Merge tag 'ntb-5.3' of git://github.com/jonmason/ntb

Pull NTB updates from Jon Mason:
 "New feature to add support for NTB virtual MSI interrupts, the ability
  to test and use this feature in the NTB transport layer.

  Also, bug fixes for the AMD and Switchtec drivers, as well as some
  general patches"

* tag 'ntb-5.3' of git://github.com/jonmason/ntb: (22 commits)
  NTB: Describe the ntb_msi_test client in the documentation.
  NTB: Add MSI interrupt support to ntb_transport
  NTB: Add ntb_msi_test support to ntb_test
  NTB: Introduce NTB MSI Test Client
  NTB: Introduce MSI library
  NTB: Rename ntb.c to support multiple source files in the module
  NTB: Introduce functions to calculate multi-port resource index
  NTB: Introduce helper functions to calculate logical port number
  PCI/switchtec: Add module parameter to request more interrupts
  PCI/MSI: Support allocating virtual MSI interrupts
  ntb_hw_switchtec: Fix setup MW with failure bug
  ntb_hw_switchtec: Skip unnecessary re-setup of shared memory window for crosslink case
  ntb_hw_switchtec: Remove redundant steps of switchtec_ntb_reinit_peer() function
  NTB: correct ntb_dev_ops and ntb_dev comment typos
  NTB: amd: Silence shift wrapping warning in amd_ntb_db_vector_mask()
  ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()
  NTB: ntb_transport: Ensure qp->tx_mw_dma_addr is initaliazed
  NTB: ntb_hw_amd: set peer limit register
  NTB: ntb_perf: Clear stale values in doorbell and command SPAD register
  NTB: ntb_perf: Disable NTB link after clearing peer XLAT registers
  ...

Documentation/driver-api/ntb.rst

@@ -200,6 +200,33 @@ Debugfs Files:
 	This file is used to read and write peer scratchpads.  See
 	*spad* for details.
 
+NTB MSI Test Client (ntb\_msi\_test)
+------------------------------------
+
+The MSI test client serves to test and debug the MSI library which
+allows for passing MSI interrupts across NTB memory windows. The
+test client is interacted with through the debugfs filesystem:
+
+* *debugfs*/ntb\_tool/*hw*/
+	A directory in debugfs will be created for each
+	NTB device probed by the tool.  This directory is shortened to *hw*
+	below.
+* *hw*/port
+	This file describes the local port number
+* *hw*/irq*_occurrences
+	One occurrences file exists for each interrupt and, when read,
+	returns the number of times the interrupt has been triggered.
+* *hw*/peer*/port
+	This file describes the port number for each peer
+* *hw*/peer*/count
+	This file describes the number of interrupts that can be
+	triggered on each peer
+* *hw*/peer*/trigger
+	Writing an interrupt number (any number less than the value
+	specified in count) will trigger the interrupt on the
+	specified peer. That peer's interrupt's occurrence file
+	should be incremented.
+
 NTB Hardware Drivers
 ====================
 

drivers/ntb/Kconfig

@@ -13,6 +13,17 @@ menuconfig NTB
 
 if NTB
 
+config NTB_MSI
+	bool "MSI Interrupt Support"
+	depends on PCI_MSI
+	help
+	 Support using MSI interrupt forwarding instead of (or in addition to)
+	 hardware doorbells. MSI interrupts typically offer lower latency
+	 than doorbells and more MSI interrupts can be made available to
+	 clients. However this requires an extra memory window and support
+	 in the hardware driver for creating the MSI interrupts.
+
+	 If unsure, say N.
 source "drivers/ntb/hw/Kconfig"
 
 source "drivers/ntb/test/Kconfig"

drivers/ntb/Makefile

@@ -1,3 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_NTB) += ntb.o hw/ test/
 obj-$(CONFIG_NTB_TRANSPORT) += ntb_transport.o
+
+ntb-y			:= core.o
+ntb-$(CONFIG_NTB_MSI)	+= msi.o

drivers/ntb/hw/amd/ntb_hw_amd.c

@@ -160,8 +160,8 @@ static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
 		}
 
 		/* set and verify setting the limit */
-		write64(limit, mmio + limit_reg);
-		reg_val = read64(mmio + limit_reg);
+		write64(limit, peer_mmio + limit_reg);
+		reg_val = read64(peer_mmio + limit_reg);
 		if (reg_val != limit) {
 			write64(base_addr, mmio + limit_reg);
 			write64(0, peer_mmio + xlat_reg);
@@ -183,8 +183,8 @@ static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
 		}
 
 		/* set and verify setting the limit */
-		writel(limit, mmio + limit_reg);
-		reg_val = readl(mmio + limit_reg);
+		writel(limit, peer_mmio + limit_reg);
+		reg_val = readl(peer_mmio + limit_reg);
 		if (reg_val != limit) {
 			writel(base_addr, mmio + limit_reg);
 			writel(0, peer_mmio + xlat_reg);
@@ -333,7 +333,7 @@ static u64 amd_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
 	if (db_vector < 0 || db_vector > ndev->db_count)
 		return 0;
 
-	return ntb_ndev(ntb)->db_valid_mask & (1 << db_vector);
+	return ntb_ndev(ntb)->db_valid_mask & (1ULL << db_vector);
 }
 
 static u64 amd_ntb_db_read(struct ntb_dev *ntb)

drivers/ntb/hw/intel/ntb_hw_gen3.c

@@ -532,9 +532,9 @@ static int intel_ntb3_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
 	return 0;
 }
 
