[RFC PATCH v12 02/17] dlb: initialize DLB device

Mike Ximing Chen
2021-12-21T06:50:21Z

Map the PCI BAR space, create a char device, and set the DMA API mask for
64-bit addressing. Add the corresponding undo/remove operations.

Signed-off-by: Mike Ximing Chen <mike.ximing.chen@intel.com>
---
drivers/misc/dlb/Makefile | 1 +
drivers/misc/dlb/dlb_main.c | 57 +++++++++++++++++++++++++++++++++++
drivers/misc/dlb/dlb_main.h | 19 ++++++++++++
drivers/misc/dlb/dlb_pf_ops.c | 33 ++++++++++++++++++++
4 files changed, 110 insertions(+)
create mode 100644 drivers/misc/dlb/dlb_pf_ops.c

diff --git a/drivers/misc/dlb/Makefile b/drivers/misc/dlb/Makefile
index a5cd3eec3304..027556fd3f1f 100644
--- a/drivers/misc/dlb/Makefile
+++ b/drivers/misc/dlb/Makefile
@@ -3,3 +3,4 @@
obj-$(CONFIG_INTEL_DLB) := dlb.o

dlb-objs := dlb_main.o
+dlb-objs += dlb_pf_ops.o
diff --git a/drivers/misc/dlb/dlb_main.c b/drivers/misc/dlb/dlb_main.c
index 12346ee8acf7..00f7949e4d95 100644
--- a/drivers/misc/dlb/dlb_main.c
+++ b/drivers/misc/dlb/dlb_main.c
@@ -16,10 +16,38 @@ MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel(R) Dynamic Load Balancer (DLB) Driver");

static struct class *dlb_class;
+static struct cdev dlb_cdev;
static dev_t dlb_devt;
static DEFINE_IDR(dlb_ids);
static DEFINE_MUTEX(dlb_ids_lock);

+static int dlb_device_create(struct dlb *dlb, struct pci_dev *pdev)
+{
+ /*
+ * Create a new device in order to create a /dev/dlb node. This device
+ * is a child of the DLB PCI device.
+ */
+ dlb->dev_number = MKDEV(MAJOR(dlb_devt), dlb->id);
+ dlb->dev = device_create(dlb_class, &pdev->dev, dlb->dev_number, dlb,
+ "dlb%d", dlb->id);
+ if (IS_ERR(dlb->dev)) {
+ dev_err(dlb->dev, "device_create() returned %ld\n",
+ PTR_ERR(dlb->dev));
+
+ return PTR_ERR(dlb->dev);
+ }
+
+ return 0;
+}
+
+/********************************/
+/****** Char dev callbacks ******/
+/********************************/
+
+static const struct file_operations dlb_fops = {
+ .owner = THIS_MODULE,
+};
+
/**********************************/
/****** PCI driver callbacks ******/
/**********************************/
@@ -71,8 +99,24 @@ static int dlb_probe(struct pci_dev *pdev, const struct pci_device_id *pdev_id)
if (ret != 0)
dev_info(&pdev->dev, "AER is not supported\n");

+ ret = dlb_pf_map_pci_bar_space(dlb, pdev);
+ if (ret)
+ goto map_pci_bar_fail;
+
+ ret = dlb_device_create(dlb, pdev);
+ if (ret)
+ goto map_pci_bar_fail;
+
+ ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+ if (ret)
+ goto dma_set_mask_fail;
+
return 0;

+dma_set_mask_fail:
+ device_destroy(dlb_class, dlb->dev_number);
+map_pci_bar_fail:
+ pci_disable_pcie_error_reporting(pdev);
pci_enable_device_fail:
mutex_lock(&dlb_ids_lock);
idr_remove(&dlb_ids, dlb->id);
@@ -85,6 +129,8 @@ static void dlb_remove(struct pci_dev *pdev)
{
struct dlb *dlb = pci_get_drvdata(pdev);

+ device_destroy(dlb_class, dlb->dev_number);
+
pci_disable_pcie_error_reporting(pdev);

mutex_lock(&dlb_ids_lock);
@@ -107,6 +153,7 @@ static struct pci_driver dlb_pci_driver = {

static int __init dlb_init_module(void)
{
+ int dlb_major;
int err;

dlb_class = class_create(THIS_MODULE, "dlb");
@@ -126,6 +173,12 @@ static int __init dlb_init_module(void)
goto alloc_chrdev_fail;
}

