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Message-ID: <20200514145927.17555-16-kishon@ti.com>
Date: Thu, 14 May 2020 20:29:23 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
Arnd Bergmann <arnd@...db.de>, Jon Mason <jdmason@...zu.us>,
Dave Jiang <dave.jiang@...el.com>,
Allen Hubbe <allenbh@...il.com>,
Tom Joseph <tjoseph@...ence.com>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Rob Herring <robh+dt@...nel.org>
CC: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Jonathan Corbet <corbet@....net>, <linux-pci@...r.kernel.org>,
<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<devicetree@...r.kernel.org>, <linux-ntb@...glegroups.com>,
Kishon Vijay Abraham I <kishon@...com>
Subject: [PATCH 15/19] PCI: endpoint: Add EP function driver to provide NTB functionality
Add a new endpoint function driver to provide NTB functionality
using multiple PCIe endpoint instances.
Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
---
drivers/pci/endpoint/functions/Kconfig | 12 +
drivers/pci/endpoint/functions/Makefile | 1 +
drivers/pci/endpoint/functions/pci-epf-ntb.c | 2038 ++++++++++++++++++
3 files changed, 2051 insertions(+)
create mode 100644 drivers/pci/endpoint/functions/pci-epf-ntb.c
diff --git a/drivers/pci/endpoint/functions/Kconfig b/drivers/pci/endpoint/functions/Kconfig
index 8820d0f7ec77..55ac7bb2d469 100644
--- a/drivers/pci/endpoint/functions/Kconfig
+++ b/drivers/pci/endpoint/functions/Kconfig
@@ -12,3 +12,15 @@ config PCI_EPF_TEST
for PCI Endpoint.
If in doubt, say "N" to disable Endpoint test driver.
+
+config PCI_EPF_NTB
+ tristate "PCI Endpoint NTB driver"
+ depends on PCI_ENDPOINT
+ help
+ Select this configuration option to enable the NTB driver
+ for PCI Endpoint. NTB driver implements NTB controller
+ functionality using multiple PCIe endpoint instances. It
+ can support NTB endpoint function devices created using
+ device tree.
+
+ If in doubt, say "N" to disable Endpoint NTB driver.
diff --git a/drivers/pci/endpoint/functions/Makefile b/drivers/pci/endpoint/functions/Makefile
index d6fafff080e2..96ab932a537a 100644
--- a/drivers/pci/endpoint/functions/Makefile
+++ b/drivers/pci/endpoint/functions/Makefile
@@ -4,3 +4,4 @@
#
obj-$(CONFIG_PCI_EPF_TEST) += pci-epf-test.o
+obj-$(CONFIG_PCI_EPF_NTB) += pci-epf-ntb.o
diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
new file mode 100644
index 000000000000..0229ef456d7f
--- /dev/null
+++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
@@ -0,0 +1,2038 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Endpoint Function Driver to implement Non-Transparent Bridge functionality
+ *
+ * Copyright (C) 2020 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@...com>
+ */
+
+/*
+ *The PCI NTB function driver configures the SoC with multiple PCIe Endpoint(EP)
+ *controller instances (see diagram below) in such a way that transaction from
+ *one EP controller is routed to the other EP controller. Once PCI NTB function
+ *driver configures the SoC with multiple EP instances, HOST1 and HOST2 can
+ *communicate with each other using SoC as a bridge.
+ *
+ * +-------------+ +-------------+
+ * | | | |
+ * | HOST1 | | HOST2 |
+ * | | | |
+ * +------^------+ +------^------+
+ * | |
+ * | |
+ *+---------|-------------------------------------------------|---------+
+ *| +------v------+ +------v------+ |
+ *| | | | | |
+ *| | EP | | EP | |
+ *| | CONTROLLER1 | | CONTROLLER2 | |
+ *| | <-----------------------------------> | |
+ *| | | | | |
+ *| | | | | |
+ *| | | SoC With Multiple EP Instances | | |
+ *| | | (Configured using NTB Function) | | |
+ *| +-------------+ +-------------+ |
+ *+---------------------------------------------------------------------+
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+static struct workqueue_struct *kpcintb_workqueue;
+
+#define COMMAND_CONFIGURE_DOORBELL 1
+#define COMMAND_TEARDOWN_DOORBELL 2
+#define COMMAND_CONFIGURE_MW 3
+#define COMMAND_TEARDOWN_MW 4
+#define COMMAND_LINK_UP 5
+#define COMMAND_LINK_DOWN 6
+
+#define COMMAND_STATUS_OK 1
+#define COMMAND_STATUS_ERROR 2
+
+#define LINK_STATUS_UP BIT(0)
+
+#define SPAD_COUNT 64
+#define DB_COUNT 4
+#define NTB_MW_OFFSET 2
+#define DB_COUNT_MASK GENMASK(15, 0)
+#define MSIX_ENABLE BIT(16)
+#define MAX_DB_COUNT 32
+#define MAX_MW 4
+
+enum epf_ntb_bar {
+ BAR_CONFIG,
+ BAR_PEER_SPAD,
+ BAR_DB_MW1,
+ BAR_MW2,
+ BAR_MW3,
+ BAR_MW4,
+};
+
+struct epf_ntb {
+ u32 num_mws;
+ u32 db_count;
+ u64 *mws_size;
+ u32 spad_count;
+ struct pci_epf *epf;
+ struct epf_ntb_epc *epc[2];
+};
+
+struct epf_ntb_epc {
+ u8 func_no;
+ bool linkup;
+ bool is_msix;
+ int msix_bar;
+ u32 spad_size;
+ struct pci_epc *epc;
+ struct epf_ntb *epf_ntb;
+ void __iomem *mw_addr[6];
+ size_t msix_table_offset;
+ struct epf_ntb_ctrl *reg;
+ struct pci_epf_bar *epf_bar;
+ enum pci_barno epf_ntb_bar[6];
+ struct delayed_work cmd_handler;
+ enum pci_epc_interface_type type;
+ const struct pci_epc_features *epc_features;
+};
+
+struct epf_ntb_ctrl {
+ u32 command;
+ u32 argument;
+ u16 command_status;
+ u16 link_status;
+ u32 topology;
+ u64 addr;
+ u64 size;
+ u32 num_mws;
+ u32 mw1_offset;
+ u32 spad_offset;
+ u32 spad_count;
+ u32 db_entry_size;
+ u32 db_data[MAX_DB_COUNT];
+} __packed;
+
+static struct pci_epf_header epf_ntb_header = {
+ .vendorid = PCI_ANY_ID,
+ .deviceid = PCI_ANY_ID,
+ .baseclass_code = PCI_BASE_CLASS_MEMORY,
+ .interrupt_pin = PCI_INTERRUPT_INTA,
+};
+
+/**
+ * epf_ntb_link_up() - Raise link_up interrupt to both the hosts
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @link_up: true or false indicating Link is UP or Down
+ *
+ * Once NTB function in HOST1 and the NTB function in HOST2 invoke
+ * ntb_link_enable(), this NTB function driver will trigger a link event to
+ * the NTB client in both the hosts.
+ */
+static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
+{
+ enum pci_epc_interface_type type;
+ enum pci_epc_irq_type irq_type;
+ struct epf_ntb_epc *ntb_epc;
+ struct epf_ntb_ctrl *ctrl;
+ bool is_msix;
+ u8 func_no;
+ int ret;
+
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+ ntb_epc = ntb->epc[type];
+ func_no = ntb_epc->func_no;
+ is_msix = ntb_epc->is_msix;
+ ctrl = ntb_epc->reg;
+ if (link_up)
+ ctrl->link_status |= LINK_STATUS_UP;
+ else
+ ctrl->link_status &= ~LINK_STATUS_UP;
+ irq_type = is_msix ? PCI_EPC_IRQ_MSIX : PCI_EPC_IRQ_MSI;
+ ret = pci_epc_raise_irq(ntb_epc->epc, func_no, irq_type,
+ 1);
+ if (ret < 0) {
+ WARN(1, "%s intf: Failed to raise Link Up IRQ\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_configure_mw() - Configure the Outbound Address Space for one host
+ * to access the memory window of other host
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @mw: Index of the memory window (either 0, 1, 2 or 3)
+ *
+ *+-----------------+ +----->+----------------+-----------+-----------------+
+ *| BAR0 | | | Doorbell 1 +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+ | +----------------+ +-----------------+
+ *| BAR1 | | | Doorbell 2 +---------+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR2 | | Doorbell 3 +-------+ | +-----------------+
+ *+-----------------+----+ +----------------+ | +-> MSI|X ADDRESS 2 |
+ *| BAR3 | | | Doorbell 4 +-----+ | +-----------------+
+ *+-----------------+ | |----------------+ | | | |
+ *| BAR4 | | | | | | +-----------------+
+ *+-----------------+ | | MW1 +---+ | +-->+ MSI|X ADDRESS 3||
+ *| BAR5 | | | | | | +-----------------+
+ *+-----------------+ +----->-----------------+ | | | |
+ * EP CONTROLLER 1 | | | | +-----------------+
+ * | | | +---->+ MSI|X ADDRESS 4 |
+ * +----------------+ | +-----------------+
+ * (A) EP CONTROLLER 2 | | |
+ * (OB SPACE) | | |
+ * +-------> MW1 |
+ * | |
+ * | |
+ * (B) +-----------------+
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * +-----------------+
+ * PCI Address Space
+ * (Managed by HOST2)
+ *
+ * This function performs stage (B) in the above diagram (see MW1) i.e map OB
+ * address space of memory window to PCI address space.
