2021-02-12 17:30:10

by Gustavo Pimentel

[permalink] [raw]
Subject: [PATCH v6 0/5] misc: Add Add Synopsys DesignWare xData IP driver

This patch series adds a new driver called xData-pcie for the Synopsys
DesignWare PCIe prototype.

The driver configures and enables the Synopsys DesignWare PCIe traffic
generator IP inside of prototype Endpoint which will generate upstream
and downstream PCIe traffic. This allows to quickly test the PCIe link
throughput speed and check is the prototype solution has some limitation
or not.

Changes:
V2: Rework driver according to Greg Kroah-Hartman' feedback
V3: Fixed issues detected while running on 64 bits platforms
Rebased patches on top of v5.11-rc1 version
V4: Rework driver according to Greg Kroah-Hartman' feedback
Add the ABI doc related to the sysfs implemented on this driver
V5: Rework driver accordingly to Leon Romanovsky' feedback
Rework driver accordingly to Krzysztof Wilczyński' feedback
V6: Rework driver according to Greg Kroah-Hartman' feedback
Rework driver accordingly to Krzysztof Wilczyński' feedback
Rework driver accordingly to Leon Romanovsky' feedback

Cc: Derek Kiernan <[email protected]>
Cc: Dragan Cvetic <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]

Gustavo Pimentel (5):
misc: Add Synopsys DesignWare xData IP driver
misc: Add Synopsys DesignWare xData IP driver to Makefile and Kconfig
Documentation: misc-devices: Add Documentation for dw-xdata-pcie
driver
MAINTAINERS: Add Synopsys xData IP driver maintainer
docs: ABI: Add sysfs documentation interface of dw-xdata-pcie driver

Documentation/ABI/testing/sysfs-driver-xdata | 46 ++++
Documentation/misc-devices/dw-xdata-pcie.rst | 40 +++
MAINTAINERS | 7 +
drivers/misc/Kconfig | 10 +
drivers/misc/Makefile | 1 +
drivers/misc/dw-xdata-pcie.c | 390 +++++++++++++++++++++++++++
6 files changed, 494 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-xdata
create mode 100644 Documentation/misc-devices/dw-xdata-pcie.rst
create mode 100644 drivers/misc/dw-xdata-pcie.c

--
2.7.4


2021-02-12 17:30:20

by Gustavo Pimentel

[permalink] [raw]
Subject: [PATCH v6 1/5] misc: Add Synopsys DesignWare xData IP driver

Add Synopsys DesignWare xData IP driver. This driver enables/disables
the PCI traffic generator module pertain to the Synopsys DesignWare
prototype.

Signed-off-by: Gustavo Pimentel <[email protected]>
---
drivers/misc/dw-xdata-pcie.c | 390 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 390 insertions(+)
create mode 100644 drivers/misc/dw-xdata-pcie.c

