Re: [PATCH V4 XRT Alveo 09/20] fpga: xrt: management physical function driver (root)
From: Tom Rix
Date: Wed Apr 14 2021 - 11:40:28 EST
On 4/9/21 11:50 AM, Max Zhen wrote:
Hi Tom,
On 3/31/21 6:03 AM, Tom Rix wrote:
On 3/23/21 10:29 PM, Lizhi Hou wrote:
The PCIE device driver which attaches to management function on Alveo
devices. It instantiates one or more group drivers which, in turn,
instantiate platform drivers. The instantiation of group and platform
drivers is completely dtb driven.
Signed-off-by: Sonal Santan<sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen<max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou<lizhi.hou@xxxxxxxxxx>
---
drivers/fpga/xrt/mgmt/root.c | 333
+++++++++++++++++++++++++++++++++++
1 file changed, 333 insertions(+)
create mode 100644 drivers/fpga/xrt/mgmt/root.c
diff --git a/drivers/fpga/xrt/mgmt/root.c
b/drivers/fpga/xrt/mgmt/root.c
new file mode 100644
index 000000000000..f97f92807c01
--- /dev/null
+++ b/drivers/fpga/xrt/mgmt/root.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo Management Function Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ * Cheng Zhen<maxz@xxxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/aer.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+
+#include "xroot.h"
+#include "xmgnt.h"
+#include "metadata.h"
+
+#define XMGMT_MODULE_NAME "xrt-mgmt"
ok
+#define XMGMT_DRIVER_VERSION "4.0.0"
+
+#define XMGMT_PDEV(xm) ((xm)->pdev)
+#define XMGMT_DEV(xm) (&(XMGMT_PDEV(xm)->dev))
+#define xmgmt_err(xm, fmt, args...) \
+ dev_err(XMGMT_DEV(xm), "%s: " fmt, __func__, ##args)
+#define xmgmt_warn(xm, fmt, args...) \
+ dev_warn(XMGMT_DEV(xm), "%s: " fmt, __func__, ##args)
+#define xmgmt_info(xm, fmt, args...) \
+ dev_info(XMGMT_DEV(xm), "%s: " fmt, __func__, ##args)
+#define xmgmt_dbg(xm, fmt, args...) \
+ dev_dbg(XMGMT_DEV(xm), "%s: " fmt, __func__, ##args)
+#define XMGMT_DEV_ID(_pcidev) \
+ ({ typeof(_pcidev) (pcidev) = (_pcidev); \
+ ((pci_domain_nr((pcidev)->bus) << 16) | \
+ PCI_DEVID((pcidev)->bus->number, 0)); })
+
+static struct class *xmgmt_class;
+
+/* PCI Device IDs */
add a comment on what a golden image is here something like
/*
* Golden image is preloaded on the device when it is shipped to
customer.
* Then, customer can load other shells (from Xilinx or some other
vendor).
* If something goes wrong with the shell, customer can always go back to
* golden and start over again.
*/
Will do.
+#define PCI_DEVICE_ID_U50_GOLDEN 0xD020
+#define PCI_DEVICE_ID_U50 0x5020
+static const struct pci_device_id xmgmt_pci_ids[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_U50_GOLDEN),
}, /* Alveo U50 (golden) */
+ { PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_U50), }, /*
Alveo U50 */
+ { 0, }
+};
+
+struct xmgmt {
+ struct pci_dev *pdev;
+ void *root;
+
+ bool ready;
+};
+
+static int xmgmt_config_pci(struct xmgmt *xm)
+{
+ struct pci_dev *pdev = XMGMT_PDEV(xm);
+ int rc;
+
+ rc = pcim_enable_device(pdev);
+ if (rc < 0) {
+ xmgmt_err(xm, "failed to enable device: %d", rc);
+ return rc;
+ }
+
+ rc = pci_enable_pcie_error_reporting(pdev);
+ if (rc)
ok
+ xmgmt_warn(xm, "failed to enable AER: %d", rc);
+
+ pci_set_master(pdev);
+
+ rc = pcie_get_readrq(pdev);
+ if (rc > 512)
512 is magic number, change this to a #define
Will do.
+ pcie_set_readrq(pdev, 512);
+ return 0;
+}
+
+static int xmgmt_match_slot_and_save(struct device *dev, void *data)
+{
+ struct xmgmt *xm = data;
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ if (XMGMT_DEV_ID(pdev) == XMGMT_DEV_ID(xm->pdev)) {
+ pci_cfg_access_lock(pdev);
+ pci_save_state(pdev);
+ }
+
+ return 0;
+}
+
+static void xmgmt_pci_save_config_all(struct xmgmt *xm)
+{
+ bus_for_each_dev(&pci_bus_type, NULL, xm,
xmgmt_match_slot_and_save);
refactor expected in v5 when pseudo bus change happens.
There might be some mis-understanding here...
