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f204e0b8 IM |
1 | /* |
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 | */ | |
29 | struct 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 | */ | |
b123429e IM |
37 | int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, |
38 | struct address_space *mapping) | |
f204e0b8 IM |
39 | { |
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 */ | |
b123429e IM |
46 | mutex_init(&ctx->mapping_lock); |
47 | ctx->mapping = mapping; | |
f204e0b8 IM |
48 | |
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 | */ | |
ee41d11d | 88 | mutex_lock(&afu->contexts_lock); |
f204e0b8 | 89 | idr_preload(GFP_KERNEL); |
f204e0b8 IM |
90 | i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0, |
91 | ctx->afu->num_procs, GFP_NOWAIT); | |
f204e0b8 | 92 | idr_preload_end(); |
ee41d11d | 93 | mutex_unlock(&afu->contexts_lock); |
f204e0b8 IM |
94 | 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 | ||
0712dc7e IM |
103 | static 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 | ||
139 | static const struct vm_operations_struct cxl_mmap_vmops = { | |
140 | .fault = cxl_mmap_fault, | |
141 | }; | |
142 | ||
f204e0b8 IM |
143 | /* |
144 | * Map a per-context mmio space into the given vma. | |
145 | */ | |
146 | int 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 | ||
0712dc7e IM |
151 | 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 | } | |
f204e0b8 | 157 | |
0712dc7e IM |
158 | /* Can't mmap until the AFU is enabled */ |
159 | if (!ctx->afu->enabled) | |
160 | return -EBUSY; | |
f204e0b8 IM |
161 | } |
162 | ||
f204e0b8 IM |
163 | pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__, |
164 | ctx->psn_phys, ctx->pe , ctx->master); | |
165 | ||
0712dc7e | 166 | vma->vm_flags |= VM_IO | VM_PFNMAP; |
f204e0b8 | 167 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
0712dc7e IM |
168 | vma->vm_ops = &cxl_mmap_vmops; |
169 | return 0; | |
f204e0b8 IM |
170 | } |
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 | */ | |
177 | static void __detach_context(struct cxl_context *ctx) | |
178 | { | |
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) | |
186 | return; | |
187 | ||
188 | WARN_ON(cxl_detach_process(ctx)); | |
6428832a | 189 | afu_release_irqs(ctx, ctx); |
f204e0b8 IM |
190 | flush_work(&ctx->fault_work); /* Only needed for dedicated process */ |
191 | wake_up_all(&ctx->wq); | |
192 | } | |
193 | ||
194 | /* | |
195 | * Detach the given context from the AFU. This doesn't actually | |
196 | * free the context but it should stop the context running in hardware | |
197 | * (ie. prevent this context from generating any further interrupts | |
198 | * so that it can be freed). | |
199 | */ | |
200 | void cxl_context_detach(struct cxl_context *ctx) | |
201 | { | |
202 | __detach_context(ctx); | |
203 | } | |
204 | ||
205 | /* | |
206 | * Detach all contexts on the given AFU. | |
207 | */ | |
208 | void cxl_context_detach_all(struct cxl_afu *afu) | |
209 | { | |
210 | struct cxl_context *ctx; | |
211 | int tmp; | |
212 | ||
ee41d11d IM |
213 | mutex_lock(&afu->contexts_lock); |
214 | idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { | |
f204e0b8 IM |
215 | /* |
216 | * Anything done in here needs to be setup before the IDR is | |
217 | * created and torn down after the IDR removed | |
218 | */ | |
219 | __detach_context(ctx); | |
0712dc7e IM |
220 | |
221 | /* | |
222 | * We are force detaching - remove any active PSA mappings so | |
223 | * userspace cannot interfere with the card if it comes back. | |
224 | * Easiest way to exercise this is to unbind and rebind the | |
225 | * driver via sysfs while it is in use. | |
226 | */ | |
227 | mutex_lock(&ctx->mapping_lock); | |
228 | if (ctx->mapping) | |
229 | unmap_mapping_range(ctx->mapping, 0, 0, 1); | |
230 | mutex_unlock(&ctx->mapping_lock); | |
ee41d11d IM |
231 | } |
232 | mutex_unlock(&afu->contexts_lock); | |
f204e0b8 IM |
233 | } |
234 | ||
8ac75b96 | 235 | static void reclaim_ctx(struct rcu_head *rcu) |
f204e0b8 | 236 | { |
8ac75b96 | 237 | struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu); |
f204e0b8 IM |
238 | |
239 | free_page((u64)ctx->sstp); | |
240 | ctx->sstp = NULL; | |
241 | ||
242 | put_pid(ctx->pid); | |
243 | kfree(ctx); | |
244 | } | |
8ac75b96 IM |
245 | |
246 | void cxl_context_free(struct cxl_context *ctx) | |
247 | { | |
248 | mutex_lock(&ctx->afu->contexts_lock); | |
249 | idr_remove(&ctx->afu->contexts_idr, ctx->pe); | |
250 | mutex_unlock(&ctx->afu->contexts_lock); | |
251 | call_rcu(&ctx->rcu, reclaim_ctx); | |
252 | } |