Merge tag 'ntb-3.12' of git://github.com/jonmason/ntb

Pull NTB (non-transparent bridge) updates from Jon Mason:
 "NTB driver bug fixes to address issues in NTB-RP enablement, spad,
  debugfs, and USD/DSD identification.

  Add a workaround on Xeon NTB devices for b2bdoorbell errata.  Also,
  add new NTB driver features to support 32bit x86, DMA engine support,
  and NTB-RP support.

  Finally, a few clean-ups and update to MAINTAINERS for the NTB git
  tree and wiki location"

* tag 'ntb-3.12' of git://github.com/jonmason/ntb:
  ntb: clean up unnecessary MSI/MSI-X capability find
  MAINTAINERS: Add Website and Git Tree for NTB
  NTB: Update Version
  NTB: Comment Fix
  NTB: Remove unused variable
  NTB: Remove References of non-B2B BWD HW
  NTB: NTB-RP support
  NTB: Rename Variables for NTB-RP
  NTB: Use DMA Engine to Transmit and Receive
  NTB: Enable 32bit Support
  NTB: Update Device IDs
  NTB: BWD Link Recovery
  NTB: Xeon Errata Workaround
  NTB: Correct debugfs to work with more than 1 NTB Device
  NTB: Correct USD/DSD Identification
  NTB: Correct Number of Scratch Pad Registers
  NTB: Add Error Handling in ntb_device_setup

6 files changed, 855 insertions, 227 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index b6b29c38b6b6..99c6f35fb459 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5889,6 +5889,8 @@ F:	drivers/scsi/nsp32*
 NTB DRIVER
 M:      Jon Mason <jon.mason@intel.com>
 S:      Supported
+W:      https://github.com/jonmason/ntb/wiki
+T:      git git://github.com/jonmason/ntb.git
 F:      drivers/ntb/
 F:      drivers/net/ntb_netdev.c
 F:      include/linux/ntb.h
diff --git a/drivers/ntb/Kconfig b/drivers/ntb/Kconfig
index 37ee6495acc1..f69df793dbe2 100644
--- a/drivers/ntb/Kconfig
+++ b/drivers/ntb/Kconfig
@@ -1,7 +1,7 @@
 config NTB
        tristate "Intel Non-Transparent Bridge support"
        depends on PCI
-       depends on X86_64
+       depends on X86
        help
         The PCI-E Non-transparent bridge hardware is a point-to-point PCI-E bus
         connecting 2 systems.  When configured, writes to the device's PCI
diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index 2dacd19e1b8a..1cb6e51e6bda 100644
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -46,24 +46,30 @@
  * Jon Mason <jon.mason@intel.com>
  */
 #include <linux/debugfs.h>
+#include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/random.h>
 #include <linux/slab.h>
 #include "ntb_hw.h"
 #include "ntb_regs.h"
 
 #define NTB_NAME        "Intel(R) PCI-E Non-Transparent Bridge Driver"
-#define NTB_VER         "0.25"
+#define NTB_VER         "1.0"
 
 MODULE_DESCRIPTION(NTB_NAME);
 MODULE_VERSION(NTB_VER);
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_AUTHOR("Intel Corporation");
 
+static bool xeon_errata_workaround = true;
+module_param(xeon_errata_workaround, bool, 0644);
+MODULE_PARM_DESC(xeon_errata_workaround, "Workaround for the Xeon Errata");
+
 enum {
-        NTB_CONN_CLASSIC = 0,
+        NTB_CONN_TRANSPARENT = 0,
         NTB_CONN_B2B,
         NTB_CONN_RP,
 };
@@ -78,17 +84,27 @@ enum {
         BWD_HW,
 };
 
+static struct dentry *debugfs_dir;
+
+#define BWD_LINK_RECOVERY_TIME  500
+
 /* Translate memory window 0,1 to BAR 2,4 */
-#define MW_TO_BAR(mw)   (mw * 2 + 2)
+#define MW_TO_BAR(mw)   (mw * NTB_MAX_NUM_MW + 2)
 
 static DEFINE_PCI_DEVICE_TABLE(ntb_pci_tbl) = {
         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_BWD)},
         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_JSF)},
-        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_CLASSIC_JSF)},
-        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_RP_JSF)},
-        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_RP_SNB)},
         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SNB)},
-        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_CLASSIC_SNB)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_IVT)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_HSX)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_JSF)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_SNB)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_IVT)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_HSX)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_JSF)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_SNB)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_IVT)},
+        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_HSX)},
         {0}
 };
 MODULE_DEVICE_TABLE(pci, ntb_pci_tbl);
@@ -129,6 +145,7 @@ void ntb_unregister_event_callback(struct ntb_device *ndev)
  * ntb_register_db_callback() - register a callback for doorbell interrupt
  * @ndev: pointer to ntb_device instance
  * @idx: doorbell index to register callback, zero based
+ * @data: pointer to be returned to caller with every callback
  * @func: callback function to register
  *
  * This function registers a callback function for the doorbell interrupt
@@ -151,9 +168,9 @@ int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,
         ndev->db_cb[idx].data = data;
 
         /* unmask interrupt */
-        mask = readw(ndev->reg_ofs.pdb_mask);
+        mask = readw(ndev->reg_ofs.ldb_mask);
         clear_bit(idx * ndev->bits_per_vector, &mask);
-        writew(mask, ndev->reg_ofs.pdb_mask);
+        writew(mask, ndev->reg_ofs.ldb_mask);
 
         return 0;
 }
@@ -173,9 +190,9 @@ void ntb_unregister_db_callback(struct ntb_device *ndev, unsigned int idx)
         if (idx >= ndev->max_cbs || !ndev->db_cb[idx].callback)
                 return;
 
-        mask = readw(ndev->reg_ofs.pdb_mask);
+        mask = readw(ndev->reg_ofs.ldb_mask);
         set_bit(idx * ndev->bits_per_vector, &mask);
-        writew(mask, ndev->reg_ofs.pdb_mask);
+        writew(mask, ndev->reg_ofs.ldb_mask);
 
         ndev->db_cb[idx].callback = NULL;
 }
@@ -334,6 +351,23 @@ int ntb_read_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 *val)
 }
 
 /**
+ * ntb_get_mw_base() - get addr for the NTB memory window
+ * @ndev: pointer to ntb_device instance
+ * @mw: memory window number
+ *
+ * This function provides the base address of the memory window specified.
+ *
+ * RETURNS: address, or NULL on error.
+ */
+resource_size_t ntb_get_mw_base(struct ntb_device *ndev, unsigned int mw)
+{
+        if (mw >= ntb_max_mw(ndev))
+                return 0;
+
+        return pci_resource_start(ndev->pdev, MW_TO_BAR(mw));
+}
+
+/**
  * ntb_get_mw_vbase() - get virtual addr for the NTB memory window
  * @ndev: pointer to ntb_device instance
  * @mw: memory window number
@@ -345,7 +379,7 @@ int ntb_read_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 *val)
  */
 void __iomem *ntb_get_mw_vbase(struct ntb_device *ndev, unsigned int mw)
 {
-        if (mw >= NTB_NUM_MW)
+        if (mw >= ntb_max_mw(ndev))
                 return NULL;
 
         return ndev->mw[mw].vbase;
@@ -360,9 +394,9 @@ void __iomem *ntb_get_mw_vbase(struct ntb_device *ndev, unsigned int mw)
  *
  * RETURNS: the size of the memory window or zero on error
  */
-resource_size_t ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw)
+u64 ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw)
 {
-        if (mw >= NTB_NUM_MW)
+        if (mw >= ntb_max_mw(ndev))
                 return 0;
 
         return ndev->mw[mw].bar_sz;
@@ -380,7 +414,7 @@ resource_size_t ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw)
  */
 void ntb_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr)
 {
-        if (mw >= NTB_NUM_MW)
+        if (mw >= ntb_max_mw(ndev))
                 return;
 
         dev_dbg(&ndev->pdev->dev, "Writing addr %Lx to BAR %d\n", addr,
@@ -390,16 +424,16 @@ void ntb_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr)
 
         switch (MW_TO_BAR(mw)) {
         case NTB_BAR_23:
-                writeq(addr, ndev->reg_ofs.sbar2_xlat);
+                writeq(addr, ndev->reg_ofs.bar2_xlat);
                 break;
         case NTB_BAR_45:
-                writeq(addr, ndev->reg_ofs.sbar4_xlat);
+                writeq(addr, ndev->reg_ofs.bar4_xlat);
                 break;
         }
 }
 
 /**
- * ntb_ring_sdb() - Set the doorbell on the secondary/external side
+ * ntb_ring_doorbell() - Set the doorbell on the secondary/external side
  * @ndev: pointer to ntb_device instance
  * @db: doorbell to ring
  *
@@ -408,15 +442,58 @@ void ntb_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr)
  *
  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
  */
-void ntb_ring_sdb(struct ntb_device *ndev, unsigned int db)
+void ntb_ring_doorbell(struct ntb_device *ndev, unsigned int db)
 {
         dev_dbg(&ndev->pdev->dev, "%s: ringing doorbell %d\n", __func__, db);
 