No matter how we reorganize our code (using platform_device bus type
or defining our own bus type), it's a driver that drives a PCIE device
after all. So, this mgmt/root.c must be a PCIE driver, which may
interact with a whole bunch of IP drivers through a pseudo bus we are
about to create.
What this code is doing here is completely of PCIE business (PCIE
config space access). So, I think it is appropriate code in a PCIE
driver.
The PCIE device we are driving is a multi-function device. The mgmt pf
is of function 0, which, according to PCIE spec, can manage other
functions on the same device. So, I think it's appropriate for mgmt pf
driver (this root driver) to find it's peer function (through PCIE bus
type) on the same device and do something about it in certain special
cases.
Please let me know why you expect this code to be refactored and how
you want it to be refactored. I might have missed something here...
ok, i get it.
thanks for the explanation.
Tom
+}
+
+static int xmgmt_match_slot_and_restore(struct device *dev, void
*data)
+{
+ struct xmgmt *xm = data;
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ if (XMGMT_DEV_ID(pdev) == XMGMT_DEV_ID(xm->pdev)) {
+ pci_restore_state(pdev);
+ pci_cfg_access_unlock(pdev);
+ }
+
+ return 0;
+}
+
+static void xmgmt_pci_restore_config_all(struct xmgmt *xm)
+{
+ bus_for_each_dev(&pci_bus_type, NULL, xm,
xmgmt_match_slot_and_restore);
+}
+
+static void xmgmt_root_hot_reset(struct pci_dev *pdev)
+{
+ struct xmgmt *xm = pci_get_drvdata(pdev);
+ struct pci_bus *bus;
+ u8 pci_bctl;
+ u16 pci_cmd, devctl;
+ int i, ret;
+
+ xmgmt_info(xm, "hot reset start");
+
+ xmgmt_pci_save_config_all(xm);
+
+ pci_disable_device(pdev);
+
+ bus = pdev->bus;
whitespace, all these nl's are not needed
Will remove them.
+
+ /*
+ * When flipping the SBR bit, device can fall off the bus.
This is
+ * usually no problem at all so long as drivers are working
properly
+ * after SBR. However, some systems complain bitterly when the
device
+ * falls off the bus.
+ * The quick solution is to temporarily disable the SERR
reporting of
+ * switch port during SBR.
+ */
+
+ pci_read_config_word(bus->self, PCI_COMMAND, &pci_cmd);
+ pci_write_config_word(bus->self, PCI_COMMAND, (pci_cmd &
~PCI_COMMAND_SERR));
+ pcie_capability_read_word(bus->self, PCI_EXP_DEVCTL, &devctl);
+ pcie_capability_write_word(bus->self, PCI_EXP_DEVCTL, (devctl
& ~PCI_EXP_DEVCTL_FERE));
+ pci_read_config_byte(bus->self, PCI_BRIDGE_CONTROL, &pci_bctl);
+ pci_write_config_byte(bus->self, PCI_BRIDGE_CONTROL, pci_bctl
| PCI_BRIDGE_CTL_BUS_RESET);
ok
+ msleep(100);
+ pci_write_config_byte(bus->self, PCI_BRIDGE_CONTROL, pci_bctl);
+ ssleep(1);
+
+ pcie_capability_write_word(bus->self, PCI_EXP_DEVCTL, devctl);
+ pci_write_config_word(bus->self, PCI_COMMAND, pci_cmd);
+
+ ret = pci_enable_device(pdev);
+ if (ret)
+ xmgmt_err(xm, "failed to enable device, ret %d", ret);
+
+ for (i = 0; i < 300; i++) {
+ pci_read_config_word(pdev, PCI_COMMAND, &pci_cmd);
+ if (pci_cmd != 0xffff)
+ break;
+ msleep(20);
+ }
+ if (i == 300)
+ xmgmt_err(xm, "time'd out waiting for device to be
online after reset");
time'd -> timed
Will do.
Thanks,
Max
Tom
+
+ xmgmt_info(xm, "waiting for %d ms", i * 20);
+ xmgmt_pci_restore_config_all(xm);
+ xmgmt_config_pci(xm);
+}
+
+static int xmgmt_create_root_metadata(struct xmgmt *xm, char
**root_dtb)
+{
+ char *dtb = NULL;
+ int ret;
+
+ ret = xrt_md_create(XMGMT_DEV(xm), &dtb);
+ if (ret) {
+ xmgmt_err(xm, "create metadata failed, ret %d", ret);
+ goto failed;
+ }
+
+ ret = xroot_add_vsec_node(xm->root, dtb);
+ if (ret == -ENOENT) {
+ /*
+ * We may be dealing with a MFG board.
+ * Try vsec-golden which will bring up all hard-coded
leaves
+ * at hard-coded offsets.
