cciss: add performant mode support for Stars/Sirius

Add a mode of controller operation called Performant Mode.  Even though
cciss has been deprecated in favor of hpsa there are new controllers due
out next year that HP must support in older vendor distros.  Vendors
require all fixes/features be upstream.  These new controllers support
only 16 commands in simple mode but support up to 1024 in performant mode.
This requires us to add this support at this late date.

The performant mode transport minimizes host PCI accesses by performinf
many completions per read.  PCI writes are posted so the host can write
then immediately get off the bus not waiting for the writwe to complete to
the target.  In the context of performant mode the host read out to a
controller pulls all posted writes into host memory ensuring the reply
queue is coherent.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 103 insertions, 6 deletions

diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index c527932d223a..8a9f5b58daa8 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -85,8 +85,8 @@ struct ctlr_info
         int     max_cmd_sgentries;
         SGDescriptor_struct **cmd_sg_list;
 
-#       define DOORBELL_INT     0
-#       define PERF_MODE_INT    1
+#       define PERF_MODE_INT    0
+#       define DOORBELL_INT     1
 #       define SIMPLE_MODE_INT  2
 #       define MEMQ_MODE_INT    3
         unsigned int intr[4];
@@ -137,10 +137,27 @@ struct ctlr_info
         struct list_head scan_list;
         struct completion scan_wait;
         struct device dev;
+        /*
+         * Performant mode tables.
+         */
+        u32 trans_support;
+        u32 trans_offset;
+        struct TransTable_struct *transtable;
+        unsigned long transMethod;
+
+        /*
+         * Performant mode completion buffer
+         */
+        u64 *reply_pool;
+        dma_addr_t reply_pool_dhandle;
+        u64 *reply_pool_head;
+        size_t reply_pool_size;
+        unsigned char reply_pool_wraparound;
+        u32 *blockFetchTable;
 };
 
-/*  Defining the diffent access_menthods */
-/*
+/*  Defining the diffent access_methods
+ *
  * Memory mapped FIFO interface (SMART 53xx cards)
  */
 #define SA5_DOORBELL    0x20
@@ -159,6 +176,15 @@ struct ctlr_info
 #define SA5B_INTR_PENDING       0x04
 #define FIFO_EMPTY              0xffffffff      
 #define CCISS_FIRMWARE_READY    0xffff0000 /* value in scratchpad register */
+/* Perf. mode flags */
+#define SA5_PERF_INTR_PENDING   0x04
+#define SA5_PERF_INTR_OFF       0x05
+#define SA5_OUTDB_STATUS_PERF_BIT       0x01
+#define SA5_OUTDB_CLEAR_PERF_BIT        0x01
+#define SA5_OUTDB_CLEAR         0xA0
+#define SA5_OUTDB_CLEAR_PERF_BIT        0x01
+#define SA5_OUTDB_STATUS        0x9C
+
 
 #define  CISS_ERROR_BIT         0x02
 
@@ -170,8 +196,9 @@ struct ctlr_info
 static void SA5_submit_command( ctlr_info_t *h, CommandList_struct *c) 
 {
 #ifdef CCISS_DEBUG
-         printk("Sending %x - down to controller\n", c->busaddr );
-#endif /* CCISS_DEBUG */ 
+        printk(KERN_WARNING "cciss%d: Sending %08x - down to controller\n",
+                        h->ctlr, c->busaddr);
+#endif /* CCISS_DEBUG */
          writel(c->busaddr, h->vaddr + SA5_REQUEST_PORT_OFFSET);
          h->commands_outstanding++;
          if ( h->commands_outstanding > h->max_outstanding)
@@ -214,6 +241,20 @@ static void SA5B_intr_mask(ctlr_info_t *h, unsigned long val)
                         h->vaddr + SA5_REPLY_INTR_MASK_OFFSET);
         }
 }
+
+/* Performant mode intr_mask */
+static void SA5_performant_intr_mask(ctlr_info_t *h, unsigned long val)
+{
+        if (val) { /* turn on interrupts */
+                h->interrupts_enabled = 1;
+                writel(0, h->vaddr + SA5_REPLY_INTR_MASK_OFFSET);
+        } else {
+                h->interrupts_enabled = 0;
+                writel(SA5_PERF_INTR_OFF,
+                                h->vaddr + SA5_REPLY_INTR_MASK_OFFSET);
+        }
+}
+
 /*
  *  Returns true if fifo is full.  
  * 
@@ -250,6 +291,40 @@ static unsigned long SA5_completed(ctlr_info_t *h)
         return ( register_value); 
 
 }
+
+/* Performant mode command completed */
+static unsigned long SA5_performant_completed(ctlr_info_t *h)
+{
+        unsigned long register_value = FIFO_EMPTY;
+
+        /* flush the controller write of the reply queue by reading
+         * outbound doorbell status register.
+         */
+        register_value = readl(h->vaddr + SA5_OUTDB_STATUS);
+        /* msi auto clears the interrupt pending bit. */
+        if (!(h->msi_vector || h->msix_vector)) {
+                writel(SA5_OUTDB_CLEAR_PERF_BIT, h->vaddr + SA5_OUTDB_CLEAR);
+                /* Do a read in order to flush the write to the controller
+                 * (as per spec.)
+                 */
+                register_value = readl(h->vaddr + SA5_OUTDB_STATUS);
+        }
+
+        if ((*(h->reply_pool_head) & 1) == (h->reply_pool_wraparound)) {
+                register_value = *(h->reply_pool_head);
+                (h->reply_pool_head)++;
+                h->commands_outstanding--;
+        } else {
+                register_value = FIFO_EMPTY;
+        }
+        /* Check for wraparound */
+        if (h->reply_pool_head == (h->reply_pool + h->max_commands)) {
+                h->reply_pool_head = h->reply_pool;
+                h->reply_pool_wraparound ^= 1;
+        }
+
+        return register_value;
+}
 /*
  *      Returns true if an interrupt is pending.. 
  */
@@ -280,6 +355,20 @@ static bool SA5B_intr_pending(ctlr_info_t *h)
         return 0 ;
 }
 
+static bool SA5_performant_intr_pending(ctlr_info_t *h)
+{
+        unsigned long register_value = readl(h->vaddr + SA5_INTR_STATUS);
+
+        if (!register_value)
+                return false;
+
+        if (h->msi_vector || h->msix_vector)
+                return true;
+
+        /* Read outbound doorbell to flush */
+        register_value = readl(h->vaddr + SA5_OUTDB_STATUS);
+        return register_value & SA5_OUTDB_STATUS_PERF_BIT;
+}
 
 static struct access_method SA5_access = {
         SA5_submit_command,
@@ -297,6 +386,14 @@ static struct access_method SA5B_access = {
         SA5_completed,
 };
 
+static struct access_method SA5_performant_access = {
+        SA5_submit_command,
+        SA5_performant_intr_mask,
+        SA5_fifo_full,
+        SA5_performant_intr_pending,
+        SA5_performant_completed,
+};
+
 struct board_type {
         __u32   board_id;
         char    *product_name;