diff --git a/drivers/misc/dw-xdata-pcie.c b/drivers/misc/dw-xdata-pcie.c
new file mode 100644
index 00000000..62c6fa9
--- /dev/null
+++ b/drivers/misc/dw-xdata-pcie.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Synopsys, Inc. and/or its affiliates.
+ * Synopsys DesignWare xData driver
+ *
+ * Author: Gustavo Pimentel <[email protected]>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/pci-epf.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+
+#define DW_XDATA_DRIVER_NAME "dw-xdata-pcie"
+
+#define DW_XDATA_EP_MEM_OFFSET 0x8000000
+
+struct dw_xdata_pcie_data {
+ /* xData registers location */
+ enum pci_barno rg_bar;
+ off_t rg_off;
+ size_t rg_sz;
+};
+
+static const struct dw_xdata_pcie_data snps_edda_data = {
+ /* xData registers location */
+ .rg_bar = BAR_0,
+ .rg_off = 0x00000000, /* 0 Kbytes */
+ .rg_sz = 0x0000012c, /* 300 bytes */
+};
+
+#define STATUS_DONE BIT(0)
+
+#define CONTROL_DOORBELL BIT(0)
+#define CONTROL_IS_WRITE BIT(1)
+#define CONTROL_LENGTH(a) FIELD_PREP(GENMASK(13, 2), a)
+#define CONTROL_PATTERN_INC BIT(16)
+#define CONTROL_NO_ADDR_INC BIT(18)
+
+#define XPERF_CONTROL_ENABLE BIT(5)
+
+#define BURST_REPEAT BIT(31)
+#define BURST_VALUE 0x1001
+
+#define PATTERN_VALUE 0x0
+
+struct dw_xdata_regs {
+ u32 addr_lsb; /* 0x000 */
+ u32 addr_msb; /* 0x004 */
+ u32 burst_cnt; /* 0x008 */
+ u32 control; /* 0x00c */
+ u32 pattern; /* 0x010 */
+ u32 status; /* 0x014 */
+ u32 RAM_addr; /* 0x018 */
+ u32 RAM_port; /* 0x01c */
+ u32 _reserved0[14]; /* 0x020..0x054 */
+ u32 perf_control; /* 0x058 */
+ u32 _reserved1[41]; /* 0x05c..0x0fc */
+ u32 wr_cnt_lsb; /* 0x100 */
+ u32 wr_cnt_msb; /* 0x104 */
+ u32 rd_cnt_lsb; /* 0x108 */
+ u32 rd_cnt_msb; /* 0x10c */
+} __packed;
+
+struct dw_xdata_region {
+ phys_addr_t paddr; /* physical address */
+ void __iomem *vaddr; /* virtual address */
+ size_t sz; /* size */
+};
+
+struct dw_xdata {
+ struct dw_xdata_region rg_region; /* registers */
+ size_t max_wr_len; /* max wr xfer len */
+ size_t max_rd_len; /* max rd xfer len */
+ struct mutex mutex;
+ struct pci_dev *pdev;
+};
+
+static inline struct dw_xdata_regs __iomem *__dw_regs(struct dw_xdata *dw)
+{
+ return dw->rg_region.vaddr;
+}
+
+static void dw_xdata_stop(struct dw_xdata *dw)
+{
+ u32 burst;
+
+ mutex_lock(&dw->mutex);
+
+ burst = readl(&(__dw_regs(dw)->burst_cnt));
+
+ if (burst & BURST_REPEAT) {
+ burst &= ~(u32)BURST_REPEAT;
+ writel(burst, &(__dw_regs(dw)->burst_cnt));
+ }
+
+ mutex_unlock(&dw->mutex);
+}
+
+static void dw_xdata_start(struct dw_xdata *dw, bool write)
+{
+ u32 control, status;
+
+ /* Stop first if xfer in progress */
+ dw_xdata_stop(dw);
+
+ mutex_lock(&dw->mutex);
+
+ /* Clear status register */
+ writel(0x0, &(__dw_regs(dw)->status));
+
+ /* Burst count register set for continuous until stopped */
+ writel(BURST_REPEAT | BURST_VALUE, &(__dw_regs(dw)->burst_cnt));
+
+ /* Pattern register */
+ writel(PATTERN_VALUE, &(__dw_regs(dw)->pattern));
+
+ /* Control register */
+ control = CONTROL_DOORBELL | CONTROL_PATTERN_INC | CONTROL_NO_ADDR_INC;
+ if (write) {
+ control |= CONTROL_IS_WRITE;
+ control |= CONTROL_LENGTH(dw->max_wr_len);
+ } else {
+ control |= CONTROL_LENGTH(dw->max_rd_len);
+ }
+ writel(control, &(__dw_regs(dw)->control));
+
+ /*
+ * The xData HW block needs about 100 ms to initiate the traffic
+ * generation according this HW block datasheet.
+ */
+ usleep_range(100, 150);
+
+ status = readl(&(__dw_regs(dw)->status));
+
+ mutex_unlock(&dw->mutex);
+
+ if (!(status & STATUS_DONE))
+ pci_dbg(dw->pdev, "xData: started %s direction\n",
+ write ? "write" : "read");
+}
+
+static void dw_xdata_perf_meas(struct dw_xdata *dw, u64 *data, bool write)
+{
+ if (write) {
+ *data = readl(&(__dw_regs(dw)->wr_cnt_msb));
+ *data <<= 32;
+ *data |= readl(&(__dw_regs(dw)->wr_cnt_lsb));
+ } else {
+ *data = readl(&(__dw_regs(dw)->rd_cnt_msb));
+ *data <<= 32;
+ *data |= readl(&(__dw_regs(dw)->rd_cnt_lsb));
+ }
+}
+
+static u64 dw_xdata_perf_diff(u64 *m1, u64 *m2, u64 time)
+{
+ u64 rate = (*m1 - *m2);
+
+ rate *= (1000 * 1000 * 1000);
+ rate >>= 20;
+ rate = DIV_ROUND_CLOSEST_ULL(rate, time);
+
+ return rate;
+}
+
+static void dw_xdata_perf(struct dw_xdata *dw, u64 *rate, bool write)
+{
+ u64 data[2], time[2], diff;
+
+ mutex_lock(&dw->mutex);
+
+ /* First acquisition of current count frames */
+ writel(0x0, &(__dw_regs(dw)->perf_control));
+ dw_xdata_perf_meas(dw, &data[0], write);
+ time[0] = jiffies;
+ writel((u32)XPERF_CONTROL_ENABLE, &(__dw_regs(dw)->perf_control));
+
+ /*