+ *
+ * This operation requires 3 parameters
+ * 1) Address in the outbound address space
+ * 2) Address in the PCIe Address space
+ * 3) Size of the address region that is requested to be mapped
+ *
+ * The address in the outbound address space (for MW1, MW2, MW3 and MW4) is
+ * stored in epf_bar corresponding to BAR_DB_MW1 for MW1 and BAR_MW2, BAR_MW3
+ * BAR_MW4 for rest of the BARs of epf_ntb_epc that is connected to HOST1. This
+ * is populated in epf_ntb_alloc_peer_mem() in this driver.
+ *
+ * The address and size of the PCIe address region that has to be mapped would
+ * be provided by HOST2 in ctrl->addr and ctrl->size of epf_ntb_epc that is
+ * connected to HOST2.
+ *
+ * Please note Memory window1 (MW1) and Doorbell registers together will be
+ * mapped to a single BAR (BAR2) above for 32-bit BARs. The exact BAR that's
+ * used for Memory window (MW) can be obtained from epf_ntb_bar[BAR_DB_MW1],
+ * epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2].
+ */
+static int
+epf_ntb_configure_mw(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+ u32 mw)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *peer_epf_bar;
+ enum pci_barno peer_barno;
+ struct epf_ntb_ctrl *ctrl;
+ phys_addr_t phys_addr;
+ struct pci_epc *epc;
+ u64 addr, size;
+ int ret = 0;
+ u8 func_no;
+
+ ntb_epc = ntb->epc[type];
+ epc = ntb_epc->epc;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
+ peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+
+ phys_addr = peer_epf_bar->phys_addr;
+ ctrl = ntb_epc->reg;
+ addr = ctrl->addr;
+ size = ctrl->size;
+ if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
+ phys_addr += ctrl->mw1_offset;
+
+ if (size > ntb->mws_size[mw]) {
+ WARN(1, "%s intf: MW: %d Req Sz:%llxx > Supported Sz:%llx\n",
+ pci_epc_interface_string(type), mw, size,
+ ntb->mws_size[mw]);
+ ret = -EINVAL;
+ goto err_invalid_size;
+ }
+
+ func_no = ntb_epc->func_no;
+
+ ret = pci_epc_map_addr(epc, func_no, phys_addr, addr, size);
+ WARN(ret < 0, "%s intf: Failed to map memory window %d address\n",
+ pci_epc_interface_string(type), mw);
+
+err_invalid_size:
+
+ return ret;
+}
+
+/**
+ * epf_ntb_teardown_mw() - Teardown the configured OB ATU
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @mw: Index of the memory window (either 0, 1, 2 or 3)
+ *
+ * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
+ * pci_epc_unmap_addr()
+ */
+static void
+epf_ntb_teardown_mw(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+ u32 mw)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *peer_epf_bar;
+ enum pci_barno peer_barno;
+ struct epf_ntb_ctrl *ctrl;
+ phys_addr_t phys_addr;
+ struct pci_epc *epc;
+ u8 func_no;
+
+ ntb_epc = ntb->epc[type];
+ epc = ntb_epc->epc;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
+ peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+
+ phys_addr = peer_epf_bar->phys_addr;
+ ctrl = ntb_epc->reg;
+ if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
+ phys_addr += ctrl->mw1_offset;
+ func_no = ntb_epc->func_no;
+
+ pci_epc_unmap_addr(epc, func_no, phys_addr);
+}
+
+/**
+ * epf_ntb_configure_msi() - Map OB address space to MSI address
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @db_count: Number of doorbell interrupts to map
+ *
+ *+-----------------+ +----->+----------------+-----------+-----------------+
+ *| BAR0 | | | Doorbell 1 +---+-------> MSI ADDRESS |
+ *+-----------------+ | +----------------+ | +-----------------+
+ *| BAR1 | | | Doorbell 2 +---+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR2 | | Doorbell 3 +---+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR3 | | | Doorbell 4 +---+ | |
+ *+-----------------+ | |----------------+ | |
+ *| BAR4 | | | | | |
+ *+-----------------+ | | MW1 | | |
+ *| BAR5 | | | | | |
+ *+-----------------+ +----->-----------------+ | |
+ * EP CONTROLLER 1 | | | |
+ * | | | |
+ * +----------------+ +-----------------+
+ * (A) EP CONTROLLER 2 | |
+ * (OB SPACE) | |
+ * | MW1 |
+ * | |
+ * | |
+ * (B) +-----------------+
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * +-----------------+
+ * PCI Address Space
+ * (Managed by HOST2)
+ *
+ *
+ * This function performs stage (B) in the above diagram (see Doorbell 1,
+ * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
+ * doorbell to MSI address in PCI address space.
+ *
+ * This operation requires 3 parameters
+ * 1) Address reserved for doorbell in the outbound address space
+ * 2) MSI-X address in the PCIe Address space
+ * 3) Number of MSI-X interrupts that has to be configured
+ *
+ * The address in the outbound address space (for the Doorbell) is stored in
+ * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
+ * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
+ * with address for MW1.
+ *
+ * pci_epc_map_msi_irq() takes the MSI address from MSI capability register
+ * and maps the OB address (obtained in epf_ntb_alloc_peer_mem()) to the MSI
+ * address.
+ *
+ * epf_ntb_configure_msi() also stores the MSI data to raise each interrupt
+ * in db_data of the peer's control region. This helps the peer to raise
+ * doorbell of the other host by writing db_data to the BAR corresponding to
+ * BAR_DB_MW1.
+ */
+static int
+epf_ntb_configure_msi(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+ u16 db_count)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *peer_epf_bar;
+ struct epf_ntb_ctrl *peer_ctrl;
+ u32 db_entry_size, db_data;
+ enum pci_barno peer_barno;
+ phys_addr_t phys_addr;
+ struct pci_epc *epc;
+ u8 func_no;
+ int ret, i;
+
+ ntb_epc = ntb->epc[type];
+ epc = ntb_epc->epc;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
+ peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+ peer_ctrl = peer_ntb_epc->reg;
+ db_entry_size = peer_ctrl->db_entry_size;
+
+ phys_addr = peer_epf_bar->phys_addr;
+ func_no = ntb_epc->func_no;
+
+ ret = pci_epc_map_msi_irq(epc, func_no, phys_addr, db_count,
+ db_entry_size, &db_data);
+ if (ret < 0) {
+ WARN(1, "%s intf: Failed to map MSI IRQ\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+
+ for (i = 0; i < db_count; i++)
+ peer_ctrl->db_data[i] = db_data | i;
+
+ return 0;
+}
+
+/**
+ * epf_ntb_configure_msix() - Map OB address space to MSI-X address
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @db_count: Number of doorbell interrupts to map
+ *
+ *+-----------------+ +----->+----------------+-----------+-----------------+
+ *| BAR0 | | | Doorbell 1 +-----------> MSI-X ADDRESS 1 |
+ *+-----------------+ | +----------------+ +-----------------+
+ *| BAR1 | | | Doorbell 2 +---------+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR2 | | Doorbell 3 +-------+ | +-----------------+
+ *+-----------------+----+ +----------------+ | +-> MSI-X ADDRESS 2 |
+ *| BAR3 | | | Doorbell 4 +-----+ | +-----------------+
+ *+-----------------+ | |----------------+ | | | |
+ *| BAR4 | | | | | | +-----------------+
+ *+-----------------+ | | MW1 + | +-->+ MSI-X ADDRESS 3||
+ *| BAR5 | | | | | +-----------------+
+ *+-----------------+ +----->-----------------+ | | |
+ * EP CONTROLLER 1 | | | +-----------------+
+ * | | +---->+ MSI-X ADDRESS 4 |
+ * +----------------+ +-----------------+
+ * (A) EP CONTROLLER 2 | |
+ * (OB SPACE) | |
+ * | MW1 |
+ * | |
+ * | |
+ * (B) +-----------------+
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * +-----------------+
+ * PCI Address Space
+ * (Managed by HOST2)
+ *
+ * This function performs stage (B) in the above diagram (see Doorbell 1,
+ * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
+ * doorbell to MSI-X address in PCI address space.
