[RESEND v4 1/6] misc: Add Synopsys DesignWare xData IP driver

Gustavo Pimentel
2021-02-03T22:14:14Z

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 <gustavo.pimentel@synopsys.com>
---
drivers/misc/dw-xdata-pcie.c | 378 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 378 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..3e1bc35
--- /dev/null
+++ b/drivers/misc/dw-xdata-pcie.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Synopsys, Inc. and/or its affiliates.
+ * Synopsys DesignWare xData driver
+ *
+ * Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
+ */
+
+#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)
+
+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 = readl(&(__dw_regs(dw)->burst_cnt));
+
+ if (burst & BIT(31)) {
+ burst &= ~(u32)BIT(31);
+ writel(burst, &(__dw_regs(dw)->burst_cnt));
+ }
+}
+
+static void dw_xdata_start(struct dw_xdata *dw, bool write)
+{
+ u32 control, status;
+
+ /* Stop first if xfer in progress */
+ dw_xdata_stop(dw);
+
+ /* Clear status register */
+ writel(0x0, &(__dw_regs(dw)->status));
+
+ /* Burst count register set for continuous until stopped */
+ writel(0x80001001, &(__dw_regs(dw)->burst_cnt));
+
+ /* Pattern register */
+ writel(0x0, &(__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));
+
+ usleep_range(100, 150);
+
+ status = readl(&(__dw_regs(dw)->status));
+ 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;
+
+ /* First measurement */
+ 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));
+
+ /* Delay 100ms */
+ mdelay(100);
+
+ /* Second measurement */
+ 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));
+
+ /* Calculations */
+ diff = jiffies_to_nsecs(time[1] - time[0]);
+ *rate = dw_xdata_perf_diff(&data[1], &data[0], diff);
+
+ 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;
+
+ mutex_lock(&dw->mutex);
+ dw_xdata_perf(dw, &rate, true);
+ mutex_unlock(&dw->mutex);
+
+ return sysfs_emit(buf, "%llu MB/s\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");
+
+ mutex_lock(&dw->mutex);
+ dw_xdata_start(dw, true);
+ mutex_unlock(&dw->mutex);
+
+ 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;
+
+ mutex_lock(&dw->mutex);
+ dw_xdata_perf(dw, &rate, false);
+ mutex_unlock(&dw->mutex);
+
+ return sysfs_emit(buf, "%llu MB/s\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");
+
+ mutex_lock(&dw->mutex);
+ dw_xdata_start(dw, false);
+ mutex_unlock(&dw->mutex);
+
+ 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");
+
+ mutex_lock(&dw->mutex);
+ dw_xdata_stop(dw);
+ mutex_unlock(&dw->mutex);
+
+ 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 err;
+
+ err = sysfs_create_link(kernel_kobj, &pdev->dev.kobj,
+ DW_XDATA_DRIVER_NAME);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+static void dw_xdata_pcie_remove(struct pci_dev *pdev)
+{
+ struct dw_xdata *dw = pci_get_drvdata(pdev);
+
+ if (dw) {
+ mutex_lock(&dw->mutex);
+ dw_xdata_stop(dw);
+ mutex_unlock(&dw->mutex);
+ }
+
+ sysfs_remove_link(kernel_kobj, DW_XDATA_DRIVER_NAME);
+ 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 <gustavo.pimentel@synopsys.com>");
+
--
2.7.4