         if (ndev->hw_type == BWD_HW)
-                writeq((u64) 1 << db, ndev->reg_ofs.sdb);
+                writeq((u64) 1 << db, ndev->reg_ofs.rdb);
         else
                 writew(((1 << ndev->bits_per_vector) - 1) <<
-                       (db * ndev->bits_per_vector), ndev->reg_ofs.sdb);
+                       (db * ndev->bits_per_vector), ndev->reg_ofs.rdb);
+}
+
+static void bwd_recover_link(struct ntb_device *ndev)
+{
+        u32 status;
+
+        /* Driver resets the NTB ModPhy lanes - magic! */
+        writeb(0xe0, ndev->reg_base + BWD_MODPHY_PCSREG6);
+        writeb(0x40, ndev->reg_base + BWD_MODPHY_PCSREG4);
+        writeb(0x60, ndev->reg_base + BWD_MODPHY_PCSREG4);
+        writeb(0x60, ndev->reg_base + BWD_MODPHY_PCSREG6);
+
+        /* Driver waits 100ms to allow the NTB ModPhy to settle */
+        msleep(100);
+
+        /* Clear AER Errors, write to clear */
+        status = readl(ndev->reg_base + BWD_ERRCORSTS_OFFSET);
+        dev_dbg(&ndev->pdev->dev, "ERRCORSTS = %x\n", status);
+        status &= PCI_ERR_COR_REP_ROLL;
+        writel(status, ndev->reg_base + BWD_ERRCORSTS_OFFSET);
+
+        /* Clear unexpected electrical idle event in LTSSM, write to clear */
+        status = readl(ndev->reg_base + BWD_LTSSMERRSTS0_OFFSET);
+        dev_dbg(&ndev->pdev->dev, "LTSSMERRSTS0 = %x\n", status);
+        status |= BWD_LTSSMERRSTS0_UNEXPECTEDEI;
+        writel(status, ndev->reg_base + BWD_LTSSMERRSTS0_OFFSET);
+
+        /* Clear DeSkew Buffer error, write to clear */
+        status = readl(ndev->reg_base + BWD_DESKEWSTS_OFFSET);
+        dev_dbg(&ndev->pdev->dev, "DESKEWSTS = %x\n", status);
+        status |= BWD_DESKEWSTS_DBERR;
+        writel(status, ndev->reg_base + BWD_DESKEWSTS_OFFSET);
+
+        status = readl(ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET);
+        dev_dbg(&ndev->pdev->dev, "IBSTERRRCRVSTS0 = %x\n", status);
+        status &= BWD_IBIST_ERR_OFLOW;
+        writel(status, ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET);
+
+        /* Releases the NTB state machine to allow the link to retrain */
+        status = readl(ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET);
+        dev_dbg(&ndev->pdev->dev, "LTSSMSTATEJMP = %x\n", status);
+        status &= ~BWD_LTSSMSTATEJMP_FORCEDETECT;
+        writel(status, ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET);
 }
 
 static void ntb_link_event(struct ntb_device *ndev, int link_state)
@@ -433,7 +510,8 @@ static void ntb_link_event(struct ntb_device *ndev, int link_state)
                 ndev->link_status = NTB_LINK_UP;
                 event = NTB_EVENT_HW_LINK_UP;
 
-                if (ndev->hw_type == BWD_HW)
+                if (ndev->hw_type == BWD_HW ||
+                    ndev->conn_type == NTB_CONN_TRANSPARENT)
                         status = readw(ndev->reg_ofs.lnk_stat);
                 else {
                         int rc = pci_read_config_word(ndev->pdev,
@@ -442,13 +520,16 @@ static void ntb_link_event(struct ntb_device *ndev, int link_state)
                         if (rc)
                                 return;
                 }
+
+                ndev->link_width = (status & NTB_LINK_WIDTH_MASK) >> 4;
+                ndev->link_speed = (status & NTB_LINK_SPEED_MASK);
                 dev_info(&ndev->pdev->dev, "Link Width %d, Link Speed %d\n",
-                         (status & NTB_LINK_WIDTH_MASK) >> 4,
-                         (status & NTB_LINK_SPEED_MASK));
+                         ndev->link_width, ndev->link_speed);
         } else {
                 dev_info(&ndev->pdev->dev, "Link Down\n");
                 ndev->link_status = NTB_LINK_DOWN;
                 event = NTB_EVENT_HW_LINK_DOWN;
+                /* Don't modify link width/speed, we need it in link recovery */
         }
 
         /* notify the upper layer if we have an event change */
@@ -488,6 +569,47 @@ static int ntb_link_status(struct ntb_device *ndev)
         return 0;
 }
 
+static void bwd_link_recovery(struct work_struct *work)
+{
+        struct ntb_device *ndev = container_of(work, struct ntb_device,
+                                               lr_timer.work);
+        u32 status32;
+
+        bwd_recover_link(ndev);
+        /* There is a potential race between the 2 NTB devices recovering at the
+         * same time.  If the times are the same, the link will not recover and
+         * the driver will be stuck in this loop forever.  Add a random interval
+         * to the recovery time to prevent this race.
+         */
+        msleep(BWD_LINK_RECOVERY_TIME + prandom_u32() % BWD_LINK_RECOVERY_TIME);
+
+        status32 = readl(ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET);
+        if (status32 & BWD_LTSSMSTATEJMP_FORCEDETECT)
+                goto retry;
+
+        status32 = readl(ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET);
+        if (status32 & BWD_IBIST_ERR_OFLOW)
+                goto retry;
+
+        status32 = readl(ndev->reg_ofs.lnk_cntl);
+        if (!(status32 & BWD_CNTL_LINK_DOWN)) {
+                unsigned char speed, width;
+                u16 status16;
+
+                status16 = readw(ndev->reg_ofs.lnk_stat);
+                width = (status16 & NTB_LINK_WIDTH_MASK) >> 4;
+                speed = (status16 & NTB_LINK_SPEED_MASK);
+                if (ndev->link_width != width || ndev->link_speed != speed)
+                        goto retry;
+        }
+
+        schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT);
+        return;
+
+retry:
+        schedule_delayed_work(&ndev->lr_timer, NTB_HB_TIMEOUT);
+}
+
 /* BWD doesn't have link status interrupt, poll on that platform */
 static void bwd_link_poll(struct work_struct *work)
 {
@@ -503,6 +625,16 @@ static void bwd_link_poll(struct work_struct *work)
                 if (rc)
                         dev_err(&ndev->pdev->dev,
                                 "Error determining link status\n");
+
+                /* Check to see if a link error is the cause of the link down */
+                if (ndev->link_status == NTB_LINK_DOWN) {
+                        u32 status32 = readl(ndev->reg_base +
+                                             BWD_LTSSMSTATEJMP_OFFSET);
+                        if (status32 & BWD_LTSSMSTATEJMP_FORCEDETECT) {
+                                schedule_delayed_work(&ndev->lr_timer, 0);
+                                return;
+                        }
+                }
         }
 
         schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT);
@@ -519,41 +651,174 @@ static int ntb_xeon_setup(struct ntb_device *ndev)
         if (rc)
                 return rc;
 
