[PATCH v4 22/25] nvdimm/ocxl: Add debug IOCTLs

["Alastair D'Silva" <alastair@d-silva.org>]

These IOCTLs provide low level access to the card to aid in debugging
controller/FPGA firmware.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
 drivers/nvdimm/ocxl/Kconfig    |   6 +
 drivers/nvdimm/ocxl/main.c     | 198 +++++++++++++++++++++++++++++++++
 drivers/nvdimm/ocxl/ocxlpmem.h |   2 +-
 include/uapi/nvdimm/ocxlpmem.h |  31 ++++++
 4 files changed, 236 insertions(+), 1 deletion(-)

diff --git a/drivers/nvdimm/ocxl/Kconfig b/drivers/nvdimm/ocxl/Kconfig
index c5d927520920..3f44429d70c9 100644
--- a/drivers/nvdimm/ocxl/Kconfig
+++ b/drivers/nvdimm/ocxl/Kconfig
@@ -12,4 +12,10 @@ config OCXL_PMEM
 
 	  Select N if unsure.
 
+config OCXL_PMEM_DEBUG
+	bool "OpenCAPI Persistent Memory debugging"
+	depends on OCXL_PMEM
+	help
+	  Enables low level IOCTLs for OpenCAPI Persistent Memory firmware development
+
 endif
diff --git a/drivers/nvdimm/ocxl/main.c b/drivers/nvdimm/ocxl/main.c
index 2fbe3f2f77d9..2811bf7efbab 100644
--- a/drivers/nvdimm/ocxl/main.c
+++ b/drivers/nvdimm/ocxl/main.c
@@ -1027,6 +1027,183 @@ int req_controller_health_perf(struct ocxlpmem *ocxlpmem)
 				      GLOBAL_MMIO_HCI_REQ_HEALTH_PERF);
 }
 
