[no-relnote] Refactor CDI mode handling

Signed-off-by: Evan Lezar <elezar@nvidia.com>

pkg/nvcdi/mode.go

@@ -0,0 +1,117 @@
+/**
+# Copyright 2024 NVIDIA CORPORATION
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package nvcdi
+
+import (
+	"sync"
+
+	"github.com/NVIDIA/go-nvlib/pkg/nvlib/info"
+)
+
+type Mode string
+
+const (
+	// ModeAuto configures the CDI spec generator to automatically detect the system configuration
+	ModeAuto = Mode("auto")
+	// ModeNvml configures the CDI spec generator to use the NVML library.
+	ModeNvml = Mode("nvml")
+	// ModeWsl configures the CDI spec generator to generate a WSL spec.
+	ModeWsl = Mode("wsl")
+	// ModeManagement configures the CDI spec generator to generate a management spec.
+	ModeManagement = Mode("management")
+	// ModeGds configures the CDI spec generator to generate a GDS spec.
+	ModeGds = Mode("gds")
+	// ModeMofed configures the CDI spec generator to generate a MOFED spec.
+	ModeMofed = Mode("mofed")
+	// ModeCSV configures the CDI spec generator to generate a spec based on the contents of CSV
+	// mountspec files.
+	ModeCSV = Mode("csv")
+)
+
+type modeConstraint interface {
+	string | Mode
+}
+
+type modes struct {
+	lookup map[Mode]bool
+	all    []Mode
+}
+
+var validModes modes
+var validModesOnce sync.Once
+
+func getModes() modes {
+	validModesOnce.Do(func() {
+		all := []Mode{
+			ModeAuto,
+			ModeNvml,
+			ModeWsl,
+			ModeManagement,
+			ModeGds,
+			ModeMofed,
+			ModeCSV,
+		}
+		lookup := make(map[Mode]bool)
+
+		for _, m := range all {
+			lookup[m] = true
+		}
+
+		validModes = modes{
+			lookup: lookup,
+			all:    all,
+		}
+	},
+	)
+	return validModes
+}
+
+// AllModes returns the set of valid modes.
+func AllModes[T modeConstraint]() []T {
+	var output []T
+	for _, m := range getModes().all {
+		output = append(output, T(m))
+	}
+	return output
+}
+
+// IsValidMode checks whether a specified mode is valid.
+func IsValidMode[T modeConstraint](mode T) bool {
+	return getModes().lookup[Mode(mode)]
+}
+
+// resolveMode resolves the mode for CDI spec generation based on the current system.
+func (l *nvcdilib) resolveMode() (rmode Mode) {
+	if l.mode != ModeAuto {
+		return l.mode
+	}
+	defer func() {
+		l.logger.Infof("Auto-detected mode as '%v'", rmode)
+	}()
+
+	platform := l.infolib.ResolvePlatform()
+	switch platform {
+	case info.PlatformNVML:
+		return ModeNvml
+	case info.PlatformTegra:
+		return ModeCSV
+	case info.PlatformWSL:
+		return ModeWsl
+	}
+	l.logger.Warningf("Unsupported platform detected: %v; assuming %v", platform, ModeNvml)
+	return ModeNvml
+}