+        if (val & SNB_PPD_DEV_TYPE)
+                ndev->dev_type = NTB_DEV_USD;
+        else
+                ndev->dev_type = NTB_DEV_DSD;
+
         switch (val & SNB_PPD_CONN_TYPE) {
         case NTB_CONN_B2B:
+                dev_info(&ndev->pdev->dev, "Conn Type = B2B\n");
                 ndev->conn_type = NTB_CONN_B2B;
+                ndev->reg_ofs.ldb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
+                ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_PDBMSK_OFFSET;
+                ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET;
+                ndev->reg_ofs.bar2_xlat = ndev->reg_base + SNB_SBAR2XLAT_OFFSET;
+                ndev->reg_ofs.bar4_xlat = ndev->reg_base + SNB_SBAR4XLAT_OFFSET;
+                ndev->limits.max_spads = SNB_MAX_B2B_SPADS;
+
+                /* There is a Xeon hardware errata related to writes to
+                 * SDOORBELL or B2BDOORBELL in conjunction with inbound access
+                 * to NTB MMIO Space, which may hang the system.  To workaround
+                 * this use the second memory window to access the interrupt and
+                 * scratch pad registers on the remote system.
+                 */
+                if (xeon_errata_workaround) {
+                        if (!ndev->mw[1].bar_sz)
+                                return -EINVAL;
+
+                        ndev->limits.max_mw = SNB_ERRATA_MAX_MW;
+                        ndev->reg_ofs.spad_write = ndev->mw[1].vbase +
+                                                   SNB_SPAD_OFFSET;
+                        ndev->reg_ofs.rdb = ndev->mw[1].vbase +
+                                            SNB_PDOORBELL_OFFSET;
+
+                        /* Set the Limit register to 4k, the minimum size, to
+                         * prevent an illegal access
+                         */
+                        writeq(ndev->mw[1].bar_sz + 0x1000, ndev->reg_base +
+                               SNB_PBAR4LMT_OFFSET);
+                } else {
+                        ndev->limits.max_mw = SNB_MAX_MW;
+                        ndev->reg_ofs.spad_write = ndev->reg_base +
+                                                   SNB_B2B_SPAD_OFFSET;
+                        ndev->reg_ofs.rdb = ndev->reg_base +
+                                            SNB_B2B_DOORBELL_OFFSET;
+
+                        /* Disable the Limit register, just incase it is set to
+                         * something silly
+                         */
+                        writeq(0, ndev->reg_base + SNB_PBAR4LMT_OFFSET);
+                }
+
+                /* The Xeon errata workaround requires setting SBAR Base
+                 * addresses to known values, so that the PBAR XLAT can be
+                 * pointed at SBAR0 of the remote system.
+                 */
+                if (ndev->dev_type == NTB_DEV_USD) {
+                        writeq(SNB_MBAR23_DSD_ADDR, ndev->reg_base +
+                               SNB_PBAR2XLAT_OFFSET);
+                        if (xeon_errata_workaround)
+                                writeq(SNB_MBAR01_DSD_ADDR, ndev->reg_base +
+                                       SNB_PBAR4XLAT_OFFSET);
+                        else {
+                                writeq(SNB_MBAR45_DSD_ADDR, ndev->reg_base +
+                                       SNB_PBAR4XLAT_OFFSET);
+                                /* B2B_XLAT_OFFSET is a 64bit register, but can
+                                 * only take 32bit writes
+                                 */
+                                writel(SNB_MBAR01_DSD_ADDR & 0xffffffff,
+                                       ndev->reg_base + SNB_B2B_XLAT_OFFSETL);
+                                writel(SNB_MBAR01_DSD_ADDR >> 32,
+                                       ndev->reg_base + SNB_B2B_XLAT_OFFSETU);
+                        }
+
+                        writeq(SNB_MBAR01_USD_ADDR, ndev->reg_base +
+                               SNB_SBAR0BASE_OFFSET);
+                        writeq(SNB_MBAR23_USD_ADDR, ndev->reg_base +
+                               SNB_SBAR2BASE_OFFSET);
+                        writeq(SNB_MBAR45_USD_ADDR, ndev->reg_base +
+                               SNB_SBAR4BASE_OFFSET);
+                } else {
+                        writeq(SNB_MBAR23_USD_ADDR, ndev->reg_base +
+                               SNB_PBAR2XLAT_OFFSET);
+                        if (xeon_errata_workaround)
+                                writeq(SNB_MBAR01_USD_ADDR, ndev->reg_base +
+                                       SNB_PBAR4XLAT_OFFSET);
+                        else {
+                                writeq(SNB_MBAR45_USD_ADDR, ndev->reg_base +
+                                       SNB_PBAR4XLAT_OFFSET);
+                                /* B2B_XLAT_OFFSET is a 64bit register, but can
+                                 * only take 32bit writes
+                                 */
+                                writel(SNB_MBAR01_DSD_ADDR & 0xffffffff,
+                                       ndev->reg_base + SNB_B2B_XLAT_OFFSETL);
+                                writel(SNB_MBAR01_USD_ADDR >> 32,
+                                       ndev->reg_base + SNB_B2B_XLAT_OFFSETU);
+                        }
+                        writeq(SNB_MBAR01_DSD_ADDR, ndev->reg_base +
+                               SNB_SBAR0BASE_OFFSET);
+                        writeq(SNB_MBAR23_DSD_ADDR, ndev->reg_base +
+                               SNB_SBAR2BASE_OFFSET);
+                        writeq(SNB_MBAR45_DSD_ADDR, ndev->reg_base +
+                               SNB_SBAR4BASE_OFFSET);
+                }
                 break;
-        case NTB_CONN_CLASSIC:
         case NTB_CONN_RP:
+                dev_info(&ndev->pdev->dev, "Conn Type = RP\n");
+                ndev->conn_type = NTB_CONN_RP;
+
+                if (xeon_errata_workaround) {
+                        dev_err(&ndev->pdev->dev, 
+                                "NTB-RP disabled due to hardware errata.  To disregard this warning and potentially lock-up the system, add the parameter 'xeon_errata_workaround=0'.\n");
+                        return -EINVAL;
+                }
+
+                /* Scratch pads need to have exclusive access from the primary
+                 * or secondary side.  Halve the num spads so that each side can
+                 * have an equal amount.
+                 */
+                ndev->limits.max_spads = SNB_MAX_COMPAT_SPADS / 2;
+                /* Note: The SDOORBELL is the cause of the errata.  You REALLY
+                 * don't want to touch it.
+                 */
+                ndev->reg_ofs.rdb = ndev->reg_base + SNB_SDOORBELL_OFFSET;
+                ndev->reg_ofs.ldb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
+                ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_PDBMSK_OFFSET;
+                /* Offset the start of the spads to correspond to whether it is
+                 * primary or secondary
+                 */
+                ndev->reg_ofs.spad_write = ndev->reg_base + SNB_SPAD_OFFSET +
+                                           ndev->limits.max_spads * 4;
+                ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET;
+                ndev->reg_ofs.bar2_xlat = ndev->reg_base + SNB_SBAR2XLAT_OFFSET;
+                ndev->reg_ofs.bar4_xlat = ndev->reg_base + SNB_SBAR4XLAT_OFFSET;
+                ndev->limits.max_mw = SNB_MAX_MW;
+                break;
+        case NTB_CONN_TRANSPARENT:
+                dev_info(&ndev->pdev->dev, "Conn Type = TRANSPARENT\n");
+                ndev->conn_type = NTB_CONN_TRANSPARENT;
+                /* Scratch pads need to have exclusive access from the primary
+                 * or secondary side.  Halve the num spads so that each side can
+                 * have an equal amount.
+                 */
+                ndev->limits.max_spads = SNB_MAX_COMPAT_SPADS / 2;
+                ndev->reg_ofs.rdb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
+                ndev->reg_ofs.ldb = ndev->reg_base + SNB_SDOORBELL_OFFSET;
+                ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_SDBMSK_OFFSET;
+                ndev->reg_ofs.spad_write = ndev->reg_base + SNB_SPAD_OFFSET;
+                /* Offset the start of the spads to correspond to whether it is
+                 * primary or secondary
+                 */
+                ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET +
+                                          ndev->limits.max_spads * 4;
+                ndev->reg_ofs.bar2_xlat = ndev->reg_base + SNB_PBAR2XLAT_OFFSET;
+                ndev->reg_ofs.bar4_xlat = ndev->reg_base + SNB_PBAR4XLAT_OFFSET;
+
+                ndev->limits.max_mw = SNB_MAX_MW;
+                break;
         default:
-                dev_err(&ndev->pdev->dev, "Only B2B supported at this time\n");
+                /* Most likely caused by the remote NTB-RP device not being
+                 * configured
+                 */
+                dev_err(&ndev->pdev->dev, "Unknown PPD %x\n", val);
                 return -EINVAL;
         }
 
-        if (val & SNB_PPD_DEV_TYPE)
-                ndev->dev_type = NTB_DEV_DSD;
-        else
-                ndev->dev_type = NTB_DEV_USD;
-
-        ndev->reg_ofs.pdb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
-        ndev->reg_ofs.pdb_mask = ndev->reg_base + SNB_PDBMSK_OFFSET;
-        ndev->reg_ofs.sbar2_xlat = ndev->reg_base + SNB_SBAR2XLAT_OFFSET;
-        ndev->reg_ofs.sbar4_xlat = ndev->reg_base + SNB_SBAR4XLAT_OFFSET;
         ndev->reg_ofs.lnk_cntl = ndev->reg_base + SNB_NTBCNTL_OFFSET;
-        ndev->reg_ofs.lnk_stat = ndev->reg_base + SNB_LINK_STATUS_OFFSET;
-        ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET;
+        ndev->reg_ofs.lnk_stat = ndev->reg_base + SNB_SLINK_STATUS_OFFSET;
         ndev->reg_ofs.spci_cmd = ndev->reg_base + SNB_PCICMD_OFFSET;
 
-        if (ndev->conn_type == NTB_CONN_B2B) {
-                ndev->reg_ofs.sdb = ndev->reg_base + SNB_B2B_DOORBELL_OFFSET;
-                ndev->reg_ofs.spad_write = ndev->reg_base + SNB_B2B_SPAD_OFFSET;
-                ndev->limits.max_spads = SNB_MAX_SPADS;
-        } else {
-                ndev->reg_ofs.sdb = ndev->reg_base + SNB_SDOORBELL_OFFSET;
-                ndev->reg_ofs.spad_write = ndev->reg_base + SNB_SPAD_OFFSET;
-                ndev->limits.max_spads = SNB_MAX_COMPAT_SPADS;
-        }
-
         ndev->limits.max_db_bits = SNB_MAX_DB_BITS;
         ndev->limits.msix_cnt = SNB_MSIX_CNT;
         ndev->bits_per_vector = SNB_DB_BITS_PER_VEC;
@@ -578,7 +843,7 @@ static int ntb_bwd_setup(struct ntb_device *ndev)
                 break;
         case NTB_CONN_RP:
         default:
-                dev_err(&ndev->pdev->dev, "Only B2B supported at this time\n");
+                dev_err(&ndev->pdev->dev, "Unsupported NTB configuration\n");
                 return -EINVAL;
         }
 
@@ -593,31 +858,25 @@ static int ntb_bwd_setup(struct ntb_device *ndev)
         if (rc)
                 return rc;
 
-        ndev->reg_ofs.pdb = ndev->reg_base + BWD_PDOORBELL_OFFSET;
-        ndev->reg_ofs.pdb_mask = ndev->reg_base + BWD_PDBMSK_OFFSET;
-        ndev->reg_ofs.sbar2_xlat = ndev->reg_base + BWD_SBAR2XLAT_OFFSET;
-        ndev->reg_ofs.sbar4_xlat = ndev->reg_base + BWD_SBAR4XLAT_OFFSET;
+        ndev->reg_ofs.ldb = ndev->reg_base + BWD_PDOORBELL_OFFSET;
+        ndev->reg_ofs.ldb_mask = ndev->reg_base + BWD_PDBMSK_OFFSET;
+        ndev->reg_ofs.rdb = ndev->reg_base + BWD_B2B_DOORBELL_OFFSET;
+        ndev->reg_ofs.bar2_xlat = ndev->reg_base + BWD_SBAR2XLAT_OFFSET;
+        ndev->reg_ofs.bar4_xlat = ndev->reg_base + BWD_SBAR4XLAT_OFFSET;
         ndev->reg_ofs.lnk_cntl = ndev->reg_base + BWD_NTBCNTL_OFFSET;
         ndev->reg_ofs.lnk_stat = ndev->reg_base + BWD_LINK_STATUS_OFFSET;
         ndev->reg_ofs.spad_read = ndev->reg_base + BWD_SPAD_OFFSET;
+        ndev->reg_ofs.spad_write = ndev->reg_base + BWD_B2B_SPAD_OFFSET;
         ndev->reg_ofs.spci_cmd = ndev->reg_base + BWD_PCICMD_OFFSET;
-
-        if (ndev->conn_type == NTB_CONN_B2B) {
-                ndev->reg_ofs.sdb = ndev->reg_base + BWD_B2B_DOORBELL_OFFSET;
-                ndev->reg_ofs.spad_write = ndev->reg_base + BWD_B2B_SPAD_OFFSET;
-                ndev->limits.max_spads = BWD_MAX_SPADS;
-        } else {
-                ndev->reg_ofs.sdb = ndev->reg_base + BWD_PDOORBELL_OFFSET;
-                ndev->reg_ofs.spad_write = ndev->reg_base + BWD_SPAD_OFFSET;
-                ndev->limits.max_spads = BWD_MAX_COMPAT_SPADS;
-        }
-
+        ndev->limits.max_mw = BWD_MAX_MW;
+        ndev->limits.max_spads = BWD_MAX_SPADS;
         ndev->limits.max_db_bits = BWD_MAX_DB_BITS;
         ndev->limits.msix_cnt = BWD_MSIX_CNT;
         ndev->bits_per_vector = BWD_DB_BITS_PER_VEC;
 
