@@ -6,6 +6,14 @@ menu "DesignWare-based PCIe controllers"
config PCIE_DW
bool
+config PCIE_DW_DEBUGFS
+ bool "DWC PCIe debugfs entries"
+ help
+ Enables debugfs entries for the DWC PCIe Controller.
+ These entries make use of the RAS features in the DW
+ controller to help in debug, error injection and statistical
+ counters
+
config PCIE_DW_HOST
bool
select PCIE_DW
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_PCIE_DW) += pcie-designware.o
+obj-$(CONFIG_PCIE_DW_DEBUGFS) += pcie-designware-debugfs.o
obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o
obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
new file mode 100644
@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Synopsys DesignWare PCIe controller debugfs driver
+ *
+ * Copyright (C) 2023 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * Author: Shradha Todi <shradha.t@samsung.com>
+ */
+
+#include <linux/debugfs.h>
+
+#include "pcie-designware.h"
+
+#define RAS_DES_EVENT_COUNTER_CTRL_REG 0x8
+#define RAS_DES_EVENT_COUNTER_DATA_REG 0xc
+#define SD_STATUS_L1LANE_REG 0xb0
+#define ERR_INJ_ENABLE_REG 0x30
+#define ERR_INJ0_OFF 0x34
+
+#define LANE_DETECT_SHIFT 17
+#define LANE_DETECT_MASK 0x1
+#define PIPE_RXVALID_SHIFT 18
+#define PIPE_RXVALID_MASK 0x1
+
+#define LANE_SELECT_SHIFT 8
+#define LANE_SELECT_MASK 0xf
+#define EVENT_COUNTER_STATUS_SHIFT 7
+#define EVENT_COUNTER_STATUS_MASK 0x1
+#define EVENT_COUNTER_ENABLE (0x7 << 2)
+#define PER_EVENT_OFF (0x1 << 2)
+#define PER_EVENT_ON (0x3 << 2)
+
+#define EINJ_COUNT_MASK 0xff
+#define EINJ_TYPE_MASK 0xf
+#define EINJ_TYPE_SHIFT 8
+#define EINJ_INFO_MASK 0xfffff
+#define EINJ_INFO_SHIFT 12
+
+#define DWC_DEBUGFS_MAX 128
+
+struct rasdes_info {
+ /* to store rasdes capability offset */
+ u32 ras_cap;
+ struct mutex dbg_mutex;
+ struct dentry *rasdes;
+};
+
+struct rasdes_priv {
+ struct dw_pcie *pci;
+ int idx;
+};
+
+struct event_counter {
+ const char *name;
+ /* values can be between 0-15 */
+ u32 group_no;
+ /* values can be between 0-32 */
+ u32 event_no;
+};
+
+static const struct event_counter event_counters[] = {
+ {"ebuf_overflow", 0x0, 0x0},
+ {"ebuf_underrun", 0x0, 0x1},
+ {"decode_err", 0x0, 0x2},
+ {"running_disparity_err", 0x0, 0x3},
+ {"skp_os_parity_err", 0x0, 0x4},
+ {"sync_header_err", 0x0, 0x5},
+ {"detect_ei_infer", 0x1, 0x5},
+ {"receiver_err", 0x1, 0x6},
+ {"rx_recovery_req", 0x1, 0x7},
+ {"framing_err", 0x1, 0x9},
+ {"deskew_err", 0x1, 0xa},
+ {"bad_tlp", 0x2, 0x0},
+ {"lcrc_err", 0x2, 0x1},
+ {"bad_dllp", 0x2, 0x2},
+};
+
+struct err_inj {
+ const char *name;
+ /* values can be from group 0 - 6 */
+ u32 err_inj_group;
+ /* within each group there can be types */
+ u32 err_inj_type;
+ /* More details about the error */
+ u32 err_inj_12_31;
+};
+
+static const struct err_inj err_inj_list[] = {
+ {"tx_lcrc", 0x0, 0x0, 0x0},
+ {"tx_ecrc", 0x0, 0x3, 0x0},
+ {"rx_lcrc", 0x0, 0x8, 0x0},
+ {"rx_ecrc", 0x0, 0xb, 0x0},
+};
+
+static ssize_t dbg_lane_detect_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct dw_pcie *pci = file->private_data;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ ssize_t off = 0;
+ char debugfs_buf[DWC_DEBUGFS_MAX];
+
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap + SD_STATUS_L1LANE_REG);
+ val = (val >> LANE_DETECT_SHIFT) & LANE_DETECT_MASK;
+ if (val)
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Detected\n");
+ else
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Undetected\n");
+
+ return simple_read_from_buffer(buf, count, ppos, debugfs_buf, off);
+}
+
+static ssize_t dbg_lane_detect_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct dw_pcie *pci = file->private_data;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ u32 lane;