+ *
+ * This operation requires 3 parameters
+ * 1) Address reserved for doorbell in the outbound address space
+ * 2) MSI-X address in the PCIe Address space
+ * 3) Number of MSI-X interrupts that has to be configured
+ *
+ * The address in the outbound address space (for the Doorbell) is stored in
+ * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
+ * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
+ * with address for MW1.
+ * The MSI-X address is in the MSI-X table of EP CONTROLLER 2 and
+ * the count of doorbell is in ctrl->argument of epf_ntb_epc that is connected
+ * to HOST2. MSI-X table is stored memory mapped to ntb_epc->msix_bar and the
+ * offset is in ntb_epc->msix_table_offset. From this epf_ntb_configure_msix()
+ * gets the MSI-X address and MSI-X data
+ *
+ * epf_ntb_configure_msix() also stores the MSI-X data to raise each interrupt
+ * in db_data of the peer's control region. This helps the peer to raise
+ * doorbell of the other host by writing db_data to the BAR corresponding to
+ * BAR_DB_MW1.
+ */
+static int epf_ntb_configure_msix(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type,
+ u16 db_count)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *peer_epf_bar, *epf_bar;
+ struct pci_epf_msix_tbl *msix_tbl;
+ struct epf_ntb_ctrl *peer_ctrl;
+ u32 db_entry_size, msg_data;
+ enum pci_barno peer_barno;
+ phys_addr_t phys_addr;
+ struct pci_epc *epc;
+ u64 msg_addr;
+ u8 func_no;
+ int ret, i;
+
+ ntb_epc = ntb->epc[type];
+ epc = ntb_epc->epc;
+
+ epf_bar = &ntb_epc->epf_bar[ntb_epc->msix_bar];
+ msix_tbl = epf_bar->addr + ntb_epc->msix_table_offset;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
+ peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+ phys_addr = peer_epf_bar->phys_addr;
+ peer_ctrl = peer_ntb_epc->reg;
+
+ func_no = ntb_epc->func_no;
+ db_entry_size = peer_ctrl->db_entry_size;
+
+ for (i = 0; i < db_count; i++) {
+ msg_addr = msix_tbl[i].msg_addr;
+ msg_data = msix_tbl[i].msg_data;
+ ret = pci_epc_map_addr(epc, func_no, phys_addr, msg_addr,
+ db_entry_size);
+ if (ret)
+ return ret;
+ phys_addr = phys_addr + db_entry_size;
+ peer_ctrl->db_data[i] = msg_data;
+ }
+ ntb_epc->is_msix = true;
+
+ return 0;
+}
+
+/**
+ * epf_ntb_configure_db() - Configure the Outbound Address Space for one host
+ * to ring the doorbell of other host
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @db_count: Count of the number of doorbells that has to be configured
+ * @msix: Indicates whether MSI-X or MSI should be used
+ *
+ * Invokes epf_ntb_configure_msix() or epf_ntb_configure_msi() required for
+ * one HOST to ring the doorbell of other HOST.
+ */
+static int
+epf_ntb_configure_db(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+ u16 db_count, bool msix)
+{
+ int ret;
+
+ if (db_count > MAX_DB_COUNT)
+ return -EINVAL;
+
+ if (msix)
+ ret = epf_ntb_configure_msix(ntb, type, db_count);
+ else
+ ret = epf_ntb_configure_msi(ntb, type, db_count);
+
+ WARN(ret < 0, "%s intf: Failed to configure DB\n",
+ pci_epc_interface_string(type));
+
+ return ret;
+}
+
+/**
+ * epf_ntb_teardown_db() - Unmap address in OB address space to MSI/MSI-X
+ * address
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Invoke pci_epc_unmap_addr() to unmap OB address to MSI/MSI-X address.
+ */
+static void
+epf_ntb_teardown_db(struct epf_ntb *ntb, enum pci_epc_interface_type type)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *peer_epf_bar;
+ enum pci_barno peer_barno;
+ phys_addr_t phys_addr;
+ struct pci_epc *epc;
+ u8 func_no;
+
+ ntb_epc = ntb->epc[type];
+ epc = ntb_epc->epc;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
+ peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+ phys_addr = peer_epf_bar->phys_addr;
+ func_no = ntb_epc->func_no;
+
+ pci_epc_unmap_addr(epc, func_no, phys_addr);
+}
+
+/**
+ * epf_ntb_cmd_handler() - Handle commands provided by the NTB Host
+ * @work: work_struct for the two epf_ntb_epc (PRIMARY and SECONDARY)
+ *
+ * Workqueue function that gets invoked for the two epf_ntb_epc
+ * periodically (once every 5ms) to see if it has received any commands
+ * from NTB host. The host can send commands to configure doorbell or
+ * configure memory window or to update link status.
+ */
+static void epf_ntb_cmd_handler(struct work_struct *work)
+{
+ enum pci_epc_interface_type type;
+ struct epf_ntb_epc *ntb_epc;
+ struct epf_ntb_ctrl *ctrl;
+ u32 command, argument;
+ struct epf_ntb *ntb;
+ struct device *dev;
+ u16 db_count;
+ bool is_msix;
+ int ret;
+
+ ntb_epc = container_of(work, struct epf_ntb_epc, cmd_handler.work);
+ ctrl = ntb_epc->reg;
+ command = ctrl->command;
+ if (!command)
+ goto reset_handler;
+ argument = ctrl->argument;
+
+ ctrl->command = 0;
+ ctrl->argument = 0;
+
+ ctrl = ntb_epc->reg;
+ type = ntb_epc->type;
+ ntb = ntb_epc->epf_ntb;
+ dev = &ntb->epf->dev;
+
+ switch (command) {
+ case COMMAND_CONFIGURE_DOORBELL:
+ db_count = argument & DB_COUNT_MASK;
+ is_msix = argument & MSIX_ENABLE;
+ ret = epf_ntb_configure_db(ntb, type, db_count, is_msix);
+ if (ret < 0)
+ ctrl->command_status = COMMAND_STATUS_ERROR;
+ else
+ ctrl->command_status = COMMAND_STATUS_OK;
+ break;
+ case COMMAND_TEARDOWN_DOORBELL:
+ epf_ntb_teardown_db(ntb, type);
+ ctrl->command_status = COMMAND_STATUS_OK;
+ break;
+ case COMMAND_CONFIGURE_MW:
+ ret = epf_ntb_configure_mw(ntb, type, argument);
+ if (ret < 0)
+ ctrl->command_status = COMMAND_STATUS_ERROR;
+ else
+ ctrl->command_status = COMMAND_STATUS_OK;
+ break;
+ case COMMAND_TEARDOWN_MW:
+ epf_ntb_teardown_mw(ntb, type, argument);
+ ctrl->command_status = COMMAND_STATUS_OK;
+ break;
+ case COMMAND_LINK_UP:
+ ntb_epc->linkup = true;
+ if (ntb->epc[PRIMARY_INTERFACE]->linkup &&
+ ntb->epc[SECONDARY_INTERFACE]->linkup) {
+ ret = epf_ntb_link_up(ntb, true);
+ if (ret < 0)
+ ctrl->command_status = COMMAND_STATUS_ERROR;
+ else
+ ctrl->command_status = COMMAND_STATUS_OK;
+ goto reset_handler;
+ }
+ ctrl->command_status = COMMAND_STATUS_OK;
+ break;
+ case COMMAND_LINK_DOWN:
+ ntb_epc->linkup = false;
+ ret = epf_ntb_link_up(ntb, false);
+ if (ret < 0)
+ ctrl->command_status = COMMAND_STATUS_ERROR;
+ else
+ ctrl->command_status = COMMAND_STATUS_OK;
+ break;
+ default:
+ dev_err(dev, "%s intf UNKNOWN command: %d\n",
+ pci_epc_interface_string(type), command);
+ break;
+ }
+
+reset_handler:
+ queue_delayed_work(kpcintb_workqueue, &ntb_epc->cmd_handler,
+ msecs_to_jiffies(5));
+}
+
+/**
+ * epf_ntb_peer_spad_bar_clear() - Clears Peer Scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+ +-----------------+
+ *| BAR0 | | CONFIG REGION | | BAR0 |
+ *+-----------------+----+ +------------------+<-------+-----------------+
+ *| BAR1 | | |SCRATCHPAD REGION | | BAR1 |
+ *+-----------------+ +-->+------------------+<-------+-----------------+
+ *| BAR2 | Local Memory | BAR2 |
+ *+-----------------+ +-----------------+
+ *| BAR3 | | BAR3 |
+ *+-----------------+ +-----------------+
+ *| BAR4 | | BAR4 |
+ *+-----------------+ +-----------------+
+ *| BAR5 | | BAR5 |
+ *+-----------------+ +-----------------+
+ * EP CONTROLLER 1 EP CONTROLLER 2
+ *
+ * It clears BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
+ * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
+ * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
+ * This function can get the exact BAR used for peer scratchpad from
+ * epf_ntb_bar[BAR_PEER_SPAD].
