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IBM VSCSI Client: handle large scatter/gather lists

PATCH In review Linda Xie 4 participants 4 messages Jun 29, 2005 – Sep 6, 2005

Subsystems (3)
SCSI PowerPC IBM Power Virtual SCSI Device Drivers
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Linda Xie

author
#0 lore raw

PATCH 1/1 IBM VSCSI Client: handle large scatter/gather lists

Hi James,

The maximum size of a scatter-gather list that the current IBM VSCSI Client can handle is 10. This patch adds large scatter-gather support to the client so that it is capable of handling up to
SG_ALL(255) number of requests in the scatter-gather list. Please consider it for inclusion in upstream.

Comments are always welcome.

Linda Xie
IBM LTC

Signed-off-by Linda Xie <[email protected]>
drivers/scsi/ibmvscsi/ibmvscsi.c +114 -42
diff -X ../dontdiff -purN madinfo/drivers/scsi/ibmvscsi/ibmvscsi.c large-sg/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -87,7 +87,7 @@ static int max_channel = 3;
 static int init_timeout = 5;
 static int max_requests = 50;
 
-#define IBMVSCSI_VERSION "1.5.6"
+#define IBMVSCSI_VERSION "1.5.7"
 
 MODULE_DESCRIPTION("IBM Virtual SCSI");
 MODULE_AUTHOR("Dave Boutcher");

@@ -145,6 +145,8 @@ static int initialize_event_pool(struct 
 			sizeof(*evt->xfer_iu) * i;
 		evt->xfer_iu = pool->iu_storage + i;
 		evt->hostdata = hostdata;
+		evt->ext_list = NULL;
+		evt->ext_list_token = 0;
 	}
 
 	return 0;

@@ -161,9 +163,16 @@ static void release_event_pool(struct ev
 			       struct ibmvscsi_host_data *hostdata)
 {
 	int i, in_use = 0;
-	for (i = 0; i < pool->size; ++i)
+	for (i = 0; i < pool->size; ++i) {
 		if (atomic_read(&pool->events[i].free) != 1)
 			++in_use;
+		if (pool->events[i].ext_list) {
+			dma_free_coherent(hostdata->dev,
+				  SG_ALL * sizeof(struct memory_descriptor),
+				  pool->events[i].ext_list,
+				  pool->events[i].ext_list_token);
+		}
+	}
 	if (in_use)
 		printk(KERN_WARNING
 		       "ibmvscsi: releasing event pool with %d "

@@ -286,24 +295,41 @@ static void set_srp_direction(struct scs
 	} else {
 		if (cmd->sc_data_direction == DMA_TO_DEVICE) {
 			srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
-			srp_cmd->data_out_count = numbuf;
+			srp_cmd->data_out_count =
+				numbuf < MAX_INDIRECT_BUFS ?
+					numbuf: MAX_INDIRECT_BUFS;
 		} else {
 			srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
-			srp_cmd->data_in_count = numbuf;
+			srp_cmd->data_in_count =
+				numbuf < MAX_INDIRECT_BUFS ?
+					numbuf: MAX_INDIRECT_BUFS;
 		}
 	}
 }
 
+static void unmap_sg_list(int num_entries, 
+		struct device *dev,
+		struct memory_descriptor *md)
+{ 
+	int i;
+
+	for (i = 0; i < num_entries; ++i) {
+		dma_unmap_single(dev,
+			md[i].virtual_address,
+			md[i].length, DMA_BIDIRECTIONAL);
+	}
+}
+
 /**
  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
  * @cmd:	srp_cmd whose additional_data member will be unmapped
  * @dev:	device for which the memory is mapped
  *
 */
-static void unmap_cmd_data(struct srp_cmd *cmd, struct device *dev)
+static void unmap_cmd_data(struct srp_cmd *cmd,
+			   struct srp_event_struct *evt_struct,
+			   struct device *dev)
 {
-	int i;
-
 	if ((cmd->data_out_format == SRP_NO_BUFFER) &&
 	    (cmd->data_in_format == SRP_NO_BUFFER))
 		return;

