firewire: octlet AT payloads can be stack-allocated

We do not need slab allocations anymore in order to satisfy streaming DMA mapping constraints, thanks to commit da28947e7e36 "firewire: ohci: avoid separate DMA mapping for small AT payloads". (Besides, the slab-allocated buffers that firewire-core, firewire-sbp2, and firedtv used to provide for 8-byte write and lock requests were still not fully portable since they crossed cacheline boundaries or shared a cacheline with unrelated CPU-accessed data. snd-firewire-lib got this aspect right by using an extra kmalloc/ kfree just for the 8-byte transaction buffer.) This change replaces kmalloc'ed lock transaction scratch buffers in firewire-core, firedtv, and snd-firewire-lib by local stack allocations. Perhaps the most notable result of the change is simpler locking because there is no need to serialize usages of preallocated per-device buffers anymore. Also, allocations and deallocations are simpler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Acked-by: Clemens Ladisch <clemens@ladisch.de>

firewire: octlet AT payloads can be stack-allocated
We do not need slab allocations anymore in order to satisfy streaming DMA mapping constraints, thanks to commit da28947e7e36 "firewire: ohci: avoid separate DMA mapping for small AT payloads". (Besides, the slab-allocated buffers that firewire-core, firewire-sbp2, and firedtv used to provide for 8-byte write and lock requests were still not fully portable since they crossed cacheline boundaries or shared a cacheline with unrelated CPU-accessed data. snd-firewire-lib got this aspect right by using an extra kmalloc/ kfree just for the 8-byte transaction buffer.) This change replaces kmalloc'ed lock transaction scratch buffers in firewire-core, firedtv, and snd-firewire-lib by local stack allocations. Perhaps the most notable result of the change is simpler locking because there is no need to serialize usages of preallocated per-device buffers anymore. Also, allocations and deallocations are simpler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Acked-by: Clemens Ladisch <clemens@ladisch.de>
Stefan Richter
1 parent 020abf03cd
Showing 9 changed files with 30 additions and 52 deletions Side-by-side Diff
drivers/firewire/core-card.c
drivers/firewire/core-cdev.c
drivers/firewire/core-iso.c
drivers/firewire/core-transaction.c
drivers/media/dvb/firewire/firedtv-avc.c
include/linux/firewire.h
sound/firewire/cmp.c
sound/firewire/iso-resources.c
sound/firewire/iso-resources.h
@@ -258,8 +258,7 @@
  
 	if (!card->broadcast_channel_allocated) {
 		fw_iso_resource_manage(card, generation, 1ULL << 31,
-				       &channel, &bandwidth, true,
-				       card->bm_transaction_data);
+				       &channel, &bandwidth, true);
 		if (channel != 31) {
 			fw_notify("failed to allocate broadcast channel\n");
 			return;
@@ -294,6 +293,7 @@
 	bool root_device_is_cmc;
 	bool irm_is_1394_1995_only;
 	bool keep_this_irm;
+	__be32 transaction_data[2];
  
 	spin_lock_irq(&card->lock);
  
  
  
@@ -355,21 +355,21 @@
 			goto pick_me;
 		}
  
-		card->bm_transaction_data[0] = cpu_to_be32(0x3f);
-		card->bm_transaction_data[1] = cpu_to_be32(local_id);
+		transaction_data[0] = cpu_to_be32(0x3f);
+		transaction_data[1] = cpu_to_be32(local_id);
  
 		spin_unlock_irq(&card->lock);
  
 		rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
 				irm_id, generation, SCODE_100,
 				CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
-				card->bm_transaction_data, 8);
+				transaction_data, 8);
  
 		if (rcode == RCODE_GENERATION)
 			/* Another bus reset, BM work has been rescheduled. */
 			goto out;
  
-		bm_id = be32_to_cpu(card->bm_transaction_data[0]);
+		bm_id = be32_to_cpu(transaction_data[0]);
  
 		spin_lock_irq(&card->lock);
 		if (rcode == RCODE_COMPLETE && generation == card->generation)
  
@@ -490,11 +490,11 @@
 		/*
 		 * Make sure that the cycle master sends cycle start packets.
 		 */
-		card->bm_transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
+		transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
 		rcode = fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 				root_id, generation, SCODE_100,
 				CSR_REGISTER_BASE + CSR_STATE_SET,
-				card->bm_transaction_data, 4);
+				transaction_data, 4);
 		if (rcode == RCODE_GENERATION)
 			goto out;
 	}
@@ -141,7 +141,6 @@
 	int generation;
 	u64 channels;
 	s32 bandwidth;
-	__be32 transaction_data[2];
 	struct iso_resource_event *e_alloc, *e_dealloc;
 };
  
