tree 3f9b7d8d03a1436c45c38256b1dc438053136ca3
parent 4d1e4ff63ce7c23256b24c3f1722d1abccb26451
author Aurelien Jarno <aurelien@aurel32.net> 1265136651 +0100
committer Aurelien Jarno <aurelien@aurel32.net> 1265746085 +0100

target-sh4: MMU: optimize UTLB accesses

With the current code, the QEMU TLB is setup to match the read/write
mode of the MMU fault. This means when read access is done, the page
is setup in read-only mode. When the page is later accessed in write
mode, an MMU fault happened, and the page is switch in write-only
mode. This flip-flop causes a lot of calls to the MMU code and slow
down the emulation.

This patch changes the MMU emulation, so that the QEMU TLB is setup
to match the UTLB protection key. This impressively increase the
speed of the emulation.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>