+ *
+ * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
+ * gets the address of peer scratchpad from
+ * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG]
+ */
+static void epf_ntb_peer_spad_bar_clear(struct epf_ntb_epc *ntb_epc)
+{
+ struct pci_epf_bar *epf_bar;
+ enum pci_barno barno;
+ struct pci_epc *epc;
+ u8 func_no;
+
+ epc = ntb_epc->epc;
+ func_no = ntb_epc->func_no;
+ barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
+ epf_bar = &ntb_epc->epf_bar[barno];
+ pci_epc_clear_bar(epc, func_no, epf_bar);
+}
+
+/**
+ * epf_ntb_peer_spad_bar_set() - Sets peer scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+ +-----------------+
+ *| BAR0 | | CONFIG REGION | | BAR0 |
+ *+-----------------+----+ +------------------+<-------+-----------------+
+ *| BAR1 | | |SCRATCHPAD REGION | | BAR1 |
+ *+-----------------+ +-->+------------------+<-------+-----------------+
+ *| BAR2 | Local Memory | BAR2 |
+ *+-----------------+ +-----------------+
+ *| BAR3 | | BAR3 |
+ *+-----------------+ +-----------------+
+ *| BAR4 | | BAR4 |
+ *+-----------------+ +-----------------+
+ *| BAR5 | | BAR5 |
+ *+-----------------+ +-----------------+
+ * EP CONTROLLER 1 EP CONTROLLER 2
+ *
+ * It sets BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
+ * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
+ * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
+ * This function can get the exact BAR used for peer scratchpad from
+ * epf_ntb_bar[BAR_PEER_SPAD].
+ *
+ * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
+ * gets the address of peer scratchpad from
+ * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG]
+ */
+static int
+epf_ntb_peer_spad_bar_set(struct epf_ntb *ntb, enum pci_epc_interface_type type)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *peer_epf_bar, *epf_bar;
+ enum pci_barno peer_barno, barno;
+ u32 peer_spad_offset;
+ struct pci_epc *epc;
+ struct device *dev;
+ u8 func_no;
+ int ret;
+
+ dev = &ntb->epf->dev;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_CONFIG];
+ peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+
+ ntb_epc = ntb->epc[type];
+ barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
+ epf_bar = &ntb_epc->epf_bar[barno];
+ func_no = ntb_epc->func_no;
+ epc = ntb_epc->epc;
+
+ peer_spad_offset = peer_ntb_epc->reg->spad_offset;
+ epf_bar->phys_addr = peer_epf_bar->phys_addr + peer_spad_offset;
+ epf_bar->size = peer_ntb_epc->spad_size;
+ epf_bar->barno = barno;
+ epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
+
+ ret = pci_epc_set_bar(ntb_epc->epc, func_no, epf_bar);
+ if (ret) {
+ dev_err(dev, "%s intf: peer SPAD BAR set failed\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_config_sspad_bar_clear() - Clears Config + Self scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+ +-----------------+
+ *| BAR0 | | CONFIG REGION | | BAR0 |
+ *+-----------------+----+ +------------------+<-------+-----------------+
+ *| BAR1 | | |SCRATCHPAD REGION | | BAR1 |
+ *+-----------------+ +-->+------------------+<-------+-----------------+
+ *| BAR2 | Local Memory | BAR2 |
+ *+-----------------+ +-----------------+
+ *| BAR3 | | BAR3 |
+ *+-----------------+ +-----------------+
+ *| BAR4 | | BAR4 |
+ *+-----------------+ +-----------------+
+ *| BAR5 | | BAR5 |
+ *+-----------------+ +-----------------+
+ * EP CONTROLLER 1 EP CONTROLLER 2
+ *
+ * It clears BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
+ * self scratchpad region (removes inbound ATU configuration). While BAR0 is
+ * the default self scratchpad BAR, an NTB could have other BARs for self
+ * scratchpad (because of reserved BARs). This function can get the exact BAR
+ * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
+ *
+ * Please note the self scratchpad region and config region is combined to
+ * a single region and mapped using the same BAR. Also note HOST2's peer
+ * scratchpad is HOST1's self scratchpad.
+ */
+static void epf_ntb_config_sspad_bar_clear(struct epf_ntb_epc *ntb_epc)
+{
+ struct pci_epf_bar *epf_bar;
+ enum pci_barno barno;
+ struct pci_epc *epc;
+ u8 func_no;
+
+ epc = ntb_epc->epc;
+ func_no = ntb_epc->func_no;
+ barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+ epf_bar = &ntb_epc->epf_bar[barno];
+ pci_epc_clear_bar(epc, func_no, epf_bar);
+}
+
+/**
+ * epf_ntb_config_sspad_bar_set() - Sets Config + Self scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+ +-----------------+
+ *| BAR0 | | CONFIG REGION | | BAR0 |
+ *+-----------------+----+ +------------------+<-------+-----------------+
+ *| BAR1 | | |SCRATCHPAD REGION | | BAR1 |
+ *+-----------------+ +-->+------------------+<-------+-----------------+
+ *| BAR2 | Local Memory | BAR2 |
+ *+-----------------+ +-----------------+
+ *| BAR3 | | BAR3 |
+ *+-----------------+ +-----------------+
+ *| BAR4 | | BAR4 |
+ *+-----------------+ +-----------------+
+ *| BAR5 | | BAR5 |
+ *+-----------------+ +-----------------+
+ * EP CONTROLLER 1 EP CONTROLLER 2
+ *
+ * It maps BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
+ * self scratchpad region. While BAR0 is the default self scratchpad BAR, an
+ * NTB could have other BARs for self scratchpad (because of reserved BARs).
+ * This function can get the exact BAR used for self scratchpad from
+ * epf_ntb_bar[BAR_CONFIG].
+ *
+ * Please note the self scratchpad region and config region is combined to
+ * a single region and mapped using the same BAR. Also note HOST2's peer
+ * scratchpad is HOST1's self scratchpad.
+ */
+static int epf_ntb_config_sspad_bar_set(struct epf_ntb_epc *ntb_epc)
+{
+ struct pci_epf_bar *epf_bar;
+ enum pci_barno barno;
+ struct epf_ntb *ntb;
+ struct pci_epc *epc;
+ struct device *dev;
+ u8 func_no;
+ int ret;
+
+ ntb = ntb_epc->epf_ntb;
+ dev = &ntb->epf->dev;
+
+ epc = ntb_epc->epc;
+ func_no = ntb_epc->func_no;
+ barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+ epf_bar = &ntb_epc->epf_bar[barno];
+
+ ret = pci_epc_set_bar(epc, func_no, epf_bar);
+ if (ret) {
+ dev_err(dev, "%s inft: Config/Status/SPAD BAR set failed\n",
+ pci_epc_interface_string(ntb_epc->type));
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
+ * config + scratchpad region
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+ +-----------------+
+ *| BAR0 | | CONFIG REGION | | BAR0 |
+ *+-----------------+----+ +------------------+<-------+-----------------+
+ *| BAR1 | | |SCRATCHPAD REGION | | BAR1 |
+ *+-----------------+ +-->+------------------+<-------+-----------------+
+ *| BAR2 | Local Memory | BAR2 |
+ *+-----------------+ +-----------------+
+ *| BAR3 | | BAR3 |
+ *+-----------------+ +-----------------+
+ *| BAR4 | | BAR4 |
+ *+-----------------+ +-----------------+
+ *| BAR5 | | BAR5 |
+ *+-----------------+ +-----------------+
+ * EP CONTROLLER 1 EP CONTROLLER 2
+ *
+ * This function frees the Local Memory mentioned in the above diagram. After
+ * invoking this function, any of config + self scrathpad region of HOST1 or
+ * peer scratchpad region of HOST2 should not be accessed.