@@ -1229,8 +1228,7 @@
 			r->channels, &channel, &bandwidth,
 			todo == ISO_RES_ALLOC ||
 			todo == ISO_RES_REALLOC ||
-			todo == ISO_RES_ALLOC_ONCE,
-			r->transaction_data);
+			todo == ISO_RES_ALLOC_ONCE);
 	/*
 	 * Is this generation outdated already?  As long as this resource sticks
 	 * in the idr, it will be scheduled again for a newer generation or at
@@ -196,9 +196,10 @@
  */
  
 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
-			    int bandwidth, bool allocate, __be32 data[2])
+			    int bandwidth, bool allocate)
 {
 	int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
+	__be32 data[2];
  
 	/*
 	 * On a 1394a IRM with low contention, try < 1 is enough.
  
@@ -233,9 +234,10 @@
 }
  
 static int manage_channel(struct fw_card *card, int irm_id, int generation,
-		u32 channels_mask, u64 offset, bool allocate, __be32 data[2])
+		u32 channels_mask, u64 offset, bool allocate)
 {
 	__be32 bit, all, old;
+	__be32 data[2];
 	int channel, ret = -EIO, retry = 5;
  
 	old = all = allocate ? cpu_to_be32(~0) : 0;
@@ -284,7 +286,7 @@
 }
  
 static void deallocate_channel(struct fw_card *card, int irm_id,
-			       int generation, int channel, __be32 buffer[2])
+			       int generation, int channel)
 {
 	u32 mask;
 	u64 offset;
@@ -293,7 +295,7 @@
 	offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
 				CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
  
-	manage_channel(card, irm_id, generation, mask, offset, false, buffer);
+	manage_channel(card, irm_id, generation, mask, offset, false);
 }
  
 /**
@@ -322,7 +324,7 @@
  */
 void fw_iso_resource_manage(struct fw_card *card, int generation,
 			    u64 channels_mask, int *channel, int *bandwidth,
-			    bool allocate, __be32 buffer[2])
+			    bool allocate)
 {
 	u32 channels_hi = channels_mask;	/* channels 31...0 */
 	u32 channels_lo = channels_mask >> 32;	/* channels 63...32 */
  
@@ -335,11 +337,11 @@
 	if (channels_hi)
 		c = manage_channel(card, irm_id, generation, channels_hi,
 				CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
-				allocate, buffer);
+				allocate);
 	if (channels_lo && c < 0) {
 		c = manage_channel(card, irm_id, generation, channels_lo,
 				CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
-				allocate, buffer);
+				allocate);
 		if (c >= 0)
 			c += 32;
 	}
  
@@ -351,14 +353,13 @@
 	if (*bandwidth == 0)
 		return;
  
-	ret = manage_bandwidth(card, irm_id, generation, *bandwidth,
-			       allocate, buffer);
+	ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
 	if (ret < 0)
 		*bandwidth = 0;
  
 	if (allocate && ret < 0) {
 		if (c >= 0)
-			deallocate_channel(card, irm_id, generation, c, buffer);
+			deallocate_channel(card, irm_id, generation, c);
 		*channel = ret;
 	}
 }
@@ -326,8 +326,8 @@
  * It will contain tag, channel, and sy data instead of a node ID then.
  *
  * The payload buffer at @data is going to be DMA-mapped except in case of
- * quadlet-sized payload or of local (loopback) requests.  Hence make sure that
- * the buffer complies with the restrictions for DMA-mapped memory.  The
+ * @length <= 8 or of local (loopback) requests.  Hence make sure that the
+ * buffer complies with the restrictions of the streaming DMA mapping API.
  * @payload must not be freed before the @callback is called.
  *
  * In case of request types without payload, @data is NULL and @length is 0.
@@ -411,7 +411,8 @@
  *
  * Returns the RCODE.  See fw_send_request() for parameter documentation.
  * Unlike fw_send_request(), @data points to the payload of the request or/and
- * to the payload of the response.
+ * to the payload of the response.  DMA mapping restrictions apply to outbound
+ * request payloads of >= 8 bytes but not to inbound response payloads.
  */
 int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
 		       int generation, int speed, unsigned long long offset,
@@ -1320,14 +1320,10 @@
 {
 	int ret;
  
