Add support for EPF PCI-Express Non-Transparent Bridge (NTB) device.
This driver is platform independent and could be used by any platform
which have multiple PCIe endpoint instances configured using the
pci-epf-ntb driver. The driver connnects to the standard NTB sub-system
interface. The EPF NTB device has configurable number of memory windows
(Max 4), configurable number of doorbell (Max 32), and configurable
number of scratch-pad registers.

Signed-off-by: Kishon Vijay Abraham I <kis...@ti.com>
---
 drivers/ntb/hw/Kconfig          |   1 +
 drivers/ntb/hw/Makefile         |   1 +
 drivers/ntb/hw/epf/Kconfig      |   6 +
 drivers/ntb/hw/epf/Makefile     |   1 +
 drivers/ntb/hw/epf/ntb_hw_epf.c | 751 ++++++++++++++++++++++++++++++++
 5 files changed, 760 insertions(+)
 create mode 100644 drivers/ntb/hw/epf/Kconfig
 create mode 100644 drivers/ntb/hw/epf/Makefile
 create mode 100644 drivers/ntb/hw/epf/ntb_hw_epf.c

diff --git a/drivers/ntb/hw/Kconfig b/drivers/ntb/hw/Kconfig
index e77c587060ff..c325be526b80 100644
--- a/drivers/ntb/hw/Kconfig
+++ b/drivers/ntb/hw/Kconfig
@@ -2,4 +2,5 @@
 source "drivers/ntb/hw/amd/Kconfig"
 source "drivers/ntb/hw/idt/Kconfig"
 source "drivers/ntb/hw/intel/Kconfig"
+source "drivers/ntb/hw/epf/Kconfig"
 source "drivers/ntb/hw/mscc/Kconfig"
diff --git a/drivers/ntb/hw/Makefile b/drivers/ntb/hw/Makefile
index 4714d6238845..223ca592b5f9 100644
--- a/drivers/ntb/hw/Makefile
+++ b/drivers/ntb/hw/Makefile
@@ -2,4 +2,5 @@
 obj-$(CONFIG_NTB_AMD)  += amd/
 obj-$(CONFIG_NTB_IDT)  += idt/
 obj-$(CONFIG_NTB_INTEL)        += intel/
+obj-$(CONFIG_NTB_EPF)  += epf/
 obj-$(CONFIG_NTB_SWITCHTEC) += mscc/
diff --git a/drivers/ntb/hw/epf/Kconfig b/drivers/ntb/hw/epf/Kconfig
new file mode 100644
index 000000000000..6197d1aab344
--- /dev/null
+++ b/drivers/ntb/hw/epf/Kconfig
@@ -0,0 +1,6 @@
+config NTB_EPF
+       tristate "Generic EPF Non-Transparent Bridge support"
+       depends on m
+       help
+         This driver supports EPF NTB on configurable endpoint.
+         If unsure, say N.
