Have a look at your CPU info

$ grep -E "^(model|microcode|cpu family)" /proc/cpuinfo  | sort -u
cpu family	: 21
microcode	: 0x6000852
model		: 2
model name	: AMD FX(tm)-8350 Eight-Core Processor

The "cpu family" is shown in decimal, convert to hex, i.e. 21 becomes 15h

Clone these repos

git clone https://github.com/AMDESE/amd_ucode_info
git clone --depth=1 git://git.kernel.org/pub/scm/linux/kernel/git/dwmw2/linux-firmware.git

Get the info about the latest version of the microcode for the appropriate family.

$ cd linux-firmware
$ ../amd_ucode_info/amd_ucode_info.py amd-ucode/microcode_amd_fam15h.bin
Microcode patches in amd-ucode/microcode_amd_fam15h.bin:
  Family=0x15 Model=0x01 Stepping=0x02: Patch=0x0600063e Length=2592 bytes
  Family=0x15 Model=0x02 Stepping=0x00: Patch=0x06000852 Length=2592 bytes
  Family=0x15 Model=0x10 Stepping=0x01: Patch=0x06001119 Length=2592 bytes

Check the version from "cpuinfo" matches the line for your Family/Model