2 * Copyright 2014 IBM Corp.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/bitmap.h>
13 #include <linux/sched.h>
14 #include <linux/pid.h>
17 #include <linux/debugfs.h>
18 #include <linux/slab.h>
19 #include <linux/idr.h>
20 #include <asm/cputable.h>
21 #include <asm/current.h>
22 #include <asm/copro.h>
27 * Allocates space for a CXL context.
29 struct cxl_context *cxl_context_alloc(void)
31 return kzalloc(sizeof(struct cxl_context), GFP_KERNEL);
35 * Initialises a CXL context.
37 int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
41 spin_lock_init(&ctx->sste_lock);
44 ctx->pid = ctx->glpid = NULL; /* Set in start work ioctl */
45 mutex_init(&ctx->mapping_lock);
49 * Allocate the segment table before we put it in the IDR so that we
50 * can always access it when dereferenced from IDR. For the same
51 * reason, the segment table is only destroyed after the context is
52 * removed from the IDR. Access to this in the IOCTL is protected by
53 * Linux filesytem symantics (can't IOCTL until open is complete).
55 i = cxl_alloc_sst(ctx);
59 INIT_WORK(&ctx->fault_work, cxl_handle_fault);
61 init_waitqueue_head(&ctx->wq);
62 spin_lock_init(&ctx->lock);
64 ctx->irq_bitmap = NULL;
65 ctx->pending_irq = false;
66 ctx->pending_fault = false;
67 ctx->pending_afu_err = false;
69 INIT_LIST_HEAD(&ctx->irq_names);
70 INIT_LIST_HEAD(&ctx->extra_irq_contexts);
73 * When we have to destroy all contexts in cxl_context_detach_all() we
74 * end up with afu_release_irqs() called from inside a
75 * idr_for_each_entry(). Hence we need to make sure that anything
76 * dereferenced from this IDR is ok before we allocate the IDR here.
77 * This clears out the IRQ ranges to ensure this.
79 for (i = 0; i < CXL_IRQ_RANGES; i++)
80 ctx->irqs.range[i] = 0;
82 mutex_init(&ctx->status_mutex);
87 * Allocating IDR! We better make sure everything's setup that
88 * dereferences from it.
90 mutex_lock(&afu->contexts_lock);
91 idr_preload(GFP_KERNEL);
92 i = idr_alloc(&ctx->afu->contexts_idr, ctx, ctx->afu->adapter->min_pe,
93 ctx->afu->num_procs, GFP_NOWAIT);
95 mutex_unlock(&afu->contexts_lock);
100 if (cpu_has_feature(CPU_FTR_HVMODE)) {
101 ctx->elem = &ctx->afu->native->spa[i];
102 ctx->external_pe = ctx->pe;
104 ctx->external_pe = -1; /* assigned when attaching */
106 ctx->pe_inserted = false;
109 * take a ref on the afu so that it stays alive at-least till
110 * this context is reclaimed inside reclaim_ctx.
116 void cxl_context_set_mapping(struct cxl_context *ctx,
117 struct address_space *mapping)
119 mutex_lock(&ctx->mapping_lock);
120 ctx->mapping = mapping;
121 mutex_unlock(&ctx->mapping_lock);
124 static int cxl_mmap_fault(struct vm_fault *vmf)
126 struct vm_area_struct *vma = vmf->vma;
127 struct cxl_context *ctx = vma->vm_file->private_data;
130 offset = vmf->pgoff << PAGE_SHIFT;
132 pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n",
133 __func__, ctx->pe, vmf->address, offset);
135 if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
136 area = ctx->afu->psn_phys;
137 if (offset >= ctx->afu->adapter->ps_size)
138 return VM_FAULT_SIGBUS;
140 area = ctx->psn_phys;
141 if (offset >= ctx->psn_size)
142 return VM_FAULT_SIGBUS;
145 mutex_lock(&ctx->status_mutex);
147 if (ctx->status != STARTED) {
148 mutex_unlock(&ctx->status_mutex);
149 pr_devel("%s: Context not started, failing problem state access\n", __func__);
150 if (ctx->mmio_err_ff) {
152 ctx->ff_page = alloc_page(GFP_USER);
155 memset(page_address(ctx->ff_page), 0xff, PAGE_SIZE);
157 get_page(ctx->ff_page);
158 vmf->page = ctx->ff_page;
159 vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
162 return VM_FAULT_SIGBUS;
165 vm_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);
167 mutex_unlock(&ctx->status_mutex);
169 return VM_FAULT_NOPAGE;
172 static const struct vm_operations_struct cxl_mmap_vmops = {
173 .fault = cxl_mmap_fault,
177 * Map a per-context mmio space into the given vma.
