According to the Federal Student Aid Office, a qualifying loan for PSLF is any non-defaulted loan you received under the William D. Ford Federal Direct Loan (Direct Loan) Program, except for Direct Parent Plus Loans.
You may have received loans under other federal student loan programs, such as the Federal Family Education Loan (FFEL) Program or the Federal Perkins Loan (Perkins Loan) Program, or a Direct Parent Plus loan. Loans from these programs do not qualify for PSLF, but they may become eligible if you consolidate them into a Direct Consolidation Loan.
Parent PLUS loans will receive a weighted average for qualifying payments once consolidated.
FFEL loans and Perkins loans are not eligible for the weighted average and will fully reset when consolidated.
You can read more about the weighted averages here: https://bysavi.zendesk.com/hc/en-us/articles/31467536459027-Consolidation-and-It-s-Effects-on-PSLF-and-IDR-Forgiveness-Progress