isci: unify request data structures

Make scic_sds_request a proper member of isci_request.  Also let's us
get rid of the dma pool object size tracking since we now know that all
requests are sizeof(isci_request).  While cleaning up the construct
routine incidentally replaced SCI_FIELD_OFFSET with offsetof.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

8 files changed, 26 insertions, 128 deletions

diff --git a/drivers/scsi/isci/core/sci_util.c b/drivers/scsi/isci/core/sci_util.c
index 0c75d14..4e60d55 100644
--- a/drivers/scsi/isci/core/sci_util.c
+++ b/drivers/scsi/isci/core/sci_util.c
@@ -59,14 +59,14 @@
 
 void *scic_request_get_virt_addr(struct scic_sds_request *sci_req, dma_addr_t phys_addr)
 {
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	dma_addr_t offset;
 
 	BUG_ON(phys_addr < ireq->request_daddr);
 
 	offset = phys_addr - ireq->request_daddr;
 
-	BUG_ON(offset >= ireq->request_alloc_size);
+	BUG_ON(offset >= sizeof(*ireq));
 
 	return (char *)ireq + offset;
 }
@@ -74,14 +74,13 @@ void *scic_request_get_virt_addr(struct scic_sds_request *sci_req, dma_addr_t ph
 dma_addr_t scic_io_request_get_dma_addr(struct scic_sds_request *sds_request,
 					void *virt_addr)
 {
-	struct isci_request *isci_request = sds_request->ireq;
+	struct isci_request *isci_request = sci_req_to_ireq(sds_request);
 
 	char *requested_addr = (char *)virt_addr;
 	char *base_addr = (char *)isci_request;
 
 	BUG_ON(requested_addr < base_addr);
-	BUG_ON((requested_addr - base_addr) >=
-			isci_request->request_alloc_size);
+	BUG_ON((requested_addr - base_addr) >= sizeof(*isci_request));
 
 	return isci_request->request_daddr + (requested_addr - base_addr);
 }
diff --git a/drivers/scsi/isci/core/sci_util.h b/drivers/scsi/isci/core/sci_util.h
index 4e9c318..0f9dd0f 100644
--- a/drivers/scsi/isci/core/sci_util.h
+++ b/drivers/scsi/isci/core/sci_util.h
@@ -66,9 +66,6 @@
 		| ((char_buffer)[3]) \
 	)
 
-#define SCI_FIELD_OFFSET(type, field)   ((unsigned long)&(((type *)0)->field))
-
-
 #define sci_cb_make_physical_address(physical_addr, addr_upper, addr_lower) \
 	((physical_addr) = (addr_lower) | ((u64)addr_upper) << 32)
 
diff --git a/drivers/scsi/isci/core/scic_io_request.h b/drivers/scsi/isci/core/scic_io_request.h
index cb3667d..f7c6d42 100644
--- a/drivers/scsi/isci/core/scic_io_request.h
+++ b/drivers/scsi/isci/core/scic_io_request.h
@@ -102,41 +102,10 @@ typedef enum {
 
 } SCIC_TRANSPORT_PROTOCOL;
 
-
-/**
- * scic_io_request_construct() - This method is called by the SCI user to
- *    construct all SCI Core IO requests.  Memory initialization and
- *    functionality common to all IO request types is performed in this method.
- * @scic_controller: the handle to the core controller object for which to
- *    build an IO request.
- * @scic_remote_device: the handle to the core remote device object for which
- *    to build an IO request.
- * @io_tag: This parameter specifies the IO tag to be associated with this
- *    request.  If SCI_CONTROLLER_INVALID_IO_TAG is passed, then a copy of the
- *    request is built internally.  The request will be copied into the actual
- *    controller request memory when the IO tag is allocated internally during
- *    the scic_controller_start_io() method.
- * @user_io_request_object: This parameter specifies the user IO request to be
- *    utilized during IO construction.  This IO pointer will become the
- *    associated object for the core IO request object.
- * @scic_io_request_memory: This parameter specifies the memory location to be
- *    utilized when building the core request.
- * @new_scic_io_request_handle: This parameter specifies a pointer to the
- *    handle the core will expect in further interactions with the core IO
- *    request object.
- *
- * The SCI core implementation will create an association between the user IO
- * request object and the core IO request object. Indicate if the controller
- * successfully built the IO request. SCI_SUCCESS This value is returned if the
- * IO request was successfully built.
- */
 enum sci_status scic_io_request_construct(
 	struct scic_sds_controller *scic_controller,
 	struct scic_sds_remote_device *scic_remote_device,
-	u16 io_tag,
-	void *user_io_request_object,
-	struct scic_sds_request *scic_io_request_memory,
-	struct scic_sds_request **new_scic_io_request_handle);
+	u16 io_tag, struct scic_sds_request *sci_req);
 