diff --git a/drivers/ntb/hw/epf/Makefile b/drivers/ntb/hw/epf/Makefile
new file mode 100644
index 000000000000..2f560a422bc6
--- /dev/null
+++ b/drivers/ntb/hw/epf/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_EPF) += ntb_hw_epf.o
diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c
new file mode 100644
index 000000000000..2989f2b41fda
--- /dev/null
+++ b/drivers/ntb/hw/epf/ntb_hw_epf.c
@@ -0,0 +1,751 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Host side endpoint driver to implement Non-Transparent Bridge functionality
+ *
+ * Copyright (C) 2020 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kis...@ti.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#define NTB_EPF_COMMAND                0x0
+#define CMD_CONFIGURE_DOORBELL 1
+#define CMD_TEARDOWN_DOORBELL  2
+#define CMD_CONFIGURE_MW       3
+#define CMD_TEARDOWN_MW                4
+#define CMD_LINK_UP            5
+#define CMD_LINK_DOWN          6
+
+#define NTB_EPF_ARGUMENT       0x4
+#define MSIX_ENABLE            BIT(16)
+
+#define NTB_EPF_CMD_STATUS     0x8
+#define COMMAND_STATUS_OK      1
+#define COMMAND_STATUS_ERROR   2
+
+#define NTB_EPF_LINK_STATUS    0x0A
+#define LINK_STATUS_UP         BIT(0)
+
+#define NTB_EPF_TOPOLOGY       0x0C
+#define NTB_EPF_LOWER_ADDR     0x10
+#define NTB_EPF_UPPER_ADDR     0x14
+#define NTB_EPF_LOWER_SIZE     0x18
+#define NTB_EPF_UPPER_SIZE     0x1C
+#define NTB_EPF_MW_COUNT       0x20
+#define NTB_EPF_MW1_OFFSET     0x24
+#define NTB_EPF_SPAD_OFFSET    0x28
+#define NTB_EPF_SPAD_COUNT     0x2C
+#define NTB_EPF_DB_ENTRY_SIZE  0x30
+#define NTB_EPF_DB_DATA(n)     (0x34 + (n) * 4)
+
+#define NTB_EPF_MIN_DB_COUNT   3
+#define NTB_EPF_MAX_DB_COUNT   31
+#define NTB_EPF_MW_OFFSET      2
+
+#define NTB_EPF_COMMAND_TIMEOUT        1000 /* 1 Sec */
+
+enum pci_barno {
+       BAR_0,
+       BAR_1,
+       BAR_2,
+       BAR_3,
+       BAR_4,
+       BAR_5,
+};
+
+struct ntb_epf_dev {
+       struct ntb_dev ntb;
+       struct device *dev;
+       /* Mutex to protect providing commands to NTB EPF */
+       struct mutex cmd_lock;
+
+       enum pci_barno ctrl_reg_bar;
+       enum pci_barno peer_spad_reg_bar;
+       enum pci_barno db_reg_bar;
+
+       unsigned int mw_count;
+       unsigned int spad_count;
+       unsigned int db_count;
+
+       void __iomem *ctrl_reg;
+       void __iomem *db_reg;
+       void __iomem *peer_spad_reg;
+
+       unsigned int self_spad;
+       unsigned int peer_spad;
+
+       int db_val;
+       u64 db_valid_mask;
+};
+
+#define ntb_ndev(__ntb) container_of(__ntb, struct ntb_epf_dev, ntb)
+
+struct ntb_epf_data {
+       /* BAR that contains both control region and self spad region */
+       enum pci_barno ctrl_reg_bar;
+       /* BAR that contains peer spad region */
+       enum pci_barno peer_spad_reg_bar;
+       /* BAR that contains Doorbell region and Memory window '1' */
+       enum pci_barno db_reg_bar;
+};
+
+static int ntb_epf_send_command(struct ntb_epf_dev *ndev, u32 command,
+                               u32 argument)
+{
+       ktime_t timeout;
+       bool timedout;
+       int ret = 0;
+       u32 status;
+
+       mutex_lock(&ndev->cmd_lock);
+       writel(argument, ndev->ctrl_reg + NTB_EPF_ARGUMENT);
+       writel(command, ndev->ctrl_reg + NTB_EPF_COMMAND);
+
+       timeout = ktime_add_ms(ktime_get(), NTB_EPF_COMMAND_TIMEOUT);
+       while (1) {
+               timedout = ktime_after(ktime_get(), timeout);
+               status = readw(ndev->ctrl_reg + NTB_EPF_CMD_STATUS);
+
+               if (status == COMMAND_STATUS_ERROR) {
+                       ret = -EINVAL;
