habanalabs: add sysfs and hwmon support

This patch add the sysfs and hwmon entries that are exposed by the driver.

Goya has several sensors, from various categories such as temperature,
voltage, current, etc. The driver exposes those sensors in the standard
hwmon mechanism.

In addition, the driver exposes a couple of interfaces in sysfs, both for
configuration and for providing status of the device or driver.

The configuration attributes is for Power Management:
- Automatic or manual
- Frequency value when moving to high frequency mode
- Maximum power the device is allowed to consume

The rest of the attributes are read-only and provide the following
information:
- Versions of the various firmwares running on the device
- Contents of the device's EEPROM
- The device type (currently only Goya is supported)
- PCI address of the device (to allow user-space to connect between
  /dev/hlX to PCI address)
- Status of the device (operational, malfunction, in_reset)
- How many processes are open on the device's file

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/misc/habanalabs/device.c b/drivers/misc/habanalabs/device.c
index 20f4b980fbb4..f879de310915 100644
--- a/drivers/misc/habanalabs/device.c
+++ b/drivers/misc/habanalabs/device.c
@@ -9,6 +9,7 @@
 
 #include <linux/pci.h>
 #include <linux/delay.h>
+#include <linux/hwmon.h>
 
 static void hpriv_release(struct kref *ref)
 {
@@ -188,6 +189,13 @@ static int device_early_init(struct hl_device *hdev)
 		goto free_cq_wq;
 	}
 
+	hdev->hl_chip_info = kzalloc(sizeof(struct hwmon_chip_info),
+					GFP_KERNEL);
+	if (!hdev->hl_chip_info) {
+		rc = -ENOMEM;
+		goto free_eq_wq;
+	}
+
 	hl_cb_mgr_init(&hdev->kernel_cb_mgr);
 
 	mutex_init(&hdev->fd_open_cnt_lock);
@@ -196,6 +204,8 @@ static int device_early_init(struct hl_device *hdev)
 
 	return 0;
 
+free_eq_wq:
+	destroy_workqueue(hdev->eq_wq);
 free_cq_wq:
 	destroy_workqueue(hdev->cq_wq);
 asid_fini:
@@ -219,6 +229,8 @@ static void device_early_fini(struct hl_device *hdev)
 
 	hl_cb_mgr_fini(hdev, &hdev->kernel_cb_mgr);
 
+	kfree(hdev->hl_chip_info);
+
 	destroy_workqueue(hdev->eq_wq);
 	destroy_workqueue(hdev->cq_wq);
 
@@ -230,6 +242,118 @@ static void device_early_fini(struct hl_device *hdev)
 	mutex_destroy(&hdev->fd_open_cnt_lock);
 }
 