-	mutex_lock(&fdtv->avc_mutex);
-
 	ret = fdtv_read(fdtv, addr, data);
 	if (ret < 0)
 		dev_err(fdtv->device, "CMP: read I/O error\n");
  
-	mutex_unlock(&fdtv->avc_mutex);
-
 	return ret;
 }
  
  
@@ -1335,18 +1331,9 @@
 {
 	int ret;
  
-	mutex_lock(&fdtv->avc_mutex);
-
-	/* data[] is stack-allocated and should not be DMA-mapped. */
-	memcpy(fdtv->avc_data, data, 8);
-
-	ret = fdtv_lock(fdtv, addr, fdtv->avc_data);
+	ret = fdtv_lock(fdtv, addr, data);
 	if (ret < 0)
 		dev_err(fdtv->device, "CMP: lock I/O error\n");
-	else
-		memcpy(data, fdtv->avc_data, 8);
-
-	mutex_unlock(&fdtv->avc_mutex);
  
 	return ret;
 }
@@ -125,7 +125,6 @@
 	struct delayed_work bm_work; /* bus manager job */
 	int bm_retries;
 	int bm_generation;
-	__be32 bm_transaction_data[2];
 	int bm_node_id;
 	bool bm_abdicate;
  
@@ -447,7 +446,7 @@
 void fw_iso_context_destroy(struct fw_iso_context *ctx);
 void fw_iso_resource_manage(struct fw_card *card, int generation,
 			    u64 channels_mask, int *channel, int *bandwidth,
-			    bool allocate, __be32 buffer[2]);
+			    bool allocate);
  
 #endif /* _LINUX_FIREWIRE_H */
@@ -49,10 +49,9 @@
 		      enum bus_reset_handling bus_reset_handling)
 {
 	struct fw_device *device = fw_parent_device(c->resources.unit);
-	__be32 *buffer = c->resources.buffer;
 	int generation = c->resources.generation;
 	int rcode, errors = 0;
-	__be32 old_arg;
+	__be32 old_arg, buffer[2];
 	int err;
  
 	buffer[0] = c->last_pcr_value;
@@ -11,7 +11,6 @@
 #include <linux/jiffies.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
-#include <linux/slab.h>
 #include <linux/spinlock.h>
 #include "iso-resources.h"
  
@@ -25,10 +24,6 @@
  */
 int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit)
 {
-	r->buffer = kmalloc(2 * 4, GFP_KERNEL);
-	if (!r->buffer)
-		return -ENOMEM;
-
 	r->channels_mask = ~0uLL;
 	r->unit = fw_unit_get(unit);
 	mutex_init(&r->mutex);
@@ -44,7 +39,6 @@
 void fw_iso_resources_destroy(struct fw_iso_resources *r)
 {
 	WARN_ON(r->allocated);
-	kfree(r->buffer);
 	mutex_destroy(&r->mutex);
 	fw_unit_put(r->unit);
 }
@@ -131,7 +125,7 @@
  
 	bandwidth = r->bandwidth + r->bandwidth_overhead;
 	fw_iso_resource_manage(card, r->generation, r->channels_mask,
-			       &channel, &bandwidth, true, r->buffer);
+			       &channel, &bandwidth, true);
 	if (channel == -EAGAIN) {
 		mutex_unlock(&r->mutex);
 		goto retry_after_bus_reset;
@@ -184,7 +178,7 @@
 	bandwidth = r->bandwidth + r->bandwidth_overhead;
  
 	fw_iso_resource_manage(card, r->generation, 1uLL << r->channel,
-			       &channel, &bandwidth, true, r->buffer);
+			       &channel, &bandwidth, true);
 	/*
 	 * When another bus reset happens, pretend that the allocation
 	 * succeeded; we will try again for the new generation later.
@@ -220,7 +214,7 @@
 	if (r->allocated) {
 		bandwidth = r->bandwidth + r->bandwidth_overhead;
 		fw_iso_resource_manage(card, r->generation, 1uLL << r->channel,
-				       &channel, &bandwidth, false, r->buffer);
+				       &channel, &bandwidth, false);
 		if (channel < 0)
 			dev_err(&r->unit->device,
 				"isochronous resource deallocation failed\n");
@@ -24,7 +24,6 @@
 	unsigned int bandwidth_overhead;
 	int generation; /* in which allocation is valid */
 	bool allocated;
-	__be32 *buffer;
 };
  