+                       break;
+               }
+
+               if (status == COMMAND_STATUS_OK)
+                       break;
+
+               if (WARN_ON(timedout)) {
+                       ret = -ETIMEDOUT;
+                       break;
+               }
+
+               usleep_range(5, 10);
+       }
+
+       writew(0, ndev->ctrl_reg + NTB_EPF_CMD_STATUS);
+       mutex_unlock(&ndev->cmd_lock);
+
+       return ret;
+}
+
+static int ntb_epf_mw_to_bar(struct ntb_epf_dev *ndev, int idx)
+{
+       struct device *dev = ndev->dev;
+
+       if (idx < 0 || idx > ndev->mw_count) {
+               dev_err(dev, "Unsupported Memory Window index %d\n", idx);
+               return -EINVAL;
+       }
+
+       return idx + 2;
+}
+
+static int ntb_epf_mw_count(struct ntb_dev *ntb, int pidx)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+
+       if (pidx != NTB_DEF_PEER_IDX) {
+               dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+               return -EINVAL;
+       }
+
+       return ndev->mw_count;
+}
+
+static int ntb_epf_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+                               resource_size_t *addr_align,
+                               resource_size_t *size_align,
+                               resource_size_t *size_max)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       int bar;
+
+       if (pidx != NTB_DEF_PEER_IDX) {
+               dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+               return -EINVAL;
+       }
+
+       bar = ntb_epf_mw_to_bar(ndev, idx);
+       if (bar < 0)
+               return bar;
+
+       if (addr_align)
+               *addr_align = SZ_4K;
+
+       if (size_align)
+               *size_align = 1;
+
+       if (size_max)
+               *size_max = pci_resource_len(ndev->ntb.pdev, bar);
+
+       return 0;
+}
+
+static u64 ntb_epf_link_is_up(struct ntb_dev *ntb,
+                             enum ntb_speed *speed,
+                             enum ntb_width *width)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       u32 status;
+
+       status = readw(ndev->ctrl_reg + NTB_EPF_LINK_STATUS);
+
+       return status & LINK_STATUS_UP;
+}
+
+static u32 ntb_epf_spad_read(struct ntb_dev *ntb, int idx)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       u32 offset;
+
+       if (idx < 0 || idx >= ndev->spad_count) {
+               dev_err(dev, "READ: Invalid ScratchPad Index %d\n", idx);
+               return 0;
+       }
+
+       offset = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+       offset += (idx << 2);
+
+       return readl(ndev->ctrl_reg + offset);
+}
+
+static int ntb_epf_spad_write(struct ntb_dev *ntb,
+                             int idx, u32 val)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       u32 offset;
+
+       if (idx < 0 || idx >= ndev->spad_count) {
+               dev_err(dev, "WRITE: Invalid ScratchPad Index %d\n", idx);
+               return -EINVAL;
+       }
+
+       offset = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+       offset += (idx << 2);
+       writel(val, ndev->ctrl_reg);
+
+       return 0;
+}
+
+static u32 ntb_epf_peer_spad_read(struct ntb_dev *ntb, int pidx, int idx)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       u32 offset;
+
+       if (pidx != NTB_DEF_PEER_IDX) {
+               dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+               return -EINVAL;
+       }
+
+       if (idx < 0 || idx >= ndev->spad_count) {
+               dev_err(dev, "WRITE: Invalid Peer ScratchPad Index %d\n", idx);
+               return -EINVAL;