+
+ val = kstrtou32_from_user(buf, count, 0, &lane);
+ if (val)
+ return val;
+
+ if (lane > 15)
+ return -EINVAL;
+
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap + SD_STATUS_L1LANE_REG);
+ val &= ~LANE_SELECT_MASK;
+ val |= lane;
+ dw_pcie_writel_dbi(pci, rinfo->ras_cap + SD_STATUS_L1LANE_REG, val);
+
+ return count;
+}
+
+static ssize_t dbg_rx_valid_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct dw_pcie *pci = file->private_data;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ ssize_t off = 0;
+ char debugfs_buf[DWC_DEBUGFS_MAX];
+
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap + SD_STATUS_L1LANE_REG);
+ val = (val >> PIPE_RXVALID_SHIFT) & PIPE_RXVALID_MASK;
+ if (val)
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Valid\n");
+ else
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Invalid\n");
+
+ return simple_read_from_buffer(buf, count, ppos, debugfs_buf, off);
+}
+
+static ssize_t dbg_rx_valid_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return dbg_lane_detect_write(file, buf, count, ppos);
+}
+
+static void set_event_number(struct rasdes_priv *pdata, struct dw_pcie *pci,
+ struct rasdes_info *rinfo)
+{
+ u32 val;
+
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG);
+ val &= ~EVENT_COUNTER_ENABLE;
+ val &= ~(0xFFF << 16);
+ val |= (event_counters[pdata->idx].group_no << 24);
+ val |= (event_counters[pdata->idx].event_no << 16);
+ dw_pcie_writel_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG, val);
+}
+
+static ssize_t cnt_en_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ ssize_t off = 0;
+ char debugfs_buf[DWC_DEBUGFS_MAX];
+
+ mutex_lock(&rinfo->dbg_mutex);
+ set_event_number(pdata, pci, rinfo);
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG);
+ mutex_unlock(&rinfo->dbg_mutex);
+ val = (val >> EVENT_COUNTER_STATUS_SHIFT) & EVENT_COUNTER_STATUS_MASK;
+ if (val)
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Enabled\n");
+ else
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Disabled\n");
+
+ return simple_read_from_buffer(buf, count, ppos, debugfs_buf, off);
+}
+
+static ssize_t cnt_en_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ u32 enable;
+
+ val = kstrtou32_from_user(buf, count, 0, &enable);
+ if (val)
+ return val;
+
+ mutex_lock(&rinfo->dbg_mutex);
+ set_event_number(pdata, pci, rinfo);
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG);
+ if (enable)
+ val |= PER_EVENT_ON;
+ else
+ val |= PER_EVENT_OFF;
+
+ dw_pcie_writel_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG, val);
+ mutex_unlock(&rinfo->dbg_mutex);
+
+ return count;
+}
+
+static ssize_t cnt_lane_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ ssize_t off = 0;
+ char debugfs_buf[DWC_DEBUGFS_MAX];
+
+ mutex_lock(&rinfo->dbg_mutex);
+ set_event_number(pdata, pci, rinfo);
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG);
+ mutex_unlock(&rinfo->dbg_mutex);
+ val = (val >> LANE_SELECT_SHIFT) & LANE_SELECT_MASK;
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Lane: %d\n", val);
+
+ return simple_read_from_buffer(buf, count, ppos, debugfs_buf, off);
+}
+
+static ssize_t cnt_lane_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ u32 lane;
+
+ val = kstrtou32_from_user(buf, count, 0, &lane);
+ if (val)
+ return val;
+
+ if (lane > 15)
+ return -EINVAL;
+
+ mutex_lock(&rinfo->dbg_mutex);
+ set_event_number(pdata, pci, rinfo);
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG);
+ val &= ~(LANE_SELECT_MASK << LANE_SELECT_SHIFT);
+ val |= (lane << LANE_SELECT_SHIFT);
