[PATCH v8 1/2] drm/xe/sysctrl: Add helper to query application status

["Anoop, Vijay" <anoop.c.vijay@intel.com>]

From: Anoop Vijay <anoop.c.vijay@intel.com>

Add xe_sysctrl_check_app_status() to query the state of a System
Controller application using get_app_status_by_id mailbox command.

The helper maps xe_sysctrl_app_id values to firmware application
IDs and returns the reported application state. Add a convenience
wrapper to check diag firmware application readiness.

Signed-off-by: Anoop Vijay <anoop.c.vijay@intel.com>
---
v2: (Badal)
- Return SysCtrl firmware application states instead of errno for
  application lifecycle conditions

v3: (Riana, Badal)
- Replace string-based app identifiers with enum xe_sysctrl_app_id
- Use get_app_status_by_id (opcode 0x05)
- Move mailbox definitions to xe_sysctrl_mailbox_types.h
- Return enum xe_sysctrl_fw_status consistently
- Map communication failures to COMM_FAILURE
- Add INITIALIZED state and status helpers
- Fix Diagnostics typo

v4: (Anshuman)
- Make xe_sysctrl_check_app_status() internal
- Remove unused app identifier

v5: (Anshuman)
- Rename OOBMSM status helper to use xe_sysctrl_* prefix
- Remove xe_is_diag_fw_ready() helper

v6: (Riana)
- Use xe_sysctrl_create_command() helper instead of manual FIELD_PREP
  header packing
- Rename xe_sysctrl_get_app_status_by_id_{req,resp} to shorter names
- Use hex constant for application ID
- Move oCode application readiness helper to a separate patch
- Add xe_sysctrl_is_diag_fw_ready() helper.

v7: (Umesh)
- Clarify xe_sysctrl_is_diag_fw_ready() comment for sysctrl-less platforms
- Move XE_SYSCTRL_APP_RESP_* flags and enum xe_sysctrl_app_id to xe_sysctrl.c

v8: (Umesh, Rodrigo, Mike)
- Drop XE_SYSCTRL_FIRMWARE_APP_NOTSUPP handling
- Simplify diag readiness helpers to a single
  XE_SYSCTRL_FIRMWARE_APP_INITIALIZED check
---
 drivers/gpu/drm/xe/xe_sysctrl.c               | 73 +++++++++++++++++++
 drivers/gpu/drm/xe/xe_sysctrl.h               |  1 +
 drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h | 45 ++++++++++++
 3 files changed, 119 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_sysctrl.c b/drivers/gpu/drm/xe/xe_sysctrl.c
index 62ccc9be71b4..3b7fa2c9c333 100644
--- a/drivers/gpu/drm/xe/xe_sysctrl.c
+++ b/drivers/gpu/drm/xe/xe_sysctrl.c
@@ -13,9 +13,11 @@
 #include "xe_device.h"
 #include "xe_mmio.h"
 #include "xe_pm.h"
+#include "xe_printk.h"
 #include "xe_soc_remapper.h"
 #include "xe_sysctrl.h"
 #include "xe_sysctrl_mailbox.h"
+#include "xe_sysctrl_mailbox_types.h"
 #include "xe_sysctrl_types.h"
 
 /**
@@ -29,6 +31,20 @@
  * This module provides initialization and support code for interacting
  * with System Controller through the mailbox interface.
  */
+
+/* Application status flags reported in xe_sysctrl_app_status_resp.flags */
+#define XE_SYSCTRL_APP_RESP_VALID		BIT(0)
+#define XE_SYSCTRL_APP_RESP_BOOTED		BIT(1)
+#define XE_SYSCTRL_APP_RESP_INITIALIZED	BIT(2)
+
+/*
+ * Known System Controller application identifiers, keyed by firmware
+ * application ID.
+ */
+enum xe_sysctrl_app_id {
+	XE_SYSCTRL_APP_DIAG	= 0x0D,
+};
+
 static void sysctrl_fini(void *arg)
 {
 	struct xe_device *xe = arg;
@@ -125,3 +141,60 @@ void xe_sysctrl_pm_resume(struct xe_device *xe)
 
