The coprocessor 0 Config register includes 9 implementation defined
bits, which in some processors do things like enable write combining or
other functionality. We ought not to wipe them to 0 during boot. Rather
than doing so, preserve their value & only clear the bits standardised
by the MIPS architecture.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
In commit a18a477 (MIPS: use common code from lib/time.c) MIPS platforms
started using common the common timer functions which are based around
the fact that many platforms have a 32-bit free running counter register
that can be used see commit 8dfafdd (Introduce common timer functions).
Even MIPS64 has such a 32-bit register (some have an additional 64-bit free
running counter, but that's something for another time).
The problem is that in __read_32bit_c0_register() we read the value from
this register into an _signed_ int and as it's returned up the call
chain to timer_read_counter() it gets assigned to an unsigned long. On a
32-bit system there is no problem. On a 64-bit system odd things happen,
sign extension seems to kick in and all of a sudden if the counter
register happens to have the MSb (i.e. the sign bit) set the negative
int gets sign extended into a very large unsigned long value. This in
turn throws out things from get_ticks() up.
Update __read_32bit_c0_register() and __read_32bit_c0_ctrl_register() to
use "unsigned int res;" instead of "int res;". There seems to be little
reason to treat these register values as signed. They are either
counters (which by definition are unsigned) or are made up of various
bit fields to be interpreted as per the CPU datasheet.
Reported-by: Sachin Surendran <sachin.surendran@alliedtelesis.co.nz>
Signed-off-by: Chris Packham <judge.packham@gmail.com>
For boards such as the MIPS Malta with an FPGA core card it is desirable
to be able to detect the L1 cache sizes at runtime, since they are not
dependant upon the board but on the FPGA bitstream in use. This patch
performs that detection when the CONFIG_SYS_[DI]CACHE_SIZE macros are
not defined by the board configuration. In cases where the sizes are
detected this patch also removes the restriction that the I-cache &
D-cache line sizes must be the same, as this is not necessarily true.
If the cache sizes are defined by a configuration then they will be
hardcoded as before, so this patch will not add overhead to such
boards.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This helps to clean up the include/ directory so that it only contains
non-architecture-specific headers and also matches Linux's directory
layout which many U-Boot developers are already familiar with.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
2010-04-13 09:13:12 +02:00
Renamed from include/asm-mips/mipsregs.h (Browse further)
