Merge tag 'isci-for-3.5' into misc

isci update for 3.5

1/ Rework remote-node-context (RNC) handling for proper management of
   the silicon state machine in error handling and hot-plug conditions.
   Further details below, suffice to say if the RNC is mismanaged the
   silicon state machines may lock up.

2/ Refactor the initialization code to be reused for suspend/resume support

3/ Miscellaneous bug fixes to address discovery issues and hardware
   compatibility.

RNC rework details from Jeff Skirvin:

In the controller, devices as they appear on a SAS domain (or
direct-attached SATA devices) are represented by memory structures known
as "Remote Node Contexts" (RNCs).  These structures are transferred from
main memory to the controller using a set of register commands; these
commands include setting up the context ("posting"), removing the
context ("invalidating"), and commands to control the scheduling of
commands and connections to that remote device ("suspensions" and
"resumptions").  There is a similar path to control RNC scheduling from
the protocol engine, which interprets the results of command and data
transmission and reception.

In general, the controller chooses among non-suspended RNCs to find one
that has work requiring scheduling the transmission of command and data
frames to a target.  Likewise, when a target tries to return data back
to the initiator, the state of the RNC is used by the controller to
determine how to treat the incoming request. As an example, if the RNC
is in the state "TX/RX Suspended", incoming SSP connection requests from
the target will be rejected by the controller hardware.  When an RNC is
"TX Suspended", it will not be selected by the controller hardware to
start outgoing command or data operations (with certain priority-based
exceptions).

As mentioned above, there are two sources for management of the RNC
states: commands from driver software, and the result of transmission
and reception conditions of commands and data signaled by the controller
hardware.  As an example of the latter, if an outgoing SSP command ends
with a OPEN_REJECT(BAD_DESTINATION) status, the RNC state will
transition to the "TX Suspended" state, and this is signaled by the
controller hardware in the status to the completion of the pending
command as well as signaled in a controller hardware event.  Examples of
the former are included in the patch changelogs.

Driver software is required to suspend the RNC in a "TX/RX Suspended"
condition before any outstanding commands can be terminated.  Failure to
guarantee this can lead to a complete hardware hang condition.  Earlier
versions of the driver software did not guarantee that an RNC was
correctly managed before I/O termination, and so operated in an unsafe
way.

Further, the driver performed unnecessary contortions to preserve the
remote device command state and so was more complicated than it needed
to be.  A simplifying driver assumption is that once an I/O has entered
the error handler path without having completed in the target, the
requirement on the driver is that all use of the sas_task must end.
Beyond that, recovery of operation is dependent on libsas and other
components to reset, rediscover and reconfigure the device before normal
operation can restart.  In the driver, this simplifying assumption meant
that the RNC management could be reduced to entry into the suspended
state, terminating the targeted I/O request, and resuming the RNC as
needed for device-specific management such as an SSP Abort Task or LUN
Reset Management request.

1 files changed, 5 insertions, 120 deletions

diff --git a/drivers/scsi/isci/request.h b/drivers/scsi/isci/request.h
index 057f2378452d..aff95317fcf4 100644
--- a/drivers/scsi/isci/request.h
+++ b/drivers/scsi/isci/request.h
@@ -61,30 +61,6 @@
 #include "scu_task_context.h"
 
 /**
- * struct isci_request_status - This enum defines the possible states of an I/O
- *    request.
- *
- *
- */
-enum isci_request_status {
-	unallocated = 0x00,
-	allocated   = 0x01,
-	started     = 0x02,
-	completed   = 0x03,
-	aborting    = 0x04,
-	aborted     = 0x05,
-	terminating = 0x06,
-	dead        = 0x07
-};
-
-enum sci_request_protocol {
-	SCIC_NO_PROTOCOL,
-	SCIC_SMP_PROTOCOL,
-	SCIC_SSP_PROTOCOL,
-	SCIC_STP_PROTOCOL
-}; /* XXX remove me, use sas_task.{dev|task_proto} instead */;
-
-/**
  * isci_stp_request - extra request infrastructure to handle pio/atapi protocol
  * @pio_len - number of bytes requested at PIO setup
  * @status - pio setup ending status value to tell us if we need
@@ -104,11 +80,14 @@ struct isci_stp_request {
 };
 
