habanalabs: add new IOCTL for debug, tracing and profiling

Habanalabs ASICs use the ARM coresight infrastructure to support debug,
tracing and profiling of neural networks topologies.

Because the coresight is configured using register writes and reads, and
some of the registers hold sensitive information (e.g. the address in
the device's DRAM where the trace data is written to), the user must go
through the kernel driver to configure this mechanism.

This patch implements the common code of the IOCTL and calls the
ASIC-specific function for the actual H/W configuration.

The IOCTL supports configuration of seven coresight components:
ETR, ETF, STM, FUNNEL, BMON, SPMU and TIMESTAMP

The user specifies which component he wishes to configure and provides a
pointer to a structure (located in its process space) that contains the
relevant configuration.

The common code copies the relevant data from the user-space to kernel
space and then calls the ASIC-specific function to do the H/W
configuration.

After the configuration is done, which is usually composed
of several IOCTL calls depending on what the user wanted to trace, the
user can start executing the topology. The trace data will be written to
the user's area in the device's DRAM.

After the tracing operation is complete, and user will call the IOCTL
again to disable the tracing operation. The user also need to read
values from registers for some of the components (e.g. the size of the
trace data in the device's DRAM). In that case, the user will provide a
pointer to an "output" structure in user-space, which the IOCTL code will
fill according the to selected component.

Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

1 files changed, 112 insertions, 1 deletions

diff --git a/drivers/misc/habanalabs/habanalabs_ioctl.c b/drivers/misc/habanalabs/habanalabs_ioctl.c
index 9000ff615805..810e65446075 100644
--- a/drivers/misc/habanalabs/habanalabs_ioctl.c
+++ b/drivers/misc/habanalabs/habanalabs_ioctl.c
@@ -12,6 +12,17 @@
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 
+static u32 hl_debug_struct_size[HL_DEBUG_OP_TIMESTAMP + 1] = {
+	[HL_DEBUG_OP_ETR] = sizeof(struct hl_debug_params_etr),
+	[HL_DEBUG_OP_ETF] = sizeof(struct hl_debug_params_etf),
+	[HL_DEBUG_OP_STM] = sizeof(struct hl_debug_params_stm),
+	[HL_DEBUG_OP_FUNNEL] = 0,
+	[HL_DEBUG_OP_BMON] = sizeof(struct hl_debug_params_bmon),
+	[HL_DEBUG_OP_SPMU] = sizeof(struct hl_debug_params_spmu),
+	[HL_DEBUG_OP_TIMESTAMP] = 0
+
+};
+
 static int device_status_info(struct hl_device *hdev, struct hl_info_args *args)
 {
 	struct hl_info_device_status dev_stat = {0};
@@ -114,6 +125,71 @@ static int hw_idle(struct hl_device *hdev, struct hl_info_args *args)
 		min((size_t) max_size, sizeof(hw_idle))) ? -EFAULT : 0;
 }
 
+static int debug_coresight(struct hl_device *hdev, struct hl_debug_args *args)
+{
+	struct hl_debug_params *params;
+	void *input = NULL, *output = NULL;
+	int rc;
+
+	params = kzalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+
+	params->reg_idx = args->reg_idx;
+	params->enable = args->enable;
+	params->op = args->op;
+
+	if (args->input_ptr && args->input_size) {
+		input = memdup_user((const void __user *) args->input_ptr,
+					args->input_size);
+		if (IS_ERR(input)) {
+			rc = PTR_ERR(input);
+			input = NULL;
+			dev_err(hdev->dev,
+				"error %d when copying input debug data\n", rc);
+			goto out;
+		}
+
+		params->input = input;
+	}
+
+	if (args->output_ptr && args->output_size) {
+		output = kzalloc(args->output_size, GFP_KERNEL);
+		if (!output) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		params->output = output;
+		params->output_size = args->output_size;
+	}
+
+	rc = hdev->asic_funcs->debug_coresight(hdev, params);
+	if (rc) {
+		dev_err(hdev->dev,
+			"debug coresight operation failed %d\n", rc);
+		goto out;
+	}
+
+	if (output) {
+		if (copy_to_user((void __user *) (uintptr_t) args->output_ptr,
+					output,
+					args->output_size)) {
+			dev_err(hdev->dev,
+				"copy to user failed in debug ioctl\n");
+			rc = -EFAULT;
+			goto out;
+		}
+	}
+
+out:
+	kfree(params);
+	kfree(output);
+	kfree(input);
+
+	return rc;
+}
+
 static int hl_info_ioctl(struct hl_fpriv *hpriv, void *data)
 {
 	struct hl_info_args *args = data;
@@ -156,6 +232,40 @@ static int hl_info_ioctl(struct hl_fpriv *hpriv, void *data)
 	return rc;
 }
 
+static int hl_debug_ioctl(struct hl_fpriv *hpriv, void *data)
+{
+	struct hl_debug_args *args = data;
+	struct hl_device *hdev = hpriv->hdev;
+	int rc = 0;
+
+	if (hl_device_disabled_or_in_reset(hdev)) {
+		dev_warn_ratelimited(hdev->dev,
+			"Device is %s. Can't execute DEBUG IOCTL\n",
+			atomic_read(&hdev->in_reset) ? "in_reset" : "disabled");
+		return -EBUSY;
+	}
+
+	switch (args->op) {
+	case HL_DEBUG_OP_ETR:
+	case HL_DEBUG_OP_ETF:
+	case HL_DEBUG_OP_STM:
+	case HL_DEBUG_OP_FUNNEL:
+	case HL_DEBUG_OP_BMON:
+	case HL_DEBUG_OP_SPMU:
+	case HL_DEBUG_OP_TIMESTAMP:
+		args->input_size =
+			min(args->input_size, hl_debug_struct_size[args->op]);
+		rc = debug_coresight(hdev, args);
+		break;
+	default:
+		dev_err(hdev->dev, "Invalid request %d\n", args->op);
+		rc = -ENOTTY;
+		break;
+	}
+
+	return rc;
+}
+
 #define HL_IOCTL_DEF(ioctl, _func) \
 	[_IOC_NR(ioctl)] = {.cmd = ioctl, .func = _func}
 
@@ -164,7 +274,8 @@ static const struct hl_ioctl_desc hl_ioctls[] = {
 	HL_IOCTL_DEF(HL_IOCTL_CB, hl_cb_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_CS, hl_cs_ioctl),
 	HL_IOCTL_DEF(HL_IOCTL_WAIT_CS, hl_cs_wait_ioctl),
-	HL_IOCTL_DEF(HL_IOCTL_MEMORY, hl_mem_ioctl)
+	HL_IOCTL_DEF(HL_IOCTL_MEMORY, hl_mem_ioctl),
+	HL_IOCTL_DEF(HL_IOCTL_DEBUG, hl_debug_ioctl)
 };
 
 #define HL_CORE_IOCTL_COUNT	ARRAY_SIZE(hl_ioctls)