 /**
  * scic_io_request_construct_basic_ssp() - This method is called by the SCI
diff --git a/drivers/scsi/isci/core/scic_sds_controller.c b/drivers/scsi/isci/core/scic_sds_controller.c
index 4179bdf3..852b7d5 100644
--- a/drivers/scsi/isci/core/scic_sds_controller.c
+++ b/drivers/scsi/isci/core/scic_sds_controller.c
@@ -1572,7 +1572,7 @@ void scic_sds_controller_copy_task_context(
 
 	memcpy(task_context_buffer,
 	       sci_req->task_context_buffer,
-	       SCI_FIELD_OFFSET(struct scu_task_context, sgl_snapshot_ac));
+	       offsetof(struct scu_task_context, sgl_snapshot_ac));
 
 	/*
 	 * Now that the soft copy of the TC has been copied into the TC
diff --git a/drivers/scsi/isci/core/scic_sds_request.c b/drivers/scsi/isci/core/scic_sds_request.c
index 36c2b31..50dd19b 100644
--- a/drivers/scsi/isci/core/scic_sds_request.c
+++ b/drivers/scsi/isci/core/scic_sds_request.c
@@ -117,7 +117,7 @@ static struct scu_sgl_element_pair *scic_sds_request_get_sgl_element_pair(
  */
 void scic_sds_request_build_sgl(struct scic_sds_request *sds_request)
 {
-	struct isci_request *isci_request = sds_request->ireq;
+	struct isci_request *isci_request = sci_req_to_ireq(sds_request);
 	struct isci_host *isci_host = isci_request->isci_host;
 	struct sas_task *task = isci_request_access_task(isci_request);
 	struct scatterlist *sg = NULL;
@@ -190,7 +190,7 @@ static void scic_sds_ssp_io_request_assign_buffers(struct scic_sds_request *sci_
 static void scic_sds_io_request_build_ssp_command_iu(struct scic_sds_request *sci_req)
 {
 	struct ssp_cmd_iu *cmd_iu;
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	struct sas_task *task = isci_request_access_task(ireq);
 
 	cmd_iu = &sci_req->ssp.cmd;
@@ -211,7 +211,7 @@ static void scic_sds_io_request_build_ssp_command_iu(struct scic_sds_request *sc
 static void scic_sds_task_request_build_ssp_task_iu(struct scic_sds_request *sci_req)
 {
 	struct ssp_task_iu *task_iu;
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	struct sas_task *task = isci_request_access_task(ireq);
 	struct isci_tmf *isci_tmf = isci_request_access_tmf(ireq);
 
@@ -429,7 +429,7 @@ scic_io_request_construct_sata(struct scic_sds_request *sci_req,
 			       bool copy)
 {
 	enum sci_status status = SCI_SUCCESS;
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	struct sas_task *task = isci_request_access_task(ireq);
 
 	/* check for management protocols */
@@ -478,7 +478,7 @@ scic_io_request_construct_sata(struct scic_sds_request *sci_req,
 enum sci_status scic_io_request_construct_basic_ssp(
 	struct scic_sds_request *sci_req)
 {
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	struct sas_task *task = isci_request_access_task(ireq);
 
 	sci_req->protocol = SCIC_SSP_PROTOCOL;
@@ -519,7 +519,7 @@ enum sci_status scic_io_request_construct_basic_sata(
 	enum sci_status status;
 	struct scic_sds_stp_request *stp_req;
 	bool copy = false;
-	struct isci_request *isci_request = sci_req->ireq;
+	struct isci_request *isci_request = sci_req_to_ireq(sci_req);
 	struct sas_task *task = isci_request_access_task(isci_request);
 
 	stp_req = &sci_req->stp.req;
@@ -540,11 +540,10 @@ enum sci_status scic_io_request_construct_basic_sata(
 }
 
