]> git.ipfire.org Git - thirdparty/linux.git/commitdiff
PCI: dwc: Add debugfs based Error Injection support for DWC
authorShradha Todi <shradha.t@samsung.com>
Fri, 21 Feb 2025 13:15:47 +0000 (18:45 +0530)
committerKrzysztof Wilczyński <kwilczynski@kernel.org>
Thu, 6 Mar 2025 08:55:53 +0000 (08:55 +0000)
Add support to provide Error Injection interface to userspace.

This set of debug registers are part of the RAS DES feature present in
DesignWare PCIe controllers.

Signed-off-by: Shradha Todi <shradha.t@samsung.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Tested-by: Hrishikesh Deleep <hrishikesh.d@samsung.com>
Link: https://lore.kernel.org/r/20250221131548.59616-5-shradha.t@samsung.com
[kwilczynski: commit log, tidy up code comments, update documentation,
change debugfs property name from "duplicate_dllp" to "duplicate_tlp"]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Documentation/ABI/testing/debugfs-dwc-pcie
drivers/pci/controller/dwc/pcie-designware-debugfs.c

index 5b87471dfee3219757b5947ecbcc11e7b3a9746b..9a6782f256704cf7ef8f79532dce59fd987d7239 100644 (file)
@@ -11,3 +11,77 @@ Contact:     Shradha Todi <shradha.t@samsung.com>
 Description:   (RW) Write the lane number to be checked as valid or invalid.
                Read will return the status of PIPE RXVALID signal of the
                selected lane. The default selected lane is Lane0.
+
+What:          /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>
+Date:          February 2025
+Contact:       Shradha Todi <shradha.t@samsung.com>
+Description:   The "rasdes_err_inj" is a directory which can be used to inject
+               errors into the system. The possible errors that can be injected
+               are:
+
+                 1) tx_lcrc            - TLP LCRC error injection TX Path
+                 2) b16_crc_dllp       - 16b CRC error injection of ACK/NAK DLLP
+                 3) b16_crc_upd_fc     - 16b CRC error injection of Update-FC DLLP
+                 4) tx_ecrc            - TLP ECRC error injection TX Path
+                 5) fcrc_tlp           - TLP's FCRC error injection TX Path
+                 6) parity_tsos        - Parity error of TSOS
+                 7) parity_skpos       - Parity error on SKPOS
+                 8) rx_lcrc            - LCRC error injection RX Path
+                 9) rx_ecrc            - ECRC error injection RX Path
+                 10) tlp_err_seq       - TLPs SEQ# error
+                 11) ack_nak_dllp_seq  - DLLPS ACK/NAK SEQ# error
+                 12) ack_nak_dllp      - ACK/NAK DLLPs transmission block
+                 13) upd_fc_dllp       - UpdateFC DLLPs transmission block
+                 14) nak_dllp          - Always transmission for NAK DLLP
+                 15) inv_sync_hdr_sym  - Invert SYNC header
+                 16) com_pad_ts1       - COM/PAD TS1 order set
+                 17) com_pad_ts2       - COM/PAD TS2 order set
+                 18) com_fts           - COM/FTS FTS order set
+                 19) com_idl           - COM/IDL E-idle order set
+                 20) end_edb           - END/EDB symbol
+                 21) stp_sdp           - STP/SDP symbol
+                 22) com_skp           - COM/SKP SKP order set
+                 23) posted_tlp_hdr    - Posted TLP Header credit value control
+                 24) non_post_tlp_hdr  - Non-Posted TLP Header credit value control
+                 25) cmpl_tlp_hdr      - Completion TLP Header credit value control
+                 26) posted_tlp_data   - Posted TLP Data credit value control
+                 27) non_post_tlp_data - Non-Posted TLP Data credit value control
+                 28) cmpl_tlp_data     - Completion TLP Data credit value control
+                 29) duplicate_tlp     - Generates duplicate TLPs
+                 30) nullified_tlp     - Generates Nullified TLPs
+
+               (WO) Write to the attribute will prepare controller to inject
+               the respective error in the next transmission of data.
+
+               Parameter required to write will change in the following ways:
+
+               - Errors 9 and 10 are sequence errors. The write command:
+
+                   echo <count> <diff> > /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>
+
+                   <count>
+                           Number of errors to be injected
+                   <diff>
+                           The difference to add or subtract from natural
+                           sequence number to generate sequence error.
+                           Allowed range from -4095 to 4095
+
+               - Errors 23 to 28 are credit value error insertions. The write
+                 command:
+
+                   echo <count> <diff> <vc> > /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>
+
+                   <count>
+                           Number of errors to be injected
+                   <diff>
+                           The difference to add or subtract from UpdateFC
+                           credit value. Allowed range from -4095 to 4095
+                   <vc>
+                           Target VC number
+
+               - All other errors. The write command:
+
+                   echo <count> > /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>
+
+                   <count>
+                           Number of errors to be injected
index c86befa2fdb071e99b8deca4e96e41136b25c615..dc35db1cd49bb6dfeaec08cc5fe09bec6d996b24 100644 (file)
 #define PIPE_DETECT_LANE               BIT(17)
 #define LANE_SELECT                    GENMASK(3, 0)
 
