The TLB miss fast-path presently calls in to update_mmu_cache() to
set up the entry, and does so with a NULL vma. Check for vma validity
in the __update_tlb() ptrace checks.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This splits out a separate __update_cache()/__update_tlb() for
update_mmu_cache() to wrap in to. This lets us share the common
__update_cache() bits while keeping special __update_tlb() handling
broken out.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This inverts the delayed dcache flush a bit to be more in line with other
platforms. At the same time this also gives us the ability to do some
more optimizations and cleanup. Now that the update_mmu_cache() callsite
only tests for the bit, the implementation can gradually be split out and
made generic, rather than relying on special implementations for each of
the peculiar CPU types.
SH7705 in 32kB mode and SH-4 still need slightly different handling, but
this is something that can remain isolated in the varying page copy/clear
routines. On top of that, SH-X3 is dcache coherent, so there is no need
to bother with any of these tests in the PTEAEX version of
update_mmu_cache(), so we kill that off too.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
While harmless, PTEA has different semantics on these parts, and is only
used in extended TLB mode. Kill off the legacy support.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This adds support for extended ASIDs (up to 16-bits) on newer SH-X3 cores
that implement the PTAEX register and respective functionality. Presently
only the 65nm SH7786 (90nm only supports legacy 8-bit ASIDs).
The main change is in how the PTE is written out when loading the entry
in to the TLB, as well as in how the TLB entry is selectively flushed.
While SH-X2 extended mode splits out the memory-mapped U and I-TLB data
arrays for extra bits, extended ASID mode splits out the address arrays.
While we don't use the memory-mapped data array access, the address
array accesses are necessary for selective TLB flushes, so these are
implemented newly and replace the generic SH-4 implementation.
With this, TLB flushes in switch_mm() are almost non-existent on newer
parts.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