 
-enum sci_status scic_task_request_construct_sata(
-	struct scic_sds_request *sci_req)
+enum sci_status scic_task_request_construct_sata(struct scic_sds_request *sci_req)
 {
 	enum sci_status status = SCI_SUCCESS;
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 
 	/* check for management protocols */
 	if (ireq->ttype == tmf_task) {
@@ -740,7 +739,7 @@ void scic_sds_io_request_copy_response(struct scic_sds_request *sci_req)
 	void *resp_buf;
 	u32 len;
 	struct ssp_response_iu *ssp_response;
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	struct isci_tmf *isci_tmf = isci_request_access_tmf(ireq);
 
 	ssp_response = &sci_req->ssp.rsp;
@@ -1342,7 +1341,7 @@ static void scic_sds_request_completed_state_enter(void *object)
 	struct scic_sds_controller *scic =
 		scic_sds_request_get_controller(sci_req);
 	struct isci_host *ihost = scic_to_ihost(scic);
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 
 	SET_STATE_HANDLER(sci_req,
 			  scic_sds_request_state_handler_table,
@@ -1424,16 +1423,13 @@ static const struct sci_base_state scic_sds_request_state_table[] = {
 
 static void scic_sds_general_request_construct(struct scic_sds_controller *scic,
 					       struct scic_sds_remote_device *sci_dev,
-					       u16 io_tag,
-					       void *user_io_request_object,
-					       struct scic_sds_request *sci_req)
+					       u16 io_tag, struct scic_sds_request *sci_req)
 {
 	sci_base_state_machine_construct(&sci_req->state_machine, sci_req,
 			scic_sds_request_state_table, SCI_BASE_REQUEST_STATE_INITIAL);
 	sci_base_state_machine_start(&sci_req->state_machine);
 
 	sci_req->io_tag = io_tag;
-	sci_req->user_request = user_io_request_object;
 	sci_req->owning_controller = scic;
 	sci_req->target_device = sci_dev;
 	sci_req->has_started_substate_machine = false;
@@ -1461,20 +1457,13 @@ static void scic_sds_general_request_construct(struct scic_sds_controller *scic,
 enum sci_status
 scic_io_request_construct(struct scic_sds_controller *scic,
 			  struct scic_sds_remote_device *sci_dev,
-			  u16 io_tag,
-			  void *user_req,
-			  struct scic_sds_request *sci_req,
-			  struct scic_sds_request **new_sci_req)
+			  u16 io_tag, struct scic_sds_request *sci_req)
 {
 	struct domain_device *dev = sci_dev_to_domain(sci_dev);
 	enum sci_status status = SCI_SUCCESS;
 
 	/* Build the common part of the request */
-	scic_sds_general_request_construct(scic,
-					   sci_dev,
-					   io_tag,
-					   user_req,
-					   sci_req);
+	scic_sds_general_request_construct(scic, sci_dev, io_tag, sci_req);
 
 	if (sci_dev->rnc.remote_node_index ==
 			SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
@@ -1493,10 +1482,8 @@ scic_io_request_construct(struct scic_sds_controller *scic,
 		status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;
 
 	if (status == SCI_SUCCESS) {
-		memset(sci_req->task_context_buffer,
-		       0,
-		       SCI_FIELD_OFFSET(struct scu_task_context, sgl_pair_ab));
-		*new_sci_req = sci_req;
+		memset(sci_req->task_context_buffer, 0,
+		       offsetof(struct scu_task_context, sgl_pair_ab));
 	}
 
 	return status;
@@ -1504,18 +1491,13 @@ scic_io_request_construct(struct scic_sds_controller *scic,
 
 enum sci_status scic_task_request_construct(struct scic_sds_controller *scic,
 					    struct scic_sds_remote_device *sci_dev,
-					    u16 io_tag,
-					    void *user_io_request_object,
-					    struct scic_sds_request *sci_req,
-					    struct scic_sds_request **new_sci_req)
+					    u16 io_tag, struct scic_sds_request *sci_req)
 {
 	struct domain_device *dev = sci_dev_to_domain(sci_dev);
 	enum sci_status status = SCI_SUCCESS;
 
 	/* Build the common part of the request */
-	scic_sds_general_request_construct(scic, sci_dev, io_tag,
-					   user_io_request_object,
-					   sci_req);
+	scic_sds_general_request_construct(scic, sci_dev, io_tag, sci_req);
 
 	if (dev->dev_type == SAS_END_DEV) {
 		scic_sds_ssp_task_request_assign_buffers(sci_req);
@@ -1537,7 +1519,6 @@ enum sci_status scic_task_request_construct(struct scic_sds_controller *scic,
 	if (status == SCI_SUCCESS) {
 		sci_req->is_task_management_request = true;
 		memset(sci_req->task_context_buffer, 0, sizeof(struct scu_task_context));
-		*new_sci_req = sci_req;
 	}
 
 	return status;
diff --git a/drivers/scsi/isci/core/scic_sds_request.h b/drivers/scsi/isci/core/scic_sds_request.h
index 3f551ea..1dd98aa 100644
--- a/drivers/scsi/isci/core/scic_sds_request.h
+++ b/drivers/scsi/isci/core/scic_sds_request.h
@@ -113,26 +113,12 @@ enum scic_sds_smp_request_started_substates {
 	SCIC_SDS_SMP_REQUEST_STARTED_SUBSTATE_AWAIT_TC_COMPLETION,
 };
 
