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-rw-r--r--crypto/async_tx/async_tx.c146
1 files changed, 4 insertions, 142 deletions
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index 43fe4cbe71e6..b88bb1f608fc 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -38,25 +38,10 @@ static struct dma_client async_tx_dma = {
38}; 38};
39 39
40/** 40/**
41 * dma_cap_mask_all - enable iteration over all operation types
42 */
43static dma_cap_mask_t dma_cap_mask_all;
44
45/**
46 * chan_ref_percpu - tracks channel allocations per core/opertion
47 */
48struct chan_ref_percpu {
49 struct dma_chan_ref *ref;
50};
51
52static int channel_table_initialized;
53static struct chan_ref_percpu *channel_table[DMA_TX_TYPE_END];
54
55/**
56 * async_tx_lock - protect modification of async_tx_master_list and serialize 41 * async_tx_lock - protect modification of async_tx_master_list and serialize
57 * rebalance operations 42 * rebalance operations
58 */ 43 */
59static spinlock_t async_tx_lock; 44static DEFINE_SPINLOCK(async_tx_lock);
60 45
61static LIST_HEAD(async_tx_master_list); 46static LIST_HEAD(async_tx_master_list);
62 47
@@ -89,85 +74,6 @@ init_dma_chan_ref(struct dma_chan_ref *ref, struct dma_chan *chan)
89 atomic_set(&ref->count, 0); 74 atomic_set(&ref->count, 0);
90} 75}
91 76
92/**
93 * get_chan_ref_by_cap - returns the nth channel of the given capability
94 * defaults to returning the channel with the desired capability and the
95 * lowest reference count if the index can not be satisfied
96 * @cap: capability to match
97 * @index: nth channel desired, passing -1 has the effect of forcing the
98 * default return value
99 */
100static struct dma_chan_ref *
101get_chan_ref_by_cap(enum dma_transaction_type cap, int index)
102{
103 struct dma_chan_ref *ret_ref = NULL, *min_ref = NULL, *ref;
104
105 rcu_read_lock();
106 list_for_each_entry_rcu(ref, &async_tx_master_list, node)
107 if (dma_has_cap(cap, ref->chan->device->cap_mask)) {
108 if (!min_ref)
109 min_ref = ref;
110 else if (atomic_read(&ref->count) <
111 atomic_read(&min_ref->count))
112 min_ref = ref;
113
114 if (index-- == 0) {
115 ret_ref = ref;
116 break;
117 }
118 }
119 rcu_read_unlock();
120
121 if (!ret_ref)
122 ret_ref = min_ref;
123
124 if (ret_ref)
125 atomic_inc(&ret_ref->count);
126
127 return ret_ref;
128}
129
130/**
131 * async_tx_rebalance - redistribute the available channels, optimize
132 * for cpu isolation in the SMP case, and opertaion isolation in the
133 * uniprocessor case
134 */
135static void async_tx_rebalance(void)
136{
137 int cpu, cap, cpu_idx = 0;
138 unsigned long flags;
139
140 if (!channel_table_initialized)
141 return;
142
143 spin_lock_irqsave(&async_tx_lock, flags);
144
145 /* undo the last distribution */
146 for_each_dma_cap_mask(cap, dma_cap_mask_all)
147 for_each_possible_cpu(cpu) {
148 struct dma_chan_ref *ref =
149 per_cpu_ptr(channel_table[cap], cpu)->ref;
150 if (ref) {
151 atomic_set(&ref->count, 0);
152 per_cpu_ptr(channel_table[cap], cpu)->ref =
153 NULL;
154 }
155 }
156
157 for_each_dma_cap_mask(cap, dma_cap_mask_all)
158 for_each_online_cpu(cpu) {
159 struct dma_chan_ref *new;
160 if (NR_CPUS > 1)
161 new = get_chan_ref_by_cap(cap, cpu_idx++);
162 else
163 new = get_chan_ref_by_cap(cap, -1);
164
165 per_cpu_ptr(channel_table[cap], cpu)->ref = new;
166 }
167
168 spin_unlock_irqrestore(&async_tx_lock, flags);
169}
170