+       }
+
+       offset = (idx << 2);
+       return readl(ndev->peer_spad_reg + offset);
+}
+
+static int ntb_epf_peer_spad_write(struct ntb_dev *ntb, int pidx,
+                                  int idx, u32 val)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       u32 offset;
+
+       if (pidx != NTB_DEF_PEER_IDX) {
+               dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+               return -EINVAL;
+       }
+
+       if (idx < 0 || idx >= ndev->spad_count) {
+               dev_err(dev, "WRITE: Invalid Peer ScratchPad Index %d\n", idx);
+               return -EINVAL;
+       }
+
+       offset = (idx << 2);
+       writel(val, ndev->peer_spad_reg + offset);
+
+       return 0;
+}
+
+static int ntb_epf_link_enable(struct ntb_dev *ntb,
+                              enum ntb_speed max_speed,
+                              enum ntb_width max_width)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       int ret;
+
+       ret = ntb_epf_send_command(ndev, CMD_LINK_UP, 0);
+       if (ret) {
+               dev_err(dev, "Fail to enable link\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int ntb_epf_link_disable(struct ntb_dev *ntb)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       int ret;
+
+       ret = ntb_epf_send_command(ndev, CMD_LINK_DOWN, 0);
+       if (ret) {
+               dev_err(dev, "Fail to disable link\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static irqreturn_t ntb_epf_vec_isr(int irq, void *dev)
+{
+       struct ntb_epf_dev *ndev = dev;
+       int irq_no;
+
+       irq_no = irq - pci_irq_vector(ndev->ntb.pdev, 0);
+       ndev->db_val = irq_no + 1;
+
+       if (irq_no == 0)
+               ntb_link_event(&ndev->ntb);
+       else
+               ntb_db_event(&ndev->ntb, irq_no);
+
+       return IRQ_HANDLED;
+}
+
+static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int msi_min, int msi_max)
+{
+       struct pci_dev *pdev = ndev->ntb.pdev;
+       struct device *dev = ndev->dev;
+       u32 argument = MSIX_ENABLE;
+       int irq;
+       int ret;
+       int i;
+
+       irq = pci_alloc_irq_vectors(pdev, msi_min, msi_max, PCI_IRQ_MSIX);
+       if (irq < 0) {
+               dev_dbg(dev, "Failed to get MSIX interrupts\n");
+               irq = pci_alloc_irq_vectors(pdev, msi_min, msi_max,
+                                           PCI_IRQ_MSI);
+               if (irq < 0) {
+                       dev_err(dev, "Failed to get MSI interrupts\n");
+                       return irq;
+               }
+               argument &= ~MSIX_ENABLE;
+       }
+
+       for (i = 0; i < irq; i++) {
+               ret = devm_request_irq(&pdev->dev, pci_irq_vector(pdev, i),
+                                      ntb_epf_vec_isr, 0, "ntb_epf", ndev);
+               if (ret) {
+                       dev_err(dev, "Failed to request irq\n");
+                       goto err_request_irq;
+               }
+       }
+
+       ndev->db_count = irq - 1;
+
+       ret = ntb_epf_send_command(ndev, CMD_CONFIGURE_DOORBELL,
+                                  argument | irq);
+       if (ret) {
+               dev_err(dev, "Failed to configure doorbell\n");
+               goto err_configure_db;
+       }
+
+       return 0;
+
+err_configure_db:
+       for (i = 0; i < ndev->db_count + 1; i++)
+               devm_free_irq(dev, pci_irq_vector(pdev, i), ndev);
+
+err_request_irq:
+       pci_free_irq_vectors(pdev);
+
+       return ret;
+}
+
+static int ntb_epf_peer_mw_count(struct ntb_dev *ntb)
+{
+       return ntb_ndev(ntb)->mw_count;
+}
+
+static int ntb_epf_spad_count(struct ntb_dev *ntb)