 int fw_iso_resources_init(struct fw_iso_resources *r,
...	...	@@ -258,8 +258,7 @@
258	258
259	259	if (!card->broadcast_channel_allocated) {
260	260	fw_iso_resource_manage(card, generation, 1ULL << 31,
261		- &channel, &bandwidth, true,
262		- card->bm_transaction_data);
	261	+ &channel, &bandwidth, true);
263	262	if (channel != 31) {
264	263	fw_notify("failed to allocate broadcast channel\n");
265	264	return;
...	...	@@ -294,6 +293,7 @@
294	293	bool root_device_is_cmc;
295	294	bool irm_is_1394_1995_only;
296	295	bool keep_this_irm;
	296	+ __be32 transaction_data[2];
297	297
298	298	spin_lock_irq(&card->lock);
299	299
300	300
301	301
...	...	@@ -355,21 +355,21 @@
355	355	goto pick_me;
356	356	}
357	357
358		- card->bm_transaction_data[0] = cpu_to_be32(0x3f);
359		- card->bm_transaction_data[1] = cpu_to_be32(local_id);
	358	+ transaction_data[0] = cpu_to_be32(0x3f);
	359	+ transaction_data[1] = cpu_to_be32(local_id);
360	360
361	361	spin_unlock_irq(&card->lock);
362	362
363	363	rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
364	364	irm_id, generation, SCODE_100,
365	365	CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
366		- card->bm_transaction_data, 8);
	366	+ transaction_data, 8);
367	367
368	368	if (rcode == RCODE_GENERATION)
369	369	/* Another bus reset, BM work has been rescheduled. */
370	370	goto out;
371	371
372		- bm_id = be32_to_cpu(card->bm_transaction_data[0]);
	372	+ bm_id = be32_to_cpu(transaction_data[0]);
373	373
374	374	spin_lock_irq(&card->lock);
375	375	if (rcode == RCODE_COMPLETE && generation == card->generation)
376	376
...	...	@@ -490,11 +490,11 @@
490	490	/*
491	491	* Make sure that the cycle master sends cycle start packets.
492	492	*/
493		- card->bm_transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
	493	+ transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
494	494	rcode = fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
495	495	root_id, generation, SCODE_100,
496	496	CSR_REGISTER_BASE + CSR_STATE_SET,
497		- card->bm_transaction_data, 4);
	497	+ transaction_data, 4);
498	498	if (rcode == RCODE_GENERATION)
499	499	goto out;
500	500	}
...	...	@@ -141,7 +141,6 @@
141	141	int generation;
142	142	u64 channels;
143	143	s32 bandwidth;
144		- __be32 transaction_data[2];
145	144	struct iso_resource_event e_alloc, e_dealloc;
146	145	};
147	146
...	...	@@ -1229,8 +1228,7 @@
1229	1228	r->channels, &channel, &bandwidth,
1230	1229	todo == ISO_RES_ALLOC \|\|
1231	1230	todo == ISO_RES_REALLOC \|\|
1232		- todo == ISO_RES_ALLOC_ONCE,
1233		- r->transaction_data);
	1231	+ todo == ISO_RES_ALLOC_ONCE);
1234	1232	/*
1235	1233	* Is this generation outdated already? As long as this resource sticks
1236	1234	* in the idr, it will be scheduled again for a newer generation or at
...	...	@@ -196,9 +196,10 @@
196	196	*/
197	197
198	198	static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
199		- int bandwidth, bool allocate, __be32 data[2])
	199	+ int bandwidth, bool allocate)
200	200	{
201	201	int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
	202	+ __be32 data[2];
202	203
203	204	/*
204	205	* On a 1394a IRM with low contention, try < 1 is enough.
205	206
...	...	@@ -233,9 +234,10 @@
233	234	}
234	235
235	236	static int manage_channel(struct fw_card *card, int irm_id, int generation,
236		- u32 channels_mask, u64 offset, bool allocate, __be32 data[2])
	237	+ u32 channels_mask, u64 offset, bool allocate)
237	238	{
238	239	__be32 bit, all, old;
	240	+ __be32 data[2];
239	241	int channel, ret = -EIO, retry = 5;
240	242
241	243	old = all = allocate ? cpu_to_be32(~0) : 0;
...	...	@@ -284,7 +286,7 @@