171static enum dma_state_client 77static enum dma_state_client
172dma_channel_add_remove(struct dma_client *client, 78dma_channel_add_remove(struct dma_client *client,
173 struct dma_chan *chan, enum dma_state state) 79 struct dma_chan *chan, enum dma_state state)
@@ -211,8 +117,6 @@ dma_channel_add_remove(struct dma_client *client,
211 " (-ENOMEM)\n"); 117 " (-ENOMEM)\n");
212 return 0; 118 return 0;
213 } 119 }
214
215 async_tx_rebalance();
216 break; 120 break;
217 case DMA_RESOURCE_REMOVED: 121 case DMA_RESOURCE_REMOVED:
218 found = 0; 122 found = 0;
@@ -233,8 +137,6 @@ dma_channel_add_remove(struct dma_client *client,
233 ack = DMA_ACK; 137 ack = DMA_ACK;
234 else 138 else
235 break; 139 break;
236
237 async_tx_rebalance();
238 break; 140 break;
239 case DMA_RESOURCE_SUSPEND: 141 case DMA_RESOURCE_SUSPEND:
240 case DMA_RESOURCE_RESUME: 142 case DMA_RESOURCE_RESUME:
@@ -248,51 +150,18 @@ dma_channel_add_remove(struct dma_client *client,
248 return ack; 150 return ack;
249} 151}
250 152
251static int __init 153static int __init async_tx_init(void)
252async_tx_init(void)
253{ 154{
254 enum dma_transaction_type cap;
255
256 spin_lock_init(&async_tx_lock);
257 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
258
259 /* an interrupt will never be an explicit operation type.
260 * clearing this bit prevents allocation to a slot in 'channel_table'
261 */
262 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
263
264 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
265 channel_table[cap] = alloc_percpu(struct chan_ref_percpu);
266 if (!channel_table[cap])
267 goto err;
268 }
269
270 channel_table_initialized = 1;
271 dma_async_client_register(&async_tx_dma); 155 dma_async_client_register(&async_tx_dma);
272 dma_async_client_chan_request(&async_tx_dma); 156 dma_async_client_chan_request(&async_tx_dma);
273 157
274 printk(KERN_INFO "async_tx: api initialized (async)\n"); 158 printk(KERN_INFO "async_tx: api initialized (async)\n");
275 159
276 return 0; 160 return 0;
277err:
278 printk(KERN_ERR "async_tx: initialization failure\n");
279
280 while (--cap >= 0)
281 free_percpu(channel_table[cap]);
282
283 return 1;
284} 161}
285 162
286static void __exit async_tx_exit(void) 163static void __exit async_tx_exit(void)
287{ 164{
288 enum dma_transaction_type cap;
289
290 channel_table_initialized = 0;
291
292 for_each_dma_cap_mask(cap, dma_cap_mask_all)
293 if (channel_table[cap])
294 free_percpu(channel_table[cap]);
295
296 dma_async_client_unregister(&async_tx_dma); 165 dma_async_client_unregister(&async_tx_dma);
297} 166}
298 167
@@ -308,16 +177,9 @@ __async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx,
308{ 177{
309 /* see if we can keep the chain on one channel */ 178 /* see if we can keep the chain on one channel */
310 if (depend_tx && 179 if (depend_tx &&
311 dma_has_cap(tx_type, depend_tx->chan->device->cap_mask)) 180 dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
312 return depend_tx->chan; 181 return depend_tx->chan;
313 else if (likely(channel_table_initialized)) { 182 return dma_find_channel(tx_type);
314 struct dma_chan_ref *ref;
315 int cpu = get_cpu();
316 ref = per_cpu_ptr(channel_table[tx_type], cpu)->ref;
317 put_cpu();
318 return ref ? ref->chan : NULL;
319 } else
320 return NULL;
321} 183}
322EXPORT_SYMBOL_GPL(__async_tx_find_channel); 184EXPORT_SYMBOL_GPL(__async_tx_find_channel);
323#else 185#else