blob: 2a4c80ac322ad2500a13fc6162d8920ac4a6b8db [file] [log] [blame]
Ian Munsief204e0b2014-10-08 19:55:02 +11001/*
2 * Copyright 2014 IBM Corp.
3 *
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.
8 */
9
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>
15#include <linux/fs.h>
16#include <linux/mm.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>
23
24#include "cxl.h"
25
26/*
27 * Allocates space for a CXL context.
28 */
29struct cxl_context *cxl_context_alloc(void)
30{
31 return kzalloc(sizeof(struct cxl_context), GFP_KERNEL);
32}
33
34/*
35 * Initialises a CXL context.
36 */
Ian Munsieb1234292014-12-08 19:18:01 +110037int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
38 struct address_space *mapping)
Ian Munsief204e0b2014-10-08 19:55:02 +110039{
40 int i;
41
42 spin_lock_init(&ctx->sste_lock);
43 ctx->afu = afu;
44 ctx->master = master;
45 ctx->pid = NULL; /* Set in start work ioctl */
Ian Munsieb1234292014-12-08 19:18:01 +110046 mutex_init(&ctx->mapping_lock);
47 ctx->mapping = mapping;
Ian Munsief204e0b2014-10-08 19:55:02 +110048
49 /*
50 * Allocate the segment table before we put it in the IDR so that we
51 * can always access it when dereferenced from IDR. For the same
52 * reason, the segment table is only destroyed after the context is
53 * removed from the IDR. Access to this in the IOCTL is protected by
54 * Linux filesytem symantics (can't IOCTL until open is complete).
55 */
56 i = cxl_alloc_sst(ctx);
57 if (i)
58 return i;
59
60 INIT_WORK(&ctx->fault_work, cxl_handle_fault);
61
62 init_waitqueue_head(&ctx->wq);
63 spin_lock_init(&ctx->lock);
64
65 ctx->irq_bitmap = NULL;
66 ctx->pending_irq = false;
67 ctx->pending_fault = false;
68 ctx->pending_afu_err = false;
69
70 /*
71 * When we have to destroy all contexts in cxl_context_detach_all() we
72 * end up with afu_release_irqs() called from inside a
73 * idr_for_each_entry(). Hence we need to make sure that anything
74 * dereferenced from this IDR is ok before we allocate the IDR here.
75 * This clears out the IRQ ranges to ensure this.
76 */
77 for (i = 0; i < CXL_IRQ_RANGES; i++)
78 ctx->irqs.range[i] = 0;
79
80 mutex_init(&ctx->status_mutex);
81
82 ctx->status = OPENED;
83
84 /*
85 * Allocating IDR! We better make sure everything's setup that
86 * dereferences from it.
87 */
Ian Munsieee41d112014-12-08 19:17:55 +110088 mutex_lock(&afu->contexts_lock);
Ian Munsief204e0b2014-10-08 19:55:02 +110089 idr_preload(GFP_KERNEL);
Ian Munsief204e0b2014-10-08 19:55:02 +110090 i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0,
91 ctx->afu->num_procs, GFP_NOWAIT);
Ian Munsief204e0b2014-10-08 19:55:02 +110092 idr_preload_end();
Ian Munsieee41d112014-12-08 19:17:55 +110093 mutex_unlock(&afu->contexts_lock);
Ian Munsief204e0b2014-10-08 19:55:02 +110094 if (i < 0)
95 return i;
96
97 ctx->pe = i;
98 ctx->elem = &ctx->afu->spa[i];
99 ctx->pe_inserted = false;
100 return 0;
101}
102
Ian Munsie0712dc72015-01-07 16:33:04 +1100103static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
104{
105 struct cxl_context *ctx = vma->vm_file->private_data;
106 unsigned long address = (unsigned long)vmf->virtual_address;
107 u64 area, offset;
108
109 offset = vmf->pgoff << PAGE_SHIFT;
110
111 pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n",
112 __func__, ctx->pe, address, offset);
113
114 if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
115 area = ctx->afu->psn_phys;
116 if (offset > ctx->afu->adapter->ps_size)
117 return VM_FAULT_SIGBUS;
118 } else {
119 area = ctx->psn_phys;
120 if (offset > ctx->psn_size)
121 return VM_FAULT_SIGBUS;
122 }
123
124 mutex_lock(&ctx->status_mutex);
125
126 if (ctx->status != STARTED) {
127 mutex_unlock(&ctx->status_mutex);
128 pr_devel("%s: Context not started, failing problem state access\n", __func__);
129 return VM_FAULT_SIGBUS;
130 }
131
132 vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
133
134 mutex_unlock(&ctx->status_mutex);
135
136 return VM_FAULT_NOPAGE;
137}
138
139static const struct vm_operations_struct cxl_mmap_vmops = {
140 .fault = cxl_mmap_fault,
141};
142
Ian Munsief204e0b2014-10-08 19:55:02 +1100143/*
144 * Map a per-context mmio space into the given vma.