 struct isci_request {
-	enum isci_request_status status;
 	#define IREQ_COMPLETE_IN_TARGET 0
 	#define IREQ_TERMINATED 1
 	#define IREQ_TMF 2
 	#define IREQ_ACTIVE 3
+	#define IREQ_PENDING_ABORT 4 /* Set == device was not suspended yet */
+	#define IREQ_TC_ABORT_POSTED 5
+	#define IREQ_ABORT_PATH_ACTIVE 6
+	#define IREQ_NO_AUTO_FREE_TAG 7 /* Set when being explicitly managed */
 	unsigned long flags;
 	/* XXX kill ttype and ttype_ptr, allocate full sas_task */
 	union ttype_ptr_union {
@@ -116,11 +95,6 @@ struct isci_request {
 		struct isci_tmf *tmf_task_ptr;  /* When ttype==tmf_task */
 	} ttype_ptr;
 	struct isci_host *isci_host;
-	/* For use in the requests_to_{complete|abort} lists: */
-	struct list_head completed_node;
-	/* For use in the reqs_in_process list: */
-	struct list_head dev_node;
-	spinlock_t state_lock;
 	dma_addr_t request_daddr;
 	dma_addr_t zero_scatter_daddr;
 	unsigned int num_sg_entries;
@@ -140,7 +114,7 @@ struct isci_request {
 	struct isci_host *owning_controller;
 	struct isci_remote_device *target_device;
 	u16 io_tag;
-	enum sci_request_protocol protocol;
+	enum sas_protocol protocol;
 	u32 scu_status; /* hardware result */
 	u32 sci_status; /* upper layer disposition */
 	u32 post_context;
@@ -309,92 +283,6 @@ sci_io_request_get_dma_addr(struct isci_request *ireq, void *virt_addr)
 	return ireq->request_daddr + (requested_addr - base_addr);
 }
 
-/**
- * isci_request_change_state() - This function sets the status of the request
- *    object.
- * @request: This parameter points to the isci_request object
- * @status: This Parameter is the new status of the object
- *
- */
-static inline enum isci_request_status
-isci_request_change_state(struct isci_request *isci_request,
-			  enum isci_request_status status)
-{
-	enum isci_request_status old_state;
-	unsigned long flags;
-
-	dev_dbg(&isci_request->isci_host->pdev->dev,
-		"%s: isci_request = %p, state = 0x%x\n",
-		__func__,
-		isci_request,
-		status);
-
-	BUG_ON(isci_request == NULL);
-
-	spin_lock_irqsave(&isci_request->state_lock, flags);
-	old_state = isci_request->status;
-	isci_request->status = status;
-	spin_unlock_irqrestore(&isci_request->state_lock, flags);
-
-	return old_state;
-}
-
-/**
- * isci_request_change_started_to_newstate() - This function sets the status of
- *    the request object.
- * @request: This parameter points to the isci_request object
- * @status: This Parameter is the new status of the object
- *
- * state previous to any change.
- */
-static inline enum isci_request_status
-isci_request_change_started_to_newstate(struct isci_request *isci_request,
-					struct completion *completion_ptr,
-					enum isci_request_status newstate)
-{
-	enum isci_request_status old_state;
-	unsigned long flags;
-
-	spin_lock_irqsave(&isci_request->state_lock, flags);
-
-	old_state = isci_request->status;
-
-	if (old_state == started || old_state == aborting) {
-		BUG_ON(isci_request->io_request_completion != NULL);
-
-		isci_request->io_request_completion = completion_ptr;
-		isci_request->status = newstate;
-	}
-
-	spin_unlock_irqrestore(&isci_request->state_lock, flags);
-
-	dev_dbg(&isci_request->isci_host->pdev->dev,
-		"%s: isci_request = %p, old_state = 0x%x\n",
-		__func__,
-		isci_request,
-		old_state);
-
-	return old_state;
-}
-
-/**
- * isci_request_change_started_to_aborted() - This function sets the status of
- *    the request object.
- * @request: This parameter points to the isci_request object
- * @completion_ptr: This parameter is saved as the kernel completion structure
- *    signalled when the old request completes.
- *
- * state previous to any change.
- */
-static inline enum isci_request_status
-isci_request_change_started_to_aborted(struct isci_request *isci_request,
-				       struct completion *completion_ptr)
-{
-	return isci_request_change_started_to_newstate(isci_request,
-						       completion_ptr,
-						       aborted);
-}
-
 #define isci_request_access_task(req) ((req)->ttype_ptr.io_task_ptr)
 
 #define isci_request_access_tmf(req) ((req)->ttype_ptr.tmf_task_ptr)
@@ -404,8 +292,6 @@ struct isci_request *isci_tmf_request_from_tag(struct isci_host *ihost,
 					       u16 tag);
 int isci_request_execute(struct isci_host *ihost, struct isci_remote_device *idev,
 			 struct sas_task *task, u16 tag);
-void isci_terminate_pending_requests(struct isci_host *ihost,
-				     struct isci_remote_device *idev);
 enum sci_status
 sci_task_request_construct(struct isci_host *ihost,
 			    struct isci_remote_device *idev,
@@ -421,5 +307,4 @@ static inline int isci_task_is_ncq_recovery(struct sas_task *task)
 		task->ata_task.fis.lbal == ATA_LOG_SATA_NCQ);
 
 }
-
 #endif /* !defined(_ISCI_REQUEST_H_) */