+ * Wait 100ms between the 1st count frame acquisition and the 2nd
+ * count frame acquisition, in order to calculate the speed later
+ */
+ mdelay(100);
+
+ /* Second acquisition of current count frames */
+ writel(0x0, &(__dw_regs(dw)->perf_control));
+ dw_xdata_perf_meas(dw, &data[1], write);
+ time[1] = jiffies;
+ writel((u32)XPERF_CONTROL_ENABLE, &(__dw_regs(dw)->perf_control));
+
+ /*
+ * Speed calculation
+ *
+ * rate = (2nd count frames - 1st count frames) / (time elapsed)
+ */
+ diff = jiffies_to_nsecs(time[1] - time[0]);
+ *rate = dw_xdata_perf_diff(&data[1], &data[0], diff);
+
+ mutex_unlock(&dw->mutex);
+
+ pci_dbg(dw->pdev, "xData: time=%llu us, %s=%llu MB/s\n",
+ diff, write ? "write" : "read", *rate);
+}
+
+static ssize_t write_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+ u64 rate;
+
+ dw_xdata_perf(dw, &rate, true);
+
+ return sysfs_emit(buf, "%llu\n", rate);
+}
+
+static ssize_t write_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+
+ pci_dbg(pdev, "xData: requested write transfer\n");
+
+ dw_xdata_start(dw, true);
+
+ return size;
+}
+
+static DEVICE_ATTR_RW(write);
+
+static ssize_t read_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+ u64 rate;
+
+ dw_xdata_perf(dw, &rate, false);
+
+ return sysfs_emit(buf, "%llu\n", rate);
+}
+
+static ssize_t read_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+
+ pci_dbg(pdev, "xData: requested read transfer\n");
+
+ dw_xdata_start(dw, false);
+
+ return size;
+}
+
+static DEVICE_ATTR_RW(read);
+
+static ssize_t stop_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+
+ pci_dbg(pdev, "xData: requested stop any transfer\n");
+
+ dw_xdata_stop(dw);
+
+ return size;
+}
+
+static DEVICE_ATTR_WO(stop);
+
+static struct attribute *default_attrs[] = {
+ &dev_attr_write.attr,
+ &dev_attr_read.attr,
+ &dev_attr_stop.attr,
+ NULL,
+};
+
+static const struct attribute_group xdata_attr_group = {
+ .attrs = default_attrs,
+ .name = DW_XDATA_DRIVER_NAME,
+};
+
+static int dw_xdata_pcie_probe(struct pci_dev *pdev,
+ const struct pci_device_id *pid)
+{
+ const struct dw_xdata_pcie_data *pdata = (void *)pid->driver_data;
+ struct dw_xdata *dw;
+ u64 addr;
+ int err;
+
+ /* Enable PCI device */
+ err = pcim_enable_device(pdev);
+ if (err) {
+ pci_err(pdev, "enabling device failed\n");
+ return err;
+ }
+
+ /* Mapping PCI BAR regions */
+ err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar), pci_name(pdev));
+ if (err) {
+ pci_err(pdev, "xData BAR I/O remapping failed\n");
+ return err;
+ }
+
+ pci_set_master(pdev);
+
+ /* Allocate memory */
+ dw = devm_kzalloc(&pdev->dev, sizeof(*dw), GFP_KERNEL);
+ if (!dw)
+ return -ENOMEM;
+
+ /* Data structure initialization */
+ mutex_init(&dw->mutex);
+
+ dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
+ if (!dw->rg_region.vaddr)
+ return -ENOMEM;
+
+ dw->rg_region.vaddr += pdata->rg_off;
+ dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
+ dw->rg_region.paddr += pdata->rg_off;
+ dw->rg_region.sz = pdata->rg_sz;
+
+ dw->max_wr_len = pcie_get_mps(pdev);
+ dw->max_wr_len >>= 2;
+
+ dw->max_rd_len = pcie_get_readrq(pdev);
+ dw->max_rd_len >>= 2;
+
+ dw->pdev = pdev;
+
+ writel(0x0, &(__dw_regs(dw)->RAM_addr));
+ writel(0x0, &(__dw_regs(dw)->RAM_port));
+
+ addr = dw->rg_region.paddr + DW_XDATA_EP_MEM_OFFSET;
+ writel(lower_32_bits(addr), &(__dw_regs(dw)->addr_lsb));
+ writel(upper_32_bits(addr), &(__dw_regs(dw)->addr_msb));
+ pci_dbg(pdev, "xData: target address = 0x%.16llx\n", addr);
+
+ pci_dbg(pdev, "xData: wr_len=%zu, rd_len=%zu\n",
+ dw->max_wr_len * 4, dw->max_rd_len * 4);
+
+ /* Saving data structure reference */
+ pci_set_drvdata(pdev, dw);
+
+ /* Sysfs */
+ err = sysfs_create_group(&pdev->dev.kobj, &xdata_attr_group);
+ if (err)
+ return -ENODEV;
+
+ return 0;
+}
+
+static void dw_xdata_pcie_remove(struct pci_dev *pdev)
+{
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+
+ if (dw)
+ dw_xdata_stop(dw);
+
+ sysfs_remove_group(&pdev->dev.kobj, &xdata_attr_group);
+}
+
+static const struct pci_device_id dw_xdata_pcie_id_table[] = {
+ { PCI_DEVICE_DATA(SYNOPSYS, EDDA, &snps_edda_data) },
+ { }
+};
+MODULE_DEVICE_TABLE(pci, dw_xdata_pcie_id_table);
+
+static struct pci_driver dw_xdata_pcie_driver = {
+ .name = DW_XDATA_DRIVER_NAME,
+ .id_table = dw_xdata_pcie_id_table,
+ .probe = dw_xdata_pcie_probe,
+ .remove = dw_xdata_pcie_remove,
+};
+
+module_pci_driver(dw_xdata_pcie_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Synopsys DesignWare xData PCIe driver");
+MODULE_AUTHOR("Gustavo Pimentel <[email protected]>");
+
--
2.7.4