145 */
146int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma)
147{
148 u64 len = vma->vm_end - vma->vm_start;
149 len = min(len, ctx->psn_size);
150
Ian Munsie0712dc72015-01-07 16:33:04 +1100151 if (ctx->afu->current_mode != CXL_MODE_DEDICATED) {
152 /* make sure there is a valid per process space for this AFU */
153 if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) {
154 pr_devel("AFU doesn't support mmio space\n");
155 return -EINVAL;
156 }
Ian Munsief204e0b2014-10-08 19:55:02 +1100157
Ian Munsie0712dc72015-01-07 16:33:04 +1100158 /* Can't mmap until the AFU is enabled */
159 if (!ctx->afu->enabled)
160 return -EBUSY;
Ian Munsief204e0b2014-10-08 19:55:02 +1100161 }
162
Ian Munsief204e0b2014-10-08 19:55:02 +1100163 pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__,
164 ctx->psn_phys, ctx->pe , ctx->master);
165
Ian Munsie0712dc72015-01-07 16:33:04 +1100166 vma->vm_flags |= VM_IO | VM_PFNMAP;
Ian Munsief204e0b2014-10-08 19:55:02 +1100167 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
Ian Munsie0712dc72015-01-07 16:33:04 +1100168 vma->vm_ops = &cxl_mmap_vmops;
169 return 0;
Ian Munsief204e0b2014-10-08 19:55:02 +1100170}
171
172/*
173 * Detach a context from the hardware. This disables interrupts and doesn't
174 * return until all outstanding interrupts for this context have completed. The
175 * hardware should no longer access *ctx after this has returned.
176 */
Michael Neulingeda36932015-05-27 16:07:08 +1000177int __detach_context(struct cxl_context *ctx)
Ian Munsief204e0b2014-10-08 19:55:02 +1100178{
179 enum cxl_context_status status;
180
181 mutex_lock(&ctx->status_mutex);
182 status = ctx->status;
183 ctx->status = CLOSED;
184 mutex_unlock(&ctx->status_mutex);
185 if (status != STARTED)
Michael Neulingeda36932015-05-27 16:07:08 +1000186 return -EBUSY;
Ian Munsief204e0b2014-10-08 19:55:02 +1100187
188 WARN_ON(cxl_detach_process(ctx));
Michael Neuling7bb5d91a2015-05-27 16:07:14 +1000189 flush_work(&ctx->fault_work); /* Only needed for dedicated process */
190 put_pid(ctx->pid);
191 cxl_ctx_put();
Michael Neulingeda36932015-05-27 16:07:08 +1000192 return 0;
Ian Munsief204e0b2014-10-08 19:55:02 +1100193}
194
195/*
196 * Detach the given context from the AFU. This doesn't actually
197 * free the context but it should stop the context running in hardware
198 * (ie. prevent this context from generating any further interrupts
199 * so that it can be freed).
200 */
201void cxl_context_detach(struct cxl_context *ctx)
202{
Michael Neulingeda36932015-05-27 16:07:08 +1000203 int rc;
204
205 rc = __detach_context(ctx);
206 if (rc)
207 return;
208
209 afu_release_irqs(ctx, ctx);
Michael Neulingeda36932015-05-27 16:07:08 +1000210 wake_up_all(&ctx->wq);
Ian Munsief204e0b2014-10-08 19:55:02 +1100211}
212
213/*
214 * Detach all contexts on the given AFU.
215 */
216void cxl_context_detach_all(struct cxl_afu *afu)
217{
218 struct cxl_context *ctx;
219 int tmp;
220
Ian Munsieee41d112014-12-08 19:17:55 +1100221 mutex_lock(&afu->contexts_lock);
222 idr_for_each_entry(&afu->contexts_idr, ctx, tmp) {
Ian Munsief204e0b2014-10-08 19:55:02 +1100223 /*
224 * Anything done in here needs to be setup before the IDR is
225 * created and torn down after the IDR removed
226 */
Michael Neulingeda36932015-05-27 16:07:08 +1000227 cxl_context_detach(ctx);
Ian Munsie0712dc72015-01-07 16:33:04 +1100228
229 /*
230 * We are force detaching - remove any active PSA mappings so
231 * userspace cannot interfere with the card if it comes back.
232 * Easiest way to exercise this is to unbind and rebind the
233 * driver via sysfs while it is in use.
234 */
235 mutex_lock(&ctx->mapping_lock);
236 if (ctx->mapping)
237 unmap_mapping_range(ctx->mapping, 0, 0, 1);
238 mutex_unlock(&ctx->mapping_lock);
Ian Munsieee41d112014-12-08 19:17:55 +1100239 }
240 mutex_unlock(&afu->contexts_lock);
Ian Munsief204e0b2014-10-08 19:55:02 +1100241}
242
Ian Munsie8ac75b92015-05-08 22:55:18 +1000243static void reclaim_ctx(struct rcu_head *rcu)
Ian Munsief204e0b2014-10-08 19:55:02 +1100244{
Ian Munsie8ac75b92015-05-08 22:55:18 +1000245 struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu);
Ian Munsief204e0b2014-10-08 19:55:02 +1100246
247 free_page((u64)ctx->sstp);
248 ctx->sstp = NULL;
249
Ian Munsief204e0b2014-10-08 19:55:02 +1100250 kfree(ctx);
251}
Ian Munsie8ac75b92015-05-08 22:55:18 +1000252
253void cxl_context_free(struct cxl_context *ctx)
254{
255 mutex_lock(&ctx->afu->contexts_lock);
256 idr_remove(&ctx->afu->contexts_idr, ctx->pe);
257 mutex_unlock(&ctx->afu->contexts_lock);
258 call_rcu(&ctx->rcu, reclaim_ctx);
259}