+{
+       return ntb_ndev(ntb)->spad_count;
+}
+
+static u64 ntb_epf_db_valid_mask(struct ntb_dev *ntb)
+{
+       return ntb_ndev(ntb)->db_valid_mask;
+}
+
+static int ntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+       return 0;
+}
+
+static int ntb_epf_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+                               dma_addr_t addr, resource_size_t size)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       resource_size_t mw_size;
+       int bar;
+
+       if (pidx != NTB_DEF_PEER_IDX) {
+               dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+               return -EINVAL;
+       }
+
+       bar = idx + NTB_EPF_MW_OFFSET;
+
+       mw_size = pci_resource_len(ntb->pdev, bar);
+
+       if (size > mw_size) {
+               dev_err(dev, "Size:%pa is greater than the MW size %pa\n",
+                       &size, &mw_size);
+               return -EINVAL;
+       }
+
+       writel(lower_32_bits(addr), ndev->ctrl_reg + NTB_EPF_LOWER_ADDR);
+       writel(upper_32_bits(addr), ndev->ctrl_reg + NTB_EPF_UPPER_ADDR);
+       writel(lower_32_bits(size), ndev->ctrl_reg + NTB_EPF_LOWER_SIZE);
+       writel(upper_32_bits(size), ndev->ctrl_reg + NTB_EPF_UPPER_SIZE);
+       ntb_epf_send_command(ndev, CMD_CONFIGURE_MW, idx);
+
+       return 0;
+}
+
+static int ntb_epf_mw_clear_trans(struct ntb_dev *ntb, int pidx, int idx)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       struct device *dev = ndev->dev;
+       int ret = 0;
+
+       ntb_epf_send_command(ndev, CMD_TEARDOWN_MW, idx);
+       if (ret)
+               dev_err(dev, "Failed to teardown memory window\n");
+
+       return ret;
+}
+
+static int ntb_epf_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+                                   phys_addr_t *base, resource_size_t *size)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       u32 offset = 0;
+       int bar;
+
+       if (idx == 0)
+               offset = readl(ndev->ctrl_reg + NTB_EPF_MW1_OFFSET);
+
+       bar = idx + NTB_EPF_MW_OFFSET;
+
+       if (base)
+               *base = pci_resource_start(ndev->ntb.pdev, bar) + offset;
+
+       if (size)
+               *size = pci_resource_len(ndev->ntb.pdev, bar) - offset;
+
+       return 0;
+}
+
+static int ntb_epf_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+       u32 interrupt_num = ffs(db_bits) + 1;
+       struct device *dev = ndev->dev;
+       u32 db_entry_size;
+       u32 db_data;
+
+       if (interrupt_num > ndev->db_count) {
+               dev_err(dev, "DB interrupt %d greater than Max Supported %d\n",
+                       interrupt_num, ndev->db_count);
+               return -EINVAL;
+       }
+
+       db_entry_size = readl(ndev->ctrl_reg + NTB_EPF_DB_ENTRY_SIZE);
+
+       db_data = readl(ndev->ctrl_reg + NTB_EPF_DB_DATA(interrupt_num));
+       writel(db_data, ndev->db_reg + (db_entry_size * interrupt_num));
+
+       return 0;
+}
+
+static u64 ntb_epf_db_read(struct ntb_dev *ntb)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+       return ndev->db_val;
+}
+
+static int ntb_epf_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+       return 0;
+}
+
+static int ntb_epf_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+       ndev->db_val = 0;
+
+       return 0;
+}
+
+static const struct ntb_dev_ops ntb_epf_ops = {
+       .mw_count               = ntb_epf_mw_count,
+       .spad_count             = ntb_epf_spad_count,
+       .peer_mw_count          = ntb_epf_peer_mw_count,
+       .db_valid_mask          = ntb_epf_db_valid_mask,
+       .db_set_mask            = ntb_epf_db_set_mask,