2021-02-12 17:30:52

by Gustavo Pimentel

[permalink] [raw]
Subject: [PATCH v6 3/5] Documentation: misc-devices: Add Documentation for dw-xdata-pcie driver

Add Documentation for dw-xdata-pcie driver.

Signed-off-by: Gustavo Pimentel <[email protected]>
---
Documentation/misc-devices/dw-xdata-pcie.rst | 40 ++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
create mode 100644 Documentation/misc-devices/dw-xdata-pcie.rst

diff --git a/Documentation/misc-devices/dw-xdata-pcie.rst b/Documentation/misc-devices/dw-xdata-pcie.rst
new file mode 100644
index 00000000..3d241ae
--- /dev/null
+++ b/Documentation/misc-devices/dw-xdata-pcie.rst
@@ -0,0 +1,40 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================================================================
+Driver for Synopsys DesignWare PCIe traffic generator (also known as xData)
+===========================================================================
+
+This driver should be used as a host-side (Root Complex) driver and Synopsys
+DesignWare prototype that includes this IP.
+
+The "dw-xdata-pcie" driver can be used to enable/disable PCIe traffic
+generator in either direction (mutual exclusion) besides allowing the
+PCIe link performance analysis.
+
+The interaction with this driver is done through the module parameter and
+can be changed in runtime. The driver outputs the requested command state
+information to /var/log/kern.log or dmesg.
+
+Request write TLPs traffic generation - Root Complex to Endpoint direction
+- Command:
+ echo 1 > /sys/bus/pci/drivers/dw-xdata-pcie/.../write
+
+Get write TLPs traffic link throughput in MB/s
+- Command:
+ cat /sys/bus/pci/drivers/dw-xdata-pcie/.../write
+- Output example:
+ 204
+
+Request read TLPs traffic generation - Endpoint to Root Complex direction:
+- Command:
+ echo 1 > /sys/bus/pci/drivers/dw-xdata-pcie/.../read
+
+Get read TLPs traffic link throughput in MB/s
+- Command:
+ cat /sys/bus/pci/drivers/dw-xdata-pcie/.../read
+- Output example:
+ 199
+
+Request to stop any current TLP transfer:
+- Command:
+ echo 1 > /sys/bus/pci/drivers/dw-xdata-pcie/.../stop
--
2.7.4

