Commit 080b47de authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Bjorn Helgaas
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MicroSemi Switchtec management interface driver

Microsemi's "Switchtec" line of PCI switch devices is already well
supported by the kernel with standard PCI switch drivers.  However, the
Switchtec device advertises a special management endpoint with a separate
PCI function address and class code.  This endpoint enables some additional
functionality which includes:

 * Packet and Byte Counters
 * Switch Firmware Upgrades
 * Event and Error logs
 * Querying port link status
 * Custom user firmware commands

Add a switchtec kernel module which provides PCI driver that exposes a char
device.  The char device provides userspace access to this interface
through read, write and (optionally) poll calls.

A userspace tool and library which utilizes this interface is available
at [1].  This tool takes inspiration (and borrows some code) from
nvme-cli [2].  The tool is largely complete at this time but additional
features may be added in the future.

[1] https://github.com/sbates130272/switchtec-user
[2] https://github.com/linux-nvme/nvme-cli



[Dan Carpenter <dan.carpenter@oracle.com>: don't invert error codes]
[Christophe JAILLET <christophe.jaillet@wanadoo.fr>: fix
switchtec_dev_open() error handling]
Tested-by: default avatarKrishna Dhulipala <krishnad@fb.com>
Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarStephen Bates <stephen.bates@microsemi.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarWei Zhang <wzhang@fb.com>
Reviewed-by: default avatarJens Axboe <axboe@fb.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c1ae3cfa
......@@ -9655,6 +9655,14 @@ S: Maintained
F: Documentation/devicetree/bindings/pci/aardvark-pci.txt
F: drivers/pci/host/pci-aardvark.c
PCI DRIVER FOR MICROSEMI SWITCHTEC
M: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
M: Stephen Bates <stephen.bates@microsemi.com>
M: Logan Gunthorpe <logang@deltatee.com>
L: linux-pci@vger.kernel.org
S: Maintained
F: drivers/pci/switch/switchtec*
PCI DRIVER FOR NVIDIA TEGRA
M: Thierry Reding <thierry.reding@gmail.com>
L: linux-tegra@vger.kernel.org
......
......@@ -134,3 +134,4 @@ config PCI_HYPERV
source "drivers/pci/hotplug/Kconfig"
source "drivers/pci/dwc/Kconfig"
source "drivers/pci/host/Kconfig"
source "drivers/pci/switch/Kconfig"
......@@ -68,3 +68,4 @@ ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG
# PCI host controller drivers
obj-y += host/
obj-y += switch/
menu "PCI switch controller drivers"
depends on PCI
config PCI_SW_SWITCHTEC
tristate "MicroSemi Switchtec PCIe Switch Management Driver"
help
Enables support for the management interface for the MicroSemi
Switchtec series of PCIe switches. Supports userspace access
to submit MRPC commands to the switch via /dev/switchtecX
devices. See <file:Documentation/switchtec.txt> for more
information.