 	xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);
 }
+
+static enum xe_sysctrl_fw_status
+xe_sysctrl_check_app_status(struct xe_device *xe, enum xe_sysctrl_app_id app_id)
+{
+	struct xe_sysctrl_app_status_req req = {};
+	struct xe_sysctrl_app_status_resp resp = {};
+	struct xe_sysctrl_mailbox_command cmd = {};
+	size_t out_len = 0;
+	u32 flags;
+	int ret;
+
+	req.app_id = (u8)app_id;
+
+	xe_sysctrl_create_command(&cmd, XE_SYSCTRL_GROUP_CORE, XE_SYSCTRL_CMD_GET_APP_STATUS_BY_ID,
+				  &req, sizeof(req), &resp, sizeof(resp));
+
+	ret = xe_sysctrl_send_command(&xe->sc, &cmd, &out_len);
+	if (ret)
+		return XE_SYSCTRL_FIRMWARE_COMM_FAILURE;
+
+	if (out_len != sizeof(resp)) {
+		xe_err(xe, "sysctrl: unexpected get app status response length %zu (expected %zu)\n",
+		       out_len, sizeof(resp));
+		return XE_SYSCTRL_FIRMWARE_COMM_FAILURE;
+	}
+
+	flags = resp.flags;
+
+	if (!(flags & XE_SYSCTRL_APP_RESP_VALID))
+		return XE_SYSCTRL_FIRMWARE_APP_INVALID;
+
+	if (!(flags & XE_SYSCTRL_APP_RESP_BOOTED))
+		return XE_SYSCTRL_FIRMWARE_APP_NOT_LOADED;
+
+	if (!(flags & XE_SYSCTRL_APP_RESP_INITIALIZED))
+		return XE_SYSCTRL_FIRMWARE_APP_BOOTED;
+
+	return XE_SYSCTRL_FIRMWARE_APP_INITIALIZED;
+}
+
+/**
+ * xe_sysctrl_is_diag_fw_ready() - Check if diag firmware is fully initialized
+ * @xe: xe device instance
+ *
+ * Returns true if diag firmware has reached the initialized state, indicating
+ * it is ready to handle requests.
+ *
+ * Callers must only invoke this on platforms where System Controller is
+ * present (xe->info.has_sysctrl).
+ *
+ * Return: true if diag firmware is initialized, false otherwise
+ */
+bool xe_sysctrl_is_diag_fw_ready(struct xe_device *xe)
+{
+	return xe_sysctrl_check_app_status(xe, XE_SYSCTRL_APP_DIAG) ==
+	       XE_SYSCTRL_FIRMWARE_APP_INITIALIZED;
+}
diff --git a/drivers/gpu/drm/xe/xe_sysctrl.h b/drivers/gpu/drm/xe/xe_sysctrl.h
index 090dffb6d55f..8dc576796890 100644
--- a/drivers/gpu/drm/xe/xe_sysctrl.h
+++ b/drivers/gpu/drm/xe/xe_sysctrl.h
@@ -20,5 +20,6 @@ void xe_sysctrl_event(struct xe_sysctrl *sc);
 int xe_sysctrl_init(struct xe_device *xe);
 void xe_sysctrl_irq_handler(struct xe_device *xe, u32 master_ctl);
 void xe_sysctrl_pm_resume(struct xe_device *xe);
+bool xe_sysctrl_is_diag_fw_ready(struct xe_device *xe);
 
 #endif
diff --git a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
index 66e7cbcc3f91..c236e5377f30 100644
--- a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
+++ b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
@@ -14,9 +14,11 @@
  * enum xe_sysctrl_group - System Controller command groups
  *
  * @XE_SYSCTRL_GROUP_GFSP: GFSP group
+ * @XE_SYSCTRL_GROUP_CORE: Core group
  */
 enum xe_sysctrl_group {
 	XE_SYSCTRL_GROUP_GFSP			= 0x01,
+	XE_SYSCTRL_GROUP_CORE			= 0xFF,
 };
 
 /**
@@ -42,6 +44,49 @@ enum xe_sysctrl_gfsp_cmd {
 	XE_SYSCTRL_CMD_SET_HEALTH		= 0x0C,
 };
 
+/**
+ * enum xe_sysctrl_core_cmd - Commands supported by Core group
+ *
+ * @XE_SYSCTRL_CMD_GET_APP_STATUS_BY_ID: Retrieve application status by ID
+ */
+enum xe_sysctrl_core_cmd {
+	XE_SYSCTRL_CMD_GET_APP_STATUS_BY_ID		= 0x05,
+};
+
+/**
+ * struct xe_sysctrl_app_status_req - Get application status request
+ *
+ * @app_id: Application ID for which to retrieve status
+ */
+struct xe_sysctrl_app_status_req {
+	u8 app_id;
+} __packed;
+
+/**
+ * struct xe_sysctrl_app_status_resp - Get application status response
+ * @flags: Application status flags interpreted by xe_sysctrl_check_app_status()
+ */
+struct xe_sysctrl_app_status_resp {
+	u32 flags;
+} __packed;
+
+/**
+ * enum xe_sysctrl_fw_status - System Controller firmware application lifecycle states
+ *
+ * @XE_SYSCTRL_FIRMWARE_APP_INVALID: app_id is not recognized by firmware
+ * @XE_SYSCTRL_FIRMWARE_APP_NOT_LOADED: application is known but has not yet booted
+ * @XE_SYSCTRL_FIRMWARE_APP_BOOTED: boot sequence completed, post-boot init pending
+ * @XE_SYSCTRL_FIRMWARE_APP_INITIALIZED: application fully operational
+ * @XE_SYSCTRL_FIRMWARE_COMM_FAILURE: communication with System Controller firmware failed
+ */
+enum xe_sysctrl_fw_status {
+	XE_SYSCTRL_FIRMWARE_APP_INVALID,
+	XE_SYSCTRL_FIRMWARE_APP_NOT_LOADED,
+	XE_SYSCTRL_FIRMWARE_APP_BOOTED,
+	XE_SYSCTRL_FIRMWARE_APP_INITIALIZED,
+	XE_SYSCTRL_FIRMWARE_COMM_FAILURE,
+};
+
 /**
  * struct xe_sysctrl_mailbox_command - System Controller mailbox command
  */
-- 
2.43.0