2021-02-12 17:30:53

by Gustavo Pimentel

[permalink] [raw]
Subject: [PATCH v6 4/5] MAINTAINERS: Add Synopsys xData IP driver maintainer

Add Synopsys xData IP driver maintainer.

This driver aims to support Synopsys xData IP and is normally distributed
along with Synopsys PCIe EndPoint IP as a PCIe traffic generator (depends
of the use and licensing agreement).

Signed-off-by: Gustavo Pimentel <[email protected]>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 546aa66..f9d681b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5061,6 +5061,13 @@ S: Maintained
F: drivers/dma/dw-edma/
F: include/linux/dma/edma.h

+DESIGNWARE XDATA IP DRIVER
+M: Gustavo Pimentel <[email protected]>
+L: [email protected]
+S: Maintained
+F: Documentation/misc-devices/dw-xdata-pcie.rst
+F: drivers/misc/dw-xdata-pcie.c
+
DESIGNWARE USB2 DRD IP DRIVER
M: Minas Harutyunyan <[email protected]>
L: [email protected]
--
2.7.4

2021-02-12 17:31:19

by Gustavo Pimentel

[permalink] [raw]
Subject: [PATCH v6 2/5] misc: Add Synopsys DesignWare xData IP driver to Makefile and Kconfig

Add Synopsys DesignWare xData IP driver to Makefile and Kconfig.

This driver enables/disables the PCIe traffic generator module
pertain to the Synopsys DesignWare prototype.

Signed-off-by: Gustavo Pimentel <[email protected]>
---
drivers/misc/Kconfig | 10 ++++++++++
drivers/misc/Makefile | 1 +
2 files changed, 11 insertions(+)

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index fafa8b0..e42b171 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -423,6 +423,16 @@ config SRAM
config SRAM_EXEC
bool

+config DW_XDATA_PCIE
+ depends on PCI
+ tristate "Synopsys DesignWare xData PCIe driver"
+ help
+ This driver allows controlling Synopsys DesignWare PCIe traffic
+ generator IP also known as xData, present in Synopsys DesignWare
+ PCIe Endpoint prototype.
+
+ If unsure, say N.
+
config PCI_ENDPOINT_TEST
depends on PCI
select CRC32
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index d23231e..bf22021 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_SRAM_EXEC) += sram-exec.o
obj-$(CONFIG_GENWQE) += genwqe/
obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_CXL_BASE) += cxl/
+obj-$(CONFIG_DW_XDATA_PCIE) += dw-xdata-pcie.o
obj-$(CONFIG_PCI_ENDPOINT_TEST) += pci_endpoint_test.o
obj-$(CONFIG_OCXL) += ocxl/
obj-y += cardreader/
--
2.7.4

2021-02-12 17:31:50

by Gustavo Pimentel

[permalink] [raw]
Subject: [PATCH v6 5/5] docs: ABI: Add sysfs documentation interface of dw-xdata-pcie driver

This patch describes the sysfs interface implemented on the dw-xdata-pcie
driver.

Signed-off-by: Gustavo Pimentel <[email protected]>
---
Documentation/ABI/testing/sysfs-driver-xdata | 46 ++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-xdata