endmenu
obj-$(CONFIG_PCI_SW_SWITCHTEC) += switchtec.o
/*
* Microsemi Switchtec(tm) PCIe Management Driver
* Copyright (c) 2017, Microsemi Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/poll.h>
#include <linux/pci.h>
#include <linux/cdev.h>
#include <linux/wait.h>
MODULE_DESCRIPTION("Microsemi Switchtec(tm) PCIe Management Driver");
MODULE_VERSION("0.1");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Microsemi Corporation");
static int max_devices = 16;
module_param(max_devices, int, 0644);
MODULE_PARM_DESC(max_devices, "max number of switchtec device instances");
static dev_t switchtec_devt;
static struct class *switchtec_class;
static DEFINE_IDA(switchtec_minor_ida);
#define MICROSEMI_VENDOR_ID 0x11f8
#define MICROSEMI_NTB_CLASSCODE 0x068000
#define MICROSEMI_MGMT_CLASSCODE 0x058000
#define SWITCHTEC_MRPC_PAYLOAD_SIZE 1024
#define SWITCHTEC_MAX_PFF_CSR 48
#define SWITCHTEC_EVENT_OCCURRED BIT(0)
#define SWITCHTEC_EVENT_CLEAR BIT(0)
#define SWITCHTEC_EVENT_EN_LOG BIT(1)
#define SWITCHTEC_EVENT_EN_CLI BIT(2)
#define SWITCHTEC_EVENT_EN_IRQ BIT(3)
#define SWITCHTEC_EVENT_FATAL BIT(4)
enum {
SWITCHTEC_GAS_MRPC_OFFSET = 0x0000,
SWITCHTEC_GAS_TOP_CFG_OFFSET = 0x1000,
SWITCHTEC_GAS_SW_EVENT_OFFSET = 0x1800,
SWITCHTEC_GAS_SYS_INFO_OFFSET = 0x2000,
SWITCHTEC_GAS_FLASH_INFO_OFFSET = 0x2200,
SWITCHTEC_GAS_PART_CFG_OFFSET = 0x4000,
SWITCHTEC_GAS_NTB_OFFSET = 0x10000,
SWITCHTEC_GAS_PFF_CSR_OFFSET = 0x134000,
};
struct mrpc_regs {
u8 input_data[SWITCHTEC_MRPC_PAYLOAD_SIZE];
u8 output_data[SWITCHTEC_MRPC_PAYLOAD_SIZE];
u32 cmd;
u32 status;
u32 ret_value;
} __packed;
enum mrpc_status {
SWITCHTEC_MRPC_STATUS_INPROGRESS = 1,
SWITCHTEC_MRPC_STATUS_DONE = 2,
SWITCHTEC_MRPC_STATUS_ERROR = 0xFF,
SWITCHTEC_MRPC_STATUS_INTERRUPTED = 0x100,
};
struct sw_event_regs {
u64 event_report_ctrl;
u64 reserved1;
u64 part_event_bitmap;
u64 reserved2;
u32 global_summary;
u32 reserved3[3];
u32 stack_error_event_hdr;
u32 stack_error_event_data;
u32 reserved4[4];
u32 ppu_error_event_hdr;
u32 ppu_error_event_data;
u32 reserved5[4];
u32 isp_error_event_hdr;
u32 isp_error_event_data;
u32 reserved6[4];
u32 sys_reset_event_hdr;
u32 reserved7[5];
u32 fw_exception_hdr;
u32 reserved8[5];
u32 fw_nmi_hdr;
u32 reserved9[5];
u32 fw_non_fatal_hdr;
u32 reserved10[5];
u32 fw_fatal_hdr;
u32 reserved11[5];
u32 twi_mrpc_comp_hdr;
u32 twi_mrpc_comp_data;
u32 reserved12[4];
u32 twi_mrpc_comp_async_hdr;
u32 twi_mrpc_comp_async_data;
u32 reserved13[4];
u32 cli_mrpc_comp_hdr;
u32 cli_mrpc_comp_data;
u32 reserved14[4];
u32 cli_mrpc_comp_async_hdr;
u32 cli_mrpc_comp_async_data;
u32 reserved15[4];
u32 gpio_interrupt_hdr;
u32 gpio_interrupt_data;
u32 reserved16[4];
} __packed;
struct sys_info_regs {
u32 device_id;
u32 device_version;
u32 firmware_version;
u32 reserved1;
u32 vendor_table_revision;
u32 table_format_version;
u32 partition_id;
u32 cfg_file_fmt_version;
u32 reserved2[58];
char vendor_id[8];
char product_id[16];
char product_revision[4];
char component_vendor[8];
u16 component_id;
