1 // SPDX-License-Identifier: GPL-2.0+ 2 // Copyright 2017 IBM Corp. 3 #include <linux/sched/mm.h> 4 #include "trace.h" 5 #include "ocxl_internal.h" 6 7 int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu, 8 struct address_space *mapping) 9 { 10 int pasid; 11 struct ocxl_context *ctx; 12 13 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 14 if (!ctx) 15 return -ENOMEM; 16 17 ctx->afu = afu; 18 mutex_lock(&afu->contexts_lock); 19 pasid = idr_alloc(&afu->contexts_idr, ctx, afu->pasid_base, 20 afu->pasid_base + afu->pasid_max, GFP_KERNEL); 21 if (pasid < 0) { 22 mutex_unlock(&afu->contexts_lock); 23 kfree(ctx); 24 return pasid; 25 } 26 afu->pasid_count++; 27 mutex_unlock(&afu->contexts_lock); 28 29 ctx->pasid = pasid; 30 ctx->status = OPENED; 31 mutex_init(&ctx->status_mutex); 32 ctx->mapping = mapping; 33 mutex_init(&ctx->mapping_lock); 34 init_waitqueue_head(&ctx->events_wq); 35 mutex_init(&ctx->xsl_error_lock); 36 mutex_init(&ctx->irq_lock); 37 idr_init(&ctx->irq_idr); 38 ctx->tidr = 0; 39 40 /* 41 * Keep a reference on the AFU to make sure it's valid for the 42 * duration of the life of the context 43 */ 44 ocxl_afu_get(afu); 45 *context = ctx; 46 return 0; 47 } 48 EXPORT_SYMBOL_GPL(ocxl_context_alloc); 49 50 /* 51 * Callback for when a translation fault triggers an error 52 * data: a pointer to the context which triggered the fault 53 * addr: the address that triggered the error 54 * dsisr: the value of the PPC64 dsisr register 55 */ 56 static void xsl_fault_error(void *data, u64 addr, u64 dsisr) 57 { 58 struct ocxl_context *ctx = (struct ocxl_context *) data; 59 60 mutex_lock(&ctx->xsl_error_lock); 61 ctx->xsl_error.addr = addr; 62 ctx->xsl_error.dsisr = dsisr; 63 ctx->xsl_error.count++; 64 mutex_unlock(&ctx->xsl_error_lock); 65 66 wake_up_all(&ctx->events_wq); 67 } 68 69 int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) 70 { 71 int rc; 72 unsigned long pidr = 0; 73 struct pci_dev *dev; 74 75 // Locks both status & tidr 76 mutex_lock(&ctx->status_mutex); 77 if (ctx->status != OPENED) { 78 rc = -EIO; 79 goto out; 80 } 81 82 if (mm) 83 pidr = mm->context.id; 84 85 dev = to_pci_dev(ctx->afu->fn->dev.parent); 86 rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, pidr, ctx->tidr, 87 amr, pci_dev_id(dev), mm, xsl_fault_error, ctx); 88 if (rc) 89 goto out; 90 91 ctx->status = ATTACHED; 92 out: 93 mutex_unlock(&ctx->status_mutex); 94 return rc; 95 } 96 EXPORT_SYMBOL_GPL(ocxl_context_attach); 97 98 static vm_fault_t map_afu_irq(struct vm_area_struct *vma, unsigned long address, 99 u64 offset, struct ocxl_context *ctx) 100 { 101 u64 trigger_addr; 102 int irq_id = ocxl_irq_offset_to_id(ctx, offset); 103 104 trigger_addr = ocxl_afu_irq_get_addr(ctx, irq_id); 105 if (!trigger_addr) 106 return VM_FAULT_SIGBUS; 107 108 return vmf_insert_pfn(vma, address, trigger_addr >> PAGE_SHIFT); 109 } 110 111 static vm_fault_t map_pp_mmio(struct vm_area_struct *vma, unsigned long address, 112 u64 offset, struct ocxl_context *ctx) 113 { 114 u64 pp_mmio_addr; 115 int pasid_off; 116 vm_fault_t ret; 117 118 if (offset >= ctx->afu->config.pp_mmio_stride) 119 return VM_FAULT_SIGBUS; 120 121 mutex_lock(&ctx->status_mutex); 122 if (ctx->status != ATTACHED) { 123 mutex_unlock(&ctx->status_mutex); 124 pr_debug("%s: Context not attached, failing mmio mmap\n", 125 __func__); 126 return VM_FAULT_SIGBUS; 127 } 128 129 pasid_off = ctx->pasid - ctx->afu->pasid_base; 130 pp_mmio_addr = ctx->afu->pp_mmio_start + 131 pasid_off * ctx->afu->config.pp_mmio_stride + 132 offset; 133 134 ret = vmf_insert_pfn(vma, address, pp_mmio_addr >> PAGE_SHIFT); 135 mutex_unlock(&ctx->status_mutex); 136 return ret; 137 } 138 139 static vm_fault_t ocxl_mmap_fault(struct vm_fault *vmf) 140 { 141 struct vm_area_struct *vma = vmf->vma; 142 struct ocxl_context *ctx = vma->vm_file->private_data; 143 u64 offset; 144 vm_fault_t ret; 145 146 offset = vmf->pgoff << PAGE_SHIFT; 147 pr_debug("%s: pasid %d address 0x%lx offset 0x%llx\n", __func__, 148 ctx->pasid, vmf->address, offset); 149 150 if (offset < ctx->afu->irq_base_offset) 151 ret = map_pp_mmio(vma, vmf->address, offset, ctx); 152 else 153 ret = map_afu_irq(vma, vmf->address, offset, ctx); 