+ dlb_major = MAJOR(dlb_devt);
+ cdev_init(&dlb_cdev, &dlb_fops);
+ err = cdev_add(&dlb_cdev, MKDEV(dlb_major, 0), DLB_MAX_NUM_DEVICES);
+ if (err)
+ goto cdev_add_fail;
+
err = pci_register_driver(&dlb_pci_driver);
if (err < 0) {
pr_err("dlb: pci_register_driver() returned %d\n", err);
@@ -136,6 +189,8 @@ static int __init dlb_init_module(void)
return 0;

pci_register_fail:
+ cdev_del(&dlb_cdev);
+cdev_add_fail:
unregister_chrdev_region(dlb_devt, DLB_MAX_NUM_DEVICES);
alloc_chrdev_fail:
class_destroy(dlb_class);
@@ -147,6 +202,8 @@ static void __exit dlb_exit_module(void)
{
pci_unregister_driver(&dlb_pci_driver);

+ cdev_del(&dlb_cdev);
+
unregister_chrdev_region(dlb_devt, DLB_MAX_NUM_DEVICES);

class_destroy(dlb_class);
diff --git a/drivers/misc/dlb/dlb_main.h b/drivers/misc/dlb/dlb_main.h
index 23f059ec86f1..efe74ffcbf0c 100644
--- a/drivers/misc/dlb/dlb_main.h
+++ b/drivers/misc/dlb/dlb_main.h
@@ -16,6 +16,7 @@
* Hardware related #defines and data structures.
*
*/
+
#define DLB_MAX_NUM_VDEVS 16
#define DLB_MAX_NUM_DOMAINS 32
#define DLB_MAX_NUM_LDB_QUEUES 32 /* LDB == load-balanced */
@@ -41,6 +42,15 @@

#define PCI_DEVICE_ID_INTEL_DLB_PF 0x2710

+struct dlb_hw {
+ /* BAR 0 address */
+ void __iomem *csr_kva;
+ unsigned long csr_phys_addr;
+ /* BAR 2 address */
+ void __iomem *func_kva;
+ unsigned long func_phys_addr;
+};
+
/*
* The dlb driver uses a different minor number for each device file, of which
* there are:
@@ -56,9 +66,18 @@ enum dlb_device_type {
DLB_PF,
};

+struct dlb;
+
+int dlb_pf_map_pci_bar_space(struct dlb *dlb, struct pci_dev *pdev);
+void dlb_pf_unmap_pci_bar_space(struct dlb *dlb, struct pci_dev *pdev);
+
struct dlb {
struct pci_dev *pdev;
+ struct dlb_hw hw;
+ struct device *dev;
+ enum dlb_device_type type;
int id;
+ dev_t dev_number;
};

#endif /* __DLB_MAIN_H */
diff --git a/drivers/misc/dlb/dlb_pf_ops.c b/drivers/misc/dlb/dlb_pf_ops.c
new file mode 100644
index 000000000000..77ca7bf2d961
--- /dev/null
+++ b/drivers/misc/dlb/dlb_pf_ops.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(C) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include "dlb_main.h"
+
+/********************************/
+/****** PCI BAR management ******/
+/********************************/
+
+int dlb_pf_map_pci_bar_space(struct dlb *dlb, struct pci_dev *pdev)
+{
+ dlb->hw.func_kva = pcim_iomap_table(pdev)[DLB_FUNC_BAR];
+ dlb->hw.func_phys_addr = pci_resource_start(pdev, DLB_FUNC_BAR);
+
+ if (!dlb->hw.func_kva) {
+ dev_err(&pdev->dev, "Cannot iomap BAR 0 (size %llu)\n",
+ pci_resource_len(pdev, 0));
+
+ return -EIO;
+ }
+
+ dlb->hw.csr_kva = pcim_iomap_table(pdev)[DLB_CSR_BAR];
+ dlb->hw.csr_phys_addr = pci_resource_start(pdev, DLB_CSR_BAR);
+
+ if (!dlb->hw.csr_kva) {
+ dev_err(&pdev->dev, "Cannot iomap BAR 2 (size %llu)\n",
+ pci_resource_len(pdev, 2));
+
+ return -EIO;
+ }
+
+ return 0;
+}
--
2.27.0