u8 component_revision;
} __packed;
struct flash_info_regs {
u32 flash_part_map_upd_idx;
struct active_partition_info {
u32 address;
u32 build_version;
u32 build_string;
} active_img;
struct active_partition_info active_cfg;
struct active_partition_info inactive_img;
struct active_partition_info inactive_cfg;
u32 flash_length;
struct partition_info {
u32 address;
u32 length;
} cfg0;
struct partition_info cfg1;
struct partition_info img0;
struct partition_info img1;
struct partition_info nvlog;
struct partition_info vendor[8];
};
struct ntb_info_regs {
u8 partition_count;
u8 partition_id;
u16 reserved1;
u64 ep_map;
u16 requester_id;
} __packed;
struct part_cfg_regs {
u32 status;
u32 state;
u32 port_cnt;
u32 usp_port_mode;
u32 usp_pff_inst_id;
u32 vep_pff_inst_id;
u32 dsp_pff_inst_id[47];
u32 reserved1[11];
u16 vep_vector_number;
u16 usp_vector_number;
u32 port_event_bitmap;
u32 reserved2[3];
u32 part_event_summary;
u32 reserved3[3];
u32 part_reset_hdr;
u32 part_reset_data[5];
u32 mrpc_comp_hdr;
u32 mrpc_comp_data[5];
u32 mrpc_comp_async_hdr;
u32 mrpc_comp_async_data[5];
u32 dyn_binding_hdr;
u32 dyn_binding_data[5];
u32 reserved4[159];
} __packed;
enum {
SWITCHTEC_PART_CFG_EVENT_RESET = 1 << 0,
SWITCHTEC_PART_CFG_EVENT_MRPC_CMP = 1 << 1,
SWITCHTEC_PART_CFG_EVENT_MRPC_ASYNC_CMP = 1 << 2,
SWITCHTEC_PART_CFG_EVENT_DYN_PART_CMP = 1 << 3,
};
struct pff_csr_regs {
u16 vendor_id;
u16 device_id;
u32 pci_cfg_header[15];
u32 pci_cap_region[48];
u32 pcie_cap_region[448];
u32 indirect_gas_window[128];
u32 indirect_gas_window_off;
u32 reserved[127];
u32 pff_event_summary;
u32 reserved2[3];
u32 aer_in_p2p_hdr;
u32 aer_in_p2p_data[5];
u32 aer_in_vep_hdr;
u32 aer_in_vep_data[5];
u32 dpc_hdr;
u32 dpc_data[5];
u32 cts_hdr;
u32 cts_data[5];
u32 reserved3[6];
u32 hotplug_hdr;
u32 hotplug_data[5];
u32 ier_hdr;
u32 ier_data[5];
u32 threshold_hdr;
u32 threshold_data[5];
u32 power_mgmt_hdr;
u32 power_mgmt_data[5];
u32 tlp_throttling_hdr;
u32 tlp_throttling_data[5];
u32 force_speed_hdr;
u32 force_speed_data[5];
u32 credit_timeout_hdr;
u32 credit_timeout_data[5];
u32 link_state_hdr;
u32 link_state_data[5];
u32 reserved4[174];
} __packed;
struct switchtec_dev {
struct pci_dev *pdev;
struct device dev;
struct cdev cdev;
int partition;
int partition_count;
int pff_csr_count;
char pff_local[SWITCHTEC_MAX_PFF_CSR];
void __iomem *mmio;
struct mrpc_regs __iomem *mmio_mrpc;
struct sw_event_regs __iomem *mmio_sw_event;
struct sys_info_regs __iomem *mmio_sys_info;
struct flash_info_regs __iomem *mmio_flash_info;
struct ntb_info_regs __iomem *mmio_ntb;
struct part_cfg_regs __iomem *mmio_part_cfg;
struct part_cfg_regs __iomem *mmio_part_cfg_all;
struct pff_csr_regs __iomem *mmio_pff_csr;
/*
* The mrpc mutex must be held when accessing the other
* mrpc_ fields, alive flag and stuser->state field
*/
struct mutex mrpc_mutex;
struct list_head mrpc_queue;
int mrpc_busy;
struct work_struct mrpc_work;
struct delayed_work mrpc_timeout;
bool alive;
wait_queue_head_t event_wq;
atomic_t event_cnt;
};