+static void set_freq_to_low_job(struct work_struct *work)
+{
+	struct hl_device *hdev = container_of(work, struct hl_device,
+						work_freq.work);
+
+	if (atomic_read(&hdev->fd_open_cnt) == 0)
+		hl_device_set_frequency(hdev, PLL_LOW);
+
+	schedule_delayed_work(&hdev->work_freq,
+			usecs_to_jiffies(HL_PLL_LOW_JOB_FREQ_USEC));
+}
+
+/*
+ * device_late_init - do late stuff initialization for the habanalabs device
+ *
+ * @hdev: pointer to habanalabs device structure
+ *
+ * Do stuff that either needs the device H/W queues to be active or needs
+ * to happen after all the rest of the initialization is finished
+ */
+static int device_late_init(struct hl_device *hdev)
+{
+	int rc;
+
+	INIT_DELAYED_WORK(&hdev->work_freq, set_freq_to_low_job);
+	hdev->high_pll = hdev->asic_prop.high_pll;
+
+	/* force setting to low frequency */
+	atomic_set(&hdev->curr_pll_profile, PLL_LOW);
+
+	if (hdev->pm_mng_profile == PM_AUTO)
+		hdev->asic_funcs->set_pll_profile(hdev, PLL_LOW);
+	else
+		hdev->asic_funcs->set_pll_profile(hdev, PLL_LAST);
+
+	if (hdev->asic_funcs->late_init) {
+		rc = hdev->asic_funcs->late_init(hdev);
+		if (rc) {
+			dev_err(hdev->dev,
+				"failed late initialization for the H/W\n");
+			return rc;
+		}
+	}
+
+	schedule_delayed_work(&hdev->work_freq,
+			usecs_to_jiffies(HL_PLL_LOW_JOB_FREQ_USEC));
+
+	hdev->late_init_done = true;
+
+	return 0;
+}
+
+/*
+ * device_late_fini - finalize all that was done in device_late_init
+ *
+ * @hdev: pointer to habanalabs device structure
+ *
+ */
+static void device_late_fini(struct hl_device *hdev)
+{
+	if (!hdev->late_init_done)
+		return;
+
+	cancel_delayed_work_sync(&hdev->work_freq);
+
+	if (hdev->asic_funcs->late_fini)
+		hdev->asic_funcs->late_fini(hdev);
+
+	hdev->late_init_done = false;
+}
+
+/*
+ * hl_device_set_frequency - set the frequency of the device
+ *
+ * @hdev: pointer to habanalabs device structure
+ * @freq: the new frequency value
+ *
+ * Change the frequency if needed.
+ * We allose to set PLL to low only if there is no user process
+ * Returns 0 if no change was done, otherwise returns 1;
+ */
+int hl_device_set_frequency(struct hl_device *hdev, enum hl_pll_frequency freq)
+{
+	enum hl_pll_frequency old_freq =
+			(freq == PLL_HIGH) ? PLL_LOW : PLL_HIGH;
+	int ret;
+
+	if (hdev->pm_mng_profile == PM_MANUAL)
+		return 0;
+
+	ret = atomic_cmpxchg(&hdev->curr_pll_profile, old_freq, freq);
+	if (ret == freq)
+		return 0;
+
+	/*
+	 * in case we want to lower frequency, check if device is not
+	 * opened. We must have a check here to workaround race condition with
+	 * hl_device_open
+	 */
+	if ((freq == PLL_LOW) && (atomic_read(&hdev->fd_open_cnt) > 0)) {
+		atomic_set(&hdev->curr_pll_profile, PLL_HIGH);
+		return 0;
+	}
+
+	dev_dbg(hdev->dev, "Changing device frequency to %s\n",
+		freq == PLL_HIGH ? "high" : "low");
+
+	hdev->asic_funcs->set_pll_profile(hdev, freq);
+
+	return 1;
+}
+
 /*
  * hl_device_suspend - initiate device suspend
  *
@@ -390,6 +514,12 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 		goto release_ctx;
 	}
 
+	rc = hl_sysfs_init(hdev);
+	if (rc) {
+		dev_err(hdev->dev, "failed to initialize sysfs\n");
+		goto free_cb_pool;
+	}
+
 	rc = hdev->asic_funcs->hw_init(hdev);
 	if (rc) {
 		dev_err(hdev->dev, "failed to initialize the H/W\n");
@@ -407,11 +537,38 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 		goto out_disabled;
 	}
 
+	/* After test_queues, KMD can start sending messages to device CPU */
+
+	rc = device_late_init(hdev);
+	if (rc) {
+		dev_err(hdev->dev, "Failed late initialization\n");
+		rc = 0;
+		goto out_disabled;
+	}
+
+	dev_info(hdev->dev, "Found %s device with %lluGB DRAM\n",
+		hdev->asic_name,
+		hdev->asic_prop.dram_size / 1024 / 1024 / 1024);
+
+	/*
+	 * hl_hwmon_init must be called after device_late_init, because only
+	 * there we get the information from the device about which
+	 * hwmon-related sensors the device supports
+	 */
+	rc = hl_hwmon_init(hdev);
+	if (rc) {
+		dev_err(hdev->dev, "Failed to initialize hwmon\n");
+		rc = 0;
+		goto out_disabled;
+	}
+
 	dev_notice(hdev->dev,
 		"Successfully added device to habanalabs driver\n");
 
 	return 0;
 
+free_cb_pool:
+	hl_cb_pool_fini(hdev);
 release_ctx:
 	if (hl_ctx_put(hdev->kernel_ctx) != 1)
 		dev_err(hdev->dev,
@@ -461,6 +618,12 @@ void hl_device_fini(struct hl_device *hdev)
 	/* Mark device as disabled */
 	hdev->disabled = true;
 
+	hl_hwmon_fini(hdev);
+
+	device_late_fini(hdev);
+
+	hl_sysfs_fini(hdev);
+
 	/*
 	 * Halt the engines and disable interrupts so we won't get any more
 	 * completions from H/W and we won't have any accesses from the