284	286	}
285	287
286	288	static void deallocate_channel(struct fw_card *card, int irm_id,
287		- int generation, int channel, __be32 buffer[2])
	289	+ int generation, int channel)
288	290	{
289	291	u32 mask;
290	292	u64 offset;
...	...	@@ -293,7 +295,7 @@
293	295	offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
294	296	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
295	297
296		- manage_channel(card, irm_id, generation, mask, offset, false, buffer);
	298	+ manage_channel(card, irm_id, generation, mask, offset, false);
297	299	}
298	300
299	301	/**
...	...	@@ -322,7 +324,7 @@
322	324	*/
323	325	void fw_iso_resource_manage(struct fw_card *card, int generation,
324	326	u64 channels_mask, int channel, int bandwidth,
325		- bool allocate, __be32 buffer[2])
	327	+ bool allocate)
326	328	{
327	329	u32 channels_hi = channels_mask; /* channels 31...0 */
328	330	u32 channels_lo = channels_mask >> 32; /* channels 63...32 */
329	331
...	...	@@ -335,11 +337,11 @@
335	337	if (channels_hi)
336	338	c = manage_channel(card, irm_id, generation, channels_hi,
337	339	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
338		- allocate, buffer);
	340	+ allocate);
339	341	if (channels_lo && c < 0) {
340	342	c = manage_channel(card, irm_id, generation, channels_lo,
341	343	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
342		- allocate, buffer);
	344	+ allocate);
343	345	if (c >= 0)
344	346	c += 32;
345	347	}
346	348
...	...	@@ -351,14 +353,13 @@
351	353	if (*bandwidth == 0)
352	354	return;
353	355
354		- ret = manage_bandwidth(card, irm_id, generation, *bandwidth,
355		- allocate, buffer);
	356	+ ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
356	357	if (ret < 0)
357	358	*bandwidth = 0;
358	359
359	360	if (allocate && ret < 0) {
360	361	if (c >= 0)
361		- deallocate_channel(card, irm_id, generation, c, buffer);
	362	+ deallocate_channel(card, irm_id, generation, c);
362	363	*channel = ret;
363	364	}
364	365	}
...	...	@@ -326,8 +326,8 @@
326	326	* It will contain tag, channel, and sy data instead of a node ID then.
327	327	*
328	328	* The payload buffer at @data is going to be DMA-mapped except in case of
329		- * quadlet-sized payload or of local (loopback) requests. Hence make sure that
330		- * the buffer complies with the restrictions for DMA-mapped memory. The
	329	+ * @length <= 8 or of local (loopback) requests. Hence make sure that the
	330	+ * buffer complies with the restrictions of the streaming DMA mapping API.
331	331	* @payload must not be freed before the @callback is called.
332	332	*
333	333	* In case of request types without payload, @data is NULL and @length is 0.
...	...	@@ -411,7 +411,8 @@
411	411	*
412	412	* Returns the RCODE. See fw_send_request() for parameter documentation.
413	413	* Unlike fw_send_request(), @data points to the payload of the request or/and
414		- * to the payload of the response.
	414	+ * to the payload of the response. DMA mapping restrictions apply to outbound
	415	+ * request payloads of >= 8 bytes but not to inbound response payloads.
415	416	*/
416	417	int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
417	418	int generation, int speed, unsigned long long offset,
...	...	@@ -1320,14 +1320,10 @@
1320	1320	{
1321	1321	int ret;
1322	1322
1323		- mutex_lock(&fdtv->avc_mutex);
1324		-
1325	1323	ret = fdtv_read(fdtv, addr, data);
1326	1324	if (ret < 0)
1327	1325	dev_err(fdtv->device, "CMP: read I/O error\n");
1328	1326
1329		- mutex_unlock(&fdtv->avc_mutex);
1330		-
1331	1327	return ret;
1332	1328	}
1333	1329
1334	1330
...	...	@@ -1335,18 +1331,9 @@
1335	1331	{
