Memory stats exposed to fdinfo incorrect

[ThatOneCalculator]

I don't think that supports temps, power usage, etc, but that's good to know!
Also, unless I'm doing something wrong, it seems like memory and usage isn't reported at all, or at least incorrectly.

Opening /dev/accel/accel0...
Got fd: 4

Trying to read DRM stats from /proc/self/fdinfo/4:
  drm-driver:    amdxdna_accel_driver
  drm-client-id:    76
  drm-pdev:    0000:c5:00.1
  drm-engine-npu-amdxdna:    0 ns
  drm-total-memory:    0
  drm-shared-memory:    0
  drm-active-memory:    0

use std::{fs::File, io::{BufRead, BufReader}, os::fd::AsRawFd};

fn main() {
    println!("Opening /dev/accel/accel0...");
    match File::open("/dev/accel/accel0") {
        Ok(f) => {
            let fd = f.as_raw_fd();
            println!("Got fd: {}", fd);
            
            println!("\nTrying to read DRM stats from /proc/self/fdinfo/{}:", fd);
            match File::open(format!("/proc/self/fdinfo/{}", fd)) {
                Ok(fdinfo) => {
                    let reader = BufReader::new(fdinfo);
                    for line in reader.lines().flatten() {
                        if line.starts_with("drm-") {
                            println!("  {}", line);
                        }
                    }
                }
                Err(e) => println!("Error opening fdinfo: {}", e),
            }
        }
        Err(e) => println!("Error opening device: {}", e),
    }
}

Originally posted by @ThatOneCalculator in nokyan/resources#417 (comment)

Output of xrt-smi examine:

System Configuration
  OS Name              : Linux
  Release              : 6.13.0-rc2-1-mainline-um5606-dirty
  Machine              : x86_64
  CPU Cores            : 24
  Memory               : 31196 MB
  Distribution         : Arch Linux
  GLIBC                : 2.40
  Model                : ASUS Zenbook S 16 UM5606WA_UM5606WA
  BIOS Vendor          : American Megatrends International, LLC.
  BIOS Version         : UM5606WA.312

XRT
  Version              : 2.19.0
  Branch               : master
  Hash                 : 42e5fb6f572cc94b6593cba1fca0536ed8f9d49c
  Hash Date            : 2024-12-09 22:17:48
  xocl                 : unknown, unknown
  xclmgmt              : unknown, unknown
WARNING: xclmgmt version is unknown. Is xclmgmt driver loaded? Or is MSD/MPD running?
  amdxdna              : 2.19.0_20241209, 05c3d73ef7ab93405c8866c4c0c12239d3afe5fc
  NPU Firmware Version : 1.0.0.63

Device(s) Present
|BDF             |Name          |
|----------------|--------------|
|[0000:c5:00.1]  |RyzenAI-npu4  |

[houlz0507]

memory usage is supported. the test program opened the device and does not allocate any buffer. That is why zero usage is shown. I run 'xrt-smi validate -d -r df-bw' and 'cat /proc/.../fdinfo' in other window. I can see the valid memory usage.
cat /proc/57340/fdinfo/3
pos: 0
flags: 0100002
mnt_id: 28
ino: 1039
drm-driver: amdxdna_accel_driver
drm-client-id: 12
drm-pdev: 0000:c3:00.1
drm-engine-npu-amdxdna: 0 ns
drm-total-memory: 2162700 KiB
drm-shared-memory: 0
drm-active-memory: 2097156 KiB

Please modify the test program and retry. Or you may try the same xrt-smi test.