diff mbox series

[v3] PCI: dwc: Add the debugfs property to provide the LTSSM status of the PCIe link

Message ID 20250214144618.176028-1-18255117159@163.com (mailing list archive)
State New
Delegated to: Krzysztof WilczyƄski
Headers show
Series [v3] PCI: dwc: Add the debugfs property to provide the LTSSM status of the PCIe link | expand

Commit Message

Hans Zhang Feb. 14, 2025, 2:46 p.m. UTC
Add the debugfs property to provide a view of the current link's LTSSM
status from the root port device.

  /sys/kernel/debug/dwc_pcie_<dev>/ltssm_status

Signed-off-by: Hans Zhang <18255117159@163.com>
---
Changes since v2:
https://lore.kernel.org/linux-pci/20250206151343.26779-1-18255117159@163.com/

- Git pulls the latest code and fixes conflicts.
- Do not place into sysfs node as recommended by maintainer. Shradha-based patch
  is put into debugfs.
- Submissions based on the following v6 patches:
https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-2-shradha.t@samsung.com/
https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-3-shradha.t@samsung.com/
https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-4-shradha.t@samsung.com/
https://patchwork.kernel.org/project/linux-pci/patch/20250214105007.97582-5-shradha.t@samsung.com/

Changes since v1:
https://lore.kernel.org/linux-pci/20250123071326.1810751-1-18255117159@163.com/

- Do not place into sysfs node as recommended by maintainer. Shradha-based patch
  is put into debugfs.
- Submissions based on the following v5 patches:
https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-2-shradha.t@samsung.com/
https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-3-shradha.t@samsung.com/
https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-4-shradha.t@samsung.com/
https://patchwork.kernel.org/project/linux-pci/patch/20250121111421.35437-5-shradha.t@samsung.com/
---
 Documentation/ABI/testing/debugfs-dwc-pcie    |  6 +++
 .../controller/dwc/pcie-designware-debugfs.c  | 29 +++++++++++
 .../pci/controller/dwc/pcie-designware-host.c | 50 +++++++++++++++++++
 drivers/pci/controller/dwc/pcie-designware.h  | 33 ++++++++++++
 4 files changed, 118 insertions(+)


base-commit: 128c8f96eb8638c060cd3532dc394d046ce64fe1
prerequisite-patch-id: 6e5987e85df22c4d3859d21765617055faca96a1
prerequisite-patch-id: 6f9e6fb15185f106699860f3cefca108556a9baa
prerequisite-patch-id: 55d4df789f48ddbddb11b05b6bb4251dc0001d3d
prerequisite-patch-id: 753a18e3a3d8499f99e735ecf3ed1fb2c3bc4a4a

Comments

Niklas Cassel Feb. 19, 2025, 5:45 p.m. UTC | #1
On Fri, Feb 14, 2025 at 10:46:18PM +0800, Hans Zhang wrote:
> Add the debugfs property to provide a view of the current link's LTSSM
> status from the root port device.
> 
>   /sys/kernel/debug/dwc_pcie_<dev>/ltssm_status
> 
> Signed-off-by: Hans Zhang <18255117159@163.com>
> ---

FWIW:
Tested-by: Niklas Cassel <cassel@kernel.org>
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/debugfs-dwc-pcie b/Documentation/ABI/testing/debugfs-dwc-pcie
index 01aa9d3a00c6..d52e84413f59 100644
--- a/Documentation/ABI/testing/debugfs-dwc-pcie
+++ b/Documentation/ABI/testing/debugfs-dwc-pcie
@@ -142,3 +142,9 @@  Description:	(RW) Some lanes in the event list are lane specific events. These i
 		events 1) - 11) and 34) - 35).
 		Write lane number for which counter needs to be enabled/disabled/dumped.
 		Read will return the current selected lane number. Lane0 is selected by default.
+
+What:		/sys/kernel/debug/dwc_pcie_<dev>/ltssm_status
+Date:		February 2025
+Contact:	Hans Zhang <18255117159@163.com>
+Description:	(RO) Read will return the current value of the PCIe link status raw value and
+		string status.
diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.c b/drivers/pci/controller/dwc/pcie-designware-debugfs.c
index 2087185a1968..581432c2b832 100644
--- a/drivers/pci/controller/dwc/pcie-designware-debugfs.c
+++ b/drivers/pci/controller/dwc/pcie-designware-debugfs.c
@@ -561,6 +561,33 @@  static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir)
 	return ret;
 }
 
+static int dwc_pcie_ltssm_status_show(struct seq_file *s, void *v)
+{
+	struct dw_pcie *pci = s->private;
+	enum dw_pcie_ltssm val;
+
+	val = dw_pcie_get_ltssm(pci);
+	seq_printf(s, "%s (0x%02x)\n", dw_ltssm_sts_string(val), val);
+
+	return 0;
+}
+
+static int dwc_pcie_ltssm_status_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dwc_pcie_ltssm_status_show, inode->i_private);
+}
+
+static const struct file_operations dwc_pcie_ltssm_status_ops = {
+	.open = dwc_pcie_ltssm_status_open,
+	.read = seq_read,
+};
+
+static void dwc_pcie_ltssm_debugfs_init(struct dw_pcie *pci, struct dentry *dir)
+{
+	debugfs_create_file("ltssm_status", 0444, dir, pci,
+			    &dwc_pcie_ltssm_status_ops);
+}
+
 void dwc_pcie_debugfs_deinit(struct dw_pcie *pci)
 {
 	dwc_pcie_rasdes_debugfs_deinit(pci);
@@ -591,5 +618,7 @@  int dwc_pcie_debugfs_init(struct dw_pcie *pci)
 	if (ret)
 		dev_dbg(dev, "rasdes debugfs init failed\n");
 