+ */
+static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+ struct epf_ntb_epc *ntb_epc;
+ enum pci_barno barno;
+ struct pci_epf *epf;
+
+ epf = ntb->epf;
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+ ntb_epc = ntb->epc[type];
+ barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+ if (ntb_epc->reg)
+ pci_epf_free_space(epf, ntb_epc->reg, barno, type);
+ }
+}
+
+/**
+ * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
+ * region
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ *+-----------------+------->+------------------+ +-----------------+
+ *| BAR0 | | CONFIG REGION | | BAR0 |
+ *+-----------------+----+ +------------------+<-------+-----------------+
+ *| BAR1 | | |SCRATCHPAD REGION | | BAR1 |
+ *+-----------------+ +-->+------------------+<-------+-----------------+
+ *| BAR2 | Local Memory | BAR2 |
+ *+-----------------+ +-----------------+
+ *| BAR3 | | BAR3 |
+ *+-----------------+ +-----------------+
+ *| BAR4 | | BAR4 |
+ *+-----------------+ +-----------------+
+ *| BAR5 | | BAR5 |
+ *+-----------------+ +-----------------+
+ * EP CONTROLLER 1 EP CONTROLLER 2
+ *
+ * This function allocates the Local Memory mentioned in the above diagram.
+ * The size of CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of
+ * SCRATCHPAD REGION is obtained from "spad-count" device tree property.
+ *
+ * The size of both config region and scratchpad region has to be aligned,
+ * since the scratchpad region will also be mapped as PEER SCRATCHPAD of
+ * other host using a separate BAR.
+ */
+static int
+epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ const struct pci_epc_features *peer_epc_features, *epc_features;
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ size_t msix_table_size, pba_size, align;
+ enum pci_barno peer_barno, barno;
+ struct epf_ntb_ctrl *ctrl;
+ struct device_node *node;
+ u32 spad_size, ctrl_size;
+ u64 size, peer_size;
+ struct pci_epc *epc;
+ struct pci_epf *epf;
+ struct device *dev;
+ bool msix_capable;
+ u32 spad_count;
+ void *base;
+
+ epf = ntb->epf;
+ node = epf->node;
+ dev = &epf->dev;
+ ntb_epc = ntb->epc[type];
+ epc = ntb_epc->epc;
+
+ epc_features = ntb_epc->epc_features;
+ barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+ size = epc_features->bar_fixed_size[barno];
+ align = epc_features->align;
+
+ peer_ntb_epc = ntb->epc[!type];
+ peer_epc_features = peer_ntb_epc->epc_features;
+ peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
+ peer_size = peer_epc_features->bar_fixed_size[barno];
+
+ /* Check if epc_features is populated incorrectly */
+ if ((!IS_ALIGNED(size, align)))
+ return -EINVAL;
+
+ spad_count = SPAD_COUNT;
+ of_property_read_u32(node, "spad-count", &spad_count);
+
+ ctrl_size = sizeof(struct epf_ntb_ctrl);
+ spad_size = spad_count * 4;
+
+ msix_capable = epc_features->msix_capable;
+ if (msix_capable) {
+ msix_table_size = PCI_MSIX_ENTRY_SIZE * ntb->db_count;
+ ctrl_size = ALIGN(ctrl_size, 8);
+ ntb_epc->msix_table_offset = ctrl_size;
+ ntb_epc->msix_bar = barno;
+ /* Align to QWORD or 8 Bytes */
+ pba_size = ALIGN(DIV_ROUND_UP(ntb->db_count, 8), 8);
+ ctrl_size = ctrl_size + msix_table_size + pba_size;
+ }
+
+ if (!align) {
+ ctrl_size = roundup_pow_of_two(ctrl_size);
+ spad_size = roundup_pow_of_two(spad_size);
+ } else {
+ ctrl_size = ALIGN(ctrl_size, align);
+ spad_size = ALIGN(spad_size, align);
+ }
+
+ if (peer_size) {
+ if (peer_size < spad_size)
+ spad_count = peer_size / 4;
+ spad_size = peer_size;
+ }
+
+ /*
+ * In order to make sure SPAD offset is aligned to its size,
+ * expand control region size to the size of SPAD if SPAD size
+ * is greater than control region size.
+ */
+ if (spad_size > ctrl_size)
+ ctrl_size = spad_size;
+
+ if (!size)
+ size = ctrl_size + spad_size;
+ else if (size < ctrl_size + spad_size)
+ return -EINVAL;
+
+ base = pci_epf_alloc_space(epf, size, barno, align, type);
+ if (!base) {
+ dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n",
+ pci_epc_interface_string(type));
+ return -ENOMEM;
+ }
+
+ ntb_epc->reg = base;
+
+ ctrl = ntb_epc->reg;
+ ctrl->spad_offset = ctrl_size;
+ ctrl->spad_count = spad_count;
+ ctrl->num_mws = ntb->num_mws;
+ ctrl->db_entry_size = align ? align : 4;
+ ntb_epc->spad_size = spad_size;
+
+ return 0;
+}
+
+/**
+ * epf_ntb_config_spad_bar_alloc_interface() - Allocate memory for config +
+ * scratchpad region for each of PRIMARY and SECONDARY interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper for epf_ntb_config_spad_bar_alloc() which allocates memory for
+ * config + scratchpad region for a specific interface
+ */
+static int epf_ntb_config_spad_bar_alloc_interface(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+ struct device *dev;
+ int ret;
+
+ dev = &ntb->epf->dev;
+
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+ ret = epf_ntb_config_spad_bar_alloc(ntb, type);
+ if (ret) {
+ dev_err(dev, "%s intf: Config/SPAD BAR alloc failed\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_free_peer_mem() - Free's memory allocated in peers outbound address
+ * space
+ * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
+ * address regions
+ *
+ *+-----------------+ +----->+----------------+-----------+-----------------+
+ *| BAR0 | | | Doorbell 1 +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+ | +----------------+ +-----------------+
+ *| BAR1 | | | Doorbell 2 +---------+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR2 | | Doorbell 3 +-------+ | +-----------------+
+ *+-----------------+----+ +----------------+ | +-> MSI|X ADDRESS 2 |
+ *| BAR3 | | | Doorbell 4 +-----+ | +-----------------+
+ *+-----------------+ | |----------------+ | | | |
+ *| BAR4 | | | | | | +-----------------+
+ *+-----------------+ | | MW1 +---+ | +-->+ MSI|X ADDRESS 3||
+ *| BAR5 | | | | | | +-----------------+
+ *+-----------------+ +----->-----------------+ | | | |
+ * EP CONTROLLER 1 | | | | +-----------------+
+ * | | | +---->+ MSI|X ADDRESS 4 |
+ * +----------------+ | +-----------------+
+ * (A) EP CONTROLLER 2 | | |
+ * (OB SPACE) | | |
+ * +-------> MW1 |
+ * | |
+ * | |
+ * (B) +-----------------+
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * +-----------------+
+ * PCI Address Space
+ * (Managed by HOST2)
+ *
+ * This function frees memory allocated in EP CONTROLLER 2 (OB SPACE) in the
+ * above diagram. It'll free Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4,
+ * MW1 (and MW2, MW3, MW4).
+ */
+static void epf_ntb_free_peer_mem(struct epf_ntb_epc *ntb_epc)
+{
+ struct pci_epf_bar *epf_bar;
+ void __iomem *mw_addr;
+ phys_addr_t phys_addr;
+ enum epf_ntb_bar bar;
+ enum pci_barno barno;
+ struct pci_epc *epc;
+ size_t size;
+
+ epc = ntb_epc->epc;
+
+ for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
+ barno = ntb_epc->epf_ntb_bar[bar];
+ mw_addr = ntb_epc->mw_addr[barno];
+ epf_bar = &ntb_epc->epf_bar[barno];
+ phys_addr = epf_bar->phys_addr;
+ size = epf_bar->size;
+ if (mw_addr) {
+ pci_epc_mem_free_addr(epc, phys_addr, mw_addr, size);
+ ntb_epc->mw_addr[barno] = NULL;
+ }
+ }
+}
+
+/**
+ * epf_ntb_db_mw_bar_clear() - Clears doorbell and memory BAR
+ * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
+ * address
+ *
+ *+-----------------+ +----->+----------------+-----------+-----------------+
+ *| BAR0 | | | Doorbell 1 +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+ | +----------------+ +-----------------+
+ *| BAR1 | | | Doorbell 2 +---------+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR2 | | Doorbell 3 +-------+ | +-----------------+
+ *+-----------------+----+ +----------------+ | +-> MSI|X ADDRESS 2 |
+ *| BAR3 | | | Doorbell 4 +-----+ | +-----------------+
+ *+-----------------+ | |----------------+ | | | |
+ *| BAR4 | | | | | | +-----------------+
+ *+-----------------+ | | MW1 +---+ | +-->+ MSI|X ADDRESS 3||
+ *| BAR5 | | | | | | +-----------------+
+ *+-----------------+ +----->-----------------+ | | | |
+ * EP CONTROLLER 1 | | | | +-----------------+
+ * | | | +---->+ MSI|X ADDRESS 4 |
+ * +----------------+ | +-----------------+
+ * (A) EP CONTROLLER 2 | | |
+ * (OB SPACE) | | |
+ * +-------> MW1 |
+ * | |
+ * | |
+ * (B) +-----------------+
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * +-----------------+
+ * PCI Address Space
+ * (Managed by HOST2)
+ *
+ * This function clears doorbell and memory BARs (remove inbound ATU
+ * configuration). In the above diagram it clears BAR2 TO BAR5 of EP
+ * CONTROLLER 1 (Doorbell BAR, MW1 BAR, MW2 BAR, MW3 BAR and MW4 BAR).
