mpt2sas: Added Reply Descriptor Post Queue (RDPQ) Array support

Up to now, Driver allocates a single contiguous block of memory
pool for all reply queues and passes down a single address in the
ReplyDescriptorPostQueueAddress field of the IOC Init Request
Message to the firmware.

When firmware receives this address, it will program each of the
Reply Descriptor Post Queue registers, as each reply queue has its
own register. Thus the firmware, starting from a base address it
determines the starting address of the subsequent reply queues
through some simple arithmetic calculations.

The size of this contiguous block of memory pool is directly proportional
to number of MSI-X vectors and the HBA queue depth. For example higher
MSIX vectors requires larger contiguous block of memory pool.

But some of the OS kernels are unable to allocate this larger
contiguous block of memory pool.

So, the proposal is to allocate memory independently for each
Reply Queue and pass down all of the addresses to the firmware.
Then the firmware will just take each address and program the value
into the correct register.

When HBAs with older firmware(i.e. without RDPQ capability) is used
with this new driver then the max_msix_vectors value would be set
to 8 by default.

Change_set in v1:

1. Declared _base_get_ioc_facts() function at the beginning of the mpt2sas_base.c
file instead of moving all these functions before mpt2sas_base_map_resources() function
        a. _base_wait_for_doorbell_int()
        b. _base_wait_for_doorbell_ack()
        c. _base_wait_for_doorbell_not_used()
        d. _base_handshake_req_reply_wait()
        e. _base_get_ioc_facts()

2. Initially set the consistent DMA mask to 32 bit and then change it to 64 bit mask
after allocating RDPQ pools by calling the function _base_change_consistent_dma_mask.
This is to ensure that all the upper 32 bits of RDPQ entries's base address to be same.

3. Reduced the redundancy between the RDPQ and non-RDPQ support in these following functions
        a. _base_release_memory_pools()
        b. _base_allocate_memory_pools()
        c. _base_send_ioc_init()
        d. _base_make_ioc_operational()
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/mpt2sas/mpt2sas_base.h

@@ -636,6 +636,11 @@ struct mpt2sas_port_facts {
 	u16			MaxPostedCmdBuffers;
 };
 
+struct reply_post_struct {
+	Mpi2ReplyDescriptorsUnion_t	*reply_post_free;
+	dma_addr_t			reply_post_free_dma;
+};
+
 /**
  * enum mutex_type - task management mutex type
  * @TM_MUTEX_OFF: mutex is not required becuase calling function is acquiring it
@@ -663,6 +668,7 @@ typedef void (*MPT2SAS_FLUSH_RUNNING_CMDS)(struct MPT2SAS_ADAPTER *ioc);
  * @ir_firmware: IR firmware present
  * @bars: bitmask of BAR's that must be configured
  * @mask_interrupts: ignore interrupt
+ * @dma_mask: used to set the consistent dma mask
  * @fault_reset_work_q_name: fw fault work queue
  * @fault_reset_work_q: ""
  * @fault_reset_work: ""
@@ -779,8 +785,11 @@ typedef void (*MPT2SAS_FLUSH_RUNNING_CMDS)(struct MPT2SAS_ADAPTER *ioc);
  * @reply_free_dma_pool:
  * @reply_free_host_index: tail index in pool to insert free replys
  * @reply_post_queue_depth: reply post queue depth
- * @reply_post_free: pool for reply post (64bit descriptor)
- * @reply_post_free_dma:
+ * @reply_post_struct: struct for reply_post_free physical & virt address
+ * @rdpq_array_capable: FW supports multiple reply queue addresses in ioc_init
+ * @rdpq_array_enable: rdpq_array support is enabled in the driver
+ * @rdpq_array_enable_assigned: this ensures that rdpq_array_enable flag
+ *				is assigned only ones
  * @reply_queue_count: number of reply queue's
  * @reply_queue_list: link list contaning the reply queue info
  * @reply_post_host_index: head index in the pool where FW completes IO
@@ -802,6 +811,7 @@ struct MPT2SAS_ADAPTER {
 	u8		ir_firmware;
 	int		bars;
 	u8		mask_interrupts;
+	int		dma_mask;
 
 	/* fw fault handler */
 	char		fault_reset_work_q_name[20];
@@ -972,8 +982,10 @@ struct MPT2SAS_ADAPTER {
 
 	/* reply post queue */
 	u16 		reply_post_queue_depth;
-	Mpi2ReplyDescriptorsUnion_t *reply_post_free;
-	dma_addr_t	reply_post_free_dma;
+	struct reply_post_struct *reply_post;
+	u8		rdpq_array_capable;
+	u8		rdpq_array_enable;
+	u8		rdpq_array_enable_assigned;
 	struct dma_pool *reply_post_free_dma_pool;
 	u8		reply_queue_count;
 	struct list_head reply_queue_list;