1336	1332	int ret;
1337	1333
1338		- mutex_lock(&fdtv->avc_mutex);
1339		-
1340		- /* data[] is stack-allocated and should not be DMA-mapped. */
1341		- memcpy(fdtv->avc_data, data, 8);
1342		-
1343		- ret = fdtv_lock(fdtv, addr, fdtv->avc_data);
	1334	+ ret = fdtv_lock(fdtv, addr, data);
1344	1335	if (ret < 0)
1345	1336	dev_err(fdtv->device, "CMP: lock I/O error\n");
1346		- else
1347		- memcpy(data, fdtv->avc_data, 8);
1348		-
1349		- mutex_unlock(&fdtv->avc_mutex);
1350	1337
1351	1338	return ret;
1352	1339	}
...	...	@@ -125,7 +125,6 @@
125	125	struct delayed_work bm_work; /* bus manager job */
126	126	int bm_retries;
127	127	int bm_generation;
128		- __be32 bm_transaction_data[2];
129	128	int bm_node_id;
130	129	bool bm_abdicate;
131	130
...	...	@@ -447,7 +446,7 @@
447	446	void fw_iso_context_destroy(struct fw_iso_context *ctx);
448	447	void fw_iso_resource_manage(struct fw_card *card, int generation,
449	448	u64 channels_mask, int channel, int bandwidth,
450		- bool allocate, __be32 buffer[2]);
	449	+ bool allocate);
451	450
452	451	#endif /* _LINUX_FIREWIRE_H */
...	...	@@ -49,10 +49,9 @@
49	49	enum bus_reset_handling bus_reset_handling)
50	50	{
51	51	struct fw_device *device = fw_parent_device(c->resources.unit);
52		- __be32 *buffer = c->resources.buffer;
53	52	int generation = c->resources.generation;
54	53	int rcode, errors = 0;
55		- __be32 old_arg;
	54	+ __be32 old_arg, buffer[2];
56	55	int err;
57	56
58	57	buffer[0] = c->last_pcr_value;
...	...	@@ -11,7 +11,6 @@
11	11	#include <linux/jiffies.h>
12	12	#include <linux/mutex.h>
13	13	#include <linux/sched.h>
14		-#include <linux/slab.h>
15	14	#include <linux/spinlock.h>
16	15	#include "iso-resources.h"
17	16
...	...	@@ -25,10 +24,6 @@
25	24	*/
26	25	int fw_iso_resources_init(struct fw_iso_resources r, struct fw_unit unit)
27	26	{
28		- r->buffer = kmalloc(2 * 4, GFP_KERNEL);
29		- if (!r->buffer)
30		- return -ENOMEM;
31		-
32	27	r->channels_mask = ~0uLL;
33	28	r->unit = fw_unit_get(unit);
34	29	mutex_init(&r->mutex);
...	...	@@ -44,7 +39,6 @@
44	39	void fw_iso_resources_destroy(struct fw_iso_resources *r)
45	40	{
46	41	WARN_ON(r->allocated);
47		- kfree(r->buffer);
48	42	mutex_destroy(&r->mutex);
49	43	fw_unit_put(r->unit);
50	44	}
...	...	@@ -131,7 +125,7 @@
131	125
132	126	bandwidth = r->bandwidth + r->bandwidth_overhead;
133	127	fw_iso_resource_manage(card, r->generation, r->channels_mask,
134		- &channel, &bandwidth, true, r->buffer);
	128	+ &channel, &bandwidth, true);
135	129	if (channel == -EAGAIN) {
136	130	mutex_unlock(&r->mutex);
137	131	goto retry_after_bus_reset;
...	...	@@ -184,7 +178,7 @@
184	178	bandwidth = r->bandwidth + r->bandwidth_overhead;
185	179
186	180	fw_iso_resource_manage(card, r->generation, 1uLL << r->channel,
187		- &channel, &bandwidth, true, r->buffer);
	181	+ &channel, &bandwidth, true);
188	182	/*
189	183	* When another bus reset happens, pretend that the allocation
190	184	* succeeded; we will try again for the new generation later.
...	...	@@ -220,7 +214,7 @@
220	214	if (r->allocated) {
221	215	bandwidth = r->bandwidth + r->bandwidth_overhead;
222	216	fw_iso_resource_manage(card, r->generation, 1uLL << r->channel,
223		- &channel, &bandwidth, false, r->buffer);
	217	+ &channel, &bandwidth, false);
224	218	if (channel < 0)
225	219	dev_err(&r->unit->device,
226	220	"isochronous resource deallocation failed\n");
...	...	@@ -24,7 +24,6 @@
24	24	unsigned int bandwidth_overhead;
25	25	int generation; /* in which allocation is valid */
26	26	bool allocated;
27		- __be32 *buffer;
28	27	};
29	28
30	29	int fw_iso_resources_init(struct fw_iso_resources *r,