From: Shradha Todi Date: Fri, 21 Feb 2025 13:15:48 +0000 (+0530) Subject: PCI: dwc: Add debugfs based Statistical Counter support for DWC X-Git-Tag: v6.15-rc1~119^2~11^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=27491ac2ccd7e111a9c058e7654d372cbfcdad4c;p=thirdparty%2Flinux.git PCI: dwc: Add debugfs based Statistical Counter support for DWC Add support to provide Statistical Counter interface to userspace. This set of debug registers are part of the RAS DES feature present in DesignWare PCIe controllers. Co-developed-by: Manivannan Sadhasivam Signed-off-by: Shradha Todi Reviewed-by: Manivannan Sadhasivam Tested-by: Hrishikesh Deleep Link: https://lore.kernel.org/r/20250221131548.59616-6-shradha.t@samsung.com [kwilczynski: commit log, tidy up code comments, update documentation, squashed patch that checks if the event counter is supported from https://lore.kernel.org/linux-pci/20250225171239.19574-3-manivannan.sadhasivam@linaro.org] Signed-off-by: Krzysztof Wilczyński --- diff --git a/Documentation/ABI/testing/debugfs-dwc-pcie b/Documentation/ABI/testing/debugfs-dwc-pcie index 9a6782f256704..04cefe0815127 100644 --- a/Documentation/ABI/testing/debugfs-dwc-pcie +++ b/Documentation/ABI/testing/debugfs-dwc-pcie @@ -85,3 +85,67 @@ Description: The "rasdes_err_inj" is a directory which can be used to inject Number of errors to be injected + +What: /sys/kernel/debug/dwc_pcie_/rasdes_event_counters//counter_enable +Date: February 2025 +Contact: Shradha Todi +Description: The "rasdes_event_counters" is the directory which can be used + to collect statistical data about the number of times a certain + event has occurred in the controller. The list of possible + events are: + + 1) EBUF Overflow + 2) EBUF Underrun + 3) Decode Error + 4) Running Disparity Error + 5) SKP OS Parity Error + 6) SYNC Header Error + 7) Rx Valid De-assertion + 8) CTL SKP OS Parity Error + 9) 1st Retimer Parity Error + 10) 2nd Retimer Parity Error + 11) Margin CRC and Parity Error + 12) Detect EI Infer + 13) Receiver Error + 14) RX Recovery Req + 15) N_FTS Timeout + 16) Framing Error + 17) Deskew Error + 18) Framing Error In L0 + 19) Deskew Uncompleted Error + 20) Bad TLP + 21) LCRC Error + 22) Bad DLLP + 23) Replay Number Rollover + 24) Replay Timeout + 25) Rx Nak DLLP + 26) Tx Nak DLLP + 27) Retry TLP + 28) FC Timeout + 29) Poisoned TLP + 30) ECRC Error + 31) Unsupported Request + 32) Completer Abort + 33) Completion Timeout + 34) EBUF SKP Add + 35) EBUF SKP Del + + (RW) Write 1 to enable the event counter and write 0 to disable + the event counter. Read will return whether the counter is + currently enabled or disabled. Counter is disabled by default. + +What: /sys/kernel/debug/dwc_pcie_/rasdes_event_counters//counter_value +Date: February 2025 +Contact: Shradha Todi +Description: (RO) Read will return the current value of the event counter. + To reset the counter, counter should be disabled first and then + enabled back using the "counter_enable" attribute. + +What: /sys/kernel/debug/dwc_pcie_/rasdes_event_counters//lane_select +Date: February 2025 +Contact: Shradha Todi +Description: (RW) Some lanes in the event list are lane specific events. + These include events from 1 to 11, as well as, 34 and 35. Write + the lane number for which you wish the counter to be enabled, + disabled, or value dumped. Read will return the current + selected lane number. Lane0 is selected by default. diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.c b/drivers/pci/controller/dwc/pcie-designware-debugfs.c index dc35db1cd49bb..6100a0d1c7097 100644 --- a/drivers/pci/controller/dwc/pcie-designware-debugfs.c +++ b/drivers/pci/controller/dwc/pcie-designware-debugfs.c @@ -31,6 +31,17 @@ #define ERR_INJ_ENABLE_REG 0x30 +#define RAS_DES_EVENT_COUNTER_DATA_REG 0xc + +#define RAS_DES_EVENT_COUNTER_CTRL_REG 0x8 +#define EVENT_COUNTER_GROUP_SELECT GENMASK(27, 24) +#define EVENT_COUNTER_EVENT_SELECT GENMASK(23, 16) +#define EVENT_COUNTER_LANE_SELECT GENMASK(11, 8) +#define EVENT_COUNTER_STATUS BIT(7) +#define EVENT_COUNTER_ENABLE GENMASK(4, 2) +#define PER_EVENT_ON 0x3 +#define PER_EVENT_OFF 0x1 + #define DWC_DEBUGFS_BUF_MAX 128 /** @@ -115,6 +126,63 @@ static const u32 err_inj_type_mask[] = { EINJ5_TYPE, }; +/** + * struct dwc_pcie_event_counter - Store