-int intel_ntb3_peer_db_addr(struct ntb_dev *ntb, phys_addr_t *db_addr,
-				resource_size_t *db_size,
-				u64 *db_data, int db_bit)
+static int intel_ntb3_peer_db_addr(struct ntb_dev *ntb, phys_addr_t *db_addr,
+				   resource_size_t *db_size,
+				   u64 *db_data, int db_bit)
 {
 	phys_addr_t db_addr_base;
 	struct intel_ntb_dev *ndev = ntb_ndev(ntb);

drivers/ntb/hw/mscc/ntb_hw_switchtec.c

@@ -86,7 +86,8 @@ struct switchtec_ntb {
 	bool link_is_up;
 	enum ntb_speed link_speed;
 	enum ntb_width link_width;
-	struct work_struct link_reinit_work;
+	struct work_struct check_link_status_work;
+	bool link_force_down;
 };
 
 static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb)
@@ -485,33 +486,11 @@ enum switchtec_msg {
 
 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev);
 
-static void link_reinit_work(struct work_struct *work)
-{
-	struct switchtec_ntb *sndev;
-
-	sndev = container_of(work, struct switchtec_ntb, link_reinit_work);
-
-	switchtec_ntb_reinit_peer(sndev);
-}
-
-static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
-				     enum switchtec_msg msg)
+static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev)
 {
 	int link_sta;
 	int old = sndev->link_is_up;
 
-	if (msg == MSG_LINK_FORCE_DOWN) {
-		schedule_work(&sndev->link_reinit_work);
-
-		if (sndev->link_is_up) {
-			sndev->link_is_up = 0;
-			ntb_link_event(&sndev->ntb);
-			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
-		}
-
-		return;
-	}
-
 	link_sta = sndev->self_shared->link_sta;
 	if (link_sta) {
 		u64 peer = ioread64(&sndev->peer_shared->magic);
@@ -536,6 +515,38 @@ static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
 	}
 }
 
+static void check_link_status_work(struct work_struct *work)
+{
+	struct switchtec_ntb *sndev;
+
+	sndev = container_of(work, struct switchtec_ntb,
+			     check_link_status_work);
+
+	if (sndev->link_force_down) {
+		sndev->link_force_down = false;
+		switchtec_ntb_reinit_peer(sndev);
+
+		if (sndev->link_is_up) {
+			sndev->link_is_up = 0;
+			ntb_link_event(&sndev->ntb);
+			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
+		}
+
+		return;
+	}
+
+	switchtec_ntb_link_status_update(sndev);
+}
+
+static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
+				      enum switchtec_msg msg)
+{
+	if (msg == MSG_LINK_FORCE_DOWN)
+		sndev->link_force_down = true;
+
+	schedule_work(&sndev->check_link_status_work);
+}
+
 static void switchtec_ntb_link_notification(struct switchtec_dev *stdev)
 {
 	struct switchtec_ntb *sndev = stdev->sndev;
@@ -568,7 +579,7 @@ static int switchtec_ntb_link_enable(struct ntb_dev *ntb,
 	sndev->self_shared->link_sta = 1;
 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP);
 
-	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
+	switchtec_ntb_link_status_update(sndev);
 
 	return 0;
 }
@@ -582,7 +593,7 @@ static int switchtec_ntb_link_disable(struct ntb_dev *ntb)
 	sndev->self_shared->link_sta = 0;
 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN);
 
-	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
+	switchtec_ntb_link_status_update(sndev);
 
 	return 0;
 }
@@ -835,7 +846,8 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 	sndev->ntb.topo = NTB_TOPO_SWITCH;
 	sndev->ntb.ops = &switchtec_ntb_ops;
 
-	INIT_WORK(&sndev->link_reinit_work, link_reinit_work);
+	INIT_WORK(&sndev->check_link_status_work, check_link_status_work);
+	sndev->link_force_down = false;
 
 	sndev->self_partition = sndev->stdev->partition;
 
@@ -872,7 +884,7 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 		}
 
 		sndev->peer_partition = ffs(tpart_vec) - 1;
-		if (!(part_map & (1 << sndev->peer_partition))) {
+		if (!(part_map & (1ULL << sndev->peer_partition))) {
 			dev_err(&sndev->stdev->dev,
 				"ntb target partition is not NT partition\n");
 			return -ENODEV;
@@ -1448,10 +1460,16 @@ static void switchtec_ntb_deinit_db_msg_irq(struct switchtec_ntb *sndev)
 
 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev)
 {
-	dev_info(&sndev->stdev->dev, "peer reinitialized\n");
-	switchtec_ntb_deinit_shared_mw(sndev);
-	switchtec_ntb_init_mw(sndev);
-	return switchtec_ntb_init_shared_mw(sndev);
+	int rc;
+
+	if (crosslink_is_enabled(sndev))
+		return 0;
+
+	dev_info(&sndev->stdev->dev, "reinitialize shared memory window\n");
+	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
+				 sndev->self_partition,
+				 sndev->self_shared_dma);
+	return rc;
 }
 
 static int switchtec_ntb_add(struct device *dev,