+ */
+static void epf_ntb_db_mw_bar_clear(struct epf_ntb_epc *ntb_epc)
+{
+ struct pci_epf_bar *epf_bar;
+ enum epf_ntb_bar bar;
+ enum pci_barno barno;
+ struct pci_epc *epc;
+ u8 func_no;
+
+ epc = ntb_epc->epc;
+
+ func_no = ntb_epc->func_no;
+
+ for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
+ barno = ntb_epc->epf_ntb_bar[bar];
+ epf_bar = &ntb_epc->epf_bar[barno];
+ pci_epc_clear_bar(epc, func_no, epf_bar);
+ }
+}
+
+/**
+ * epf_ntb_db_mw_bar_cleanup() - Clears doorbell/memory BAR and free memory
+ * allocated in peers outbound address space
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * This function is a wrapper for epf_ntb_db_mw_bar_clear() which clears
+ * HOST1's BAR and epf_ntb_free_peer_mem() which frees up HOST2 outbound
+ * memory.
+ */
+static void epf_ntb_db_mw_bar_cleanup(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+
+ ntb_epc = ntb->epc[type];
+ peer_ntb_epc = ntb->epc[!type];
+
+ epf_ntb_db_mw_bar_clear(ntb_epc);
+ epf_ntb_free_peer_mem(peer_ntb_epc);
+}
+
+/**
+ * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capaiblity
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Configures MSI/MSI-X capability for each interface with number of
+ * interrupts equal to "db-count" device tree parameter.
+ */
+static int epf_ntb_configure_interrupt(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ const struct pci_epc_features *epc_features;
+ bool msix_capable, msi_capable;
+ struct epf_ntb_epc *ntb_epc;
+ struct device_node *node;
+ struct pci_epc *epc;
+ struct device *dev;
+ u32 db_count;
+ u8 func_no;
+ int ret;
+
+ ntb_epc = ntb->epc[type];
+ dev = &ntb->epf->dev;
+ node = ntb->epf->node;
+
+ epc_features = ntb_epc->epc_features;
+ msix_capable = epc_features->msix_capable;
+ msi_capable = epc_features->msi_capable;
+
+ if (!(msix_capable || msi_capable)) {
+ dev_err(dev, "MSI or MSI-X is required for doorbell\n");
+ return -EINVAL;
+ }
+
+ func_no = ntb_epc->func_no;
+
+ db_count = DB_COUNT;
+ of_property_read_u32(node, "db-count", &db_count);
+ if (db_count > MAX_DB_COUNT) {
+ dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
+ return -EINVAL;
+ }
+
+ ntb->db_count = db_count;
+ epc = ntb_epc->epc;
+
+ if (msi_capable) {
+ ret = pci_epc_set_msi(epc, func_no, db_count);
+ if (ret) {
+ dev_err(dev, "%s intf: MSI configuration failed\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+ }
+
+ if (msix_capable) {
+ ret = pci_epc_set_msix(epc, func_no, db_count,
+ ntb_epc->msix_bar,
+ ntb_epc->msix_table_offset);
+ if (ret) {
+ dev_err(dev, "MSI configuration failed\n");
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_alloc_peer_mem() - Allocate memory in peers outbound address space
+ * @ntb_epc: EPC associated with one of the HOST whose BAR holds peers outbound
+ * address
+ * @bar: BAR of @ntb_epc in for which memory has to be allocated (could be
+ * BAR_DB_MW1, BAR_MW2, BAR_MW3, BAR_MW4)
+ * @peer_ntb_epc: EPC associated with HOST whose outbound address space is
+ * used by @ntb_epc
+ * @size: Size of the address region that has to be allocated in peers OB SPACE
+ *
+ *
+ *+-----------------+ +----->+----------------+-----------+-----------------+
+ *| BAR0 | | | Doorbell 1 +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+ | +----------------+ +-----------------+
+ *| BAR1 | | | Doorbell 2 +---------+ | |
+ *+-----------------+----+ +----------------+ | | |
+ *| BAR2 | | Doorbell 3 +-------+ | +-----------------+
+ *+-----------------+----+ +----------------+ | +-> MSI|X ADDRESS 2 |
+ *| BAR3 | | | Doorbell 4 +-----+ | +-----------------+
+ *+-----------------+ | |----------------+ | | | |
+ *| BAR4 | | | | | | +-----------------+
+ *+-----------------+ | | MW1 +---+ | +-->+ MSI|X ADDRESS 3||
+ *| BAR5 | | | | | | +-----------------+
+ *+-----------------+ +----->-----------------+ | | | |
+ * EP CONTROLLER 1 | | | | +-----------------+
+ * | | | +---->+ MSI|X ADDRESS 4 |
+ * +----------------+ | +-----------------+
+ * (A) EP CONTROLLER 2 | | |
+ * (OB SPACE) | | |
+ * +-------> MW1 |
+ * | |
+ * | |
+ * (B) +-----------------+
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * +-----------------+
+ * PCI Address Space
+ * (Managed by HOST2)
+ *
+ * This function allocates memory in OB space of EP CONTROLLER 2 in the
+ * above diagram. It'll allocate for Doorbell 1, Doorbell 2, Doorbell 3,
+ * Doorbell 4, MW1 (and MW2, MW3, MW4).
+ */
+static int
+epf_ntb_alloc_peer_mem(struct device *dev, struct epf_ntb_epc *ntb_epc,
+ enum epf_ntb_bar bar, struct epf_ntb_epc *peer_ntb_epc,
+ size_t size)
+{
+ const struct pci_epc_features *epc_features;
+ struct pci_epf_bar *epf_bar;
+ struct pci_epc *peer_epc;
+ phys_addr_t phys_addr;
+ void __iomem *mw_addr;
+ enum pci_barno barno;
+ size_t align;
+
+ epc_features = ntb_epc->epc_features;
+ align = epc_features->align;
+
+ if (size < 128)
+ size = 128;
+
+ if (align)
+ size = ALIGN(size, align);
+ else
+ size = roundup_pow_of_two(size);
+
+ peer_epc = peer_ntb_epc->epc;
+ mw_addr = pci_epc_mem_alloc_addr(peer_epc, &phys_addr, size);
+ if (!mw_addr) {
+ dev_err(dev, "%s intf: Failed to allocate OB address\n",
+ pci_epc_interface_string(peer_ntb_epc->type));
+ return -ENOMEM;
+ }
+
+ barno = ntb_epc->epf_ntb_bar[bar];
+ epf_bar = &ntb_epc->epf_bar[barno];
+ ntb_epc->mw_addr[barno] = mw_addr;
+
+ epf_bar->phys_addr = phys_addr;
+ epf_bar->size = size;
+ epf_bar->barno = barno;
+ epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
+
+ return 0;
+}
+
+/**
+ * epf_ntb_db_mw_bar_init() - Configure Doorbell and Memory window BARs
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper for epf_ntb_alloc_peer_mem() and pci_epc_set_bar() that allocates
+ * memory in OB address space of HOST2 and configures BAR of HOST1
+ */
+static int epf_ntb_db_mw_bar_init(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ const struct pci_epc_features *epc_features;
+ struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+ struct pci_epf_bar *epf_bar;
+ struct epf_ntb_ctrl *ctrl;
+ u32 num_mws, db_count;
+ enum epf_ntb_bar bar;
+ enum pci_barno barno;
+ struct pci_epc *epc;
+ struct device *dev;
+ size_t align;
+ int ret, i;
+ u8 func_no;
+ u64 size;
+
+ ntb_epc = ntb->epc[type];
+ peer_ntb_epc = ntb->epc[!type];
+
+ dev = &ntb->epf->dev;
+ epc_features = ntb_epc->epc_features;
+ align = epc_features->align;
+ func_no = ntb_epc->func_no;
+ epc = ntb_epc->epc;
+ num_mws = ntb->num_mws;
+ db_count = ntb->db_count;
+
+ for (bar = BAR_DB_MW1, i = 0; i < num_mws; bar++, i++) {
+ if (bar == BAR_DB_MW1) {
+ align = align ? align : 4;
+ size = db_count * align;
+ size = ALIGN(size, ntb->mws_size[i]);
+ ctrl = ntb_epc->reg;
+ ctrl->mw1_offset = size;
+ size += ntb->mws_size[i];
+ } else {
+ size = ntb->mws_size[i];
+ }
+
+ ret = epf_ntb_alloc_peer_mem(dev, ntb_epc, bar,
+ peer_ntb_epc, size);
+ if (ret)
+ goto err_alloc_peer_mem;
+
+ barno = ntb_epc->epf_ntb_bar[bar];
+ epf_bar = &ntb_epc->epf_bar[barno];
+
+ ret = pci_epc_set_bar(epc, func_no, epf_bar);
+ if (ret) {
+ dev_err(dev, "%s intf: DoorBell BAR set failed\n",
+ pci_epc_interface_string(type));
+ goto err_alloc_peer_mem;
+ }
+ }
+
+ return 0;
+
+err_alloc_peer_mem:
+ epf_ntb_db_mw_bar_cleanup(ntb, type);
+
+ return ret;
+}
+
+/**
+ * epf_ntb_epc_destroy_interface() - Cleanup NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Unbind NTB function device from EPC and Relinquish reference to pci_epc
+ * for each of the interface.