+       .mw_set_trans           = ntb_epf_mw_set_trans,
+       .mw_clear_trans         = ntb_epf_mw_clear_trans,
+       .peer_mw_get_addr       = ntb_epf_peer_mw_get_addr,
+       .link_enable            = ntb_epf_link_enable,
+       .spad_read              = ntb_epf_spad_read,
+       .spad_write             = ntb_epf_spad_write,
+       .peer_spad_read         = ntb_epf_peer_spad_read,
+       .peer_spad_write        = ntb_epf_peer_spad_write,
+       .peer_db_set            = ntb_epf_peer_db_set,
+       .db_read                = ntb_epf_db_read,
+       .mw_get_align           = ntb_epf_mw_get_align,
+       .link_is_up             = ntb_epf_link_is_up,
+       .db_clear_mask          = ntb_epf_db_clear_mask,
+       .db_clear               = ntb_epf_db_clear,
+       .link_disable           = ntb_epf_link_disable,
+};
+
+static inline void ntb_epf_init_struct(struct ntb_epf_dev *ndev,
+                                      struct pci_dev *pdev)
+{
+       ndev->ntb.pdev = pdev;
+       ndev->ntb.topo = NTB_TOPO_NONE;
+       ndev->ntb.ops = &ntb_epf_ops;
+}
+
+static int ntb_epf_init_dev(struct ntb_epf_dev *ndev)
+{
+       struct device *dev = ndev->dev;
+       int ret;
+
+       /* One Link interrupt and rest doorbell interrupt */
+       ret = ntb_epf_init_isr(ndev, NTB_EPF_MIN_DB_COUNT + 1,
+                              NTB_EPF_MAX_DB_COUNT + 1);
+       if (ret) {
+               dev_err(dev, "Failed to init ISR\n");
+               return ret;
+       }
+
+       ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+       ndev->mw_count = readl(ndev->ctrl_reg + NTB_EPF_MW_COUNT);
+       ndev->spad_count = readl(ndev->ctrl_reg + NTB_EPF_SPAD_COUNT);
+
+       return 0;
+}
+
+static int ntb_epf_init_pci(struct ntb_epf_dev *ndev,
+                           struct pci_dev *pdev)
+{
+       struct device *dev = ndev->dev;
+       int ret;
+
+       pci_set_drvdata(pdev, ndev);
+
+       ret = pci_enable_device(pdev);
+       if (ret) {
+               dev_err(dev, "Cannot enable PCI device\n");
+               goto err_pci_enable;
+       }
+
+       ret = pci_request_regions(pdev, "ntb");
+       if (ret) {
+               dev_err(dev, "Cannot obtain PCI resources\n");
+               goto err_pci_regions;
+       }
+
+       pci_set_master(pdev);
+
+       ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+       if (ret) {
+               ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+               if (ret) {
+                       dev_err(dev, "Cannot set DMA mask\n");
+                       goto err_dma_mask;
+               }
+               dev_warn(&pdev->dev, "Cannot DMA highmem\n");
+       }
+
+       ndev->ctrl_reg = pci_iomap(pdev, 0, 0);
+       if (!ndev->ctrl_reg) {
+               ret = -EIO;
+               goto err_dma_mask;
+       }
+
+       ndev->peer_spad_reg = pci_iomap(pdev, 1, 0);
+       if (!ndev->peer_spad_reg) {
+               ret = -EIO;
+               goto err_dma_mask;
+       }
+
+       ndev->db_reg = pci_iomap(pdev, 2, 0);
+       if (!ndev->db_reg) {
+               ret = -EIO;
+               goto err_dma_mask;
+       }
+
+       return 0;
+
+err_dma_mask:
+       pci_clear_master(pdev);
+
+err_pci_regions:
+       pci_disable_device(pdev);
+
+err_pci_enable:
+       pci_set_drvdata(pdev, NULL);
+
+       return ret;
+}
+
+static void ntb_epf_deinit_pci(struct ntb_epf_dev *ndev)
+{
+       struct pci_dev *pdev = ndev->ntb.pdev;
+
+       pci_iounmap(pdev, ndev->ctrl_reg);
+       pci_iounmap(pdev, ndev->peer_spad_reg);
+       pci_iounmap(pdev, ndev->db_reg);
+
