From 666b0fab76e2c32622ed6ee2cbcfe94ef4ca95da Mon Sep 17 00:00:00 2001
From: Jim Harris <jimharris@FreeBSD.org>
Date: Wed, 26 Jun 2013 22:08:45 +0000
Subject: [PATCH] For ATA_PASSTHROUGH commands, pretend isci(4) supports
 multiword DMA by treating it as UDMA.

This fixes a problem introduced in r249933/r249939, where CAM sends
ATA_DSM_TRIM to SATA devices using ATA_PASSTHROUGH_16.  scsi_ata_trim()
sets protocol as DMA (not UDMA) which is for multi-word DMA, even
though no such mode is selected for the device.  isci(4) would fail
these commands which is the correct behavior but not consistent with
other HBAs, namely LSI's.

smh@ did some further testing on an LSI controller, which rejected
ATA_PASSTHROUGH_16 commands with mode=UDMA_OUT, even though only
a UDMA mode was selected on the device.  So this precludes adding
any kind of mode detection in CAM to determine which mode to use on
a per-device basis.

Sponsored by:	Intel
Discussed with:	scottl, smh
Reported by:	scottl
Tested by:	scottl
MFC after:	3 days
---
 sys/dev/isci/scil/sati_passthrough.c | 49 +++++++++++++++++++++++++---
 1 file changed, 45 insertions(+), 4 deletions(-)

diff --git a/sys/dev/isci/scil/sati_passthrough.c b/sys/dev/isci/scil/sati_passthrough.c
index e35b5eaf4175..c2f3941d0be7 100644
--- a/sys/dev/isci/scil/sati_passthrough.c
+++ b/sys/dev/isci/scil/sati_passthrough.c
@@ -85,6 +85,7 @@ __FBSDID("$FreeBSD$");
 // Protocols
 #define PASSTHROUGH_PIO_DATA_IN            0x4
 #define PASSTHROUGH_PIO_DATA_OUT           0x5
+#define PASSTHROUGH_DMA                    0x6
 #define PASSTHROUGH_UDMA_DATA_IN           0xA
 #define PASSTHROUGH_UDMA_DATA_OUT          0xB
 #define PASSTHROUGH_RETURN_RESPONSE        0xF
@@ -252,8 +253,8 @@ SATI_STATUS sati_passthrough_check_direction(
    U8           * cdb
 )
 {
-   if ((PASSTHROUGH_CDB_PROTOCOL(cdb) == PASSTHROUGH_PIO_DATA_IN) ||
-       (PASSTHROUGH_CDB_PROTOCOL(cdb) == PASSTHROUGH_UDMA_DATA_IN))
+   if ((sequence->protocol == PASSTHROUGH_PIO_DATA_IN) ||
+       (sequence->protocol == PASSTHROUGH_UDMA_DATA_IN))
    {
       if (PASSTHROUGH_CDB_T_DIR(cdb) == 0x0)
       {
@@ -264,8 +265,8 @@ SATI_STATUS sati_passthrough_check_direction(
          sequence->data_direction = SATI_DATA_DIRECTION_IN;
       }
    }
-   else if ((PASSTHROUGH_CDB_PROTOCOL(cdb) == PASSTHROUGH_PIO_DATA_OUT) ||
-            (PASSTHROUGH_CDB_PROTOCOL(cdb) == PASSTHROUGH_UDMA_DATA_OUT))
+   else if ((sequence->protocol == PASSTHROUGH_PIO_DATA_OUT) ||
+            (sequence->protocol == PASSTHROUGH_UDMA_DATA_OUT))
    {
       if (PASSTHROUGH_CDB_T_DIR(cdb) == 0x1)
       {
@@ -318,6 +319,26 @@ SATI_STATUS sati_passthrough_12_translate_command(
    sequence->protocol = PASSTHROUGH_CDB_PROTOCOL (cdb);
    register_fis = sati_cb_get_h2d_register_fis_address(ata_io);
 
+   /*
+    * CAM will send passthrough commands with protocol set to multiword
+    * DMA even though no multiword DMA mode is selected on the device.
+    * This is because some controllers (LSI) will only accept
+    * ATA_PASSTHROUGH commands with DMA mode - not UDMA_IN/OUT.
+    *
+    * Since isci does not support multiword DMA, fix this up here.
+    */
+   if (sequence->protocol == PASSTHROUGH_DMA)
+   {
+      if (PASSTHROUGH_CDB_T_DIR(cdb) == 0x1)
+      {
+         sequence->protocol = PASSTHROUGH_UDMA_DATA_IN;
+      }
+      else
+      {
+         sequence->protocol = PASSTHROUGH_UDMA_DATA_OUT;
+      }
+   }
+
    if (sati_passthrough_check_direction(sequence, cdb) != SATI_COMPLETE
        || sati_passthrough_multiple_count_error(cdb)
       )
@@ -376,6 +397,26 @@ SATI_STATUS sati_passthrough_16_translate_command(
    sequence->protocol = PASSTHROUGH_CDB_PROTOCOL(cdb);
    register_fis = sati_cb_get_h2d_register_fis_address(ata_io);
 
+   /*
+    * CAM will send passthrough commands with protocol set to multiword
+    * DMA even though no multiword DMA mode is selected on the device.
+    * This is because some controllers (LSI) will only accept
+    * ATA_PASSTHROUGH commands with DMA mode - not UDMA_IN/OUT.
+    *
+    * Since isci does not support multiword DMA, fix this up here.
+    */
+   if (sequence->protocol == PASSTHROUGH_DMA)
+   {
+      if (PASSTHROUGH_CDB_T_DIR(cdb) == 0x1)
+      {
+         sequence->protocol = PASSTHROUGH_UDMA_DATA_IN;
+      }
+      else
+      {
+         sequence->protocol = PASSTHROUGH_UDMA_DATA_OUT;
+      }
+   }
+
    if (sati_passthrough_check_direction(sequence, cdb) != SATI_COMPLETE
        || sati_passthrough_multiple_count_error(cdb)
       )