nvidia-container-toolkit/vendor/github.com/NVIDIA/go-nvlib/pkg/nvpci/resources.go
Evan Lezar 2019cd6f0a Update to go-nvlib v0.3.0 and go-nvml v0.12.0-4
Signed-off-by: Evan Lezar <elezar@nvidia.com>
2024-04-18 15:01:03 +02:00

141 lines
3.7 KiB
Go

/*
* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
*
* 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 nvpci
import (
"fmt"
"sort"
"github.com/NVIDIA/go-nvlib/pkg/nvpci/mmio"
)
const (
pmcEndianRegister = 0x4
pmcLittleEndian = 0x0
pmcBigEndian = 0x01000001
)
// MemoryResource represents a mmio region.
type MemoryResource struct {
Start uintptr
End uintptr
Flags uint64
Path string
}
// OpenRW read write mmio region.
func (mr *MemoryResource) OpenRW() (mmio.Mmio, error) {
rw, err := mmio.OpenRW(mr.Path, 0, int(mr.End-mr.Start+1))
if err != nil {
return nil, fmt.Errorf("failed to open file for mmio: %v", err)
}
switch rw.Read32(pmcEndianRegister) {
case pmcBigEndian:
return rw.BigEndian(), nil
case pmcLittleEndian:
return rw.LittleEndian(), nil
}
return nil, fmt.Errorf("unknown endianness for mmio: %v", err)
}
// OpenRO read only mmio region.
func (mr *MemoryResource) OpenRO() (mmio.Mmio, error) {
ro, err := mmio.OpenRO(mr.Path, 0, int(mr.End-mr.Start+1))
if err != nil {
return nil, fmt.Errorf("failed to open file for mmio: %v", err)
}
switch ro.Read32(pmcEndianRegister) {
case pmcBigEndian:
return ro.BigEndian(), nil
case pmcLittleEndian:
return ro.LittleEndian(), nil
}
return nil, fmt.Errorf("unknown endianness for mmio: %v", err)
}
// From Bit Twiddling Hacks, great resource for all low level bit manipulations.
func calcNextPowerOf2(n uint64) uint64 {
n--
n |= n >> 1
n |= n >> 2
n |= n >> 4
n |= n >> 8
n |= n >> 16
n |= n >> 32
n++
return n
}
// GetTotalAddressableMemory will accumulate the 32bit and 64bit memory windows
// of each BAR and round the value if needed to the next power of 2; first
// return value is the accumulated 32bit addressable memory size the second one
// is the accumulated 64bit addressable memory size in bytes. These values are
// needed to configure virtualized environments.
func (mrs MemoryResources) GetTotalAddressableMemory(roundUp bool) (uint64, uint64) {
const pciIOVNumBAR = 6
const pciBaseAddressMemTypeMask = 0x06
const pciBaseAddressMemType32 = 0x00 /* 32 bit address */
const pciBaseAddressMemType64 = 0x04 /* 64 bit address */
// We need to sort the resources so the first 6 entries are the BARs
// How a map is represented in memory is not guaranteed, it is not an
// array. Keys do not have an order.
keys := make([]int, 0, len(mrs))
for k := range mrs {
keys = append(keys, k)
}
sort.Ints(keys)
numBAR := 0
memSize32bit := uint64(0)
memSize64bit := uint64(0)
for _, key := range keys {
// The PCIe spec only defines 5 BARs per device, we're
// discarding everything after the 5th entry of the resources
// file, see lspci.c
if key >= pciIOVNumBAR || numBAR == pciIOVNumBAR {
break
}
numBAR = numBAR + 1
region := mrs[key]
flags := region.Flags & pciBaseAddressMemTypeMask
memType32bit := flags == pciBaseAddressMemType32
memType64bit := flags == pciBaseAddressMemType64
memSize := (region.End - region.Start) + 1
if memType32bit {
memSize32bit = memSize32bit + uint64(memSize)
}
if memType64bit {
memSize64bit = memSize64bit + uint64(memSize)
}
}
if roundUp {
memSize32bit = calcNextPowerOf2(memSize32bit)
memSize64bit = calcNextPowerOf2(memSize64bit)
}
return memSize32bit, memSize64bit
}