+ */
+static void epf_ntb_epc_destroy_interface(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ struct epf_ntb_epc *ntb_epc;
+ struct pci_epc *epc;
+ struct pci_epf *epf;
+
+ if (type < 0)
+ return;
+
+ epf = ntb->epf;
+ ntb_epc = ntb->epc[type];
+ if (!ntb_epc)
+ return;
+ epc = ntb_epc->epc;
+ pci_epc_remove_epf(epc, epf, type);
+ pci_epc_put(epc);
+}
+
+/**
+ * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
+ */
+static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
+ epf_ntb_epc_destroy_interface(ntb, type);
+}
+
+/**
+ * epf_ntb_epc_create_interface() - Create and initialize NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @epc: struct pci_epc to which a particular NTB interface should be associated
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Allocate memory for NTB EPC interface and initialize it.
+ */
+static int
+epf_ntb_epc_create_interface(struct epf_ntb *ntb, struct pci_epc *epc,
+ enum pci_epc_interface_type type)
+{
+ const struct pci_epc_features *epc_features;
+ struct pci_epf_bar *epf_bar;
+ struct epf_ntb_epc *ntb_epc;
+ struct pci_epf *epf;
+ struct device *dev;
+ u8 func_no;
+
+ dev = &ntb->epf->dev;
+
+ ntb_epc = devm_kzalloc(dev, sizeof(*ntb_epc), GFP_KERNEL);
+ if (!ntb_epc)
+ return -ENOMEM;
+
+ epf = ntb->epf;
+ if (type == PRIMARY_INTERFACE) {
+ func_no = epf->func_no;
+ epf_bar = epf->bar;
+ } else {
+ func_no = epf->sec_epc_func_no;
+ epf_bar = epf->sec_epc_bar;
+ }
+
+ ntb_epc->linkup = false;
+ ntb_epc->epc = epc;
+ ntb_epc->func_no = func_no;
+ ntb_epc->type = type;
+ ntb_epc->epf_bar = epf_bar;
+ ntb_epc->epf_ntb = ntb;
+
+ epc_features = pci_epc_get_features(epc, func_no);
+ if (!epc_features)
+ return -EINVAL;
+ ntb_epc->epc_features = epc_features;
+
+ ntb->epc[type] = ntb_epc;
+
+ return 0;
+}
+
+/**
+ * epf_ntb_epc_create() - Create and initialize NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Get a reference to EPC device and bind NTB function device to that EPC
+ * for each of the interface. It is also a wrapper to
+ * epf_ntb_epc_create_interface() to allocate memory for NTB EPC interface
+ * and initialize it
+ */
+static int epf_ntb_epc_create(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+ struct device_node *node;
+ const char *epc_name;
+ struct pci_epc *epc;
+ struct pci_epf *epf;
+ struct device *dev;
+ int ret;
+
+ epf = ntb->epf;
+ node = epf->node;
+ dev = &epf->dev;
+
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+ epc_name = pci_epc_interface_string(type);
+
+ epc = of_pci_epc_get_by_name(node, epc_name);
+ if (IS_ERR(epc)) {
+ if (PTR_ERR(epc) != -EPROBE_DEFER)
+ dev_err(dev, "%s intf: Failed to get EPC\n",
+ epc_name);
+ ret = PTR_ERR(epc);
+ goto err_epc_get;
+ }
+
+ ret = pci_epc_add_epf(epc, epf, type);
+ if (ret) {
+ dev_err(dev, "%s intf: Fail to add EPF to EPC\n",
+ epc_name);
+ goto err_epc_add;
+ }
+
+ ret = epf_ntb_epc_create_interface(ntb, epc, type);
+ if (ret) {
+ dev_err(dev, "%s intf: Fail to create NTB EPC\n",
+ epc_name);
+ goto err_epc_create;
+ }
+ }
+
+ return 0;
+
+err_epc_create:
+ pci_epc_remove_epf(epc, epf, type);
+
+err_epc_add:
+ pci_epc_put(epc);
+
+err_epc_get:
+ epf_ntb_epc_destroy_interface(ntb, type - 1);
+
+ return ret;
+}
+
+/**
+ * epf_ntb_init_epc_bar_interface() - Identify BARs to be used for each of
+ * the NTB constructs (scratchpad region, doorbell, memorywindow)
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Identify the free BAR's to be used for each of BAR_CONFIG, BAR_PEER_SPAD,
+ * BAR_DB_MW1, BAR_MW2, BAR_MW3 and BAR_MW4.
+ */
+static int epf_ntb_init_epc_bar_interface(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ const struct pci_epc_features *epc_features;
+ struct epf_ntb_epc *ntb_epc;
+ enum pci_barno barno;
+ enum epf_ntb_bar bar;
+ struct device *dev;
+ u32 num_mws;
+ int i;
+
+ barno = BAR_0;
+ ntb_epc = ntb->epc[type];
+ num_mws = ntb->num_mws;
+ dev = &ntb->epf->dev;
+ epc_features = ntb_epc->epc_features;
+
+ /* These are required BARs which are mandatory for NTB functionality */
+ for (bar = BAR_CONFIG; bar <= BAR_DB_MW1; bar++, barno++) {
+ barno = pci_epc_get_next_free_bar(epc_features, barno);
+ if (barno < 0) {
+ dev_err(dev, "%s intf: Fail to get NTB function BAR\n",
+ pci_epc_interface_string(type));
+ return barno;
+ }
+ ntb_epc->epf_ntb_bar[bar] = barno;
+ }
+
+ /* These are optional BARs which doesn't impact NTB functionality */
+ for (bar = BAR_MW2, i = 1; i < num_mws; bar++, barno++, i++) {
+ barno = pci_epc_get_next_free_bar(epc_features, barno);
+ if (barno < 0) {
+ ntb->num_mws = i;
+ dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
+ }
+ ntb_epc->epf_ntb_bar[bar] = barno;
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
+ * constructs (scratchpad region, doorbell, memorywindow)
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper to epf_ntb_init_epc_bar_interface() to identify the free BAR's
+ * to be used for each of BAR_CONFIG, BAR_PEER_SPAD, BAR_DB_MW1, BAR_MW2,
+ * BAR_MW3 and BAR_MW4 for all the interfaces.
+ */
+static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+ struct device *dev;
+ int ret;
+
+ dev = &ntb->epf->dev;
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+ ret = epf_ntb_init_epc_bar_interface(ntb, type);
+ if (ret) {
+ dev_err(dev, "Fail to init EPC bar for %s interface\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_epc_init_interface() - Initialize NTB interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper to initialize a particular EPC interface and start the workqueue
+ * to check for commands from host. This function will write to the
+ * EP controller HW for configuring it.