+ dw_pcie_writel_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_CTRL_REG, val);
+ mutex_unlock(&rinfo->dbg_mutex);
+
+ return count;
+}
+
+static ssize_t cnt_val_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ ssize_t off = 0;
+ char debugfs_buf[DWC_DEBUGFS_MAX];
+
+ mutex_lock(&rinfo->dbg_mutex);
+ set_event_number(pdata, pci, rinfo);
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap +
+ RAS_DES_EVENT_COUNTER_DATA_REG);
+ mutex_unlock(&rinfo->dbg_mutex);
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Value: %d\n", val);
+
+ return simple_read_from_buffer(buf, count, ppos, debugfs_buf, off);
+}
+
+static ssize_t err_inj_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ ssize_t off = 0;
+ char debugfs_buf[DWC_DEBUGFS_MAX];
+
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap + ERR_INJ0_OFF +
+ (0x4 * err_inj_list[pdata->idx].err_inj_group));
+ val &= EINJ_COUNT_MASK;
+ off += scnprintf(debugfs_buf, DWC_DEBUGFS_MAX - off,
+ "Count: %d\n", val);
+
+ return simple_read_from_buffer(buf, count, ppos, debugfs_buf, off);
+}
+
+static ssize_t err_inj_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct rasdes_priv *pdata = file->private_data;
+ struct dw_pcie *pci = pdata->pci;
+ struct rasdes_info *rinfo = pci->dump_info;
+ u32 val;
+ u32 counter;
+
+ val = kstrtou32_from_user(buf, count, 0, &counter);
+ if (val)
+ return val;
+
+ val = dw_pcie_readl_dbi(pci, rinfo->ras_cap + ERR_INJ0_OFF +
+ (0x4 * err_inj_list[pdata->idx].err_inj_group));
+ val &= ~(EINJ_TYPE_MASK << EINJ_TYPE_SHIFT);
+ val |= err_inj_list[pdata->idx].err_inj_type << EINJ_TYPE_SHIFT;
+ val &= ~(EINJ_INFO_MASK << EINJ_INFO_SHIFT);
+ val |= err_inj_list[pdata->idx].err_inj_12_31 << EINJ_INFO_SHIFT;
+ val &= ~EINJ_COUNT_MASK;
+ val |= counter;
+ dw_pcie_writel_dbi(pci, rinfo->ras_cap + ERR_INJ0_OFF +
+ (0x4 * err_inj_list[pdata->idx].err_inj_group), val);
+ dw_pcie_writel_dbi(pci, rinfo->ras_cap + ERR_INJ_ENABLE_REG,
+ (0x1 << err_inj_list[pdata->idx].err_inj_group));
+
+ return count;
+}
+
+#define dwc_debugfs_create(name) \
+debugfs_create_file(#name, 0644, rasdes_debug, pci, \
+ &dbg_ ## name ## _fops)
+
+#define DWC_DEBUGFS_FOPS(name) \
+static const struct file_operations dbg_ ## name ## _fops = { \
+ .read = dbg_ ## name ## _read, \
+ .write = dbg_ ## name ## _write \
+}
+
+DWC_DEBUGFS_FOPS(lane_detect);
+DWC_DEBUGFS_FOPS(rx_valid);
+
+static const struct file_operations cnt_en_ops = {
+ .open = simple_open,
+ .read = cnt_en_read,
+ .write = cnt_en_write,
+};
+
+static const struct file_operations cnt_lane_ops = {
+ .open = simple_open,
+ .read = cnt_lane_read,
+ .write = cnt_lane_write,
+};
+
+static const struct file_operations cnt_val_ops = {
+ .open = simple_open,
+ .read = cnt_val_read,
+};
+
+static const struct file_operations err_inj_ops = {
+ .open = simple_open,
+ .read = err_inj_read,
+ .write = err_inj_write,
+};
+
+void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci)
+{
+ struct rasdes_info *rinfo = pci->dump_info;
+
+ debugfs_remove_recursive(rinfo->rasdes);
+ mutex_destroy(&rinfo->dbg_mutex);
+}
+
+int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci)
+{
+ struct device *dev = pci->dev;
+ int ras_cap;
+ struct rasdes_info *dump_info;
+ char dirname[DWC_DEBUGFS_MAX];
+ struct dentry *dir, *rasdes_debug, *rasdes_err_inj;
+ struct dentry *rasdes_event_counter, *rasdes_events;
+ int i;
+ struct rasdes_priv *priv_tmp;
+
+ ras_cap = dw_pcie_find_vsec_capability(pci, DW_PCIE_RAS_DES_CAP);
+ if (!ras_cap) {
+ dev_err(dev, "No RASDES capability available\n");
+ return -ENODEV;
+ }
+
+ dump_info = devm_kzalloc(dev, sizeof(*dump_info), GFP_KERNEL);