static struct switchtec_dev *to_stdev(struct device *dev)
{
return container_of(dev, struct switchtec_dev, dev);
}
enum mrpc_state {
MRPC_IDLE = 0,
MRPC_QUEUED,
MRPC_RUNNING,
MRPC_DONE,
};
struct switchtec_user {
struct switchtec_dev *stdev;
enum mrpc_state state;
struct completion comp;
struct kref kref;
struct list_head list;
u32 cmd;
u32 status;
u32 return_code;
size_t data_len;
size_t read_len;
unsigned char data[SWITCHTEC_MRPC_PAYLOAD_SIZE];
int event_cnt;
};
static struct switchtec_user *stuser_create(struct switchtec_dev *stdev)
{
struct switchtec_user *stuser;
stuser = kzalloc(sizeof(*stuser), GFP_KERNEL);
if (!stuser)
return ERR_PTR(-ENOMEM);
get_device(&stdev->dev);
stuser->stdev = stdev;
kref_init(&stuser->kref);
INIT_LIST_HEAD(&stuser->list);
init_completion(&stuser->comp);
stuser->event_cnt = atomic_read(&stdev->event_cnt);
dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser);
return stuser;
}
static void stuser_free(struct kref *kref)
{
struct switchtec_user *stuser;
stuser = container_of(kref, struct switchtec_user, kref);
dev_dbg(&stuser->stdev->dev, "%s: %p\n", __func__, stuser);
put_device(&stuser->stdev->dev);
kfree(stuser);
}
static void stuser_put(struct switchtec_user *stuser)
{
kref_put(&stuser->kref, stuser_free);
}
static void stuser_set_state(struct switchtec_user *stuser,
enum mrpc_state state)
{
/* requires the mrpc_mutex to already be held when called */
const char * const state_names[] = {
[MRPC_IDLE] = "IDLE",
[MRPC_QUEUED] = "QUEUED",
[MRPC_RUNNING] = "RUNNING",
[MRPC_DONE] = "DONE",
};
stuser->state = state;
dev_dbg(&stuser->stdev->dev, "stuser state %p -> %s",
stuser, state_names[state]);
}
static void mrpc_complete_cmd(struct switchtec_dev *stdev);
static void mrpc_cmd_submit(struct switchtec_dev *stdev)
{
/* requires the mrpc_mutex to already be held when called */
struct switchtec_user *stuser;
if (stdev->mrpc_busy)
return;
if (list_empty(&stdev->mrpc_queue))
return;
stuser = list_entry(stdev->mrpc_queue.next, struct switchtec_user,
list);
stuser_set_state(stuser, MRPC_RUNNING);
stdev->mrpc_busy = 1;
memcpy_toio(&stdev->mmio_mrpc->input_data,
stuser->data, stuser->data_len);
iowrite32(stuser->cmd, &stdev->mmio_mrpc->cmd);
stuser->status = ioread32(&stdev->mmio_mrpc->status);
if (stuser->status != SWITCHTEC_MRPC_STATUS_INPROGRESS)
mrpc_complete_cmd(stdev);
schedule_delayed_work(&stdev->mrpc_timeout,
msecs_to_jiffies(500));
}
static int mrpc_queue_cmd(struct switchtec_user *stuser)
{
/* requires the mrpc_mutex to already be held when called */
struct switchtec_dev *stdev = stuser->stdev;
kref_get(&stuser->kref);
stuser->read_len = sizeof(stuser->data);
stuser_set_state(stuser, MRPC_QUEUED);
init_completion(&stuser->comp);
list_add_tail(&stuser->list, &stdev->mrpc_queue);
mrpc_cmd_submit(stdev);
return 0;
}
static void mrpc_complete_cmd(struct switchtec_dev *stdev)
{
/* requires the mrpc_mutex to already be held when called */
struct switchtec_user *stuser;
if (list_empty(&stdev->mrpc_queue))
return;
