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-rw-r--r--drivers/ieee1394/sbp2.c101
-rw-r--r--drivers/ieee1394/sbp2.h4
2 files changed, 50 insertions, 55 deletions
diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index baa063c9e6e..e312d5e2a64 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -1705,6 +1705,7 @@ static int sbp2_agent_reset(struct scsi_id_instance_data *scsi_id, int wait)
quadlet_t data;
u64 addr;
int retval;
+ unsigned long flags;
SBP2_DEBUG_ENTER();
@@ -1724,7 +1725,9 @@ static int sbp2_agent_reset(struct scsi_id_instance_data *scsi_id, int wait)
/*
* Need to make sure orb pointer is written on next command
*/
+ spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
scsi_id->last_orb = NULL;
+ spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
return 0;
}
@@ -1966,8 +1969,12 @@ static int sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id,
{
struct sbp2scsi_host_info *hi = scsi_id->hi;
struct sbp2_command_orb *command_orb = &command->command_orb;
- struct node_entry *ne = scsi_id->ne;
- u64 addr;
+ struct sbp2_command_orb *last_orb;
+ dma_addr_t last_orb_dma;
+ u64 addr = scsi_id->sbp2_command_block_agent_addr;
+ quadlet_t data[2];
+ size_t length;
+ unsigned long flags;
outstanding_orb_incr;
SBP2_ORB_DEBUG("sending command orb %p, total orbs = %x",
@@ -1982,64 +1989,50 @@ static int sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id,
/*
* Check to see if there are any previous orbs to use
*/
- if (scsi_id->last_orb == NULL) {
- quadlet_t data[2];
-
+ spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
+ last_orb = scsi_id->last_orb;
+ last_orb_dma = scsi_id->last_orb_dma;
+ if (!last_orb) {
/*
- * Ok, let's write to the target's management agent register
+ * last_orb == NULL means: We know that the target's fetch agent
+ * is not active right now.
*/
- addr = scsi_id->sbp2_command_block_agent_addr + SBP2_ORB_POINTER_OFFSET;
+ addr += SBP2_ORB_POINTER_OFFSET;
data[0] = ORB_SET_NODE_ID(hi->host->node_id);
data[1] = command->command_orb_dma;
sbp2util_cpu_to_be32_buffer(data, 8);
-
- SBP2_ORB_DEBUG("write command agent, command orb %p", command_orb);
-
- if (sbp2util_node_write_no_wait(ne, addr, data, 8) < 0) {
- SBP2_ERR("sbp2util_node_write_no_wait failed.\n");
- return -EIO;
- }
-
- SBP2_ORB_DEBUG("write command agent complete");
-
- scsi_id->last_orb = command_orb;
- scsi_id->last_orb_dma = command->command_orb_dma;
-
+ length = 8;
} else {
- quadlet_t data;
-
/*
- * We have an orb already sent (maybe or maybe not
- * processed) that we can append this orb to. So do so,
- * and ring the doorbell. Have to be very careful
- * modifying these next orb pointers, as they are accessed
- * both by the sbp2 device and us.
+ * last_orb != NULL means: We know that the target's fetch agent
+ * is (very probably) not dead or in reset state right now.
+ * We have an ORB already sent that we can append a new one to.
+ * The target's fetch agent may or may not have read this
+ * previous ORB yet.
*/
- scsi_id->last_orb->next_ORB_lo =
- cpu_to_be32(command->command_orb_dma);
+ pci_dma_sync_single_for_cpu(hi->host->pdev, last_orb_dma,
+ sizeof(struct sbp2_command_orb),
+ PCI_DMA_BIDIRECTIONAL);
+ last_orb->next_ORB_lo = cpu_to_be32(command->command_orb_dma);
+ wmb();
/* Tells hardware that this pointer is valid */
- scsi_id->last_orb->next_ORB_hi = 0x0;
- pci_dma_sync_single_for_device(hi->host->pdev,
- scsi_id->last_orb_dma,
+ last_orb->next_ORB_hi = 0;
+ pci_dma_sync_single_for_device(hi->host->pdev, last_orb_dma,
sizeof(struct sbp2_command_orb),
PCI_DMA_BIDIRECTIONAL);
+ addr += SBP2_DOORBELL_OFFSET;
+ data[0] = 0;
+ length = 4;
+ }
+ scsi_id->last_orb = command_orb;
+ scsi_id->last_orb_dma = command->command_orb_dma;
+ spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
- /*
- * Ring the doorbell
- */
- data = cpu_to_be32(command->command_orb_dma);
- addr = scsi_id->sbp2_command_block_agent_addr + SBP2_DOORBELL_OFFSET;
-
- SBP2_ORB_DEBUG("ring doorbell, command orb %p", command_orb);
-
- if (sbp2util_node_write_no_wait(ne, addr, &data, 4) < 0) {
- SBP2_ERR("sbp2util_node_write_no_wait failed");
- return -EIO;
- }
-
- scsi_id->last_orb = command_orb;
- scsi_id->last_orb_dma = command->command_orb_dma;
-
+ SBP2_ORB_DEBUG("write to %s register, command orb %p",
+ last_orb ? "DOORBELL" : "ORB_POINTER", command_orb);
+ if (sbp2util_node_write_no_wait(scsi_id->ne, addr, data, length) < 0) {
+ SBP2_ERR("sbp2util_node_write_no_wait failed.\n");
+ return -EIO;
}
return 0;
}
@@ -2231,14 +2224,16 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid, int dest
}
/*
- * Check here to see if there are no commands in-use. If there are none, we can
- * null out last orb so that next time around we write directly to the orb pointer...
- * Quick start saves one 1394 bus transaction.
+ * Check here to see if there are no commands in-use. If there
+ * are none, we know that the fetch agent left the active state
+ * _and_ that we did not reactivate it yet. Therefore clear
+ * last_orb so that next time we write directly to the
+ * ORB_POINTER register. That way the fetch agent does not need
+ * to refetch the next_ORB.
*/
spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
- if (list_empty(&scsi_id->sbp2_command_orb_inuse)) {
+ if (list_empty(&scsi_id->sbp2_command_orb_inuse))
scsi_id->last_orb = NULL;
- }
spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
} else {
diff --git a/drivers/ieee1394/sbp2.h b/drivers/ieee1394/sbp2.h
index b22ce1aa8fe..dd80906e8a9 100644
--- a/drivers/ieee1394/sbp2.h
+++ b/drivers/ieee1394/sbp2.h
@@ -46,8 +46,8 @@
#define ORB_SET_DIRECTION(value) ((value & 0x1) << 27)
struct sbp2_command_orb {
- volatile u32 next_ORB_hi;
- volatile u32 next_ORB_lo;
+ u32 next_ORB_hi;
+ u32 next_ORB_lo;
u32 data_descriptor_hi;
u32 data_descriptor_lo;
u32 misc;