On 3/23/07, Ralf Baechle <ralf@xxxxxxxxxxxxxx> wrote:
Let me illustrate this with a little example. Assume we have a page at physical address 0x5000, a page size of 4kB, an 8kB direct mapped cache and 32-byte cache lines. Then address bits 0..4 will be the byte index into the cache line, address bits 5..12 will index the cache array. So now let's map our page into userspace, at address 0x12340000. In KSEG0 it is accessible at 0x80005000. Now, compute the cache index for both addresses compare and curse ...
Yes but since the kernel page address is fixed, why not choosing userspace page addresses to share the same kernel cache index ? -- Franck