stuser = list_entry(stdev->mrpc_queue.next, struct switchtec_user,
list);
stuser->status = ioread32(&stdev->mmio_mrpc->status);
if (stuser->status == SWITCHTEC_MRPC_STATUS_INPROGRESS)
return;
stuser_set_state(stuser, MRPC_DONE);
stuser->return_code = 0;
if (stuser->status != SWITCHTEC_MRPC_STATUS_DONE)
goto out;
stuser->return_code = ioread32(&stdev->mmio_mrpc->ret_value);
if (stuser->return_code != 0)
goto out;
memcpy_fromio(stuser->data, &stdev->mmio_mrpc->output_data,
stuser->read_len);
out:
complete_all(&stuser->comp);
list_del_init(&stuser->list);
stuser_put(stuser);
stdev->mrpc_busy = 0;
mrpc_cmd_submit(stdev);
}
static void mrpc_event_work(struct work_struct *work)
{
struct switchtec_dev *stdev;
stdev = container_of(work, struct switchtec_dev, mrpc_work);
dev_dbg(&stdev->dev, "%s\n", __func__);
mutex_lock(&stdev->mrpc_mutex);
cancel_delayed_work(&stdev->mrpc_timeout);
mrpc_complete_cmd(stdev);
mutex_unlock(&stdev->mrpc_mutex);
}
static void mrpc_timeout_work(struct work_struct *work)
{
struct switchtec_dev *stdev;
u32 status;
stdev = container_of(work, struct switchtec_dev, mrpc_timeout.work);
dev_dbg(&stdev->dev, "%s\n", __func__);
mutex_lock(&stdev->mrpc_mutex);
status = ioread32(&stdev->mmio_mrpc->status);
if (status == SWITCHTEC_MRPC_STATUS_INPROGRESS) {
schedule_delayed_work(&stdev->mrpc_timeout,
msecs_to_jiffies(500));
goto out;
}
mrpc_complete_cmd(stdev);
out:
mutex_unlock(&stdev->mrpc_mutex);
}
static int switchtec_dev_open(struct inode *inode, struct file *filp)
{
struct switchtec_dev *stdev;
struct switchtec_user *stuser;
stdev = container_of(inode->i_cdev, struct switchtec_dev, cdev);
stuser = stuser_create(stdev);
if (IS_ERR(stuser))
return PTR_ERR(stuser);
filp->private_data = stuser;
nonseekable_open(inode, filp);
dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser);
return 0;
}
static int switchtec_dev_release(struct inode *inode, struct file *filp)
{
struct switchtec_user *stuser = filp->private_data;
stuser_put(stuser);
return 0;
}
static int lock_mutex_and_test_alive(struct switchtec_dev *stdev)
{
if (mutex_lock_interruptible(&stdev->mrpc_mutex))
return -EINTR;
if (!stdev->alive) {
mutex_unlock(&stdev->mrpc_mutex);
return -ENODEV;
}
return 0;
}
static ssize_t switchtec_dev_write(struct file *filp, const char __user *data,
size_t size, loff_t *off)
{
struct switchtec_user *stuser = filp->private_data;
struct switchtec_dev *stdev = stuser->stdev;
int rc;
if (size < sizeof(stuser->cmd) ||
size > sizeof(stuser->cmd) + sizeof(stuser->data))
return -EINVAL;
stuser->data_len = size - sizeof(stuser->cmd);
rc = lock_mutex_and_test_alive(stdev);
if (rc)
return rc;
if (stuser->state != MRPC_IDLE) {
rc = -EBADE;
goto out;
}
rc = copy_from_user(&stuser->cmd, data, sizeof(stuser->cmd));
if (rc) {
rc = -EFAULT;
goto out;
}
data += sizeof(stuser->cmd);
rc = copy_from_user(&stuser->data, data, size - sizeof(stuser->cmd));
if (rc) {
rc = -EFAULT;
goto out;
}
rc = mrpc_queue_cmd(stuser);
out:
mutex_unlock(&stdev->mrpc_mutex);
if (rc)
return rc;
return size;