Use linux generic asid/vmid algorithm to implement csky
switch_mm function. The algorithm is from arm and it could
work with SMP system. It'll help reduce tlb flush for
switch_mm in task/vm switch.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Current C-SKY ASID mechanism is from mips and it doesn't work well
with multi-cores. ASID per core mechanism is not suitable for C-SKY
SMP tlb maintain operations, eg: tlbi.vas need share the same asid
in all processors and it'll invalid the tlb entry in all cores with
the same asid.
This patch is prepare for new ASID mechanism.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
The name of phys_offset is so common for global export and it may
conflict with some local name. So change phys_offset to va_pa_offset
which also used by riscv.
Also use __pa() and __va() instead of using phys_offset directly.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Before this patch csky-linux need CONFIG_RAM_BASE to determine start
physical address. Now we use phys_offset variable to replace the macro
of PHYS_OFFSET and we setup phys_offset with real physical address which
is determined during startup in head.S.
With this patch we needn't re-compile kernel for different start
physical address. ie: 0x0 / 0xc0000000 start physical address could use
the same vmlinux, be care different start address must be 512MB aligned.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
It's wrong to mask/unmask highest bit in addr to translate the vaddr
to paddr. We should use PAGE_OFFSET and PHYS_OFFSET.
Wrong implement:
return ((get_pgd()|(1<<31)) - PHYS_OFFSET) & ~1;
When PHYS_OFFSET=0xc0000000 and get_pgd() return 0xe0000000, it'll
return 0x60000000. It's wrong and should be 0xa0000000.
Now correct it to:
return ((get_pgd() - PHYS_OFFSET) & ~1) + PAGE_OFFSET;
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
This patch adds files related to task_switch, sigcontext, signal,
fpu context switch.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>