+#ifdef CONFIG_OCXL_PMEM_DEBUG
+/**
+ * enable_fwdebug() - Enable FW debug on the controller
+ * @ocxlpmem: the device metadata
+ * Return: 0 on success, negative on failure
+ */
+static int enable_fwdebug(const struct ocxlpmem *ocxlpmem)
+{
+	return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCI,
+				      OCXL_LITTLE_ENDIAN,
+				      GLOBAL_MMIO_HCI_FW_DEBUG);
+}
+
+/**
+ * disable_fwdebug() - Disable FW debug on the controller
+ * @ocxlpmem: the device metadata
+ * Return: 0 on success, negative on failure
+ */
+static int disable_fwdebug(const struct ocxlpmem *ocxlpmem)
+{
+	return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCIC,
+				      OCXL_LITTLE_ENDIAN,
+				      GLOBAL_MMIO_HCI_FW_DEBUG);
+}
+
+static int ioctl_fwdebug(struct ocxlpmem *ocxlpmem,
+			 struct ioctl_ocxl_pmem_fwdebug __user *uarg)
+{
+	struct ioctl_ocxl_pmem_fwdebug args;
+	u64 val;
+	int i;
+	int rc;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	// Buffer size must be a multiple of 8
+	if ((args.buf_size & 0x07))
+		return -EINVAL;
+
+	if (args.buf_size > ocxlpmem->admin_command.data_size)
+		return -EINVAL;
+
+	mutex_lock(&ocxlpmem->admin_command.lock);
+
+	rc = enable_fwdebug(ocxlpmem);
+	if (rc)
+		goto out;
+
+	// Write DebugAction & FunctionCode
+	val = ((u64)args.debug_action << 56) | ((u64)args.function_code << 40);
+
+	rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+				      ocxlpmem->admin_command.request_offset + 0x08,
+				      OCXL_LITTLE_ENDIAN, val);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+				      ocxlpmem->admin_command.request_offset + 0x10,
+				      OCXL_LITTLE_ENDIAN,
+				      args.debug_parameter_1);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+				      ocxlpmem->admin_command.request_offset + 0x18,
+				      OCXL_LITTLE_ENDIAN,
+				      args.debug_parameter_2);
+	if (rc)
+		goto out;
+
+	// Populate admin command buffer
+	if (args.buf_size) {
+		for (i = 0; i < args.buf_size; i += sizeof(u64)) {
+			u64 val;
+
+			if (copy_from_user(&val, &args.buf[i], sizeof(u64))) {
+				rc = -EFAULT;
+				goto out;
+			}
+
+			rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+						      ocxlpmem->admin_command.data_offset + i,
+						      OCXL_HOST_ENDIAN, val);
+			if (rc)
+				goto out;
+		}
+	}
+
+	rc = admin_command_execute(ocxlpmem,
+				   ocxlpmem->timeouts[ADMIN_COMMAND_FW_DEBUG]);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		warn_status(ocxlpmem, "Unexpected status from FW Debug", rc);
+		goto out;
+	}
+
+	if (args.buf_size) {
+		for (i = 0; i < args.buf_size; i += sizeof(u64)) {
+			u64 val;
+
+			rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+						     ocxlpmem->admin_command.data_offset + i,
+						     OCXL_HOST_ENDIAN, &val);
+			if (rc)
+				goto out;
+
+			if (copy_to_user(&args.buf[i], &val, sizeof(u64))) {
+				rc = -EFAULT;
+				goto out;
+			}
+		}
+	}
+
+	rc = admin_response_handled(ocxlpmem);
+	if (rc)
+		goto out;
+
+	rc = disable_fwdebug(ocxlpmem);
+
+out:
+	mutex_unlock(&ocxlpmem->admin_command.lock);
+	return rc;
+}
+
+static int ioctl_shutdown(struct ocxlpmem *ocxlpmem)
+{
+	int rc;
+
+	mutex_lock(&ocxlpmem->admin_command.lock);
+
+	rc = admin_command_execute(ocxlpmem, ADMIN_COMMAND_SHUTDOWN);
+	if (rc)
+		goto out;
+
+	rc = admin_response_handled(ocxlpmem);
+
+out:
+	mutex_unlock(&ocxlpmem->admin_command.lock);
+	return rc;
+}
+
+static int ioctl_mmio_write(struct ocxlpmem *ocxlpmem,
+			    struct ioctl_ocxl_pmem_mmio __user *uarg)
+{
+	struct scm_ioctl_mmio args;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	return ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, args.address,
+					OCXL_LITTLE_ENDIAN, args.val);
+}
+
+static int ioctl_mmio_read(struct ocxlpmem *ocxlpmem,
+			   struct ioctl_ocxl_pmem_mmio __user *uarg)
+{
+	struct ioctl_ocxl_pmem_mmio args;
+	int rc;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, args.address,
+				     OCXL_LITTLE_ENDIAN, &args.val);
+	if (rc)
+		return rc;
+
+	if (copy_to_user(uarg, &args, sizeof(args)))
+		return -EFAULT;
+
+	return 0;
+}
+#endif /* CONFIG_OCXL_PMEM_DEBUG */
+
 static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
 {
 	struct ocxlpmem *ocxlpmem = file->private_data;
@@ -1068,6 +1245,27 @@ static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
 	case IOCTL_OCXLPMEM_REQUEST_HEALTH:
 		rc = req_controller_health_perf(ocxlpmem);
 		break;
+
+#ifdef CONFIG_OCXL_PMEM_DEBUG
+	case IOCTL_OCXL_PMEM_FWDEBUG:
+		rc = ioctl_fwdebug(ocxlpmem,
+				   (struct ioctl_ocxl_pmem_fwdebug __user *)args);
+		break;
+
+	case IOCTL_OCXL_PMEM_SHUTDOWN:
+		rc = ioctl_shutdown(ocxlpmem);
+		break;
+
+	case IOCTL_OCXL_PMEM_MMIO_WRITE:
+		rc = ioctl_mmio_write(ocxlpmem,
+				      (struct ioctl_ocxl_pmem_mmio __user *)args);
+		break;
+
+	case IOCTL_OCXL_PMEM_MMIO_READ:
+		rc = ioctl_mmio_read(ocxlpmem,
+				     (struct ioctl_ocxl_pmem_mmio __user *)args);
+		break;
+#endif
 	}
 