@@ -318,15 +344,34 @@ static void unmap_cmd_data(struct srp_cm
 			(struct indirect_descriptor *)cmd->additional_data;
 		int num_mapped = indirect->head.length / 
 			sizeof(indirect->list[0]);
-		for (i = 0; i < num_mapped; ++i) {
-			struct memory_descriptor *data = &indirect->list[i];
-			dma_unmap_single(dev,
-					 data->virtual_address,
-					 data->length, DMA_BIDIRECTIONAL);
+
+		if (num_mapped <= MAX_INDIRECT_BUFS) {
+			unmap_sg_list(num_mapped, dev, &indirect->list[0]);
+			return;
 		}
+
+		unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
 	}
 }
 
+static int map_sg_list(int num_entries, 
+		       struct scatterlist *sg,
+		       struct memory_descriptor *md)
+{
+	int i;
+	u64 total_length = 0;
+
+	for (i = 0; i < num_entries; ++i) {
+		struct memory_descriptor *descr = md + i;
+		struct scatterlist *sg_entry = &sg[i];
+		descr->virtual_address = sg_dma_address(sg_entry);
+		descr->length = sg_dma_len(sg_entry);
+		descr->memory_handle = 0;
+		total_length += sg_dma_len(sg_entry);
+ 	}
+	return total_length;
+}
+
 /**
  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
  * @cmd:	Scsi_Cmnd with the scatterlist

@@ -337,10 +382,11 @@ static void unmap_cmd_data(struct srp_cm
  * Returns 1 on success.
 */
 static int map_sg_data(struct scsi_cmnd *cmd,
+		       struct srp_event_struct *evt_struct,
 		       struct srp_cmd *srp_cmd, struct device *dev)
 {
 
-	int i, sg_mapped;
+	int sg_mapped;
 	u64 total_length = 0;
 	struct scatterlist *sg = cmd->request_buffer;
 	struct memory_descriptor *data =

@@ -363,27 +409,46 @@ static int map_sg_data(struct scsi_cmnd 
 		return 1;
 	}
 
-	if (sg_mapped > MAX_INDIRECT_BUFS) {
+	if (sg_mapped > SG_ALL) {
 		printk(KERN_ERR
 		       "ibmvscsi: More than %d mapped sg entries, got %d\n",
-		       MAX_INDIRECT_BUFS, sg_mapped);
+		       SG_ALL, sg_mapped);
 		return 0;
 	}
 
 	indirect->head.virtual_address = 0;
 	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
 	indirect->head.memory_handle = 0;
-	for (i = 0; i < sg_mapped; ++i) {
-		struct memory_descriptor *descr = &indirect->list[i];
-		struct scatterlist *sg_entry = &sg[i];
-		descr->virtual_address = sg_dma_address(sg_entry);
-		descr->length = sg_dma_len(sg_entry);
-		descr->memory_handle = 0;
-		total_length += sg_dma_len(sg_entry);
+
+	if (sg_mapped <= MAX_INDIRECT_BUFS) {
+		total_length = map_sg_list(sg_mapped, sg, &indirect->list[0]);
+		indirect->total_length = total_length;
+		return 1;
 	}
-	indirect->total_length = total_length;
 
-	return 1;
+	/* get indirect table */
+	if (!evt_struct->ext_list) {
+		evt_struct->ext_list =(struct memory_descriptor*)
+			dma_alloc_coherent(dev, 
+				SG_ALL * sizeof(struct memory_descriptor),
+				&evt_struct->ext_list_token, 0);
+		if (!evt_struct->ext_list) {
+		    printk(KERN_ERR
+		   	"ibmvscsi: Can't allocate memory for indirect table\n");
+			return 0;
+			
+		}
+	}
+
+	total_length = map_sg_list(sg_mapped, sg, evt_struct->ext_list);	
+
+	indirect->total_length = total_length;
+	indirect->head.virtual_address = evt_struct->ext_list_token;
+	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
+	memcpy(indirect->list, evt_struct->ext_list,
+		MAX_INDIRECT_BUFS * sizeof(struct memory_descriptor));
+	
+ 	return 1;
 }
 
 /**

@@ -428,6 +493,7 @@ static int map_single_data(struct scsi_c
  * Returns 1 on success.
 */
 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
+				struct srp_event_struct *evt_struct,
 				struct srp_cmd *srp_cmd, struct device *dev)
 {
 	switch (cmd->sc_data_direction) {

@@ -450,7 +516,7 @@ static int map_data_for_srp_cmd(struct s
 	if (!cmd->request_buffer)
 		return 1;
 	if (cmd->use_sg)
-		return map_sg_data(cmd, srp_cmd, dev);
+		return map_sg_data(cmd, evt_struct, srp_cmd, dev);
 	return map_single_data(cmd, srp_cmd, dev);
 }
 

@@ -486,6 +552,7 @@ static int ibmvscsi_send_srp_event(struc
 		printk(KERN_WARNING 
 		       "ibmvscsi: Warning, request_limit exceeded\n");
 		unmap_cmd_data(&evt_struct->iu.srp.cmd,
+			       evt_struct,
 			       hostdata->dev);
 		free_event_struct(&hostdata->pool, evt_struct);
 		return SCSI_MLQUEUE_HOST_BUSY;

@@ -513,7 +580,7 @@ static int ibmvscsi_send_srp_event(struc
 	return 0;
 
  send_error:
-	unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);
+	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 
 	if ((cmnd = evt_struct->cmnd) != NULL) {
 		cmnd->result = DID_ERROR << 16;

@@ -551,6 +618,7 @@ static void handle_cmd_rsp(struct srp_ev
 			       rsp->sense_and_response_data,
 			       rsp->sense_data_list_length);
 		unmap_cmd_data(&evt_struct->iu.srp.cmd, 
+			       evt_struct, 
 			       evt_struct->hostdata->dev);
 
 		if (rsp->doover)

@@ -583,6 +651,7 @@ static int ibmvscsi_queuecommand(struct 
 {
 	struct srp_cmd *srp_cmd;
 	struct srp_event_struct *evt_struct;
+	struct indirect_descriptor *indirect;
 	struct ibmvscsi_host_data *hostdata =
 		(struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
 	u16 lun = lun_from_dev(cmnd->device);

@@ -591,14 +660,6 @@ static int ibmvscsi_queuecommand(struct 
 	if (!evt_struct)
 		return SCSI_MLQUEUE_HOST_BUSY;
 
-	init_event_struct(evt_struct,
-			  handle_cmd_rsp,
-			  VIOSRP_SRP_FORMAT,
-			  cmnd->timeout);
-
-	evt_struct->cmnd = cmnd;
-	evt_struct->cmnd_done = done;
-
 	/* Set up the actual SRP IU */
 	srp_cmd = &evt_struct->iu.srp.cmd;
 	memset(srp_cmd, 0x00, sizeof(*srp_cmd));

@@ -606,17 +667,25 @@ static int ibmvscsi_queuecommand(struct 
 	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
 	srp_cmd->lun = ((u64) lun) << 48;
 
-	if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
+	if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
 		printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
 		free_event_struct(&hostdata->pool, evt_struct);
 		return SCSI_MLQUEUE_HOST_BUSY;
 	}
 
+	init_event_struct(evt_struct,
+			  handle_cmd_rsp,
+			  VIOSRP_SRP_FORMAT,
+			  cmnd->timeout);
+
+	evt_struct->cmnd = cmnd;
+	evt_struct->cmnd_done = done;
+
 	/* Fix up dma address of the buffer itself */
-	if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
-	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
-		struct indirect_descriptor *indirect =
-		    (struct indirect_descriptor *)srp_cmd->additional_data;
+	indirect = (struct indirect_descriptor *)srp_cmd->additional_data;
+	if (((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
+	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) &&
+	    (indirect->head.virtual_address == 0)) {
 		indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
 		    offsetof(struct srp_cmd, additional_data) +
 		    offsetof(struct indirect_descriptor, list);

@@ -924,7 +993,8 @@ static int ibmvscsi_eh_abort_handler(str
 
 	cmd->result = (DID_ABORT << 16);
 	list_del(&found_evt->list);
-	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
+	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
+		       found_evt->hostdata->dev);
 	free_event_struct(&found_evt->hostdata->pool, found_evt);
 	atomic_inc(&hostdata->request_limit);
 	return SUCCESS;

@@ -1011,7 +1081,8 @@ static int ibmvscsi_eh_device_reset_hand
 			if (tmp_evt->cmnd)
 				tmp_evt->cmnd->result = (DID_RESET << 16);
 			list_del(&tmp_evt->list);
-			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt->hostdata->dev);
+			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
+				       tmp_evt->hostdata->dev);
 			free_event_struct(&tmp_evt->hostdata->pool,
 						   tmp_evt);
 			atomic_inc(&hostdata->request_limit);