+#define ERR_INJ0_OFF                   0x34
+#define EINJ_VAL_DIFF                  GENMASK(28, 16)
+#define EINJ_VC_NUM                    GENMASK(14, 12)
+#define EINJ_TYPE_SHIFT                        8
+#define EINJ0_TYPE                     GENMASK(11, 8)
+#define EINJ1_TYPE                     BIT(8)
+#define EINJ2_TYPE                     GENMASK(9, 8)
+#define EINJ3_TYPE                     GENMASK(10, 8)
+#define EINJ4_TYPE                     GENMASK(10, 8)
+#define EINJ5_TYPE                     BIT(8)
+#define EINJ_COUNT                     GENMASK(7, 0)
+
+#define ERR_INJ_ENABLE_REG             0x30
+
 #define DWC_DEBUGFS_BUF_MAX            128
 
 /**
@@ -33,6 +47,74 @@ struct dwc_pcie_rasdes_info {
        struct mutex reg_event_lock;
 };
 
+/**
+ * struct dwc_pcie_rasdes_priv - Stores file specific private data information
+ * @pci: Reference to the dw_pcie structure
+ * @idx: Index of specific file related information in array of structs
+ *
+ * All debugfs files will have this struct as its private data.
+ */
+struct dwc_pcie_rasdes_priv {
+       struct dw_pcie *pci;
+       int idx;
+};
+
+/**
+ * struct dwc_pcie_err_inj - Store details about each error injection
+ *                          supported by DWC RAS DES
+ * @name: Name of the error that can be injected
+ * @err_inj_group: Group number to which the error belongs. The value
+ *                can range from 0 to 5
+ * @err_inj_type: Each group can have multiple types of error
+ */
+struct dwc_pcie_err_inj {
+       const char *name;
+       u32 err_inj_group;
+       u32 err_inj_type;
+};
+
+static const struct dwc_pcie_err_inj err_inj_list[] = {
+       {"tx_lcrc", 0x0, 0x0},
+       {"b16_crc_dllp", 0x0, 0x1},
+       {"b16_crc_upd_fc", 0x0, 0x2},
+       {"tx_ecrc", 0x0, 0x3},
+       {"fcrc_tlp", 0x0, 0x4},
+       {"parity_tsos", 0x0, 0x5},
+       {"parity_skpos", 0x0, 0x6},
+       {"rx_lcrc", 0x0, 0x8},
+       {"rx_ecrc", 0x0, 0xb},
+       {"tlp_err_seq", 0x1, 0x0},
+       {"ack_nak_dllp_seq", 0x1, 0x1},
+       {"ack_nak_dllp", 0x2, 0x0},
+       {"upd_fc_dllp", 0x2, 0x1},
+       {"nak_dllp", 0x2, 0x2},
+       {"inv_sync_hdr_sym", 0x3, 0x0},
+       {"com_pad_ts1", 0x3, 0x1},
+       {"com_pad_ts2", 0x3, 0x2},
+       {"com_fts", 0x3, 0x3},
+       {"com_idl", 0x3, 0x4},
+       {"end_edb", 0x3, 0x5},
+       {"stp_sdp", 0x3, 0x6},
+       {"com_skp", 0x3, 0x7},
+       {"posted_tlp_hdr", 0x4, 0x0},
+       {"non_post_tlp_hdr", 0x4, 0x1},
+       {"cmpl_tlp_hdr", 0x4, 0x2},
+       {"posted_tlp_data", 0x4, 0x4},
+       {"non_post_tlp_data", 0x4, 0x5},
+       {"cmpl_tlp_data", 0x4, 0x6},
+       {"duplicate_tlp", 0x5, 0x0},
+       {"nullified_tlp", 0x5, 0x1},
+};
+
+static const u32 err_inj_type_mask[] = {
+       EINJ0_TYPE,
+       EINJ1_TYPE,
+       EINJ2_TYPE,
+       EINJ3_TYPE,
+       EINJ4_TYPE,
+       EINJ5_TYPE,
+};
+
 static ssize_t lane_detect_read(struct file *file, char __user *buf,
                                size_t count, loff_t *ppos)
 {
@@ -96,6 +178,64 @@ static ssize_t rx_valid_write(struct file *file, const char __user *buf,
        return lane_detect_write(file, buf, count, ppos);
 }
 