         /* Since bwd doesn't have a link interrupt, setup a poll timer */
         INIT_DELAYED_WORK(&ndev->hb_timer, bwd_link_poll);
+        INIT_DELAYED_WORK(&ndev->lr_timer, bwd_link_recovery);
         schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT);
 
         return 0;
@@ -628,13 +887,18 @@ static int ntb_device_setup(struct ntb_device *ndev)
         int rc;
 
         switch (ndev->pdev->device) {
-        case PCI_DEVICE_ID_INTEL_NTB_2ND_SNB:
-        case PCI_DEVICE_ID_INTEL_NTB_RP_JSF:
-        case PCI_DEVICE_ID_INTEL_NTB_RP_SNB:
-        case PCI_DEVICE_ID_INTEL_NTB_CLASSIC_JSF:
-        case PCI_DEVICE_ID_INTEL_NTB_CLASSIC_SNB:
+        case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
+        case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
+        case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
+        case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
+        case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
+        case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
+        case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
+        case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
         case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
         case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
+        case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
+        case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
                 rc = ntb_xeon_setup(ndev);
                 break;
         case PCI_DEVICE_ID_INTEL_NTB_B2B_BWD:
@@ -644,16 +908,26 @@ static int ntb_device_setup(struct ntb_device *ndev)
                 rc = -ENODEV;
         }
 
-        /* Enable Bus Master and Memory Space on the secondary side */
-        writew(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER, ndev->reg_ofs.spci_cmd);
+        if (rc)
+                return rc;
+
+        dev_info(&ndev->pdev->dev, "Device Type = %s\n",
+                 ndev->dev_type == NTB_DEV_USD ? "USD/DSP" : "DSD/USP");
 
-        return rc;
+        if (ndev->conn_type == NTB_CONN_B2B)
+                /* Enable Bus Master and Memory Space on the secondary side */
+                writew(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
+                       ndev->reg_ofs.spci_cmd);
+
+        return 0;
 }
 
 static void ntb_device_free(struct ntb_device *ndev)
 {
-        if (ndev->hw_type == BWD_HW)
+        if (ndev->hw_type == BWD_HW) {
                 cancel_delayed_work_sync(&ndev->hb_timer);
+                cancel_delayed_work_sync(&ndev->lr_timer);
+        }
 }
 
 static irqreturn_t bwd_callback_msix_irq(int irq, void *data)
@@ -672,7 +946,7 @@ static irqreturn_t bwd_callback_msix_irq(int irq, void *data)
          */
         ndev->last_ts = jiffies;
 
-        writeq((u64) 1 << db_cb->db_num, ndev->reg_ofs.pdb);
+        writeq((u64) 1 << db_cb->db_num, ndev->reg_ofs.ldb);
 
         return IRQ_HANDLED;
 }
@@ -694,7 +968,7 @@ static irqreturn_t xeon_callback_msix_irq(int irq, void *data)
          * interrupts.
          */
         writew(((1 << ndev->bits_per_vector) - 1) <<
-               (db_cb->db_num * ndev->bits_per_vector), ndev->reg_ofs.pdb);
+               (db_cb->db_num * ndev->bits_per_vector), ndev->reg_ofs.ldb);
 
         return IRQ_HANDLED;
 }
@@ -712,7 +986,7 @@ static irqreturn_t xeon_event_msix_irq(int irq, void *dev)
                 dev_err(&ndev->pdev->dev, "Error determining link status\n");
 
         /* bit 15 is always the link bit */
-        writew(1 << ndev->limits.max_db_bits, ndev->reg_ofs.pdb);
+        writew(1 << ndev->limits.max_db_bits, ndev->reg_ofs.ldb);
 
         return IRQ_HANDLED;
 }
@@ -723,29 +997,28 @@ static irqreturn_t ntb_interrupt(int irq, void *dev)
         unsigned int i = 0;
 
         if (ndev->hw_type == BWD_HW) {
-                u64 pdb = readq(ndev->reg_ofs.pdb);
+                u64 ldb = readq(ndev->reg_ofs.ldb);
 
-                dev_dbg(&ndev->pdev->dev, "irq %d - pdb = %Lx\n", irq, pdb);
+                dev_dbg(&ndev->pdev->dev, "irq %d - ldb = %Lx\n", irq, ldb);
 
-                while (pdb) {
-                        i = __ffs(pdb);
-                        pdb &= pdb - 1;
+                while (ldb) {
+                        i = __ffs(ldb);
+                        ldb &= ldb - 1;
                         bwd_callback_msix_irq(irq, &ndev->db_cb[i]);
                 }
         } else {
-                u16 pdb = readw(ndev->reg_ofs.pdb);
+                u16 ldb = readw(ndev->reg_ofs.ldb);
 
-                dev_dbg(&ndev->pdev->dev, "irq %d - pdb = %x sdb %x\n", irq,
-                        pdb, readw(ndev->reg_ofs.sdb));
+                dev_dbg(&ndev->pdev->dev, "irq %d - ldb = %x\n", irq, ldb);
 
-                if (pdb & SNB_DB_HW_LINK) {
+                if (ldb & SNB_DB_HW_LINK) {
                         xeon_event_msix_irq(irq, dev);
-                        pdb &= ~SNB_DB_HW_LINK;
+                        ldb &= ~SNB_DB_HW_LINK;
                 }
 
-                while (pdb) {
-                        i = __ffs(pdb);
-                        pdb &= pdb - 1;
+                while (ldb) {
+                        i = __ffs(ldb);
+                        ldb &= ldb - 1;
                         xeon_callback_msix_irq(irq, &ndev->db_cb[i]);
                 }
         }
@@ -758,16 +1031,15 @@ static int ntb_setup_msix(struct ntb_device *ndev)
         struct pci_dev *pdev = ndev->pdev;
         struct msix_entry *msix;
         int msix_entries;
-        int rc, i, pos;
+        int rc, i;
         u16 val;
 
-        pos = pci_find_capability(pdev, PCI_CAP_ID_MSIX);
-        if (!pos) {
+        if (!pdev->msix_cap) {
                 rc = -EIO;
                 goto err;
         }
 
-        rc = pci_read_config_word(pdev, pos + PCI_MSIX_FLAGS, &val);
+        rc = pci_read_config_word(pdev, pdev->msix_cap + PCI_MSIX_FLAGS, &val);
         if (rc)
                 goto err;
 
@@ -903,10 +1175,10 @@ static int ntb_setup_interrupts(struct ntb_device *ndev)
          * Interrupt.  The rest will be unmasked as callbacks are registered.
          */
         if (ndev->hw_type == BWD_HW)
-                writeq(~0, ndev->reg_ofs.pdb_mask);
+                writeq(~0, ndev->reg_ofs.ldb_mask);
         else
                 writew(~(1 << ndev->limits.max_db_bits),
-                       ndev->reg_ofs.pdb_mask);
+                       ndev->reg_ofs.ldb_mask);
 
         rc = ntb_setup_msix(ndev);
         if (!rc)
@@ -935,9 +1207,9 @@ static void ntb_free_interrupts(struct ntb_device *ndev)
 
         /* mask interrupts */
         if (ndev->hw_type == BWD_HW)
-                writeq(~0, ndev->reg_ofs.pdb_mask);
+                writeq(~0, ndev->reg_ofs.ldb_mask);
         else
-                writew(~0, ndev->reg_ofs.pdb_mask);
+                writew(~0, ndev->reg_ofs.ldb_mask);
 
         if (ndev->num_msix) {
                 struct msix_entry *msix;
@@ -963,9 +1235,9 @@ static int ntb_create_callbacks(struct ntb_device *ndev)
 {
         int i;
 
-        /* Checken-egg issue.  We won't know how many callbacks are necessary
+        /* Chicken-egg issue.  We won't know how many callbacks are necessary
          * until we see how many MSI-X vectors we get, but these pointers need
-         * to be passed into the MSI-X register fucntion.  So, we allocate the
+         * to be passed into the MSI-X register function.  So, we allocate the
          * max, knowing that they might not all be used, to work around this.
          */
         ndev->db_cb = kcalloc(ndev->limits.max_db_bits,
@@ -992,6 +1264,28 @@ static void ntb_free_callbacks(struct ntb_device *ndev)
         kfree(ndev->db_cb);
 }
 
+static void ntb_setup_debugfs(struct ntb_device *ndev)
+{
+        if (!debugfs_initialized())
+                return;
+
+        if (!debugfs_dir)
+                debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+        ndev->debugfs_dir = debugfs_create_dir(pci_name(ndev->pdev),
+                                               debugfs_dir);
+}
+
+static void ntb_free_debugfs(struct ntb_device *ndev)
+{
+        debugfs_remove_recursive(ndev->debugfs_dir);
+
+        if (debugfs_dir && simple_empty(debugfs_dir)) {
+                debugfs_remove_recursive(debugfs_dir);
+                debugfs_dir = NULL;
+        }
+}
+
 static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
         struct ntb_device *ndev;
@@ -1004,6 +1298,7 @@ static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
         ndev->pdev = pdev;
         ndev->link_status = NTB_LINK_DOWN;
         pci_set_drvdata(pdev, ndev);
+        ntb_setup_debugfs(ndev);
 
         rc = pci_enable_device(pdev);
         if (rc)
@@ -1022,13 +1317,13 @@ static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
                 goto err2;
         }
 
-        for (i = 0; i < NTB_NUM_MW; i++) {
+        for (i = 0; i < NTB_MAX_NUM_MW; i++) {
                 ndev->mw[i].bar_sz = pci_resource_len(pdev, MW_TO_BAR(i));
                 ndev->mw[i].vbase =
                     ioremap_wc(pci_resource_start(pdev, MW_TO_BAR(i)),
                                ndev->mw[i].bar_sz);
                 dev_info(&pdev->dev, "MW %d size %llu\n", i,
-                         pci_resource_len(pdev, MW_TO_BAR(i)));
+                         (unsigned long long) ndev->mw[i].bar_sz);
                 if (!ndev->mw[i].vbase) {
                         dev_warn(&pdev->dev, "Cannot remap BAR %d\n",
                                  MW_TO_BAR(i));
@@ -1100,6 +1395,7 @@ err2:
 err1:
         pci_disable_device(pdev);
 err:
+        ntb_free_debugfs(ndev);
         kfree(ndev);
 
         dev_err(&pdev->dev, "Error loading %s module\n", KBUILD_MODNAME);
@@ -1114,7 +1410,7 @@ static void ntb_pci_remove(struct pci_dev *pdev)
 
         /* Bring NTB link down */
         ntb_cntl = readl(ndev->reg_ofs.lnk_cntl);
-        ntb_cntl |= NTB_LINK_DISABLE;
+        ntb_cntl |= NTB_CNTL_LINK_DISABLE;
         writel(ntb_cntl, ndev->reg_ofs.lnk_cntl);
 
         ntb_transport_free(ndev->ntb_transport);
@@ -1123,12 +1419,13 @@ static void ntb_pci_remove(struct pci_dev *pdev)
         ntb_free_callbacks(ndev);
         ntb_device_free(ndev);
 
-        for (i = 0; i < NTB_NUM_MW; i++)
+        for (i = 0; i < NTB_MAX_NUM_MW; i++)
                 iounmap(ndev->mw[i].vbase);
 
         iounmap(ndev->reg_base);
         pci_release_selected_regions(pdev, NTB_BAR_MASK);
         pci_disable_device(pdev);
+        ntb_free_debugfs(ndev);
         kfree(ndev);
 }
 
diff --git a/drivers/ntb/ntb_hw.h b/drivers/ntb/ntb_hw.h
index 3a3038ca83e6..0a31cedae7d4 100644
--- a/drivers/ntb/ntb_hw.h
+++ b/drivers/ntb/ntb_hw.h
@@ -47,16 +47,36 @@
  */
 
 #define PCI_DEVICE_ID_INTEL_NTB_B2B_JSF         0x3725
-#define PCI_DEVICE_ID_INTEL_NTB_CLASSIC_JSF     0x3726
-#define PCI_DEVICE_ID_INTEL_NTB_RP_JSF          0x3727
-#define PCI_DEVICE_ID_INTEL_NTB_RP_SNB          0x3C08
+#define PCI_DEVICE_ID_INTEL_NTB_PS_JSF          0x3726
+#define PCI_DEVICE_ID_INTEL_NTB_SS_JSF          0x3727
 #define PCI_DEVICE_ID_INTEL_NTB_B2B_SNB         0x3C0D
-#define PCI_DEVICE_ID_INTEL_NTB_CLASSIC_SNB     0x3C0E
-#define PCI_DEVICE_ID_INTEL_NTB_2ND_SNB         0x3C0F
+#define PCI_DEVICE_ID_INTEL_NTB_PS_SNB          0x3C0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_SNB          0x3C0F
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_IVT         0x0E0D
+#define PCI_DEVICE_ID_INTEL_NTB_PS_IVT          0x0E0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_IVT          0x0E0F
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_HSX         0x2F0D
+#define PCI_DEVICE_ID_INTEL_NTB_PS_HSX          0x2F0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_HSX          0x2F0F
 #define PCI_DEVICE_ID_INTEL_NTB_B2B_BWD         0x0C4E
 
 #define msix_table_size(control)        ((control & PCI_MSIX_FLAGS_QSIZE)+1)
 
+#ifndef readq
+static inline u64 readq(void __iomem *addr)
+{
+        return readl(addr) | (((u64) readl(addr + 4)) << 32LL);
+}
+#endif
+
+#ifndef writeq
+static inline void writeq(u64 val, void __iomem *addr)
+{
+        writel(val & 0xffffffff, addr);
+        writel(val >> 32, addr + 4);
+}
+#endif
+
 #define NTB_BAR_MMIO            0
 #define NTB_BAR_23              2
 #define NTB_BAR_45              4
@@ -68,7 +88,7 @@
 
 #define NTB_HB_TIMEOUT          msecs_to_jiffies(1000)
 
-#define NTB_NUM_MW              2
+#define NTB_MAX_NUM_MW          2
 
 enum ntb_hw_event {
         NTB_EVENT_SW_EVENT0 = 0,
@@ -96,18 +116,19 @@ struct ntb_device {
         struct pci_dev *pdev;
         struct msix_entry *msix_entries;
         void __iomem *reg_base;
-        struct ntb_mw mw[NTB_NUM_MW];
+        struct ntb_mw mw[NTB_MAX_NUM_MW];
         struct {
-                unsigned int max_spads;
-                unsigned int max_db_bits;
-                unsigned int msix_cnt;
+                unsigned char max_mw;
+                unsigned char max_spads;
+                unsigned char max_db_bits;
+                unsigned char msix_cnt;
         } limits;
         struct {
-                void __iomem *pdb;
-                void __iomem *pdb_mask;
-                void __iomem *sdb;
-                void __iomem *sbar2_xlat;
-                void __iomem *sbar4_xlat;
+                void __iomem *ldb;
+                void __iomem *ldb_mask;
+                void __iomem *rdb;
+                void __iomem *bar2_xlat;
+                void __iomem *bar4_xlat;
                 void __iomem *spad_write;
                 void __iomem *spad_read;
                 void __iomem *lnk_cntl;
@@ -124,12 +145,45 @@ struct ntb_device {
         unsigned char num_msix;
         unsigned char bits_per_vector;
         unsigned char max_cbs;
+        unsigned char link_width;
+        unsigned char link_speed;
         unsigned char link_status;
+
         struct delayed_work hb_timer;
         unsigned long last_ts;
+
+        struct delayed_work lr_timer;
+
+        struct dentry *debugfs_dir;
 };
 
 /**
+ * ntb_max_cbs() - return the max callbacks
+ * @ndev: pointer to ntb_device instance
+ *
+ * Given the ntb pointer, return the maximum number of callbacks
+ *
+ * RETURNS: the maximum number of callbacks
+ */
+static inline unsigned char ntb_max_cbs(struct ntb_device *ndev)
+{
+        return ndev->max_cbs;
+}
+
+/**
+ * ntb_max_mw() - return the max number of memory windows
+ * @ndev: pointer to ntb_device instance
+ *
+ * Given the ntb pointer, return the maximum number of memory windows
+ *
+ * RETURNS: the maximum number of memory windows
+ */
+static inline unsigned char ntb_max_mw(struct ntb_device *ndev)
+{
+        return ndev->limits.max_mw;
+}
+
+/**
  * ntb_hw_link_status() - return the hardware link status
  * @ndev: pointer to ntb_device instance
  *
@@ -146,7 +200,7 @@ static inline bool ntb_hw_link_status(struct ntb_device *ndev)
  * ntb_query_pdev() - return the pci_dev pointer
  * @ndev: pointer to ntb_device instance
  *
- * Given the ntb pointer return the pci_dev pointerfor the NTB hardware device
+ * Given the ntb pointer, return the pci_dev pointer for the NTB hardware device
  *
  * RETURNS: a pointer to the ntb pci_dev
  */
@@ -155,6 +209,20 @@ static inline struct pci_dev *ntb_query_pdev(struct ntb_device *ndev)
         return ndev->pdev;
 }
 
+/**
+ * ntb_query_debugfs() - return the debugfs pointer
+ * @ndev: pointer to ntb_device instance
+ *
+ * Given the ntb pointer, return the debugfs directory pointer for the NTB
+ * hardware device
+ *
+ * RETURNS: a pointer to the debugfs directory
+ */
+static inline struct dentry *ntb_query_debugfs(struct ntb_device *ndev)
+{
+        return ndev->debugfs_dir;
+}
+
 struct ntb_device *ntb_register_transport(struct pci_dev *pdev,
                                           void *transport);
 void ntb_unregister_transport(struct ntb_device *ndev);
@@ -172,9 +240,10 @@ int ntb_write_local_spad(struct ntb_device *ndev, unsigned int idx, u32 val);
 int ntb_read_local_spad(struct ntb_device *ndev, unsigned int idx, u32 *val);
 int ntb_write_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 val);
 int ntb_read_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 *val);
+resource_size_t ntb_get_mw_base(struct ntb_device *ndev, unsigned int mw);
 void __iomem *ntb_get_mw_vbase(struct ntb_device *ndev, unsigned int mw);
-resource_size_t ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw);
-void ntb_ring_sdb(struct ntb_device *ndev, unsigned int idx);
+u64 ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw);
+void ntb_ring_doorbell(struct ntb_device *ndev, unsigned int idx);
 void *ntb_find_transport(struct pci_dev *pdev);
 
 int ntb_transport_init(struct pci_dev *pdev);
diff --git a/drivers/ntb/ntb_regs.h b/drivers/ntb/ntb_regs.h
index 5bfa8c06c059..aa4bdd393c58 100644
--- a/drivers/ntb/ntb_regs.h
+++ b/drivers/ntb/ntb_regs.h
@@ -46,23 +46,24 @@
  * Jon Mason <jon.mason@intel.com>
  */
 
-#define NTB_LINK_ENABLE         0x0000
-#define NTB_LINK_DISABLE        0x0002
 #define NTB_LINK_STATUS_ACTIVE  0x2000
 #define NTB_LINK_SPEED_MASK     0x000f
 #define NTB_LINK_WIDTH_MASK     0x03f0
 
 #define SNB_MSIX_CNT            4
-#define SNB_MAX_SPADS           16
-#define SNB_MAX_COMPAT_SPADS    8
+#define SNB_MAX_B2B_SPADS       16
+#define SNB_MAX_COMPAT_SPADS    16
 /* Reserve the uppermost bit for link interrupt */
 #define SNB_MAX_DB_BITS         15
 #define SNB_DB_BITS_PER_VEC     5
+#define SNB_MAX_MW              2
+#define SNB_ERRATA_MAX_MW       1
 
 #define SNB_DB_HW_LINK          0x8000
 
 #define SNB_PCICMD_OFFSET       0x0504
 #define SNB_DEVCTRL_OFFSET      0x0598
+#define SNB_SLINK_STATUS_OFFSET 0x05A2
 #define SNB_LINK_STATUS_OFFSET  0x01A2
 
