Planning to move back to previous employer

[helloTechie 0]

I worked for company A for 8 years.  My company A did perm/I140 with priority date Jan 2013. I then moved to company B and worked for them for 1 year. If I go back to company A at the same designation, can company A  continue with perm/I140 that it had done in past. Or do they have to restart the process.