diff --git a/Documentation/ABI/testing/sysfs-driver-xdata b/Documentation/ABI/testing/sysfs-driver-xdata
new file mode 100644
index 00000000..09d38e1
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-xdata
@@ -0,0 +1,46 @@
+What: /sys/bus/pci/drivers/dw-xdata-pcie/.../write
+Date: February 2021
+KernelVersion: 5.12
+Contact: Gustavo Pimentel <[email protected]>
+Description: Allows the user to enable the PCIe traffic generator which
+ will create write TLPs frames - from the Root Complex to the
+ Endpoint direction.
+ Usage e.g.
+ echo 1 > /sys/bus/pci/drivers/dw-xdata-pcie/.../write
+
+ The user can read the current PCIe link throughput generated
+ through this generator in MB/s.
+ Usage e.g.
+ cat /sys/bus/pci/drivers/dw-xdata-pcie/.../write
+ 204
+
+ The file is read and write.
+
+What: /sys/bus/pci/drivers/dw-xdata-pcie/.../read
+Date: February 2021
+KernelVersion: 5.12
+Contact: Gustavo Pimentel <[email protected]>
+Description: Allows the user to enable the PCIe traffic generator which
+ will create read TLPs frames - from the Endpoint to the Root
+ Complex direction.
+ Usage e.g.
+ echo 1 > /sys/bus/pci/drivers/dw-xdata-pcie/.../read
+
+ The user can read the current PCIe link throughput generated
+ through this generator in MB/s.
+ Usage e.g.
+ cat /sys/bus/pci/drivers/dw-xdata-pcie/.../read
+ 199
+
+ The file is read and write.
+
+What: /sys/bus/pci/drivers/dw-xdata-pcie/.../stop
+Date: February 2021
+KernelVersion: 5.12
+Contact: Gustavo Pimentel <[email protected]>
+Description: Allows the user to disable the PCIe traffic generator in all
+ directions.
+ Usage e.g.
+ echo 1 > /sys/bus/pci/drivers/dw-xdata-pcie/.../stop
+
+ The file is write only.
--
2.7.4

2021-03-23 13:02:38

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v6 1/5] misc: Add Synopsys DesignWare xData IP driver

On Fri, Feb 12, 2021 at 06:28:03PM +0100, Gustavo Pimentel wrote:
> +static const struct attribute_group xdata_attr_group = {
> + .attrs = default_attrs,
> + .name = DW_XDATA_DRIVER_NAME,
> +};

ATTRIBUTE_GROUPS()?

> +static int dw_xdata_pcie_probe(struct pci_dev *pdev,
> + const struct pci_device_id *pid)
> +{
> + const struct dw_xdata_pcie_data *pdata = (void *)pid->driver_data;
> + struct dw_xdata *dw;
> + u64 addr;
> + int err;
> +
> + /* Enable PCI device */
> + err = pcim_enable_device(pdev);
> + if (err) {
> + pci_err(pdev, "enabling device failed\n");
> + return err;
> + }
> +
> + /* Mapping PCI BAR regions */
> + err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar), pci_name(pdev));
> + if (err) {
> + pci_err(pdev, "xData BAR I/O remapping failed\n");
> + return err;
> + }
> +
> + pci_set_master(pdev);
> +
> + /* Allocate memory */
> + dw = devm_kzalloc(&pdev->dev, sizeof(*dw), GFP_KERNEL);
> + if (!dw)
> + return -ENOMEM;
> +
> + /* Data structure initialization */
> + mutex_init(&dw->mutex);
> +
> + dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
> + if (!dw->rg_region.vaddr)
> + return -ENOMEM;
> +
> + dw->rg_region.vaddr += pdata->rg_off;
> + dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
> + dw->rg_region.paddr += pdata->rg_off;
> + dw->rg_region.sz = pdata->rg_sz;
> +
> + dw->max_wr_len = pcie_get_mps(pdev);
> + dw->max_wr_len >>= 2;
> +
> + dw->max_rd_len = pcie_get_readrq(pdev);
> + dw->max_rd_len >>= 2;
> +
> + dw->pdev = pdev;
> +
> + writel(0x0, &(__dw_regs(dw)->RAM_addr));
> + writel(0x0, &(__dw_regs(dw)->RAM_port));
> +
> + addr = dw->rg_region.paddr + DW_XDATA_EP_MEM_OFFSET;
> + writel(lower_32_bits(addr), &(__dw_regs(dw)->addr_lsb));
> + writel(upper_32_bits(addr), &(__dw_regs(dw)->addr_msb));
> + pci_dbg(pdev, "xData: target address = 0x%.16llx\n", addr);
> +
> + pci_dbg(pdev, "xData: wr_len=%zu, rd_len=%zu\n",
> + dw->max_wr_len * 4, dw->max_rd_len * 4);
> +
> + /* Saving data structure reference */
> + pci_set_drvdata(pdev, dw);
> +
> + /* Sysfs */
> + err = sysfs_create_group(&pdev->dev.kobj, &xdata_attr_group);