179 int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma)
181 u64 start = vma->vm_pgoff << PAGE_SHIFT;
182 u64 len = vma->vm_end - vma->vm_start;
184 if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
185 if (start + len > ctx->afu->adapter->ps_size)
188 if (start + len > ctx->psn_size)
192 if (ctx->afu->current_mode != CXL_MODE_DEDICATED) {
193 /* make sure there is a valid per process space for this AFU */
194 if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) {
195 pr_devel("AFU doesn't support mmio space\n");
199 /* Can't mmap until the AFU is enabled */
200 if (!ctx->afu->enabled)
204 pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__,
205 ctx->psn_phys, ctx->pe , ctx->master);
207 vma->vm_flags |= VM_IO | VM_PFNMAP;
208 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
209 vma->vm_ops = &cxl_mmap_vmops;
214 * Detach a context from the hardware. This disables interrupts and doesn't
215 * return until all outstanding interrupts for this context have completed. The
216 * hardware should no longer access *ctx after this has returned.
218 int __detach_context(struct cxl_context *ctx)
220 enum cxl_context_status status;
222 mutex_lock(&ctx->status_mutex);
223 status = ctx->status;
224 ctx->status = CLOSED;
225 mutex_unlock(&ctx->status_mutex);
226 if (status != STARTED)
229 /* Only warn if we detached while the link was OK.
230 * If detach fails when hw is down, we don't care.
232 WARN_ON(cxl_ops->detach_process(ctx) &&
233 cxl_ops->link_ok(ctx->afu->adapter, ctx->afu));
234 flush_work(&ctx->fault_work); /* Only needed for dedicated process */
237 * Wait until no further interrupts are presented by the PSL
240 if (cxl_ops->irq_wait)
241 cxl_ops->irq_wait(ctx);
243 /* release the reference to the group leader and mm handling pid */
249 /* Decrease the attached context count on the adapter */
250 cxl_adapter_context_put(ctx->afu->adapter);
255 * Detach the given context from the AFU. This doesn't actually
256 * free the context but it should stop the context running in hardware
257 * (ie. prevent this context from generating any further interrupts
258 * so that it can be freed).
260 void cxl_context_detach(struct cxl_context *ctx)
264 rc = __detach_context(ctx);
268 afu_release_irqs(ctx, ctx);
269 wake_up_all(&ctx->wq);
273 * Detach all contexts on the given AFU.
275 void cxl_context_detach_all(struct cxl_afu *afu)
277 struct cxl_context *ctx;
280 mutex_lock(&afu->contexts_lock);
281 idr_for_each_entry(&afu->contexts_idr, ctx, tmp) {
283 * Anything done in here needs to be setup before the IDR is
284 * created and torn down after the IDR removed
286 cxl_context_detach(ctx);
289 * We are force detaching - remove any active PSA mappings so
290 * userspace cannot interfere with the card if it comes back.
291 * Easiest way to exercise this is to unbind and rebind the
292 * driver via sysfs while it is in use.
294 mutex_lock(&ctx->mapping_lock);
296 unmap_mapping_range(ctx->mapping, 0, 0, 1);
297 mutex_unlock(&ctx->mapping_lock);
299 mutex_unlock(&afu->contexts_lock);
302 static void reclaim_ctx(struct rcu_head *rcu)
304 struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu);
306 free_page((u64)ctx->sstp);
308 __free_page(ctx->ff_page);
311 kfree(ctx->irq_bitmap);
313 /* Drop ref to the afu device taken during cxl_context_init */
314 cxl_afu_put(ctx->afu);
319 void cxl_context_free(struct cxl_context *ctx)
321 if (ctx->kernelapi && ctx->mapping)
322 cxl_release_mapping(ctx);
323 mutex_lock(&ctx->afu->contexts_lock);
324 idr_remove(&ctx->afu->contexts_idr, ctx->pe);
325 mutex_unlock(&ctx->afu->contexts_lock);
326 call_rcu(&ctx->rcu, reclaim_ctx);