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>
This provides a method for supporting fixed PMB mappings inherited from
the bootloader, as an alternative to the dynamic PMB mapping currently
used by the kernel. In the future these methods will be combined.
P1/P2 area is handled like a regular 29-bit physical address, and local
bus device are assigned P3 area addresses.
Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This converts the sh64 /proc/asids entry to debugfs and enables it for
all SH parts that have debugfs enabled.
On MMU systems this can be used to determine which processes are using
which ASIDs which in turn can be used for finer grained cache tag
analysis.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
With the PMB enabled, only P1SEG and up are covered by the PMB mappings,
meaning that situations where out-of-bounds physical addresses are read
from will lead to TLB reset after the PMB miss, allowing for use cases
like dd if=/dev/mem to reset the TLB.
Fix this up to make sure the reference is between __MEMORY_START (phys)
and __pa(high_memory). This is coherent across all variants of sh/sh64
with and without MMU, though the PMB bug itself is only applicable to
SH-4A parts.
Reported-by: Hideo Saito <saito@densan.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
