RASID must not use 0 for any slot. According with documentation:
"""The operation of the processor is undefined if any two of the
four ASIDs are equal or if it contains an ASID of zero"""
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Instead of using CONFIG_MMU_PAGE_SIZE for size of the privileged
stack, use the actual kconfig CONFIG_PRIVILEGED_STACK_SIZE.
This allows for changing the size of privileged stack, and
also aligns to the usage of CONFIG_PRIVILEGED_STACK_SIZE.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The constant used to calculate TLB entries for the way six was wrong
and causing an integer overflow. Consequently only the first 512MB where
being unmapped from the TLB.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
This follows the idea to remove any z_ prefix. Since MMU has
a large number of these, separate out these changes into one
commit to ease review effort.
Since these are no longer have z_, these need proper doxygen
doc. So add them too.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Andy Ross re-implementation of MMU layer with some subtle changes,
like re-using existent macros, fix page table cache property when
direct mapping it in TLB.
From Andy's original commit message:
This is a reworked MMU layer, sitting cleanly below the page table
handling in the OS. Notable differences from the original work:
+ Significantly smaller code and simpler API (just three functions to
be called from the OS/userspace/ptable layer).
+ Big README-MMU document containing my learnings over the process, so
hopefully fewer people need to go through this in the future.
+ No TLB flushing needed. Clean separation of ASIDs, just requires
that the upper levels match the ASID to the L1 page table page
consistently.
+ Vector mapping is done with a 4k page and not a 4M page, leading to
much more flexibility with hardware memory layout. The original
scheme required that the 4M region containing vecbase be mapped
virtually to a location other than the hardware address, which makes
confusing linkage with call0 and difficult initialization
constraints where the exception vectors run at different addresses
before and after MMU setup (effectively forcing them to be PIC
code).
+ More provably correct initialization, all MMU changes happen in a
single asm block with no memory accesses which would generate a
refill.
Signed-off-by: Andy Ross <andyross@google.com>
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