@@ -1039,6 +1110,7 @@ static void purge_requests(struct ibmvsc
 		if (tmp_evt->cmnd) {
 			tmp_evt->cmnd->result = (DID_ERROR << 16);
 			unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
+				       tmp_evt,	
 				       tmp_evt->hostdata->dev);
 			if (tmp_evt->cmnd_done)
 				tmp_evt->cmnd_done(tmp_evt->cmnd);

@@ -1343,7 +1415,7 @@ static struct scsi_host_template driver_
 	.cmd_per_lun = 16,
 	.can_queue = 1,		/* Updated after SRP_LOGIN */
 	.this_id = -1,
-	.sg_tablesize = MAX_INDIRECT_BUFS,
+	.sg_tablesize = SG_ALL,
 	.use_clustering = ENABLE_CLUSTERING,
 	.shost_attrs = ibmvscsi_attrs,
 };
drivers/scsi/ibmvscsi/ibmvscsi.h +2 -0
diff -X ../dontdiff -purN madinfo/drivers/scsi/ibmvscsi/ibmvscsi.h large-sg/drivers/scsi/ibmvscsi/ibmvscsi.h
@@ -68,6 +68,8 @@ struct srp_event_struct {
 	void (*cmnd_done) (struct scsi_cmnd *);
 	struct completion comp;
 	union viosrp_iu *sync_srp;
+	struct memory_descriptor *ext_list;
+	dma_addr_t ext_list_token;
 };
 
 /* a pool of event structs for use */
#1 lore raw

Hi,

Quoted 6 lines

The maximum size of a scatter-gather list that the current IBM VSCSI Client can handle is 10. This patch adds large scatter-gather support to the client so that it is capable of handling up to SG_ALL(255)
number of requests in the scatter-gather list. Please consider it
for inclusion in upstream.

Quoted 6 lines

Comments are always welcome.

Linda Xie
IBM LTC

Signed-off-by Linda Xie <[email protected]>

Any chance we could get this into 2.6.14? I just tested it on current git and as expected the number of sg elements increased. Testing a dd from a virtual disk with clustering disabled (to avoid physical merging effects) shows:

before:

size    sg count 
1       12295
2       54
3       28
4       45
5       32
6       19
7       17
8       69
9       13
10      18043

after:

size    sg count 
1       410
2       39
3       24
4       39
5       32
6       12
7       8
8       61
9       7
10      4
11      4
12      3
13      3
16      3
17      10
18      7
19      2
20      9
21      2
25      3
26      3
27      1
29      1
30      3
31      4
32      25844
39      1
43      1
62      1
64      1182

The peak at 32 entries is due to a 256kB limitation on the vscsi server.

Anton

drivers/scsi/ibmvscsi/ibmvscsi.c +114 -42
diff -X ../dontdiff -purN madinfo/drivers/scsi/ibmvscsi/ibmvscsi.c large-sg/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -87,7 +87,7 @@ static int max_channel = 3;
 static int init_timeout = 5;
 static int max_requests = 50;
 
-#define IBMVSCSI_VERSION "1.5.6"
+#define IBMVSCSI_VERSION "1.5.7"
 
 MODULE_DESCRIPTION("IBM Virtual SCSI");
 MODULE_AUTHOR("Dave Boutcher");

@@ -145,6 +145,8 @@ static int initialize_event_pool(struct 
 			sizeof(*evt->xfer_iu) * i;
 		evt->xfer_iu = pool->iu_storage + i;
 		evt->hostdata = hostdata;
+		evt->ext_list = NULL;
+		evt->ext_list_token = 0;
 	}
 
 	return 0;

@@ -161,9 +163,16 @@ static void release_event_pool(struct ev
 			       struct ibmvscsi_host_data *hostdata)
 {
 	int i, in_use = 0;
-	for (i = 0; i < pool->size; ++i)
+	for (i = 0; i < pool->size; ++i) {
 		if (atomic_read(&pool->events[i].free) != 1)
 			++in_use;
+		if (pool->events[i].ext_list) {
+			dma_free_coherent(hostdata->dev,
+				  SG_ALL * sizeof(struct memory_descriptor),
+				  pool->events[i].ext_list,
+				  pool->events[i].ext_list_token);
+		}
+	}
 	if (in_use)
 		printk(KERN_WARNING
 		       "ibmvscsi: releasing event pool with %d "

