmann <arndb@de.ibm.com>
0008  * Author: Jeremy Kerr <jk@ozlabs.org>
0009  */
0010 #include <linux/sched.h>
0011 #include <linux/mm.h>
0012 #include <linux/export.h>
0013 #include <asm/reg.h>
0014 #include <asm/copro.h>
0015 #include <asm/spu.h>
0016 #include <misc/cxl-base.h>
0017
0018 /*
0019  * This ought to be kept in sync with the powerpc specific do_page_fault
0020  * function. Currently, there are a few corner cases that we haven't had
0021  * to handle fortunately.
0022  */
0023 int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
0024         unsigned long dsisr, vm_fault_t *flt)
0025 {
0026     struct vm_area_struct *vma;
0027     unsigned long is_write;
0028     int ret;
0029
0030     if (mm == NULL)
0031         return -EFAULT;
0032
0033     if (mm->pgd == NULL)
0034         return -EFAULT;
0035
0036     mmap_read_lock(mm);
0037     ret = -EFAULT;
0038     vma = find_vma(mm, ea);
0039     if (!vma)
0040         goto out_unlock;
0041
0042     if (ea < vma->vm_start) {
0043         if (!(vma->vm_flags & VM_GROWSDOWN))
0044             goto out_unlock;
0045         if (expand_stack(vma, ea))
0046             goto out_unlock;
0047     }
0048
0049     is_write = dsisr & DSISR_ISSTORE;
0050     if (is_write) {
0051         if (!(vma->vm_flags & VM_WRITE))
0052             goto out_unlock;
0053     } else {
0054         if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
0055             goto out_unlock;
0056         /*
0057          * PROT_NONE is covered by the VMA check above.
0058          * and hash should get a NOHPTE fault instead of
0059          * a PROTFAULT in case fixup is needed for things
0060          * like autonuma.
0061          */
0062         if (!radix_enabled())
0063             WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
0064     }
0065
0066     ret = 0;
0067     *flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL);
0068
0069     /* The fault is fully completed (including releasing mmap lock) */
0070     if (*flt & VM_FAULT_COMPLETED)
0071         return 0;
0072
0073     if (unlikely(*flt & VM_FAULT_ERROR)) {
0074         if (*flt & VM_FAULT_OOM) {
0075             ret = -ENOMEM;
0076             goto out_unlock;
0077         } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
0078             ret = -EFAULT;
0079             goto out_unlock;
0080         }
0081         BUG();
0082     }
0083
0084 out_unlock:
0085     mmap_read_unlock(mm);
0086     return ret;
0087 }
0088 EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
0089
0090 #ifdef CONFIG_PPC_64S_HASH_MMU
0091 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
0092 {
0093     u64 vsid, vsidkey;
0094     int psize, ssize;
0095
0096     switch (get_region_id(ea)) {
0097     case USER_REGION_ID:
0098         pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
0099         if (mm == NULL)
0100             return 1;
0101         psize = get_slice_psize(mm, ea);
0102         ssize = user_segment_size(ea);
0103         vsid = get_user_vsid(&mm->context, ea, ssize);
0104         vsidkey = SLB_VSID_USER;
0105         break;
0106     case VMALLOC_REGION_ID:
0107         pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
0108         psize = mmu_vmalloc_psize;
0109         ssize = mmu_kernel_ssize;
0110         vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
0111         vsidkey = SLB_VSID_KERNEL;
0112         break;
0113     case IO_REGION_ID:
0114         pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
0115         psize = mmu_io_psize;
0116         ssize = mmu_kernel_ssize;
0117         vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
0118         vsidkey = SLB_VSID_KERNEL;
0119         break;
0120     case LINEAR_MAP_REGION_ID:
0121         pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
0122         psize = mmu_linear_psize;
0123         ssize = mmu_kernel_ssize;
0124         vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
0125         vsidkey = SLB_VSID_KERNEL;
0126         break;
0127     default:
0128         pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
0129         return 1;
0130     }
0131     /* Bad address */
0132     if (!vsid)
0133         return 1;
0134
0135     vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
0136
0137     vsid |= mmu_psize_defs[psize].sllp |
0138         ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
0139
0140     slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
0141     slb->vsid = vsid;
0142
0143     return 0;
0144 }
0145 EXPORT_SYMBOL_GPL(copro_calculate_slb);
0146
0147 void copro_flush_all_slbs(struct mm_struct *mm)
0148 {
0149 #ifdef CONFIG_SPU_BASE
0150     spu_flush_all_slbs(mm);
0151 #endif
0152     cxl_slbia(mm);
0153 }
0154 EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
0155 #endif