habanalabs/gaudi: disable CGM permanently

Due to the need of SynapseAI to configure all TPC engines from a single
QMAN, the driver must disable CGM and never allow the user to enable
it. Otherwise, the configuration of the TPC engines will fail.
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

Documentation/ABI/testing/debugfs-driver-habanalabs

@@ -12,24 +12,7 @@ What:           /sys/kernel/debug/habanalabs/hl<n>/clk_gate
 Date:           May 2020
 KernelVersion:  5.8
 Contact:        ogabbay@kernel.org
-Description:    Allow the root user to disable/enable in runtime the clock
-                gating mechanism in Gaudi. Due to how Gaudi is built, the
-                clock gating needs to be disabled in order to access the
-                registers of the TPC and MME engines. This is sometimes needed
-                during debug by the user and hence the user needs this option.
-                The user can supply a bitmask value, each bit represents
-                a different engine to disable/enable its clock gating feature.
-                The bitmask is composed of 20 bits:
-
-                =======   ============
-                0  -  7   DMA channels
-                8  - 11   MME engines
-                12 - 19   TPC engines
-                =======   ============
-
-                The bit's location of a specific engine can be determined
-                using (1 << GAUDI_ENGINE_ID_*). GAUDI_ENGINE_ID_* values
-                are defined in uapi habanalabs.h file in enum gaudi_engine_id
+Description:    This setting is now deprecated as clock gating is handled solely by the f/w
 
 What:           /sys/kernel/debug/habanalabs/hl<n>/command_buffers
 Date:           Jan 2019

drivers/misc/habanalabs/common/debugfs.c

@@ -1054,42 +1054,12 @@ static ssize_t hl_device_write(struct file *f, const char __user *buf,
 static ssize_t hl_clk_gate_read(struct file *f, char __user *buf,
 					size_t count, loff_t *ppos)
 {
-	struct hl_dbg_device_entry *entry = file_inode(f)->i_private;
-	struct hl_device *hdev = entry->hdev;
-	char tmp_buf[200];
-	ssize_t rc;
-
-	if (*ppos)
-		return 0;
-
-	sprintf(tmp_buf, "0x%llx\n", hdev->clock_gating_mask);
-	rc = simple_read_from_buffer(buf, count, ppos, tmp_buf,
-			strlen(tmp_buf) + 1);
-
-	return rc;
+	return 0;
 }
 
 static ssize_t hl_clk_gate_write(struct file *f, const char __user *buf,
 				     size_t count, loff_t *ppos)
 {
-	struct hl_dbg_device_entry *entry = file_inode(f)->i_private;
-	struct hl_device *hdev = entry->hdev;
-	u64 value;
-	ssize_t rc;
-
-	if (hdev->reset_info.in_reset) {
-		dev_warn_ratelimited(hdev->dev,
-				"Can't change clock gating during reset\n");
-		return 0;
-	}
-
-	rc = kstrtoull_from_user(buf, count, 16, &value);
-	if (rc)
-		return rc;
-
-	hdev->clock_gating_mask = value;
-	hdev->asic_funcs->set_clock_gating(hdev);
-
 	return count;
 }
 

drivers/misc/habanalabs/common/habanalabs.h

@@ -2569,9 +2569,6 @@ struct hl_reset_info {
  * @max_power: the max power of the device, as configured by the sysadmin. This
  *             value is saved so in case of hard-reset, the driver will restore
  *             this value and update the F/W after the re-initialization
- * @clock_gating_mask: is clock gating enabled. bitmask that represents the
- *                     different engines. See debugfs-driver-habanalabs for
- *                     details.
  * @boot_error_status_mask: contains a mask of the device boot error status.
  *                          Each bit represents a different error, according to
  *                          the defines in hl_boot_if.h. If the bit is cleared,
@@ -2710,7 +2707,6 @@ struct hl_device {
 	atomic64_t			dram_used_mem;
 	u64				timeout_jiffies;
 	u64				max_power;
-	u64				clock_gating_mask;
 	u64				boot_error_status_mask;
 	u64				dram_pci_bar_start;
 	u64				last_successful_open_jif;

drivers/misc/habanalabs/common/habanalabs_drv.c

@@ -256,7 +256,6 @@ static void set_driver_behavior_per_device(struct hl_device *hdev)
 	hdev->cpu_queues_enable = 1;
 	hdev->heartbeat = 1;
 	hdev->mmu_enable = 1;
-	hdev->clock_gating_mask = ULONG_MAX;
 	hdev->sram_scrambler_enable = 1;
 	hdev->dram_scrambler_enable = 1;
 	hdev->bmc_enable = 1;

drivers/misc/habanalabs/gaudi/gaudiP.h

@@ -177,7 +177,6 @@
 #define HW_CAP_MSI		BIT(6)
 #define HW_CAP_CPU_Q		BIT(7)
 #define HW_CAP_HBM_DMA		BIT(8)
-#define HW_CAP_CLK_GATE		BIT(9)
 #define HW_CAP_SRAM_SCRAMBLER	BIT(10)
 #define HW_CAP_HBM_SCRAMBLER	BIT(11)