+ */
+ ret = xroot_add_simple_node(xm->root, dtb,
XRT_MD_NODE_VSEC_GOLDEN);
+ } else if (ret == 0) {
+ ret = xroot_add_simple_node(xm->root, dtb,
XRT_MD_NODE_MGMT_MAIN);
+ }
+ if (ret)
+ goto failed;
+
+ *root_dtb = dtb;
+ return 0;
+
+failed:
+ vfree(dtb);
+ return ret;
+}
+
+static ssize_t ready_show(struct device *dev,
+ struct device_attribute *da,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct xmgmt *xm = pci_get_drvdata(pdev);
+
+ return sprintf(buf, "%d\n", xm->ready);
+}
+static DEVICE_ATTR_RO(ready);
+
+static struct attribute *xmgmt_root_attrs[] = {
+ &dev_attr_ready.attr,
+ NULL
+};
+
+static struct attribute_group xmgmt_root_attr_group = {
+ .attrs = xmgmt_root_attrs,
+};
+
+static struct xroot_physical_function_callback xmgmt_xroot_pf_cb = {
+ .xpc_hot_reset = xmgmt_root_hot_reset,
+};
+
+static int xmgmt_probe(struct pci_dev *pdev, const struct
pci_device_id *id)
+{
+ int ret;
+ struct device *dev = &pdev->dev;
+ struct xmgmt *xm = devm_kzalloc(dev, sizeof(*xm), GFP_KERNEL);
+ char *dtb = NULL;
+
+ if (!xm)
+ return -ENOMEM;
+ xm->pdev = pdev;
+ pci_set_drvdata(pdev, xm);
+
+ ret = xmgmt_config_pci(xm);
+ if (ret)
+ goto failed;
+
+ ret = xroot_probe(pdev, &xmgmt_xroot_pf_cb, &xm->root);
+ if (ret)
+ goto failed;
+
+ ret = xmgmt_create_root_metadata(xm, &dtb);
+ if (ret)
+ goto failed_metadata;
+
+ ret = xroot_create_group(xm->root, dtb);
+ vfree(dtb);
+ if (ret)
+ xmgmt_err(xm, "failed to create root group: %d", ret);
+
+ if (!xroot_wait_for_bringup(xm->root))
+ xmgmt_err(xm, "failed to bringup all groups");
+ else
+ xm->ready = true;
+
+ ret = sysfs_create_group(&pdev->dev.kobj,
&xmgmt_root_attr_group);
+ if (ret) {
+ /* Warning instead of failing the probe. */
+ xmgmt_warn(xm, "create xmgmt root attrs failed: %d",
ret);
+ }
+
+ xroot_broadcast(xm->root, XRT_EVENT_POST_CREATION);
+ xmgmt_info(xm, "%s started successfully", XMGMT_MODULE_NAME);
+ return 0;
+
+failed_metadata:
+ xroot_remove(xm->root);
+failed:
+ pci_set_drvdata(pdev, NULL);
+ return ret;
+}
+
+static void xmgmt_remove(struct pci_dev *pdev)
+{
+ struct xmgmt *xm = pci_get_drvdata(pdev);
+
+ xroot_broadcast(xm->root, XRT_EVENT_PRE_REMOVAL);
+ sysfs_remove_group(&pdev->dev.kobj, &xmgmt_root_attr_group);
+ xroot_remove(xm->root);
+ pci_disable_pcie_error_reporting(xm->pdev);
+ xmgmt_info(xm, "%s cleaned up successfully", XMGMT_MODULE_NAME);
+}
+
+static struct pci_driver xmgmt_driver = {
+ .name = XMGMT_MODULE_NAME,
+ .id_table = xmgmt_pci_ids,
+ .probe = xmgmt_probe,
+ .remove = xmgmt_remove,
+};
+
+static int __init xmgmt_init(void)
+{
+ int res = 0;
+
+ res = xmgmt_register_leaf();
+ if (res)
+ return res;
+
+ xmgmt_class = class_create(THIS_MODULE, XMGMT_MODULE_NAME);
+ if (IS_ERR(xmgmt_class))
+ return PTR_ERR(xmgmt_class);
+
+ res = pci_register_driver(&xmgmt_driver);
+ if (res) {
+ class_destroy(xmgmt_class);
+ return res;
+ }
+
+ return 0;
+}
+
+static __exit void xmgmt_exit(void)
+{
+ pci_unregister_driver(&xmgmt_driver);
+ class_destroy(xmgmt_class);
+ xmgmt_unregister_leaf();
+}
+
+module_init(xmgmt_init);
+module_exit(xmgmt_exit);
+
+MODULE_DEVICE_TABLE(pci, xmgmt_pci_ids);
+MODULE_VERSION(XMGMT_DRIVER_VERSION);
+MODULE_AUTHOR("XRT Team<runtime@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Xilinx Alveo management function driver");
+MODULE_LICENSE("GPL v2");