+ */
+static int epf_ntb_epc_init_interface(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ struct epf_ntb_epc *ntb_epc;
+ struct pci_epc *epc;
+ struct pci_epf *epf;
+ struct device *dev;
+ u8 func_no;
+ int ret;
+
+ ntb_epc = ntb->epc[type];
+ epf = ntb->epf;
+ dev = &epf->dev;
+ epc = ntb_epc->epc;
+ func_no = ntb_epc->func_no;
+
+ ret = epf_ntb_config_sspad_bar_set(ntb->epc[type]);
+ if (ret) {
+ dev_err(dev, "%s intf: Config/self SPAD BAR init failed\n",
+ pci_epc_interface_string(type));
+ return ret;
+ }
+
+ ret = epf_ntb_peer_spad_bar_set(ntb, type);
+ if (ret) {
+ dev_err(dev, "%s intf: Peer SPAD BAR init failed\n",
+ pci_epc_interface_string(type));
+ goto err_peer_spad_bar_init;
+ }
+
+ ret = epf_ntb_configure_interrupt(ntb, type);
+ if (ret) {
+ dev_err(dev, "%s intf: Interrupt configuration failed\n",
+ pci_epc_interface_string(type));
+ goto err_peer_spad_bar_init;
+ }
+
+ ret = epf_ntb_db_mw_bar_init(ntb, type);
+ if (ret) {
+ dev_err(dev, "%s intf: DB/MW BAR init failed\n",
+ pci_epc_interface_string(type));
+ goto err_db_mw_bar_init;
+ }
+
+ ret = pci_epc_write_header(epc, func_no, epf->header);
+ if (ret) {
+ dev_err(dev, "%s intf: Configuration header write failed\n",
+ pci_epc_interface_string(type));
+ goto err_write_header;
+ }
+
+ INIT_DELAYED_WORK(&ntb->epc[type]->cmd_handler, epf_ntb_cmd_handler);
+ queue_work(kpcintb_workqueue, &ntb->epc[type]->cmd_handler.work);
+
+ return 0;
+
+err_write_header:
+ epf_ntb_db_mw_bar_cleanup(ntb, type);
+
+err_db_mw_bar_init:
+ epf_ntb_peer_spad_bar_clear(ntb->epc[type]);
+
+err_peer_spad_bar_init:
+ epf_ntb_config_sspad_bar_clear(ntb->epc[type]);
+
+ return ret;
+}
+
+/**
+ * epf_ntb_epc_cleanup_interface() - Cleanup NTB interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper to cleanup a particular NTB interface.
+ */
+static void epf_ntb_epc_cleanup_interface(struct epf_ntb *ntb,
+ enum pci_epc_interface_type type)
+{
+ struct epf_ntb_epc *ntb_epc;
+
+ if (type < 0)
+ return;
+
+ ntb_epc = ntb->epc[type];
+ cancel_delayed_work(&ntb_epc->cmd_handler);
+ epf_ntb_db_mw_bar_cleanup(ntb, type);
+ epf_ntb_peer_spad_bar_clear(ntb_epc);
+ epf_ntb_config_sspad_bar_clear(ntb_epc);
+}
+
+/**
+ * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper to cleanup all NTB interfaces.
+ */
+static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
+ epf_ntb_epc_cleanup_interface(ntb, type);
+}
+
+/**
+ * epf_ntb_epc_init() - Initialize all NTB interfaces
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper to initialize all NTB interface and start the workqueue
+ * to check for commands from host.
+ */
+static int epf_ntb_epc_init(struct epf_ntb *ntb)
+{
+ enum pci_epc_interface_type type;
+ struct device *dev;
+ int ret;
+
+ dev = &ntb->epf->dev;
+
+ for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+ ret = epf_ntb_epc_init_interface(ntb, type);
+ if (ret) {
+ dev_err(dev, "%s intf: Failed to initialize\n",
+ pci_epc_interface_string(type));
+ goto err_init_type;
+ }
+ }
+
+ return 0;
+
+err_init_type:
+ epf_ntb_epc_cleanup_interface(ntb, type - 1);
+
+ return ret;
+}
+
+/**
+ * epf_ntb_of_parse_mw() - Parse NTB device tree for Memory Window configuration
+ * parameters
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @node: Device tree node of the NTB function
+ *
+ * Parse NTB device tree to get NTB Memory Window configuration parameters such
+ * as the number of memory window and the size of each memory window.
+ */
+static int epf_ntb_of_parse_mw(struct epf_ntb *ntb, struct device_node *node)
+{
+ struct device *dev;
+ u64 *mws_size;
+ u32 num_mws;
+ int ret;
+
+ dev = &ntb->epf->dev;
+ ret = of_property_read_u32(node, "num-mws", &num_mws);
+ if (ret) {
+ dev_err(dev, "Failed to get num-mws dt property\n");
+ return ret;
+ }
+
+ if (num_mws > MAX_MW) {
+ dev_err(dev, "Cannot support more than 4 memory window\n");
+ return ret;
+ }
+
+ mws_size = devm_kcalloc(dev, num_mws, sizeof(*mws_size), GFP_KERNEL);
+ if (!mws_size)
+ return -ENOMEM;
+
+ ret = of_property_read_u64_array(node, "mws-size", mws_size, num_mws);
+ if (ret) {
+ dev_err(dev, "Failed to get mws-size dt property\n");
+ return ret;
+ }
+
+ ntb->num_mws = num_mws;
+ ntb->mws_size = mws_size;
+
+ return 0;
+}
+
+/**
+ * epf_ntb_of_parse_mw() - Parse NTB device tree for configuration space header
+ * and Memory Window configuration parameters
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Parse NTB device tree to get endpoint configuration space headers like
+ * device-id, vendor-id etc., and Memory Window configuration parameters such
+ * as the number of memory window and the size of each memory window.
+ */
+static int epf_ntb_of_parse(struct epf_ntb *ntb)
+{
+ struct device_node *node;
+ struct pci_epf *epf;
+ struct device *dev;
+ int ret;
+
+ epf = ntb->epf;
+ node = epf->node;
+ dev = &epf->dev;
+
+ epf->header = &epf_ntb_header;
+ pci_epc_of_parse_header(node, epf->header);
+
+ ret = epf_ntb_of_parse_mw(ntb, node);
+ if (ret) {
+ dev_err(dev, "Invalid memory window configuration in DT\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * epf_ntb_probe() - Probe NTB function driver
+ * @epf: NTB endpoint function device
+ *
+ * Probe NTB function driver when endpoint function bus detects a NTB
+ * endpoint function. This allocates memory for epf_ntb and initializes
+ * both the endpoint controllers associated with NTB function device.
+ */
+static int epf_ntb_probe(struct pci_epf *epf)
+{
+ struct epf_ntb *ntb;
+ struct device *dev;
+ int ret;
+
+ dev = &epf->dev;
+
+ ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
+ if (!ntb)
+ return -ENOMEM;
+
+ ntb->epf = epf;
+
+ ret = epf_ntb_of_parse(ntb);
+ if (ret) {
+ dev_err(dev, "Failed to parse NTB DT node\n");
+ return ret;
+ }
+
+ ret = epf_ntb_epc_create(ntb);
+ if (ret) {
+ dev_err(dev, "Failed to create NTB EPC\n");
+ return ret;
+ }
+
+ ret = epf_ntb_init_epc_bar(ntb);
+ if (ret) {
+ dev_err(dev, "Failed to create NTB EPC\n");
+ goto err_bar_init;
+ }
+
+ ret = epf_ntb_config_spad_bar_alloc_interface(ntb);
+ if (ret) {
+ dev_err(dev, "Failed to allocate BAR memory\n");
+ goto err_bar_alloc;
+ }
+
+ ret = epf_ntb_epc_init(ntb);
+ if (ret) {
+ dev_err(dev, "Failed to initialize EPC\n");
+ goto err_bar_alloc;
+ }
+
+ epf_set_drvdata(epf, ntb);
+
+ return 0;
+
+err_bar_alloc:
+ epf_ntb_config_spad_bar_free(ntb);
+
+err_bar_init:
+ epf_ntb_epc_destroy(ntb);
+
+ return ret;
+}
+
+/**
+ * epf_ntb_remove() - Cleanup the initialization from epf_ntb_probe()
+ * @epf: NTB endpoint function device
+ *
+ * Cleanup the initialization from epf_ntb_probe()
+ */
+static int epf_ntb_remove(struct pci_epf *epf)
+{
+ struct epf_ntb *ntb = epf_get_drvdata(epf);
+
+ epf_ntb_epc_cleanup(ntb);
+ epf_ntb_config_spad_bar_free(ntb);
+ epf_ntb_epc_destroy(ntb);
+
+ return 0;
+}
+
+static const struct pci_epf_device_id epf_ntb_ids[] = {
+ {
+ .name = "pci-epf-ntb",
+ },
+ {},
+};
+
+static struct pci_epf_driver epf_ntb_driver = {
+ .driver.name = "pci_epf_ntb",
+ .probe = epf_ntb_probe,
+ .remove = epf_ntb_remove,
+ .id_table = epf_ntb_ids,
+ .owner = THIS_MODULE,
+};
+
+static int __init epf_ntb_init(void)
+{
+ int ret;
+
+ kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
+ WQ_HIGHPRI, 0);
+ ret = pci_epf_register_driver(&epf_ntb_driver);
+ if (ret) {
+ pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+module_init(epf_ntb_init);
+
+static void __exit epf_ntb_exit(void)
+{
+ pci_epf_unregister_driver(&epf_ntb_driver);
+}
+module_exit(epf_ntb_exit);
+
+MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@...com>");
+MODULE_LICENSE("GPL v2");
--
2.17.1
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