 #define SNB_PBAR2LMT_OFFSET     0x0000
@@ -74,6 +75,9 @@
 #define SNB_SBAR2XLAT_OFFSET    0x0030
 #define SNB_SBAR4XLAT_OFFSET    0x0038
 #define SNB_SBAR0BASE_OFFSET    0x0040
+#define SNB_SBAR0BASE_OFFSET    0x0040
+#define SNB_SBAR2BASE_OFFSET    0x0048
+#define SNB_SBAR4BASE_OFFSET    0x0050
 #define SNB_SBAR2BASE_OFFSET    0x0048
 #define SNB_SBAR4BASE_OFFSET    0x0050
 #define SNB_NTBCNTL_OFFSET      0x0058
@@ -88,19 +92,28 @@
 #define SNB_WCCNTRL_OFFSET      0x00e0
 #define SNB_B2B_SPAD_OFFSET     0x0100
 #define SNB_B2B_DOORBELL_OFFSET 0x0140
-#define SNB_B2B_XLAT_OFFSET     0x0144
+#define SNB_B2B_XLAT_OFFSETL    0x0144
+#define SNB_B2B_XLAT_OFFSETU    0x0148
+
+#define SNB_MBAR01_USD_ADDR     0x000000210000000CULL
+#define SNB_MBAR23_USD_ADDR     0x000000410000000CULL
+#define SNB_MBAR45_USD_ADDR     0x000000810000000CULL
+#define SNB_MBAR01_DSD_ADDR     0x000000200000000CULL
+#define SNB_MBAR23_DSD_ADDR     0x000000400000000CULL
+#define SNB_MBAR45_DSD_ADDR     0x000000800000000CULL
 
 #define BWD_MSIX_CNT            34
 #define BWD_MAX_SPADS           16
-#define BWD_MAX_COMPAT_SPADS    16
 #define BWD_MAX_DB_BITS         34
 #define BWD_DB_BITS_PER_VEC     1
+#define BWD_MAX_MW              2
 
 #define BWD_PCICMD_OFFSET       0xb004
 #define BWD_MBAR23_OFFSET       0xb018
 #define BWD_MBAR45_OFFSET       0xb020
 #define BWD_DEVCTRL_OFFSET      0xb048
 #define BWD_LINK_STATUS_OFFSET  0xb052
+#define BWD_ERRCORSTS_OFFSET    0xb110
 
 #define BWD_SBAR2XLAT_OFFSET    0x0008
 #define BWD_SBAR4XLAT_OFFSET    0x0010
@@ -118,6 +131,22 @@
 #define BWD_B2B_SPADSEMA_OFFSET 0x80c0
 #define BWD_B2B_STKYSPAD_OFFSET 0x80c4
 
+#define BWD_MODPHY_PCSREG4      0x1c004
+#define BWD_MODPHY_PCSREG6      0x1c006
+
+#define BWD_IP_BASE             0xC000
+#define BWD_DESKEWSTS_OFFSET    (BWD_IP_BASE + 0x3024)
+#define BWD_LTSSMERRSTS0_OFFSET (BWD_IP_BASE + 0x3180)
+#define BWD_LTSSMSTATEJMP_OFFSET        (BWD_IP_BASE + 0x3040)
+#define BWD_IBSTERRRCRVSTS0_OFFSET      (BWD_IP_BASE + 0x3324)
+
+#define BWD_DESKEWSTS_DBERR     (1 << 15)
+#define BWD_LTSSMERRSTS0_UNEXPECTEDEI   (1 << 20)
+#define BWD_LTSSMSTATEJMP_FORCEDETECT   (1 << 2)
+#define BWD_IBIST_ERR_OFLOW     0x7FFF7FFF
+
+#define NTB_CNTL_CFG_LOCK       (1 << 0)
+#define NTB_CNTL_LINK_DISABLE   (1 << 1)
 #define NTB_CNTL_BAR23_SNOOP    (1 << 2)
 #define NTB_CNTL_BAR45_SNOOP    (1 << 6)
 #define BWD_CNTL_LINK_DOWN      (1 << 16)
@@ -128,12 +157,3 @@
 #define BWD_PPD_INIT_LINK       0x0008
 #define BWD_PPD_CONN_TYPE       0x0300
 #define BWD_PPD_DEV_TYPE        0x1000
-
-#define BWD_PBAR2XLAT_USD_ADDR  0x0000004000000000
-#define BWD_PBAR4XLAT_USD_ADDR  0x0000008000000000
-#define BWD_MBAR23_USD_ADDR     0x000000410000000C
-#define BWD_MBAR45_USD_ADDR     0x000000810000000C
-#define BWD_PBAR2XLAT_DSD_ADDR  0x0000004100000000
-#define BWD_PBAR4XLAT_DSD_ADDR  0x0000008100000000
-#define BWD_MBAR23_DSD_ADDR     0x000000400000000C
-#define BWD_MBAR45_DSD_ADDR     0x000000800000000C
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index f8d7081ee301..12a9e83c008b 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -47,6 +47,7 @@
  */
 #include <linux/debugfs.h>
 #include <linux/delay.h>
+#include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/errno.h>
 #include <linux/export.h>
@@ -64,10 +65,14 @@ static unsigned int transport_mtu = 0x401E;
 module_param(transport_mtu, uint, 0644);
 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
 
-static unsigned char max_num_clients = 2;
+static unsigned char max_num_clients;
 module_param(max_num_clients, byte, 0644);
 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
 
+static unsigned int copy_bytes = 1024;
+module_param(copy_bytes, uint, 0644);
+MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
+
 struct ntb_queue_entry {
         /* ntb_queue list reference */
         struct list_head entry;
@@ -76,6 +81,13 @@ struct ntb_queue_entry {
         void *buf;
         unsigned int len;
         unsigned int flags;
+
+        struct ntb_transport_qp *qp;
+        union {
+                struct ntb_payload_header __iomem *tx_hdr;
+                struct ntb_payload_header *rx_hdr;
+        };
+        unsigned int index;
 };
 
 struct ntb_rx_info {
@@ -86,6 +98,7 @@ struct ntb_transport_qp {
         struct ntb_transport *transport;
         struct ntb_device *ndev;
         void *cb_data;
+        struct dma_chan *dma_chan;
 
         bool client_ready;
         bool qp_link;
@@ -99,6 +112,7 @@ struct ntb_transport_qp {
         struct list_head tx_free_q;
         spinlock_t ntb_tx_free_q_lock;
         void __iomem *tx_mw;
+        dma_addr_t tx_mw_phys;
         unsigned int tx_index;
         unsigned int tx_max_entry;
         unsigned int tx_max_frame;
@@ -114,6 +128,7 @@ struct ntb_transport_qp {
         unsigned int rx_index;
         unsigned int rx_max_entry;
         unsigned int rx_max_frame;
+        dma_cookie_t last_cookie;
 
         void (*event_handler) (void *data, int status);
         struct delayed_work link_work;
@@ -129,9 +144,14 @@ struct ntb_transport_qp {
         u64 rx_err_no_buf;
         u64 rx_err_oflow;
         u64 rx_err_ver;
+        u64 rx_memcpy;
+        u64 rx_async;
         u64 tx_bytes;
         u64 tx_pkts;
         u64 tx_ring_full;
+        u64 tx_err_no_buf;
+        u64 tx_memcpy;
+        u64 tx_async;
 };
 
 struct ntb_transport_mw {
@@ -150,14 +170,13 @@ struct ntb_transport {
         struct list_head client_devs;
 
         struct ntb_device *ndev;
-        struct ntb_transport_mw mw[NTB_NUM_MW];
+        struct ntb_transport_mw *mw;
         struct ntb_transport_qp *qps;
         unsigned int max_qps;
         unsigned long qp_bitmap;
         bool transport_link;
         struct delayed_work link_work;
         struct work_struct link_cleanup;
-        struct dentry *debugfs_dir;
 };
 
 enum {
@@ -183,7 +202,7 @@ enum {
         MAX_SPAD,
 };
 
-#define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
+#define QP_TO_MW(ndev, qp)      ((qp) % ntb_max_mw(ndev))
 #define NTB_QP_DEF_NUM_ENTRIES  100
 #define NTB_LINK_DOWN_TIMEOUT   10
 
@@ -382,7 +401,7 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
         char *buf;
         ssize_t ret, out_offset, out_count;
 
-        out_count = 600;
+        out_count = 1000;
 
         buf = kmalloc(out_count, GFP_KERNEL);
         if (!buf)
@@ -397,6 +416,10 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "rx_pkts - \t%llu\n", qp->rx_pkts);
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "rx_memcpy - \t%llu\n", qp->rx_memcpy);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "rx_async - \t%llu\n", qp->rx_async);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
@@ -416,8 +439,14 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "tx_pkts - \t%llu\n", qp->tx_pkts);
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "tx_memcpy - \t%llu\n", qp->tx_memcpy);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "tx_async - \t%llu\n", qp->tx_async);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "tx_mw - \t%p\n", qp->tx_mw);
         out_offset += snprintf(buf + out_offset, out_count - out_offset,
                                "tx_index - \t%u\n", qp->tx_index);
@@ -475,22 +504,25 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 {
         struct ntb_transport_qp *qp = &nt->qps[qp_num];
         unsigned int rx_size, num_qps_mw;
-        u8 mw_num = QP_TO_MW(qp_num);
+        u8 mw_num, mw_max;
         unsigned int i;
 
+        mw_max = ntb_max_mw(nt->ndev);
+        mw_num = QP_TO_MW(nt->ndev, qp_num);
+
         WARN_ON(nt->mw[mw_num].virt_addr == NULL);
 
-        if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
-                num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
+        if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
+                num_qps_mw = nt->max_qps / mw_max + 1;
         else
-                num_qps_mw = nt->max_qps / NTB_NUM_MW;
+                num_qps_mw = nt->max_qps / mw_max;
 
         rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
-        qp->remote_rx_info = nt->mw[mw_num].virt_addr +
-                             (qp_num / NTB_NUM_MW * rx_size);
+        qp->rx_buff = nt->mw[mw_num].virt_addr + qp_num / mw_max * rx_size;
         rx_size -= sizeof(struct ntb_rx_info);
 
-        qp->rx_buff = qp->remote_rx_info + 1;
+        qp->remote_rx_info = qp->rx_buff + rx_size;
+
         /* Due to housekeeping, there must be atleast 2 buffs */
         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
         qp->rx_max_entry = rx_size / qp->rx_max_frame;
@@ -631,7 +663,7 @@ static void ntb_transport_link_work(struct work_struct *work)
         int rc, i;
 