details about each event counter + * supported in DWC RAS DES + * @name: Name of the error counter + * @group_no: Group number that the event belongs to. The value can range + * from 0 to 4 + * @event_no: Event number of the particular event. The value ranges are: + * Group 0: 0 - 10 + * Group 1: 5 - 13 + * Group 2: 0 - 7 + * Group 3: 0 - 5 + * Group 4: 0 - 1 + */ +struct dwc_pcie_event_counter { + const char *name; + u32 group_no; + u32 event_no; +}; + +static const struct dwc_pcie_event_counter event_list[] = { + {"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}, + {"rx_valid_deassertion", 0x0, 0x6}, + {"ctl_skp_os_parity_err", 0x0, 0x7}, + {"retimer_parity_err_1st", 0x0, 0x8}, + {"retimer_parity_err_2nd", 0x0, 0x9}, + {"margin_crc_parity_err", 0x0, 0xA}, + {"detect_ei_infer", 0x1, 0x5}, + {"receiver_err", 0x1, 0x6}, + {"rx_recovery_req", 0x1, 0x7}, + {"n_fts_timeout", 0x1, 0x8}, + {"framing_err", 0x1, 0x9}, + {"deskew_err", 0x1, 0xa}, + {"framing_err_in_l0", 0x1, 0xc}, + {"deskew_uncompleted_err", 0x1, 0xd}, + {"bad_tlp", 0x2, 0x0}, + {"lcrc_err", 0x2, 0x1}, + {"bad_dllp", 0x2, 0x2}, + {"replay_num_rollover", 0x2, 0x3}, + {"replay_timeout", 0x2, 0x4}, + {"rx_nak_dllp", 0x2, 0x5}, + {"tx_nak_dllp", 0x2, 0x6}, + {"retry_tlp", 0x2, 0x7}, + {"fc_timeout", 0x3, 0x0}, + {"poisoned_tlp", 0x3, 0x1}, + {"ecrc_error", 0x3, 0x2}, + {"unsupported_request", 0x3, 0x3}, + {"completer_abort", 0x3, 0x4}, + {"completion_timeout", 0x3, 0x5}, + {"ebuf_skp_add", 0x4, 0x0}, + {"ebuf_skp_del", 0x4, 0x1}, +}; + static ssize_t lane_detect_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { @@ -236,6 +304,145 @@ static ssize_t err_inj_write(struct file *file, const char __user *buf, return count; } +static void set_event_number(struct dwc_pcie_rasdes_priv *pdata, + struct dw_pcie *pci, struct dwc_pcie_rasdes_info *rinfo) +{ + u32 val; + + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG); + val &= ~EVENT_COUNTER_ENABLE; + val &= ~(EVENT_COUNTER_GROUP_SELECT | EVENT_COUNTER_EVENT_SELECT); + val |= FIELD_PREP(EVENT_COUNTER_GROUP_SELECT, event_list[pdata->idx].group_no); + val |= FIELD_PREP(EVENT_COUNTER_EVENT_SELECT, event_list[pdata->idx].event_no); + dw_pcie_writel_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG, val); +} + +static ssize_t counter_enable_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dwc_pcie_rasdes_priv *pdata = file->private_data; + struct dw_pcie *pci = pdata->pci; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + char debugfs_buf[DWC_DEBUGFS_BUF_MAX]; + ssize_t pos; + u32 val; + + mutex_lock(&rinfo->reg_event_lock); + set_event_number(pdata, pci, rinfo); + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG); + mutex_unlock(&rinfo->reg_event_lock); + val = FIELD_GET(EVENT_COUNTER_STATUS, val); + if (val) + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "Counter Enabled\n"); + else + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "Counter Disabled\n"); + + return simple_read_from_buffer(buf, count, ppos, debugfs_buf, pos); +} + +static ssize_t counter_enable_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct dwc_pcie_rasdes_priv *pdata = file->private_data; + struct dw_pcie *pci = pdata->pci; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + u32 val, enable; + + val = kstrtou32_from_user(buf, count, 0, &enable); + if (val) + return val; + + mutex_lock(&rinfo->reg_event_lock); + set_event_number(pdata, pci, rinfo); + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG); + if (enable) + val |= FIELD_PREP(EVENT_COUNTER_ENABLE, PER_EVENT_ON); + else + val |= FIELD_PREP(EVENT_COUNTER_ENABLE, PER_EVENT_OFF); + + dw_pcie_writel_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG, val); + + /* + * While enabling the counter, always read the status back to check if + * it is enabled or not. Return error if it is not enabled to let the + * users know that the counter is not supported on the platform. + */ + if (enable) { + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + + RAS_DES_EVENT_COUNTER_CTRL_REG); + if (!FIELD_GET(EVENT_COUNTER_STATUS, val)) { + mutex_unlock(&rinfo->reg_event_lock); + return -EOPNOTSUPP; + } + } + + mutex_unlock(&rinfo->reg_event_lock); + + return count; +} + +static ssize_t counter_lane_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dwc_pcie_rasdes_priv *pdata = file->private_data; + struct dw_pcie *pci = pdata->pci; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + char debugfs_buf[DWC_DEBUGFS_BUF_MAX]; + ssize_t pos; + u32 val; + + mutex_lock(&rinfo->reg_event_lock); + set_event_number(pdata, pci, rinfo); + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG); + mutex_unlock(&rinfo->reg_event_lock); + val = FIELD_GET(EVENT_COUNTER_LANE_SELECT, val); + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "Lane: %d\n", val); + + return simple_read_from_buffer(buf, count, ppos, debugfs_buf, pos); +} + +static ssize_t counter_lane_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct dwc_pcie_rasdes_priv *pdata = file->private_data; + struct dw_pcie *pci = pdata->pci; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + u32 val, lane; + + val = kstrtou32_from_user(buf, count, 0, &lane); + if (val) + return val; + + mutex_lock(&rinfo->reg_event_lock); + set_event_number(pdata, pci, rinfo); + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG); + val &= ~(EVENT_COUNTER_LANE_SELECT); + val |= FIELD_PREP(EVENT_COUNTER_LANE_SELECT, lane); + dw_pcie_writel_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_CTRL_REG, val); + mutex_unlock(&rinfo->reg_event_lock); + + return count; +} + +static ssize_t counter_value_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dwc_pcie_rasdes_priv *pdata = file->private_data; + struct dw_pcie *pci = pdata->pci; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + char debugfs_buf[DWC_DEBUGFS_BUF_MAX]; + ssize_t pos; + u32 val; + + mutex_lock(&rinfo->reg_event_lock); + set_event_number(pdata, pci, rinfo); + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + RAS_DES_EVENT_COUNTER_DATA_REG); + mutex_unlock(&rinfo->reg_event_lock); + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "Counter value: %d\n", val); + + return simple_read_from_buffer(buf, count, ppos, debugfs_buf, pos); +} + #define dwc_debugfs_create(name) \ debugfs_create_file(#name, 0644, rasdes_debug, pci, \ &dbg_ ## name ## _fops) @@ -255,6 +462,23 @@ static const struct file_operations dwc_pcie_err_inj_ops = { .write = err_inj_write, }; +static const struct file_operations dwc_pcie_counter_enable_ops = { + .open = simple_open, + .read = counter_enable_read, + .write = counter_enable_write, +}; + +static const struct file_operations dwc_pcie_counter_lane_ops = { + .open = simple_open, + .read = counter_lane_read, + .write = counter_lane_write, +}; + +static const struct file_operations dwc_pcie_counter_value_ops = { + .open = simple_open, + .read = counter_value_read, +}; + static void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci) { struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; @@ -265,6 +489,7 @@ static void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci) static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir) { struct dentry *rasdes_debug, *rasdes_err_inj; + struct dentry *rasdes_event_counter, *rasdes_events; struct dwc_pcie_rasdes_info *rasdes_info; struct dwc_pcie_rasdes_priv *priv_tmp; struct device *dev = pci->dev; @@ -288,6 +513,7 @@ static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir) /* 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(&rasdes_info->reg_event_lock); rasdes_info->ras_cap_offset = ras_cap; @@ -310,6 +536,28 @@ static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir) debugfs_create_file(err_inj_list[i].name, 0200, rasdes_err_inj, priv_tmp, &dwc_pcie_err_inj_ops); } + + /* Create debugfs files for Statistical Counter subdirectory. */ + for (i = 0; i < ARRAY_SIZE(event_list); i++) { + priv_tmp = devm_kzalloc(dev, sizeof(*priv_tmp), GFP_KERNEL); + if (!priv_tmp) { + ret = -ENOMEM; + goto err_deinit; + } + + priv_tmp->idx = i; + priv_tmp->pci = pci; + rasdes_events = debugfs_create_dir(event_list[i].name, rasdes_event_counter); + if (event_list[i].group_no == 0 || event_list[i].group_no == 4) { + debugfs_create_file("lane_select", 0644, rasdes_events, + priv_tmp, &dwc_pcie_counter_lane_ops); + } + debugfs_create_file("counter_value", 0444, rasdes_events, priv_tmp, + &dwc_pcie_counter_value_ops); + debugfs_create_file("counter_enable", 0644, rasdes_events, priv_tmp, + &dwc_pcie_counter_enable_ops); + } + return 0; err_deinit: