Following a strict interpretation the empty definition of irq_enable_hazard
has always been a bug - but an intentional one because it didn't bite.
This has now changed, for uniprocessor kernels mm/slab.c:do_drain()
[...]
on_each_cpu(do_drain, cachep, 1, 1);
check_irq_on();
[...]
may be compiled into a mtc0 c0_status; mfc0 c0_status sequence resulting
in a back-to-back hazard.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Move FPU hazard handling to hazards.h and provide proper support for
MIPSR2 processors
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In the the sequence:
ei
..
mfc0 $x, $status
the mfc0 may not see the SR_IE bit set. This was a deliberate bug in the
kernel code because we knew this was a safe thing to do on all R2 silicon
so far but new silicon is changing this.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
NEC VR4111 and VR4121 need one more nop with mtc0_tlbw_hazard().
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The SB1 core has a three cycle interrupt disable hazard but we were
wrongly treating it as fully interlocked.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Gcc has a tradition of misscompiling the previous construct using the
address of a label as argument to inline assembler. Gas otoh has the
annoying difference between la and dla which are only usable for 32-bit
rsp. 64-bit code, so can't be used without conditional compilation.
The alterantive is switching the assembler to 64-bit code which happens
to work right even for 32-bit code ...
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