154 return ret; 155 } 156 157 static const struct vm_operations_struct ocxl_vmops = { 158 .fault = ocxl_mmap_fault, 159 }; 160 161 static int check_mmap_afu_irq(struct ocxl_context *ctx, 162 struct vm_area_struct *vma) 163 { 164 int irq_id = ocxl_irq_offset_to_id(ctx, vma->vm_pgoff << PAGE_SHIFT); 165 166 /* only one page */ 167 if (vma_pages(vma) != 1) 168 return -EINVAL; 169 170 /* check offset validty */ 171 if (!ocxl_afu_irq_get_addr(ctx, irq_id)) 172 return -EINVAL; 173 174 /* 175 * trigger page should only be accessible in write mode. 176 * 177 * It's a bit theoretical, as a page mmaped with only 178 * PROT_WRITE is currently readable, but it doesn't hurt. 179 */ 180 if ((vma->vm_flags & VM_READ) || (vma->vm_flags & VM_EXEC) || 181 !(vma->vm_flags & VM_WRITE)) 182 return -EINVAL; 183 vm_flags_clear(vma, VM_MAYREAD | VM_MAYEXEC); 184 return 0; 185 } 186 187 static int check_mmap_mmio(struct ocxl_context *ctx, 188 struct vm_area_struct *vma) 189 { 190 if ((vma_pages(vma) + vma->vm_pgoff) > 191 (ctx->afu->config.pp_mmio_stride >> PAGE_SHIFT)) 192 return -EINVAL; 193 return 0; 194 } 195 196 int ocxl_context_mmap(struct ocxl_context *ctx, struct vm_area_struct *vma) 197 { 198 int rc; 199 200 if ((vma->vm_pgoff << PAGE_SHIFT) < ctx->afu->irq_base_offset) 201 rc = check_mmap_mmio(ctx, vma); 202 else 203 rc = check_mmap_afu_irq(ctx, vma); 204 if (rc) 205 return rc; 206 207 vm_flags_set(vma, VM_IO | VM_PFNMAP); 208 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 209 vma->vm_ops = &ocxl_vmops; 210 return 0; 211 } 212 213 int ocxl_context_detach(struct ocxl_context *ctx) 214 { 215 struct pci_dev *dev; 216 int afu_control_pos; 217 enum ocxl_context_status status; 218 int rc; 219 220 mutex_lock(&ctx->status_mutex); 221 status = ctx->status; 222 ctx->status = CLOSED; 223 mutex_unlock(&ctx->status_mutex); 224 if (status != ATTACHED) 225 return 0; 226 227 dev = to_pci_dev(ctx->afu->fn->dev.parent); 228 afu_control_pos = ctx->afu->config.dvsec_afu_control_pos; 229 230 mutex_lock(&ctx->afu->afu_control_lock); 231 rc = ocxl_config_terminate_pasid(dev, afu_control_pos, ctx->pasid); 232 mutex_unlock(&ctx->afu->afu_control_lock); 233 trace_ocxl_terminate_pasid(ctx->pasid, rc); 234 if (rc) { 235 /* 236 * If we timeout waiting for the AFU to terminate the 237 * pasid, then it's dangerous to clean up the Process 238 * Element entry in the SPA, as it may be referenced 239 * in the future by the AFU. In which case, we would 240 * checkstop because of an invalid PE access (FIR 241 * register 2, bit 42). So leave the PE 242 * defined. Caller shouldn't free the context so that 243 * PASID remains allocated. 244 * 245 * A link reset will be required to cleanup the AFU 246 * and the SPA. 247 */ 248 if (rc == -EBUSY) 249 return rc; 250 } 251 rc = ocxl_link_remove_pe(ctx->afu->fn->link, ctx->pasid); 252 if (rc) { 253 dev_warn(&dev->dev, 254 "Couldn't remove PE entry cleanly: %d\n", rc); 255 } 256 return 0; 257 } 258 EXPORT_SYMBOL_GPL(ocxl_context_detach); 259 260 void ocxl_context_detach_all(struct ocxl_afu *afu) 261 { 262 struct ocxl_context *ctx; 263 int tmp; 264 265 mutex_lock(&afu->contexts_lock); 266 idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { 267 ocxl_context_detach(ctx); 268 /* 269 * We are force detaching - remove any active mmio 270 * mappings so userspace cannot interfere with the 271 * card if it comes back. Easiest way to exercise 272 * this is to unbind and rebind the driver via sysfs 273 * while it is in use. 274 */ 275 mutex_lock(&ctx->mapping_lock); 276 if (ctx->mapping) 277 unmap_mapping_range(ctx->mapping, 0, 0, 1); 278 mutex_unlock(&ctx->mapping_lock); 279 } 280 mutex_unlock(&afu->contexts_lock); 281 } 282 283 void ocxl_context_free(struct ocxl_context *ctx) 284 { 285 mutex_lock(&ctx->afu->contexts_lock); 286 ctx->afu->pasid_count--; 287 idr_remove(&ctx->afu->contexts_idr, ctx->pasid); 288 mutex_unlock(&ctx->afu->contexts_lock); 289 290 ocxl_afu_irq_free_all(ctx); 291 idr_destroy(&ctx->irq_idr); 292 /* reference to the AFU taken in ocxl_context_alloc() */ 293 ocxl_afu_put(ctx->afu); 294 kfree(ctx); 295 } 296 EXPORT_SYMBOL_GPL(ocxl_context_free); 297