         /* send the local info, in the opposite order of the way we read it */
-        for (i = 0; i < NTB_NUM_MW; i++) {
+        for (i = 0; i < ntb_max_mw(ndev); i++) {
                 rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
                                            ntb_get_mw_size(ndev, i) >> 32);
                 if (rc) {
@@ -651,10 +683,10 @@ static void ntb_transport_link_work(struct work_struct *work)
                 }
         }
 
-        rc = ntb_write_remote_spad(ndev, NUM_MWS, NTB_NUM_MW);
+        rc = ntb_write_remote_spad(ndev, NUM_MWS, ntb_max_mw(ndev));
         if (rc) {
                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
-                        NTB_NUM_MW, NUM_MWS);
+                        ntb_max_mw(ndev), NUM_MWS);
                 goto out;
         }
 
@@ -699,11 +731,11 @@ static void ntb_transport_link_work(struct work_struct *work)
                 goto out;
         }
 
-        if (val != NTB_NUM_MW)
+        if (val != ntb_max_mw(ndev))
                 goto out;
         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 
-        for (i = 0; i < NTB_NUM_MW; i++) {
+        for (i = 0; i < ntb_max_mw(ndev); i++) {
                 u64 val64;
 
                 rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
@@ -745,7 +777,7 @@ static void ntb_transport_link_work(struct work_struct *work)
         return;
 
 out1:
-        for (i = 0; i < NTB_NUM_MW; i++)
+        for (i = 0; i < ntb_max_mw(ndev); i++)
                 ntb_free_mw(nt, i);
 out:
         if (ntb_hw_link_status(ndev))
@@ -794,12 +826,16 @@ static void ntb_qp_link_work(struct work_struct *work)
                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 }
 
-static void ntb_transport_init_queue(struct ntb_transport *nt,
+static int ntb_transport_init_queue(struct ntb_transport *nt,
                                      unsigned int qp_num)
 {
         struct ntb_transport_qp *qp;
         unsigned int num_qps_mw, tx_size;
-        u8 mw_num = QP_TO_MW(qp_num);
+        u8 mw_num, mw_max;
+        u64 qp_offset;
+
+        mw_max = ntb_max_mw(nt->ndev);
+        mw_num = QP_TO_MW(nt->ndev, qp_num);
 
         qp = &nt->qps[qp_num];
         qp->qp_num = qp_num;
@@ -809,27 +845,34 @@ static void ntb_transport_init_queue(struct ntb_transport *nt,
         qp->client_ready = NTB_LINK_DOWN;
         qp->event_handler = NULL;
 
-        if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
-                num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
+        if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
+                num_qps_mw = nt->max_qps / mw_max + 1;
         else
-                num_qps_mw = nt->max_qps / NTB_NUM_MW;
+                num_qps_mw = nt->max_qps / mw_max;
 
         tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
-        qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
-                      (qp_num / NTB_NUM_MW * tx_size);
+        qp_offset = qp_num / mw_max * tx_size;
+        qp->tx_mw = ntb_get_mw_vbase(nt->ndev, mw_num) + qp_offset;
+        if (!qp->tx_mw)
+                return -EINVAL;
+
+        qp->tx_mw_phys = ntb_get_mw_base(qp->ndev, mw_num) + qp_offset;
+        if (!qp->tx_mw_phys)
+                return -EINVAL;
+
         tx_size -= sizeof(struct ntb_rx_info);
+        qp->rx_info = qp->tx_mw + tx_size;
 
-        qp->tx_mw = qp->rx_info + 1;
         /* Due to housekeeping, there must be atleast 2 buffs */
         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
         qp->tx_max_entry = tx_size / qp->tx_max_frame;
 
-        if (nt->debugfs_dir) {
+        if (ntb_query_debugfs(nt->ndev)) {
                 char debugfs_name[4];
 
                 snprintf(debugfs_name, 4, "qp%d", qp_num);
                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
-                                                     nt->debugfs_dir);
+                                                 ntb_query_debugfs(nt->ndev));
 
                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
                                                         qp->debugfs_dir, qp,
@@ -846,6 +889,8 @@ static void ntb_transport_init_queue(struct ntb_transport *nt,
         INIT_LIST_HEAD(&qp->rx_pend_q);
         INIT_LIST_HEAD(&qp->rx_free_q);
         INIT_LIST_HEAD(&qp->tx_free_q);
+
+        return 0;
 }
 
 int ntb_transport_init(struct pci_dev *pdev)
@@ -857,30 +902,38 @@ int ntb_transport_init(struct pci_dev *pdev)
         if (!nt)
                 return -ENOMEM;
 
-        if (debugfs_initialized())
-                nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
-        else
-                nt->debugfs_dir = NULL;
-
         nt->ndev = ntb_register_transport(pdev, nt);
         if (!nt->ndev) {
                 rc = -EIO;
                 goto err;
         }
 
-        nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
+        nt->mw = kcalloc(ntb_max_mw(nt->ndev), sizeof(struct ntb_transport_mw),
+                         GFP_KERNEL);
+        if (!nt->mw) {
+                rc = -ENOMEM;
+                goto err1;
+        }
+
+        if (max_num_clients)
+                nt->max_qps = min(ntb_max_cbs(nt->ndev), max_num_clients);
+        else
+                nt->max_qps = min(ntb_max_cbs(nt->ndev), ntb_max_mw(nt->ndev));
 
         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
                           GFP_KERNEL);
         if (!nt->qps) {
                 rc = -ENOMEM;
-                goto err1;
+                goto err2;
         }
 
         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 
-        for (i = 0; i < nt->max_qps; i++)
-                ntb_transport_init_queue(nt, i);
+        for (i = 0; i < nt->max_qps; i++) {
+                rc = ntb_transport_init_queue(nt, i);
+                if (rc)
+                        goto err3;
+        }
 
         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
@@ -888,26 +941,27 @@ int ntb_transport_init(struct pci_dev *pdev)
         rc = ntb_register_event_callback(nt->ndev,
                                          ntb_transport_event_callback);
         if (rc)
-                goto err2;
+                goto err3;
 
         INIT_LIST_HEAD(&nt->client_devs);
         rc = ntb_bus_init(nt);
         if (rc)
-                goto err3;
+                goto err4;
 
         if (ntb_hw_link_status(nt->ndev))
                 schedule_delayed_work(&nt->link_work, 0);
 
         return 0;
 
-err3:
+err4:
         ntb_unregister_event_callback(nt->ndev);
-err2:
+err3:
         kfree(nt->qps);
+err2:
+        kfree(nt->mw);
 err1:
         ntb_unregister_transport(nt->ndev);
 err:
-        debugfs_remove_recursive(nt->debugfs_dir);
         kfree(nt);
         return rc;
 }
@@ -915,41 +969,46 @@ err:
 void ntb_transport_free(void *transport)
 {
         struct ntb_transport *nt = transport;
-        struct pci_dev *pdev;
+        struct ntb_device *ndev = nt->ndev;
         int i;
 
         nt->transport_link = NTB_LINK_DOWN;
 
         /* verify that all the qp's are freed */
-        for (i = 0; i < nt->max_qps; i++)
+        for (i = 0; i < nt->max_qps; i++) {
                 if (!test_bit(i, &nt->qp_bitmap))
                         ntb_transport_free_queue(&nt->qps[i]);
+                debugfs_remove_recursive(nt->qps[i].debugfs_dir);
+        }
 
         ntb_bus_remove(nt);
 
         cancel_delayed_work_sync(&nt->link_work);
 
-        debugfs_remove_recursive(nt->debugfs_dir);
-
-        ntb_unregister_event_callback(nt->ndev);
-
-        pdev = ntb_query_pdev(nt->ndev);
+        ntb_unregister_event_callback(ndev);
 
-        for (i = 0; i < NTB_NUM_MW; i++)
+        for (i = 0; i < ntb_max_mw(ndev); i++)
                 ntb_free_mw(nt, i);
 
         kfree(nt->qps);
-        ntb_unregister_transport(nt->ndev);
+        kfree(nt->mw);
+        ntb_unregister_transport(ndev);
         kfree(nt);
 }
 
-static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
-                             struct ntb_queue_entry *entry, void *offset)
+static void ntb_rx_copy_callback(void *data)
 {
+        struct ntb_queue_entry *entry = data;
+        struct ntb_transport_qp *qp = entry->qp;
         void *cb_data = entry->cb_data;
         unsigned int len = entry->len;
+        struct ntb_payload_header *hdr = entry->rx_hdr;
 
-        memcpy(entry->buf, offset, entry->len);
+        /* Ensure that the data is fully copied out before clearing the flag */
+        wmb();
+        hdr->flags = 0;
+
+        iowrite32(entry->index, &qp->rx_info->entry);
 
         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 
@@ -957,6 +1016,86 @@ static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
                 qp->rx_handler(qp, qp->cb_data, cb_data, len);
 }
 
+static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
+{
+        void *buf = entry->buf;
+        size_t len = entry->len;
+
+        memcpy(buf, offset, len);
+
+        ntb_rx_copy_callback(entry);
+}
+
+static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
+                         size_t len)
+{
+        struct dma_async_tx_descriptor *txd;
+        struct ntb_transport_qp *qp = entry->qp;
+        struct dma_chan *chan = qp->dma_chan;
+        struct dma_device *device;
+        size_t pay_off, buff_off;
+        dma_addr_t src, dest;
+        dma_cookie_t cookie;
+        void *buf = entry->buf;
+        unsigned long flags;
+
+        entry->len = len;
+
+        if (!chan)
+                goto err;
+
+        if (len < copy_bytes) 
+                goto err1;
+
+        device = chan->device;
+        pay_off = (size_t) offset & ~PAGE_MASK;
+        buff_off = (size_t) buf & ~PAGE_MASK;
+
+        if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
+                goto err1;
+
+        dest = dma_map_single(device->dev, buf, len, DMA_FROM_DEVICE);
+        if (dma_mapping_error(device->dev, dest))
+                goto err1;
+
+        src = dma_map_single(device->dev, offset, len, DMA_TO_DEVICE);
+        if (dma_mapping_error(device->dev, src))
+                goto err2;
+
+        flags = DMA_COMPL_DEST_UNMAP_SINGLE | DMA_COMPL_SRC_UNMAP_SINGLE |
+                DMA_PREP_INTERRUPT;
+        txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
+        if (!txd)
+                goto err3;
+
+        txd->callback = ntb_rx_copy_callback;
+        txd->callback_param = entry;
+
+        cookie = dmaengine_submit(txd);
+        if (dma_submit_error(cookie))
+                goto err3;
+
+        qp->last_cookie = cookie;
+
+        qp->rx_async++;
+
+        return;
+
+err3:
+        dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
+err2:
+        dma_unmap_single(device->dev, dest, len, DMA_FROM_DEVICE);
+err1:
+        /* If the callbacks come out of order, the writing of the index to the
+         * last completed will be out of order.  This may result in the
+         * receive stalling forever.
+         */
+        dma_sync_wait(chan, qp->last_cookie);
+err:
+        ntb_memcpy_rx(entry, offset);
+        qp->rx_memcpy++;
+}
+
 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 {
         struct ntb_payload_header *hdr;
@@ -995,41 +1134,45 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
         if (hdr->flags & LINK_DOWN_FLAG) {
                 ntb_qp_link_down(qp);
 