-struct isci_request;
-/**
- * struct scic_sds_request - This structure contains or references all of
- *    the data necessary to process a task management or normal IO request.
- *
- *
- */
 struct scic_sds_request {
 	/**
-	 * The field specifies that the peer object for the request object.
-	 */
-	struct isci_request *ireq;
-
-	/**
 	 * This field contains the information for the base request state machine.
 	 */
 	struct sci_base_state_machine state_machine;
 
-	void *user_request;
-
 	/**
 	 * This field simply points to the controller to which this IO request
 	 * is associated.
diff --git a/drivers/scsi/isci/core/scic_sds_stp_request.c b/drivers/scsi/isci/core/scic_sds_stp_request.c
index c7a8931..2677393 100644
--- a/drivers/scsi/isci/core/scic_sds_stp_request.c
+++ b/drivers/scsi/isci/core/scic_sds_stp_request.c
@@ -627,7 +627,7 @@ scic_sds_stp_request_pio_data_in_copy_data_buffer(struct scic_sds_stp_request *s
 	int total_len = len;
 
 	sci_req = to_sci_req(stp_req);
-	ireq = scic_sds_request_get_user_request(sci_req);
+	ireq = sci_req_to_ireq(sci_req);
 	task = isci_request_access_task(ireq);
 	src_addr = data_buf;
 
@@ -737,7 +737,7 @@ static enum sci_status scic_sds_stp_request_pio_await_frame_frame_handler(struct
 {
 	struct scic_sds_controller *scic = sci_req->owning_controller;
 	struct scic_sds_stp_request *stp_req = &sci_req->stp.req;
-	struct isci_request *ireq = sci_req->ireq;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
 	struct sas_task *task = isci_request_access_task(ireq);
 	struct dev_to_host_fis *frame_header;
 	enum sci_status status;
diff --git a/drivers/scsi/isci/core/scic_task_request.h b/drivers/scsi/isci/core/scic_task_request.h
index 7e6d20a..98cfaa9 100644
--- a/drivers/scsi/isci/core/scic_task_request.h
+++ b/drivers/scsi/isci/core/scic_task_request.h
@@ -72,44 +72,10 @@ struct scic_sds_remote_device;
 struct scic_sds_controller;
 
 
-/**
- * scic_task_request_construct() - This method is called by the SCI user to
- *    construct all SCI Core task management requests, regardless of protocol.
- *    Memory initialization and functionality common to all task request types
- *    is performed in this method.
- * @scic_controller: the handle to the core controller object for which to
- *    build the task managmement request.
- * @scic_remote_device: the handle to the core remote device object for which
- *    to build the task management request. passed, then a copy of the request
- *    is built internally.  The request will be copied into the actual
- *    controller request memory when the task is allocated internally during
- *    the scic_controller_start_task() method.
- * @io_tag: This parameter specifies the IO tag to be associated with this
- *    request.  If SCI_CONTROLLER_INVALID_IO_TAG is passed, then a copy of the
- *    request is built internally.  The request will be copied into the actual
- *    controller request memory when the IO tag is allocated internally during
- *    the scic_controller_start_io() method.
- * @user_task_request_object: This parameter specifies the user task request to
- *    be utilized during construction.  This task pointer will become the
- *    associated object for the core task request object.
- * @scic_task_request_memory: This parameter specifies the memory location to
- *    be utilized when building the core request.
- * @new_scic_task_request_handle: This parameter specifies a pointer to the
- *    handle the core will expect in further interactions with the core task
- *    request object.
- *
- * The SCI core implementation will create an association between the user task
- * request object and the core task request object. Indicate if the controller
- * successfully built the task request. SCI_SUCCESS This value is returned if
- * the task request was successfully built.
- */
 enum sci_status scic_task_request_construct(
 	struct scic_sds_controller *scic_controller,
 	struct scic_sds_remote_device *scic_remote_device,
-	u16 io_tag,
-	void *user_task_request_object,
-	void *scic_task_request_memory,
-	struct scic_sds_request **new_scic_task_request_handle);
+	u16 io_tag, struct scic_sds_request *sci_req);
 
 /**
  * scic_task_request_construct_ssp() - This method is called by the SCI user to