You just raced with userspace and lost :(

Have the driver core properly create/remove your sysfs files, set the
default groups pointer in your driver and all will be fine.

thanks,

greg k-h

2021-03-24 11:07:44

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v6 1/5] misc: Add Synopsys DesignWare xData IP driver

On Wed, Mar 24, 2021 at 09:15:46AM +0000, Gustavo Pimentel wrote:
> Hi Greg,
>
> On Tue, Mar 23, 2021 at 13:0:4, Greg Kroah-Hartman
> <[email protected]> wrote:
>
> > On Fri, Feb 12, 2021 at 06:28:03PM +0100, Gustavo Pimentel wrote:
> > > +static const struct attribute_group xdata_attr_group = {
> > > + .attrs = default_attrs,
> > > + .name = DW_XDATA_DRIVER_NAME,
> > > +};
> >
> > ATTRIBUTE_GROUPS()?
>
> Nicely catched!
>
> >
> > > +static int dw_xdata_pcie_probe(struct pci_dev *pdev,
> > > + const struct pci_device_id *pid)
> > > +{
> > > + const struct dw_xdata_pcie_data *pdata = (void *)pid->driver_data;
> > > + struct dw_xdata *dw;
> > > + u64 addr;
> > > + int err;
> > > +
> > > + /* Enable PCI device */
> > > + err = pcim_enable_device(pdev);
> > > + if (err) {
> > > + pci_err(pdev, "enabling device failed\n");
> > > + return err;
> > > + }
> > > +
> > > + /* Mapping PCI BAR regions */
> > > + err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar), pci_name(pdev));
> > > + if (err) {
> > > + pci_err(pdev, "xData BAR I/O remapping failed\n");
> > > + return err;
> > > + }
> > > +
> > > + pci_set_master(pdev);
> > > +
> > > + /* Allocate memory */
> > > + dw = devm_kzalloc(&pdev->dev, sizeof(*dw), GFP_KERNEL);
> > > + if (!dw)
> > > + return -ENOMEM;
> > > +
> > > + /* Data structure initialization */
> > > + mutex_init(&dw->mutex);
> > > +
> > > + dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
> > > + if (!dw->rg_region.vaddr)
> > > + return -ENOMEM;
> > > +
> > > + dw->rg_region.vaddr += pdata->rg_off;
> > > + dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
> > > + dw->rg_region.paddr += pdata->rg_off;
> > > + dw->rg_region.sz = pdata->rg_sz;
> > > +
> > > + dw->max_wr_len = pcie_get_mps(pdev);
> > > + dw->max_wr_len >>= 2;
> > > +
> > > + dw->max_rd_len = pcie_get_readrq(pdev);
> > > + dw->max_rd_len >>= 2;
> > > +
> > > + dw->pdev = pdev;
> > > +
> > > + writel(0x0, &(__dw_regs(dw)->RAM_addr));
> > > + writel(0x0, &(__dw_regs(dw)->RAM_port));
> > > +
> > > + addr = dw->rg_region.paddr + DW_XDATA_EP_MEM_OFFSET;
> > > + writel(lower_32_bits(addr), &(__dw_regs(dw)->addr_lsb));
> > > + writel(upper_32_bits(addr), &(__dw_regs(dw)->addr_msb));
> > > + pci_dbg(pdev, "xData: target address = 0x%.16llx\n", addr);
> > > +
> > > + pci_dbg(pdev, "xData: wr_len=%zu, rd_len=%zu\n",
> > > + dw->max_wr_len * 4, dw->max_rd_len * 4);
> > > +
> > > + /* Saving data structure reference */
> > > + pci_set_drvdata(pdev, dw);
> > > +
> > > + /* Sysfs */
> > > + err = sysfs_create_group(&pdev->dev.kobj, &xdata_attr_group);
> >
> > You just raced with userspace and lost :(
> >
> > Have the driver core properly create/remove your sysfs files, set the
> > default groups pointer in your driver and all will be fine.
>
> I've gone around and around, searched in other drivers, but I'm not
> understanding your PoV or what I should do. Can you throw me a bone here?
> I'm starting to pull my hair off, lol

Set the dev_groups field of the struct device_driver in your pci driver
structure and all should be fine.

But wait, why are you adding attributes to a pci device and not your
"own" device? You should make a sub-device for this device-specific
things, otherwise it will be impossible to find these types of
attributes anywhere in sysfs.

> I would like to ask you about something, it's you the maintainer of misc
> drivers right?

MAINTAINERS shows this so I guess it must be true...

> After fixing this issue, does this driver have a chance to be pulled on
> 5.13?

No idea, I do not promise anything :)

thanks,

greg k-h

2021-03-25 02:07:40

by Gustavo Pimentel

[permalink] [raw]
Subject: RE: [PATCH v6 1/5] misc: Add Synopsys DesignWare xData IP driver

Hi Greg,

On Tue, Mar 23, 2021 at 13:0:4, Greg Kroah-Hartman
<[email protected]> wrote:

> On Fri, Feb 12, 2021 at 06:28:03PM +0100, Gustavo Pimentel wrote:
> > +static const struct attribute_group xdata_attr_group = {
> > + .attrs = default_attrs,
> > + .name = DW_XDATA_DRIVER_NAME,
> > +};
>
> ATTRIBUTE_GROUPS()?

Nicely catched!

>
> > +static int dw_xdata_pcie_probe(struct pci_dev *pdev,
> > + const struct pci_device_id *pid)
> > +{
> > + const struct dw_xdata_pcie_data *pdata = (void *)pid->driver_data;
> > + struct dw_xdata *dw;
> > + u64 addr;
> > + int err;
> > +
> > + /* Enable PCI device */
> > + err = pcim_enable_device(pdev);
> > + if (err) {
> > + pci_err(pdev, "enabling device failed\n");
> > + return err;
> > + }
> > +
> > + /* Mapping PCI BAR regions */
> > + err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar), pci_name(pdev));
> > + if (err) {
> > + pci_err(pdev, "xData BAR I/O remapping failed\n");
> > + return err;
> > + }
> > +
> > + pci_set_master(pdev);
> > +
> > + /* Allocate memory */
> > + dw = devm_kzalloc(&pdev->dev, sizeof(*dw), GFP_KERNEL);
> > + if (!dw)
> > + return -ENOMEM;
> > +
> > + /* Data structure initialization */
> > + mutex_init(&dw->mutex);
> > +
> > + dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
> > + if (!dw->rg_region.vaddr)
> > + return -ENOMEM;
> > +
> > + dw->rg_region.vaddr += pdata->rg_off;
> > + dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
> > + dw->rg_region.paddr += pdata->rg_off;
> > + dw->rg_region.sz = pdata->rg_sz;
> > +
> > + dw->max_wr_len = pcie_get_mps(pdev);
> > + dw->max_wr_len >>= 2;
> > +
> > + dw->max_rd_len = pcie_get_readrq(pdev);
> > + dw->max_rd_len >>= 2;
> > +
> > + dw->pdev = pdev;
> > +
> > + writel(0x0, &(__dw_regs(dw)->RAM_addr));
> > + writel(0x0, &(__dw_regs(dw)->RAM_port));
> > +
> > + addr = dw->rg_region.paddr + DW_XDATA_EP_MEM_OFFSET;
> > + writel(lower_32_bits(addr), &(__dw_regs(dw)->addr_lsb));
> > + writel(upper_32_bits(addr), &(__dw_regs(dw)->addr_msb));
> > + pci_dbg(pdev, "xData: target address = 0x%.16llx\n", addr);
> > +
> > + pci_dbg(pdev, "xData: wr_len=%zu, rd_len=%zu\n",
> > + dw->max_wr_len * 4, dw->max_rd_len * 4);
> > +
> > + /* Saving data structure reference */
> > + pci_set_drvdata(pdev, dw);
> > +
> > + /* Sysfs */
> > + err = sysfs_create_group(&pdev->dev.kobj, &xdata_attr_group);
>
> You just raced with userspace and lost :(
>
> Have the driver core properly create/remove your sysfs files, set the
> default groups pointer in your driver and all will be fine.

I've gone around and around, searched in other drivers, but I'm not
understanding your PoV or what I should do. Can you throw me a bone here?
I'm starting to pull my hair off, lol

I would like to ask you about something, it's you the maintainer of misc
drivers right?
After fixing this issue, does this driver have a chance to be pulled on
5.13?

-Gustavo

>
> thanks,
>
> greg k-h