RDMA/mana_ib: Allocate PAGE aligned doorbell index

Allocate a PAGE aligned doorbell index to ensure each process gets a
separate PAGE sized doorbell area space remapped to it in mana_ib_mmap

Fixes: 0266a17 ("RDMA/mana_ib: Add a driver for Microsoft Azure Network Adapter")
Signed-off-by: Shiraz Saleem <shirazsaleem@microsoft.com>
Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
Link: https://patch.msgid.link/1738751405-15041-1-git-send-email-kotaranov@linux.microsoft.com
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: Konstantin Taranov

drivers/infiniband/hw/mana/main.c

@@ -174,7 +174,7 @@ static int mana_gd_allocate_doorbell_page(struct gdma_context *gc,
 
 	req.resource_type = GDMA_RESOURCE_DOORBELL_PAGE;
 	req.num_resources = 1;
-	req.alignment = 1;
+	req.alignment = PAGE_SIZE / MANA_PAGE_SIZE;
 
 	/* Have GDMA start searching from 0 */
 	req.allocated_resources = 0;