[PATCH i-g-t 4/6] lib/xe/xe_sriov_admin: Add bulk scheduling params setter

[Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>]

Provisioning execution quantum, preemption timeout and priority is not
order independent. Priority above LOW combined with infinite timeslicing
is a risky state, which can be left via PAUSE/FLR, so timeslicing has to
be programmed before priority is raised.

Add struct xe_sriov_sched_params and a bulk setter that enforces that
order, and that rejects infinite execution quantum or preemption timeout.
Together with xe_sriov_admin_bulk_restore_sched_defaults(), which now
lowers priority first, callers get a safe setup and cleanup pair without
having to open code the sequence.

Assisted-by: Copilot:Claude-Opus-5
Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
Cc: Lukasz Laguna <lukasz.laguna@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 lib/xe/xe_sriov_admin.c | 53 +++++++++++++++++++++++++++++++++++++++++
 lib/xe/xe_sriov_admin.h | 20 ++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/lib/xe/xe_sriov_admin.c b/lib/xe/xe_sriov_admin.c
index 0433ddcfc..2f47d0965 100644
--- a/lib/xe/xe_sriov_admin.c
+++ b/lib/xe/xe_sriov_admin.c
@@ -505,6 +505,59 @@ void xe_sriov_admin_bulk_set_sched_priority(int pf_fd,
 	igt_assert_eq(0, __xe_sriov_admin_bulk_set_sched_priority(pf_fd, prio));
 }
 
+/**
+ * __xe_sriov_admin_bulk_set_sched_params - Set scheduling parameters for PF and all VFs
+ * @pf_fd:  PF device file descriptor.
+ * @params: Scheduling parameters to apply.
+ *
+ * Applies execution quantum and preemption timeout before priority, so that a
+ * priority above LOW is never active while timeslicing is still infinite.
+ *
+ * Both &xe_sriov_sched_params.exec_quantum_ms and
+ * &xe_sriov_sched_params.preempt_timeout_us must be non-zero. Use
+ * __xe_sriov_admin_bulk_restore_sched_defaults() to restore infinite timeslicing.
+ *
+ * Returns: 0 on success or negative errno on error.
+ */
+int __xe_sriov_admin_bulk_set_sched_params(int pf_fd,
+					   const struct xe_sriov_sched_params *params)
+{
+	int ret;
+
+	if (igt_warn_on_f(!params->exec_quantum_ms || !params->preempt_timeout_us,
+			  "Infinite timeslicing requires restoring defaults: eq=%u pt=%u\n",
+			  params->exec_quantum_ms, params->preempt_timeout_us))
+		return -EINVAL;
+
+	ret = __xe_sriov_admin_bulk_set_exec_quantum_ms(pf_fd, params->exec_quantum_ms);
+	if (igt_warn_on_f(ret, "Failed to bulk set exec quantum=%u: %d\n",
+			  params->exec_quantum_ms, ret))
+		return ret;
+
+	ret = __xe_sriov_admin_bulk_set_preempt_timeout_us(pf_fd, params->preempt_timeout_us);
+	if (igt_warn_on_f(ret, "Failed to bulk set preempt timeout=%u: %d\n",
+			  params->preempt_timeout_us, ret))
+		return ret;
+
+	ret = __xe_sriov_admin_bulk_set_sched_priority(pf_fd, params->priority);
+	if (igt_warn_on_f(ret, "Failed to bulk set sched priority=%d: %d\n",
+			  params->priority, ret))
+		return ret;
+
+	return 0;
+}
+
+/**
+ * xe_sriov_admin_bulk_set_sched_params - Assert wrapper for bulk scheduling params update
+ * @pf_fd:  PF device file descriptor.
+ * @params: Scheduling parameters to apply.
+ */
+void xe_sriov_admin_bulk_set_sched_params(int pf_fd,
+					  const struct xe_sriov_sched_params *params)
+{
+	igt_assert_eq(0, __xe_sriov_admin_bulk_set_sched_params(pf_fd, params));
+}
+
 /**
  * __xe_sriov_admin_vf_stop - Issue stop command for a VF
  * @pf_fd:  PF device file descriptor.
diff --git a/lib/xe/xe_sriov_admin.h b/lib/xe/xe_sriov_admin.h
index 4eb9c83a6..6d482f8bf 100644
--- a/lib/xe/xe_sriov_admin.h
+++ b/lib/xe/xe_sriov_admin.h
@@ -13,6 +13,22 @@
 
 struct igt_sysfs_choice;
 
+/**
+ * struct xe_sriov_sched_params - Scheduling parameters for a function
+ * @exec_quantum_ms: Execution quantum in milliseconds
+ * @preempt_timeout_us: Preemption timeout in microseconds
+ * @priority: Scheduling priority
+ *
+ * Zero @exec_quantum_ms or zero @preempt_timeout_us means infinity, which is
+ * only valid together with %XE_SRIOV_SCHED_PRIORITY_LOW. Use
+ * xe_sriov_admin_bulk_restore_sched_defaults() to return to that state.
+ */
+struct xe_sriov_sched_params {
+	uint32_t exec_quantum_ms;
+	uint32_t preempt_timeout_us;
+	enum xe_sriov_sched_priority priority;
+};
+
 bool xe_sriov_admin_is_present(int pf_fd);
 
 int  __xe_sriov_admin_set_exec_quantum_ms(int pf_fd, unsigned int vf_num, uint32_t eq_ms);
@@ -48,6 +64,10 @@ int __xe_sriov_admin_bulk_set_sched_priority(int pf_fd,
 					     enum xe_sriov_sched_priority prio);
 void xe_sriov_admin_bulk_set_sched_priority(int pf_fd,
 					    enum xe_sriov_sched_priority prio);
+int __xe_sriov_admin_bulk_set_sched_params(int pf_fd,
+					   const struct xe_sriov_sched_params *params);
+void xe_sriov_admin_bulk_set_sched_params(int pf_fd,
+					  const struct xe_sriov_sched_params *params);
 
 int  __xe_sriov_admin_vf_stop(int pf_fd, unsigned int vf_num);
 void  xe_sriov_admin_vf_stop(int pf_fd, unsigned int vf_num);
-- 
2.43.0