How to root Xperia P

     Go to settings > Security > Mark  "Unknown sources"

     Settings > Developer options > Mark USB debugging

1. Rooting 6.2.A.1.100 = Thread By DooMLoRD
   1. Download the latest version of rooting toolkit from the link above and extract it. Connect your phone to PC and wait for a minute.
   2. Now double click on runme , read the instructions and hit Enter. When it asks you to write commands then copy paste the following from here Rooting Toolkit Commands
   3. Wait until the toolkit finishes rooting. When it says all done , close it , You're phone will reboot on it's own.
2. Rooting 6.1.1.B.1.75 / 6.1.1.B.1.54
   
   1. Download this 6.1.B.0.599_Kernel and flash it ( to learn flashing , see above )
   2. Download Rooting Toolkit Link 1 / 2 / 3 / 4 and extract it. Now run the rooting toolkit, select Normal mode and follow the on-screen instructions it shows.
   3. If you're on .54 then download 6.1.1.B.1.54_Kernel and if your on .75 then download 6.1.1.B.1.75_Kernel
   4. Flash the kernel and you're done.