Currently the kernel supports processes running in little-endian mode on machines that have a little-endian mode (as opposed to an endian bit in the TLB entry like most embedded PowerPC processors do, which is a much better idea). Little-endian mode comes in two flavours: so-called "PowerPC" little-endian mode, which works by swizzling the bottom 3 bits of the address, and "true" little-endian mode, which actually swaps the order of the bytes read from or written to memory. The classic 32-bit processors (603, 604, 750, 74xx, and derivatives) implemented PowerPC little-endian mode, and I think some early 64-bit processors did also. POWER6 and POWER7 implement true little-endian mode. POWER4, PPC970 and POWER5 don't implement any little-endian mode.
Is anyone actually using little-endian mode processes on processors that implement PowerPC little-endian mode? One of the ways that we could make the alignment interrupt handler go faster is by removing the code for address swizzling that we have in order to handle PowerPC little-endian mode. If nobody is actually using it, we should remove it and make the code simpler and faster. Paul. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev