mpt3sas: Added Combined Reply Queue feature to extend up-to 96 MSIX vector support

mpt3sas: Added Combined Reply Queue feature to extend up-to 96 MSIX vector support

In this patch, increased the number of MSIX vector support for SAS3 C0 HBAs to
up-to 96.

Following are changes that are done in this patch

1. This feature is enabled only for SAS3 C0 and higher revision cards and also
only when reply post free queue count is greater than 8.

2. To support this feature 12 SupplementalReplyPostHostIndex system interfaces
are used. MSI-X index numbered from 0 to 7 use the first
SupplementalReplyPostHostIndex system interface to update its corresponding
ReplyPostHostIndex values, MSI-X index numbered from 8 to 15 will use the
second SupplementalReplyPostHostIndex system interface and so on. These 12
SuppementalReplyPostHostIndex system interfaces address are saved in the array
replyPostRegisterIndex[].

3. As each SupplementalReplyPostHostIndex register supports 8 MSI-X
vectors. So MSIxIndex field in these register must contain a value between 0
and 7.

4. After processing the reply descriptors from a reply post free queues then
update the new reply post host index value in ReplyPostHostIndex field and
(msix_index mod 8) value in MSIxIndex field of SupplementalReplyPostHostIndex
register. The Address of this SupplementalReplyPostHostIndex register is
retrived from (msix_index/8)th entry of replyPostRegisterIndex[] array.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>