 	return rc;
diff --git a/drivers/nvdimm/ocxl/ocxlpmem.h b/drivers/nvdimm/ocxl/ocxlpmem.h
index 01721596f982..c8794e7775ec 100644
--- a/drivers/nvdimm/ocxl/ocxlpmem.h
+++ b/drivers/nvdimm/ocxl/ocxlpmem.h
@@ -158,7 +158,7 @@ int ocxlpmem_chi(const struct ocxlpmem *ocxlpmem, u64 *chi);
  *
  * @ocxlpmem: the device metadata
  * @op_code: the code for the admin command
- * Returns 0 on success, -EINVAL for a bad op code, -EBUSY on timeout
+// * Returns 0 on success, -EINVAL for a bad op code, -EBUSY on timeout
  */
 int admin_command_execute(struct ocxlpmem *ocxlpmem, u8 op_code);
 
diff --git a/include/uapi/nvdimm/ocxlpmem.h b/include/uapi/nvdimm/ocxlpmem.h
index 9c5c8585c1c2..374b70690b3a 100644
--- a/include/uapi/nvdimm/ocxlpmem.h
+++ b/include/uapi/nvdimm/ocxlpmem.h
@@ -93,4 +93,35 @@ struct ioctl_ocxlpmem_eventfd {
 #define IOCTL_OCXLPMEM_EVENT_CHECK			_IOR(OCXLPMEM_MAGIC, 0x36, __u64)
 #define IOCTL_OCXLPMEM_REQUEST_HEALTH			_IO(OCXLPMEM_MAGIC, 0x37)
 
+/*
+ * Debug IOCTLs, these are only available if the kernel is compiled with
+ * CONFIG_OCXLPMEM_DEBUG
+ */
+
+#define	OCXLPMEM_FWDEBUG_READ_CONTROLLER_MEMORY	0x01
+#define	OCXLPMEM_FWDEBUG_WRITE_CONTROLLER_MEMORY	0x02
+#define	OCXLPMEM_FWDEBUG_ENABLE_FUNCTION		0x03
+#define	OCXLPMEM_FWDEBUG_DISABLE_FUNCTION		0x04
+#define	OCXLPMEM_FWDEBUG_GET_PEL			0x05 /* Retrieve Persistent Error Log */
+
+struct ioctl_ocxlpmem_fwdebug { /* All args are inputs */
+	__u64 debug_parameter_1;
+	__u64 debug_parameter_2;
+	__u64 buf; /* Coerced pointer to optional in/out data buffer */
+	__u16 debug_action; /* OCXLPMEM_FWDEBUG_... */
+	__u16 function_code;
+	__u16 buf_size; /* Size of optional data buffer */
+	__u16 reserved;
+};
+
+struct ioctl_ocxlpmem_mmio {
+	__u64 address; /* Offset in global MMIO space */
+	__u64 val; /* value to write/was read */
+};
+
+#define IOCTL_OCXLPMEM_FWDEBUG		_IOWR(OCXLPMEM_MAGIC, 0xf0, struct ioctl_ocxlpmem_fwdebug)
+#define IOCTL_OCXLPMEM_MMIO_WRITE	_IOW(OCXLPMEM_MAGIC, 0xf1, struct ioctl_ocxlpmem_mmio)
+#define IOCTL_OCXLPMEM_MMIO_READ	_IOWR(OCXLPMEM_MAGIC, 0xf2, struct ioctl_ocxlpmem_mmio)
+#define IOCTL_OCXLPMEM_SHUTDOWN	_IO(OCXLPMEM_MAGIC, 0xf3)
+
 #endif /* _UAPI_OCXL_SCM_H */
-- 
2.24.1