+	dwc_pcie_ltssm_debugfs_init(pci, dir);
+
 	return 0;
 }
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index fa30b745d4ae..3f23996b06da 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -418,6 +418,56 @@  static void dw_pcie_host_request_msg_tlp_res(struct dw_pcie_rp *pp)
 	}
 }
 
+char *dw_ltssm_sts_string(enum dw_pcie_ltssm ltssm)
+{
+	char *str;
+
+	switch (ltssm) {
+#define DW_PCIE_LTSSM_NAME(n) case n: str = #n; break
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DETECT_QUIET);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DETECT_ACT);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_POLL_ACTIVE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_POLL_COMPLIANCE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_POLL_CONFIG);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_PRE_DETECT_QUIET);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DETECT_WAIT);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LINKWD_START);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LINKWD_ACEPT);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LANENUM_WAI);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_LANENUM_ACEPT);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_COMPLETE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_CFG_IDLE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_LOCK);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_SPEED);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_RCVRCFG);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_IDLE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L0);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L0S);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L123_SEND_EIDLE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L1_IDLE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L2_IDLE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L2_WAKE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DISABLED_ENTRY);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DISABLED_IDLE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_DISABLED);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_ENTRY);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_ACTIVE);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_EXIT);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_LPBK_EXIT_TIMEOUT);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_HOT_RESET_ENTRY);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_HOT_RESET);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ0);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ1);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ2);
+	DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ3);
+	default:
+		str = "DW_PCIE_LTSSM_UNKNOWN";
+		break;
+	}
+
+	return str + strlen("DW_PCIE_LTSSM_");
+}
+
 int dw_pcie_host_init(struct dw_pcie_rp *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 35342120d5a8..aa86483442c9 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -330,9 +330,40 @@  enum dw_pcie_ltssm {
 	/* Need to align with PCIE_PORT_DEBUG0 bits 0:5 */
 	DW_PCIE_LTSSM_DETECT_QUIET = 0x0,
 	DW_PCIE_LTSSM_DETECT_ACT = 0x1,
+	DW_PCIE_LTSSM_POLL_ACTIVE = 0x2,
+	DW_PCIE_LTSSM_POLL_COMPLIANCE = 0x3,
+	DW_PCIE_LTSSM_POLL_CONFIG = 0x4,
+	DW_PCIE_LTSSM_PRE_DETECT_QUIET = 0x5,
 	DW_PCIE_LTSSM_DETECT_WAIT = 0x6,
+	DW_PCIE_LTSSM_CFG_LINKWD_START = 0x7,
+	DW_PCIE_LTSSM_CFG_LINKWD_ACEPT = 0x8,
+	DW_PCIE_LTSSM_CFG_LANENUM_WAI = 0x9,
+	DW_PCIE_LTSSM_CFG_LANENUM_ACEPT = 0xa,
+	DW_PCIE_LTSSM_CFG_COMPLETE = 0xb,
+	DW_PCIE_LTSSM_CFG_IDLE = 0xc,
+	DW_PCIE_LTSSM_RCVRY_LOCK = 0xd,
+	DW_PCIE_LTSSM_RCVRY_SPEED = 0xe,
+	DW_PCIE_LTSSM_RCVRY_RCVRCFG = 0xf,
+	DW_PCIE_LTSSM_RCVRY_IDLE = 0x10,
 	DW_PCIE_LTSSM_L0 = 0x11,
+	DW_PCIE_LTSSM_L0S = 0x12,
+	DW_PCIE_LTSSM_L123_SEND_EIDLE = 0x13,
+	DW_PCIE_LTSSM_L1_IDLE = 0x14,
 	DW_PCIE_LTSSM_L2_IDLE = 0x15,
+	DW_PCIE_LTSSM_L2_WAKE = 0x16,
+	DW_PCIE_LTSSM_DISABLED_ENTRY = 0x17,
+	DW_PCIE_LTSSM_DISABLED_IDLE = 0x18,
+	DW_PCIE_LTSSM_DISABLED = 0x19,
+	DW_PCIE_LTSSM_LPBK_ENTRY = 0x1a,
+	DW_PCIE_LTSSM_LPBK_ACTIVE = 0x1b,
+	DW_PCIE_LTSSM_LPBK_EXIT = 0x1c,
+	DW_PCIE_LTSSM_LPBK_EXIT_TIMEOUT = 0x1d,
+	DW_PCIE_LTSSM_HOT_RESET_ENTRY = 0x1e,
+	DW_PCIE_LTSSM_HOT_RESET = 0x1f,
+	DW_PCIE_LTSSM_RCVRY_EQ0 = 0x20,
+	DW_PCIE_LTSSM_RCVRY_EQ1 = 0x21,
+	DW_PCIE_LTSSM_RCVRY_EQ2 = 0x22,
+	DW_PCIE_LTSSM_RCVRY_EQ3 = 0x23,
 
 	DW_PCIE_LTSSM_UNKNOWN = 0xFFFFFFFF,
 };
@@ -683,6 +714,8 @@  static inline enum dw_pcie_ltssm dw_pcie_get_ltssm(struct dw_pcie *pci)
 	return (enum dw_pcie_ltssm)FIELD_GET(PORT_LOGIC_LTSSM_STATE_MASK, val);
 }
 
+char *dw_ltssm_sts_string(enum dw_pcie_ltssm ltssm);
+
 #ifdef CONFIG_PCIE_DW_HOST
 int dw_pcie_suspend_noirq(struct dw_pcie *pci);
 int dw_pcie_resume_noirq(struct dw_pcie *pci);