@@ -286,24 +295,41 @@ static void set_srp_direction(struct scs
 	} else {
 		if (cmd->sc_data_direction == DMA_TO_DEVICE) {
 			srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
-			srp_cmd->data_out_count = numbuf;
+			srp_cmd->data_out_count =
+				numbuf < MAX_INDIRECT_BUFS ?
+					numbuf: MAX_INDIRECT_BUFS;
 		} else {
 			srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
-			srp_cmd->data_in_count = numbuf;
+			srp_cmd->data_in_count =
+				numbuf < MAX_INDIRECT_BUFS ?
+					numbuf: MAX_INDIRECT_BUFS;
 		}
 	}
 }
 
+static void unmap_sg_list(int num_entries, 
+		struct device *dev,
+		struct memory_descriptor *md)
+{ 
+	int i;
+
+	for (i = 0; i < num_entries; ++i) {
+		dma_unmap_single(dev,
+			md[i].virtual_address,
+			md[i].length, DMA_BIDIRECTIONAL);
+	}
+}
+
 /**
  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
  * @cmd:	srp_cmd whose additional_data member will be unmapped
  * @dev:	device for which the memory is mapped
  *
 */
-static void unmap_cmd_data(struct srp_cmd *cmd, struct device *dev)
+static void unmap_cmd_data(struct srp_cmd *cmd,
+			   struct srp_event_struct *evt_struct,
+			   struct device *dev)
 {
-	int i;
-
 	if ((cmd->data_out_format == SRP_NO_BUFFER) &&
 	    (cmd->data_in_format == SRP_NO_BUFFER))
 		return;

@@ -318,15 +344,34 @@ static void unmap_cmd_data(struct srp_cm
 			(struct indirect_descriptor *)cmd->additional_data;
 		int num_mapped = indirect->head.length / 
 			sizeof(indirect->list[0]);
-		for (i = 0; i < num_mapped; ++i) {
-			struct memory_descriptor *data = &indirect->list[i];
-			dma_unmap_single(dev,
-					 data->virtual_address,
-					 data->length, DMA_BIDIRECTIONAL);
+
+		if (num_mapped <= MAX_INDIRECT_BUFS) {
+			unmap_sg_list(num_mapped, dev, &indirect->list[0]);
+			return;
 		}
+
+		unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
 	}
 }
 
+static int map_sg_list(int num_entries, 
+		       struct scatterlist *sg,
+		       struct memory_descriptor *md)
+{
+	int i;
+	u64 total_length = 0;
+
+	for (i = 0; i < num_entries; ++i) {
+		struct memory_descriptor *descr = md + i;
+		struct scatterlist *sg_entry = &sg[i];
+		descr->virtual_address = sg_dma_address(sg_entry);
+		descr->length = sg_dma_len(sg_entry);
+		descr->memory_handle = 0;
+		total_length += sg_dma_len(sg_entry);
+ 	}
+	return total_length;
+}
+
 /**
  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
  * @cmd:	Scsi_Cmnd with the scatterlist

@@ -337,10 +382,11 @@ static void unmap_cmd_data(struct srp_cm
  * Returns 1 on success.
 */
 static int map_sg_data(struct scsi_cmnd *cmd,
+		       struct srp_event_struct *evt_struct,
 		       struct srp_cmd *srp_cmd, struct device *dev)
 {
 
-	int i, sg_mapped;
+	int sg_mapped;
 	u64 total_length = 0;
 	struct scatterlist *sg = cmd->request_buffer;
 	struct memory_descriptor *data =

@@ -363,27 +409,46 @@ static int map_sg_data(struct scsi_cmnd 
 		return 1;
 	}
 
-	if (sg_mapped > MAX_INDIRECT_BUFS) {
+	if (sg_mapped > SG_ALL) {
 		printk(KERN_ERR
 		       "ibmvscsi: More than %d mapped sg entries, got %d\n",
-		       MAX_INDIRECT_BUFS, sg_mapped);
+		       SG_ALL, sg_mapped);
 		return 0;
 	}
 
 	indirect->head.virtual_address = 0;
 	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
 	indirect->head.memory_handle = 0;
-	for (i = 0; i < sg_mapped; ++i) {
-		struct memory_descriptor *descr = &indirect->list[i];
-		struct scatterlist *sg_entry = &sg[i];
-		descr->virtual_address = sg_dma_address(sg_entry);
-		descr->length = sg_dma_len(sg_entry);
-		descr->memory_handle = 0;
-		total_length += sg_dma_len(sg_entry);
+
+	if (sg_mapped <= MAX_INDIRECT_BUFS) {
+		total_length = map_sg_list(sg_mapped, sg, &indirect->list[0]);
+		indirect->total_length = total_length;
+		return 1;
 	}
-	indirect->total_length = total_length;
 
-	return 1;
+	/* get indirect table */
+	if (!evt_struct->ext_list) {
+		evt_struct->ext_list =(struct memory_descriptor*)
+			dma_alloc_coherent(dev, 
+				SG_ALL * sizeof(struct memory_descriptor),
+				&evt_struct->ext_list_token, 0);
+		if (!evt_struct->ext_list) {
+		    printk(KERN_ERR
+		   	"ibmvscsi: Can't allocate memory for indirect table\n");
+			return 0;
+			
+		}
+	}
+
+	total_length = map_sg_list(sg_mapped, sg, evt_struct->ext_list);	
+
+	indirect->total_length = total_length;
+	indirect->head.virtual_address = evt_struct->ext_list_token;
+	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
+	memcpy(indirect->list, evt_struct->ext_list,
+		MAX_INDIRECT_BUFS * sizeof(struct memory_descriptor));
+	
+ 	return 1;
 }
 
 /**

@@ -428,6 +493,7 @@ static int map_single_data(struct scsi_c
  * Returns 1 on success.
 */
 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
+				struct srp_event_struct *evt_struct,
 				struct srp_cmd *srp_cmd, struct device *dev)
 {
 	switch (cmd->sc_data_direction) {

@@ -450,7 +516,7 @@ static int map_data_for_srp_cmd(struct s
 	if (!cmd->request_buffer)
 		return 1;
 	if (cmd->use_sg)
-		return map_sg_data(cmd, srp_cmd, dev);
+		return map_sg_data(cmd, evt_struct, srp_cmd, dev);
 	return map_single_data(cmd, srp_cmd, dev);
 }
 

@@ -486,6 +552,7 @@ static int ibmvscsi_send_srp_event(struc
 		printk(KERN_WARNING 
 		       "ibmvscsi: Warning, request_limit exceeded\n");
 		unmap_cmd_data(&evt_struct->iu.srp.cmd,
+			       evt_struct,
 			       hostdata->dev);
 		free_event_struct(&hostdata->pool, evt_struct);
 		return SCSI_MLQUEUE_HOST_BUSY;

@@ -513,7 +580,7 @@ static int ibmvscsi_send_srp_event(struc
 	return 0;
 
  send_error:
-	unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);
+	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 
 	if ((cmnd = evt_struct->cmnd) != NULL) {
 		cmnd->result = DID_ERROR << 16;

@@ -551,6 +618,7 @@ static void handle_cmd_rsp(struct srp_ev
 			       rsp->sense_and_response_data,
 			       rsp->sense_data_list_length);
 		unmap_cmd_data(&evt_struct->iu.srp.cmd, 
+			       evt_struct, 
 			       evt_struct->hostdata->dev);
 
 		if (rsp->doover)

@@ -583,6 +651,7 @@ static int ibmvscsi_queuecommand(struct 
 {
 	struct srp_cmd *srp_cmd;
 	struct srp_event_struct *evt_struct;
+	struct indirect_descriptor *indirect;
 	struct ibmvscsi_host_data *hostdata =
 		(struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
 	u16 lun = lun_from_dev(cmnd->device);

@@ -591,14 +660,6 @@ static int ibmvscsi_queuecommand(struct 
 	if (!evt_struct)
 		return SCSI_MLQUEUE_HOST_BUSY;
 
-	init_event_struct(evt_struct,
-			  handle_cmd_rsp,
-			  VIOSRP_SRP_FORMAT,
-			  cmnd->timeout);
-
-	evt_struct->cmnd = cmnd;
-	evt_struct->cmnd_done = done;
-
 	/* Set up the actual SRP IU */
 	srp_cmd = &evt_struct->iu.srp.cmd;
 	memset(srp_cmd, 0x00, sizeof(*srp_cmd));