-                ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
-                             &qp->rx_pend_q);
-                goto out;
+                goto err;
         }
 
         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
                 "rx offset %u, ver %u - %d payload received, buf size %d\n",
                 qp->rx_index, hdr->ver, hdr->len, entry->len);
 
-        if (hdr->len <= entry->len) {
-                entry->len = hdr->len;
-                ntb_rx_copy_task(qp, entry, offset);
-        } else {
-                ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
-                             &qp->rx_pend_q);
+        qp->rx_bytes += hdr->len;
+        qp->rx_pkts++;
 
+        if (hdr->len > entry->len) {
                 qp->rx_err_oflow++;
                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
                         "RX overflow! Wanted %d got %d\n",
                         hdr->len, entry->len);
+
+                goto err;
         }
 
-        qp->rx_bytes += hdr->len;
-        qp->rx_pkts++;
+        entry->index = qp->rx_index;
+        entry->rx_hdr = hdr;
+
+        ntb_async_rx(entry, offset, hdr->len);
 
 out:
+        qp->rx_index++;
+        qp->rx_index %= qp->rx_max_entry;
+
+        return 0;
+
+err:
+        ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
+                     &qp->rx_pend_q);
         /* Ensure that the data is fully copied out before clearing the flag */
         wmb();
         hdr->flags = 0;
         iowrite32(qp->rx_index, &qp->rx_info->entry);
 
-        qp->rx_index++;
-        qp->rx_index %= qp->rx_max_entry;
-
-        return 0;
+        goto out;
 }
 
 static void ntb_transport_rx(unsigned long data)
@@ -1045,6 +1188,9 @@ static void ntb_transport_rx(unsigned long data)
                 if (rc)
                         break;
         }
+
+        if (qp->dma_chan)
+                dma_async_issue_pending(qp->dma_chan);
 }
 
 static void ntb_transport_rxc_db(void *data, int db_num)
@@ -1057,23 +1203,17 @@ static void ntb_transport_rxc_db(void *data, int db_num)
         tasklet_schedule(&qp->rx_work);
 }
 
-static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
-                             struct ntb_queue_entry *entry,
-                             void __iomem *offset)
+static void ntb_tx_copy_callback(void *data)
 {
-        struct ntb_payload_header __iomem *hdr;
+        struct ntb_queue_entry *entry = data;
+        struct ntb_transport_qp *qp = entry->qp;
+        struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
 
-        memcpy_toio(offset, entry->buf, entry->len);
-
-        hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
-        iowrite32(entry->len, &hdr->len);
-        iowrite32((u32) qp->tx_pkts, &hdr->ver);
-
-        /* Ensure that the data is fully copied out before setting the flag */
+        /* Ensure that the data is fully copied out before setting the flags */
         wmb();
         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
 
-        ntb_ring_sdb(qp->ndev, qp->qp_num);
+        ntb_ring_doorbell(qp->ndev, qp->qp_num);
 
         /* The entry length can only be zero if the packet is intended to be a
          * "link down" or similar.  Since no payload is being sent in these
@@ -1090,15 +1230,81 @@ static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
 }
 
-static int ntb_process_tx(struct ntb_transport_qp *qp,
-                          struct ntb_queue_entry *entry)
+static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
+{
+        memcpy_toio(offset, entry->buf, entry->len);
+
+        ntb_tx_copy_callback(entry);
+}
+
+static void ntb_async_tx(struct ntb_transport_qp *qp,
+                         struct ntb_queue_entry *entry)
 {
+        struct ntb_payload_header __iomem *hdr;
+        struct dma_async_tx_descriptor *txd;
+        struct dma_chan *chan = qp->dma_chan;
+        struct dma_device *device;
+        size_t dest_off, buff_off;
+        dma_addr_t src, dest;
+        dma_cookie_t cookie;
         void __iomem *offset;
+        size_t len = entry->len;
+        void *buf = entry->buf;
+        unsigned long flags;
 
         offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
+        hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
+        entry->tx_hdr = hdr;
+
+        iowrite32(entry->len, &hdr->len);
+        iowrite32((u32) qp->tx_pkts, &hdr->ver);
+
+        if (!chan)
+                goto err;
+
+        if (len < copy_bytes)
+                goto err;
+
+        device = chan->device;
+        dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
+        buff_off = (size_t) buf & ~PAGE_MASK;
+        dest_off = (size_t) dest & ~PAGE_MASK;
+
+        if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
+                goto err;
+
+        src = dma_map_single(device->dev, buf, len, DMA_TO_DEVICE);
+        if (dma_mapping_error(device->dev, src))
+                goto err;
+
+        flags = DMA_COMPL_SRC_UNMAP_SINGLE | DMA_PREP_INTERRUPT;
+        txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
+        if (!txd)
+                goto err1;
+
+        txd->callback = ntb_tx_copy_callback;
+        txd->callback_param = entry;
+
+        cookie = dmaengine_submit(txd);
+        if (dma_submit_error(cookie))
+                goto err1;
+
+        dma_async_issue_pending(chan);
+        qp->tx_async++;
 
-        dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
-                qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
+        return;
+err1:
+        dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
+err:
+        ntb_memcpy_tx(entry, offset);
+        qp->tx_memcpy++;
+}
+
+static int ntb_process_tx(struct ntb_transport_qp *qp,
+                          struct ntb_queue_entry *entry)
+{
+        dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - tx %u, entry len %d flags %x buff %p\n",
+                qp->tx_pkts, qp->tx_index, entry->len, entry->flags,
                 entry->buf);
         if (qp->tx_index == qp->remote_rx_info->entry) {
                 qp->tx_ring_full++;
@@ -1114,7 +1320,7 @@ static int ntb_process_tx(struct ntb_transport_qp *qp,
                 return 0;
         }
 
-        ntb_tx_copy_task(qp, entry, offset);
+        ntb_async_tx(qp, entry);
 
         qp->tx_index++;
         qp->tx_index %= qp->tx_max_entry;
@@ -1200,11 +1406,18 @@ ntb_transport_create_queue(void *data, struct pci_dev *pdev,
         qp->tx_handler = handlers->tx_handler;
         qp->event_handler = handlers->event_handler;
 
+        qp->dma_chan = dma_find_channel(DMA_MEMCPY);
+        if (!qp->dma_chan)
+                dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n");
+        else
+                dmaengine_get();
+
         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
                 if (!entry)
                         goto err1;
 
+                entry->qp = qp;
                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
                              &qp->rx_free_q);
         }
@@ -1214,6 +1427,7 @@ ntb_transport_create_queue(void *data, struct pci_dev *pdev,
                 if (!entry)
                         goto err2;
 
+                entry->qp = qp;
                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
                              &qp->tx_free_q);
         }
@@ -1259,11 +1473,26 @@ void ntb_transport_free_queue(struct ntb_transport_qp *qp)
 
         pdev = ntb_query_pdev(qp->ndev);
 
-        cancel_delayed_work_sync(&qp->link_work);
+        if (qp->dma_chan) {
+                struct dma_chan *chan = qp->dma_chan;
+                /* Putting the dma_chan to NULL will force any new traffic to be
+                 * processed by the CPU instead of the DAM engine
+                 */
+                qp->dma_chan = NULL;
+
+                /* Try to be nice and wait for any queued DMA engine
+                 * transactions to process before smashing it with a rock
+                 */
+                dma_sync_wait(chan, qp->last_cookie);
+                dmaengine_terminate_all(chan);
+                dmaengine_put();
+        }
 
         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
         tasklet_disable(&qp->rx_work);
 
+        cancel_delayed_work_sync(&qp->link_work);
+
         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
                 kfree(entry);
 
@@ -1354,7 +1583,7 @@ EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
  * @len: length of the data buffer
  *
  * Enqueue a new transmit buffer onto the transport queue from which a NTB
- * payload will be transmitted.  This assumes that a lock is behing held to
+ * payload will be transmitted.  This assumes that a lock is being held to
  * serialize access to the qp.
  *
  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
@@ -1369,8 +1598,10 @@ int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
                 return -EINVAL;
 
         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
-        if (!entry)
+        if (!entry) {
+                qp->tx_err_no_buf++;
                 return -ENOMEM;
+        }
 
         entry->cb_data = cb;
         entry->buf = data;
@@ -1410,7 +1641,7 @@ EXPORT_SYMBOL_GPL(ntb_transport_link_up);
  *
  * Notify NTB transport layer of client's desire to no longer receive data on
  * transport queue specified.  It is the client's responsibility to ensure all
- * entries on queue are purged or otherwise handled appropraitely.
+ * entries on queue are purged or otherwise handled appropriately.
  */
 void ntb_transport_link_down(struct ntb_transport_qp *qp)
 {
@@ -1486,9 +1717,18 @@ EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
  */
 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
 {
+        unsigned int max;
+
         if (!qp)
                 return 0;
 
-        return qp->tx_max_frame - sizeof(struct ntb_payload_header);
+        if (!qp->dma_chan)
+                return qp->tx_max_frame - sizeof(struct ntb_payload_header);
+
+        /* If DMA engine usage is possible, try to find the max size for that */
+        max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
+        max -= max % (1 << qp->dma_chan->device->copy_align);
+
+        return max;
 }
 EXPORT_SYMBOL_GPL(ntb_transport_max_size);