+static ssize_t err_inj_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, counter, vc_num, err_group, type_mask;
+       int val_diff = 0;
+       char *kern_buf;
+
+       err_group = err_inj_list[pdata->idx].err_inj_group;
+       type_mask = err_inj_type_mask[err_group];
+
+       kern_buf = memdup_user_nul(buf, count);
+       if (IS_ERR(kern_buf))
+               return PTR_ERR(kern_buf);
+
+       if (err_group == 4) {
+               val = sscanf(kern_buf, "%u %d %u", &counter, &val_diff, &vc_num);
+               if ((val != 3) || (val_diff < -4095 || val_diff > 4095)) {
+                       kfree(kern_buf);
+                       return -EINVAL;
+               }
+       } else if (err_group == 1) {
+               val = sscanf(kern_buf, "%u %d", &counter, &val_diff);
+               if ((val != 2) || (val_diff < -4095 || val_diff > 4095)) {
+                       kfree(kern_buf);
+                       return -EINVAL;
+               }
+       } else {
+               val = kstrtou32(kern_buf, 0, &counter);
+               if (val) {
+                       kfree(kern_buf);
+                       return val;
+               }
+       }
+
+       val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + ERR_INJ0_OFF + (0x4 * err_group));
+       val &= ~(type_mask | EINJ_COUNT);
+       val |= ((err_inj_list[pdata->idx].err_inj_type << EINJ_TYPE_SHIFT) & type_mask);
+       val |= FIELD_PREP(EINJ_COUNT, counter);
+
+       if (err_group == 1 || err_group == 4) {
+               val &= ~(EINJ_VAL_DIFF);
+               val |= FIELD_PREP(EINJ_VAL_DIFF, val_diff);
+       }
+       if (err_group == 4) {
+               val &= ~(EINJ_VC_NUM);
+               val |= FIELD_PREP(EINJ_VC_NUM, vc_num);
+       }
+
+       dw_pcie_writel_dbi(pci, rinfo->ras_cap_offset + ERR_INJ0_OFF + (0x4 * err_group), val);
+       dw_pcie_writel_dbi(pci, rinfo->ras_cap_offset + ERR_INJ_ENABLE_REG, (0x1 << err_group));
+
+       kfree(kern_buf);
+       return count;
+}
+
 #define dwc_debugfs_create(name)                       \
 debugfs_create_file(#name, 0644, rasdes_debug, pci,    \
                        &dbg_ ## name ## _fops)
@@ -110,6 +250,11 @@ static const struct file_operations dbg_ ## name ## _fops = {      \
 DWC_DEBUGFS_FOPS(lane_detect);
 DWC_DEBUGFS_FOPS(rx_valid);
 
+static const struct file_operations dwc_pcie_err_inj_ops = {
+       .open = simple_open,
+       .write = err_inj_write,
+};
+
 static void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci)
 {
        struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info;
@@ -119,10 +264,11 @@ 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;
+       struct dentry *rasdes_debug, *rasdes_err_inj;
        struct dwc_pcie_rasdes_info *rasdes_info;
+       struct dwc_pcie_rasdes_priv *priv_tmp;
        struct device *dev = pci->dev;
-       int ras_cap;
+       int ras_cap, i, ret;
 
        /*
         * If a given SoC has no RAS DES capability, the following call is
@@ -141,6 +287,7 @@ 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);
 
        mutex_init(&rasdes_info->reg_event_lock);
        rasdes_info->ras_cap_offset = ras_cap;
@@ -150,7 +297,24 @@ static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir)
        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) {
+                       ret = -ENOMEM;
+                       goto err_deinit;
+               }
+
+               priv_tmp->idx = i;
+               priv_tmp->pci = pci;
+               debugfs_create_file(err_inj_list[i].name, 0200, rasdes_err_inj, priv_tmp,
+                                   &dwc_pcie_err_inj_ops);
+       }
        return 0;
+
+err_deinit:
+       dwc_pcie_rasdes_debugfs_deinit(pci);
+       return ret;
 }
 
 void dwc_pcie_debugfs_deinit(struct dw_pcie *pci)