diff options
Diffstat (limited to 'drivers/misc/dw-xdata-pcie.c')
-rw-r--r-- | drivers/misc/dw-xdata-pcie.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/drivers/misc/dw-xdata-pcie.c b/drivers/misc/dw-xdata-pcie.c new file mode 100644 index 000000000..257c25da5 --- /dev/null +++ b/drivers/misc/dw-xdata-pcie.c @@ -0,0 +1,420 @@ +// 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/miscdevice.h> +#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 + +static DEFINE_IDA(xdata_ida); + +#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 */ +}; + +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; + struct miscdevice misc_dev; +}; + +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) +{ + struct device *dev = &dw->pdev->dev; + 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)) + dev_dbg(dev, "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) +{ + struct device *dev = &dw->pdev->dev; + 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); + + dev_dbg(dev, "xData: time=%llu us, %s=%llu MB/s\n", + diff, write ? "write" : "read", *rate); +} + +static struct dw_xdata *misc_dev_to_dw(struct miscdevice *misc_dev) +{ + return container_of(misc_dev, struct dw_xdata, misc_dev); +} + +static ssize_t write_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct miscdevice *misc_dev = dev_get_drvdata(dev); + struct dw_xdata *dw = misc_dev_to_dw(misc_dev); + 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 miscdevice *misc_dev = dev_get_drvdata(dev); + struct dw_xdata *dw = misc_dev_to_dw(misc_dev); + bool enabled; + int ret; + + ret = kstrtobool(buf, &enabled); + if (ret < 0) + return ret; + + if (enabled) { + dev_dbg(dev, "xData: requested write transfer\n"); + dw_xdata_start(dw, true); + } else { + dev_dbg(dev, "xData: requested stop transfer\n"); + dw_xdata_stop(dw); + } + + return size; +} + +static DEVICE_ATTR_RW(write); + +static ssize_t read_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct miscdevice *misc_dev = dev_get_drvdata(dev); + struct dw_xdata *dw = misc_dev_to_dw(misc_dev); + 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 miscdevice *misc_dev = dev_get_drvdata(dev); + struct dw_xdata *dw = misc_dev_to_dw(misc_dev); + bool enabled; + int ret; + + ret = kstrtobool(buf, &enabled); + if (ret < 0) + return ret; + + if (enabled) { + dev_dbg(dev, "xData: requested read transfer\n"); + dw_xdata_start(dw, false); + } else { + dev_dbg(dev, "xData: requested stop transfer\n"); + dw_xdata_stop(dw); + } + + return size; +} + +static DEVICE_ATTR_RW(read); + +static struct attribute *xdata_attrs[] = { + &dev_attr_write.attr, + &dev_attr_read.attr, + NULL, +}; + +ATTRIBUTE_GROUPS(xdata); + +static int dw_xdata_pcie_probe(struct pci_dev *pdev, + const struct pci_device_id *pid) +{ + struct device *dev = &pdev->dev; + struct dw_xdata *dw; + char name[24]; + u64 addr; + int err; + int id; + + /* Enable PCI device */ + err = pcim_enable_device(pdev); + if (err) { + dev_err(dev, "enabling device failed\n"); + return err; + } + + /* Mapping PCI BAR regions */ + err = pcim_iomap_regions(pdev, BIT(BAR_0), pci_name(pdev)); + if (err) { + dev_err(dev, "xData BAR I/O remapping failed\n"); + return err; + } + + pci_set_master(pdev); + + /* Allocate memory */ + dw = devm_kzalloc(dev, sizeof(*dw), GFP_KERNEL); + if (!dw) + return -ENOMEM; + + /* Data structure initialization */ + mutex_init(&dw->mutex); + + dw->rg_region.vaddr = pcim_iomap_table(pdev)[BAR_0]; + if (!dw->rg_region.vaddr) + return -ENOMEM; + + dw->rg_region.paddr = pdev->resource[BAR_0].start; + + 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; + + id = ida_simple_get(&xdata_ida, 0, 0, GFP_KERNEL); + if (id < 0) { + dev_err(dev, "xData: unable to get id\n"); + return id; + } + + snprintf(name, sizeof(name), DW_XDATA_DRIVER_NAME ".%d", id); + dw->misc_dev.name = kstrdup(name, GFP_KERNEL); + if (!dw->misc_dev.name) { + err = -ENOMEM; + goto err_ida_remove; + } + + dw->misc_dev.minor = MISC_DYNAMIC_MINOR; + dw->misc_dev.parent = dev; + dw->misc_dev.groups = xdata_groups; + + 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)); + dev_dbg(dev, "xData: target address = 0x%.16llx\n", addr); + + dev_dbg(dev, "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); + + /* Register misc device */ + err = misc_register(&dw->misc_dev); + if (err) { + dev_err(dev, "xData: failed to register device\n"); + goto err_kfree_name; + } + + return 0; + +err_kfree_name: + kfree(dw->misc_dev.name); + +err_ida_remove: + ida_simple_remove(&xdata_ida, id); + + return err; +} + +static void dw_xdata_pcie_remove(struct pci_dev *pdev) +{ + struct dw_xdata *dw = pci_get_drvdata(pdev); + int id; + + if (sscanf(dw->misc_dev.name, DW_XDATA_DRIVER_NAME ".%d", &id) != 1) + return; + + if (id < 0) + return; + + dw_xdata_stop(dw); + misc_deregister(&dw->misc_dev); + kfree(dw->misc_dev.name); + ida_simple_remove(&xdata_ida, id); +} + +static const struct pci_device_id dw_xdata_pcie_id_table[] = { + { PCI_DEVICE_DATA(SYNOPSYS, EDDA, NULL) }, + { } +}; +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>"); + |