@@ -606,17 +667,25 @@ static int ibmvscsi_queuecommand(struct 
 	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
 	srp_cmd->lun = ((u64) lun) << 48;
 
-	if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
+	if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
 		printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
 		free_event_struct(&hostdata->pool, evt_struct);
 		return SCSI_MLQUEUE_HOST_BUSY;
 	}
 
+	init_event_struct(evt_struct,
+			  handle_cmd_rsp,
+			  VIOSRP_SRP_FORMAT,
+			  cmnd->timeout);
+
+	evt_struct->cmnd = cmnd;
+	evt_struct->cmnd_done = done;
+
 	/* Fix up dma address of the buffer itself */
-	if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
-	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
-		struct indirect_descriptor *indirect =
-		    (struct indirect_descriptor *)srp_cmd->additional_data;
+	indirect = (struct indirect_descriptor *)srp_cmd->additional_data;
+	if (((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
+	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) &&
+	    (indirect->head.virtual_address == 0)) {
 		indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
 		    offsetof(struct srp_cmd, additional_data) +
 		    offsetof(struct indirect_descriptor, list);

@@ -924,7 +993,8 @@ static int ibmvscsi_eh_abort_handler(str
 
 	cmd->result = (DID_ABORT << 16);
 	list_del(&found_evt->list);
-	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
+	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
+		       found_evt->hostdata->dev);
 	free_event_struct(&found_evt->hostdata->pool, found_evt);
 	atomic_inc(&hostdata->request_limit);
 	return SUCCESS;

@@ -1011,7 +1081,8 @@ static int ibmvscsi_eh_device_reset_hand
 			if (tmp_evt->cmnd)
 				tmp_evt->cmnd->result = (DID_RESET << 16);
 			list_del(&tmp_evt->list);
-			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt->hostdata->dev);
+			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
+				       tmp_evt->hostdata->dev);
 			free_event_struct(&tmp_evt->hostdata->pool,
 						   tmp_evt);
 			atomic_inc(&hostdata->request_limit);

@@ -1039,6 +1110,7 @@ static void purge_requests(struct ibmvsc
 		if (tmp_evt->cmnd) {
 			tmp_evt->cmnd->result = (DID_ERROR << 16);
 			unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
+				       tmp_evt,	
 				       tmp_evt->hostdata->dev);
 			if (tmp_evt->cmnd_done)
 				tmp_evt->cmnd_done(tmp_evt->cmnd);

@@ -1343,7 +1415,7 @@ static struct scsi_host_template driver_
 	.cmd_per_lun = 16,
 	.can_queue = 1,		/* Updated after SRP_LOGIN */
 	.this_id = -1,
-	.sg_tablesize = MAX_INDIRECT_BUFS,
+	.sg_tablesize = SG_ALL,
 	.use_clustering = ENABLE_CLUSTERING,
 	.shost_attrs = ibmvscsi_attrs,
 };
drivers/scsi/ibmvscsi/ibmvscsi.h +2 -0
diff -X ../dontdiff -purN madinfo/drivers/scsi/ibmvscsi/ibmvscsi.h large-sg/drivers/scsi/ibmvscsi/ibmvscsi.h
@@ -68,6 +68,8 @@ struct srp_event_struct {
 	void (*cmnd_done) (struct scsi_cmnd *);
 	struct completion comp;
 	union viosrp_iu *sync_srp;
+	struct memory_descriptor *ext_list;
+	dma_addr_t ext_list_token;
 };
 
 /* a pool of event structs for use */
#2 lore raw
Quoted 4 lines · Anton Blanchard

Any chance we could get this into 2.6.14? I just tested it on current git and as expected the number of sg elements increased. Testing a dd from a virtual disk with clustering disabled (to avoid physical merging effects) shows:

Yes ... but according to my records it wasn't acked by the maintainer ... does he agree?

James

#3 lore raw
Quoted 8 lines · James Bottomley
Quoted 4 lines · Anton Blanchard

Any chance we could get this into 2.6.14? I just tested it on current git and as expected the number of sg elements increased. Testing a dd from a virtual disk with clustering disabled (to avoid physical merging effects) shows:

Yes ... but according to my records it wasn't acked by the maintainer ... does he agree?

Yes. Acking Linda's patches has been on my todo list for month..sorry for the lag.

Signature · 1 line
Dave Boutcher