+       pci_clear_master(pdev);
+       pci_release_regions(pdev);
+       pci_disable_device(pdev);
+       pci_set_drvdata(pdev, NULL);
+}
+
+static void ntb_epf_cleanup_isr(struct ntb_epf_dev *ndev)
+{
+       struct pci_dev *pdev = ndev->ntb.pdev;
+       struct device *dev = &pdev->dev;
+       int i;
+
+       ntb_epf_send_command(ndev, CMD_TEARDOWN_DOORBELL, ndev->db_count + 1);
+
+       for (i = 0; i < ndev->db_count + 1; i++)
+               devm_free_irq(dev, pci_irq_vector(pdev, i), ndev);
+       pci_free_irq_vectors(pdev);
+}
+
+static int ntb_epf_pci_probe(struct pci_dev *pdev,
+                            const struct pci_device_id *id)
+{
+       enum pci_barno peer_spad_reg_bar = BAR_1;
+       enum pci_barno ctrl_reg_bar = BAR_0;
+       enum pci_barno db_reg_bar = BAR_2;
+       struct device *dev = &pdev->dev;
+       struct ntb_epf_data *data;
+       struct ntb_epf_dev *ndev;
+       int ret;
+
+       if (pci_is_bridge(pdev))
+               return -ENODEV;
+
+       ndev = devm_kzalloc(dev, sizeof(*ndev), GFP_KERNEL);
+       if (!ndev)
+               return -ENOMEM;
+
+       data = (struct ntb_epf_data *)id->driver_data;
+       if (data) {
+               if (data->peer_spad_reg_bar)
+                       peer_spad_reg_bar = data->peer_spad_reg_bar;
+               if (data->ctrl_reg_bar)
+                       ctrl_reg_bar = data->ctrl_reg_bar;
+               if (data->db_reg_bar)
+                       db_reg_bar = data->db_reg_bar;
+       }
+
+       ndev->peer_spad_reg_bar = peer_spad_reg_bar;
+       ndev->ctrl_reg_bar = ctrl_reg_bar;
+       ndev->db_reg_bar = db_reg_bar;
+       ndev->dev = dev;
+
+       ntb_epf_init_struct(ndev, pdev);
+       mutex_init(&ndev->cmd_lock);
+
+       ret = ntb_epf_init_pci(ndev, pdev);
+       if (ret) {
+               dev_err(dev, "Failed to init PCI\n");
+               return ret;
+       }
+
+       ret = ntb_epf_init_dev(ndev);
+       if (ret) {
+               dev_err(dev, "Failed to init device\n");
+               goto err_init_dev;
+       }
+
+       ret = ntb_register_device(&ndev->ntb);
+       if (ret) {
+               dev_err(dev, "Failed to register NTB device\n");
+               goto err_register_dev;
+       }
+
+       return 0;
+
+err_register_dev:
+       ntb_epf_cleanup_isr(ndev);
+
+err_init_dev:
+       ntb_epf_deinit_pci(ndev);
+
+       return ret;
+}
+
+static void ntb_epf_pci_remove(struct pci_dev *pdev)
+{
+       struct ntb_epf_dev *ndev = pci_get_drvdata(pdev);
+
+       ntb_unregister_device(&ndev->ntb);
+       ntb_epf_cleanup_isr(ndev);
+       ntb_epf_deinit_pci(ndev);
+       kfree(ndev);
+}
+
+static const struct ntb_epf_data j721e_data = {
+       .ctrl_reg_bar = BAR_0,
+       .peer_spad_reg_bar = BAR_1,
+       .db_reg_bar = BAR_2,
+};
+
+static const struct pci_device_id ntb_epf_pci_tbl[] = {
+       {
+               PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_J721E),
+               .class = PCI_CLASS_MEMORY_RAM << 8, .class_mask = 0xffff00,
+               .driver_data = (kernel_ulong_t)&j721e_data,
+       },
+       { },
+};
+
+static struct pci_driver ntb_epf_pci_driver = {
+       .name           = KBUILD_MODNAME,
+       .id_table       = ntb_epf_pci_tbl,
+       .probe          = ntb_epf_pci_probe,
+       .remove         = ntb_epf_pci_remove,
+};
+module_pci_driver(ntb_epf_pci_driver);
+
+MODULE_DESCRIPTION("PCI ENDPOINT NTB HOST DRIVER");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kis...@ti.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

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