+ if (!dump_info)
+ return -ENOMEM;
+
+ /* Create main directory for each platform driver */
+ sprintf(dirname, "pcie_dwc_%s", dev_name(dev));
+ dir = debugfs_create_dir(dirname, NULL);
+
+ /* Create subdirectories for Debug, Error injection, Statistics */
+ rasdes_debug = debugfs_create_dir("rasdes_debug", dir);
+ rasdes_err_inj = debugfs_create_dir("rasdes_err_inj", dir);
+ rasdes_event_counter = debugfs_create_dir("rasdes_event_counter", dir);
+
+ mutex_init(&dump_info->dbg_mutex);
+ dump_info->ras_cap = ras_cap;
+ dump_info->rasdes = dir;
+ pci->dump_info = dump_info;
+
+ /* Create debugfs files for Debug subdirectory */
+ dwc_debugfs_create(lane_detect);
+ dwc_debugfs_create(rx_valid);
+
+ /* Create debugfs files for Error injection subdirectory */
+ for (i = 0; i < ARRAY_SIZE(err_inj_list); i++) {
+ priv_tmp = devm_kzalloc(dev, sizeof(*priv_tmp), GFP_KERNEL);
+ if (!priv_tmp)
+ goto err;
+
+ priv_tmp->idx = i;
+ priv_tmp->pci = pci;
+ debugfs_create_file(err_inj_list[i].name, 0644,
+ rasdes_err_inj, priv_tmp, &err_inj_ops);
+ }
+
+ /* Create debugfs files for Statistical counter subdirectory */
+ for (i = 0; i < ARRAY_SIZE(event_counters); i++) {
+ priv_tmp = devm_kzalloc(dev, sizeof(*priv_tmp), GFP_KERNEL);
+ if (!priv_tmp)
+ goto err;
+
+ priv_tmp->idx = i;
+ priv_tmp->pci = pci;
+ rasdes_events = debugfs_create_dir(event_counters[i].name,
+ rasdes_event_counter);
+ if (event_counters[i].group_no == 0) {
+ debugfs_create_file("lane_select", 0644, rasdes_events,
+ priv_tmp, &cnt_lane_ops);
+ }
+ debugfs_create_file("counter_value", 0644, rasdes_events, priv_tmp,
+ &cnt_val_ops);
+ debugfs_create_file("counter_enable", 0444, rasdes_events, priv_tmp,
+ &cnt_en_ops);
+ }
+
+ return 0;
+err:
+ dwc_pcie_rasdes_debugfs_deinit(pci);
+ return -ENOMEM;
+}
new file mode 100644
@@ -222,6 +222,8 @@
#define PCIE_RAS_DES_EVENT_COUNTER_DATA 0xc
+#define DW_PCIE_RAS_DES_CAP 0x2
+
/*
* The default address offset between dbi_base and atu_base. Root controller
* drivers are not required to initialize atu_base if the offset matches this
@@ -406,6 +408,7 @@ struct dw_pcie {
struct reset_control_bulk_data core_rsts[DW_PCIE_NUM_CORE_RSTS];
struct gpio_desc *pe_rst;
bool suspended;
+ void *dump_info;
};
#define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
@@ -643,4 +646,18 @@ dw_pcie_ep_get_func_from_ep(struct dw_pcie_ep *ep, u8 func_no)
return NULL;
}
#endif
+
+#ifdef CONFIG_PCIE_DW_DEBUGFS
+int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci);
+void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci);
+#else
+static inline int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci)
+{
+ return 0;
+}
+static inline void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci)
+{
+}
+#endif
+
#endif /* _PCIE_DESIGNWARE_H */
Add support to use the RASDES feature of DesignWare PCIe controller using debugfs entries. RASDES is a vendor specific extended PCIe capability which reads the current hardware internal state of PCIe device. Following primary features are provided to userspace via debugfs: - Debug registers - Error injection - Statistical counters Signed-off-by: Shradha Todi <shradha.t@samsung.com> --- drivers/pci/controller/dwc/Kconfig | 8 + drivers/pci/controller/dwc/Makefile | 1 + .../controller/dwc/pcie-designware-debugfs.c | 476 ++++++++++++++++++ .../controller/dwc/pcie-designware-debugfs.h | 0 drivers/pci/controller/dwc/pcie-designware.h | 17 + 5 files changed, 502 insertions(+) create mode 100644 drivers/pci/controller/dwc/pcie-designware-debugfs.c create mode 100644 drivers/pci/controller/dwc/pcie-designware-debugfs.h