The only page table duplicated is the kernel page table. This function
does not need a parameter.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
We can use some extra bits available for SW implementation to
save original permissions and avoid duplicating the kernel page tables
for the default memory domain.
Whe duplicating the page table to a new domain we just ensure
to restore the original map.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Simplify the logic around the shared attribute. Checks if a memory
region should be shared only in the function that actually maps the
memory.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Introduce z_page_frame_set() and z_page_frame_clear() to manipulate
flags. Obtain the virtual address using the existing
z_page_frame_to_virt(). This will make changes to the page frame
structure easier.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
When duplicating a page table, we don't need to copy
the mapping to the kernel l1 page table virtual address.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
The #pragma to ignore array bounds for xtensa_soc_mmu_ranges[]
was a remnant before code refactoring during review. Since
this array is no longer declared __weak and as a zero length
array, the #pragma to ignore array bounds is no longer needed.
So remove them.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds a kconfig to enable invalidating the TLBs related to
the incoming thread's memory domain during page table swaps.
It provides a workaround, if needed, to clear out stale TLB
entries used by the thread being swapped out. Those stale
entries may contain incorrect permissions and rings.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
There are several subsystems and boards which require a relatively large
system heap (used by k_malloc()) to function properly. This became even
more notable with the recent introduction of the ACPICA library, which
causes ACPI-using boards to require a system heap of up to several
megabytes in size.
Until now, subsystems and boards have tried to solve this by having
Kconfig overlays which modify the default value of HEAP_MEM_POOL_SIZE.
This works ok, except when applications start explicitly setting values
in their prj.conf files:
$ git grep CONFIG_HEAP_MEM_POOL_SIZE= tests samples|wc -l
157
The vast majority of values set by current sample or test applications
is much too small for subsystems like ACPI, which results in the
application not being able to run on such boards.
To solve this situation, we introduce support for subsystems to specify
their own custom system heap size requirement. Subsystems do
this by defining Kconfig options with the prefix HEAP_MEM_POOL_ADD_SIZE_.
The final value of the system heap is the sum of the custom
minimum requirements, or the value existing HEAP_MEM_POOL_SIZE option,
whichever is greater.
We also introduce a new HEAP_MEM_POOL_IGNORE_MIN Kconfig option which
applications can use to force a lower value than what subsystems have
specficied, however this behavior is disabled by default.
Whenever the minimum is greater than the requested value a CMake warning
will be issued in the build output.
This patch ends up modifying several places outside of kernel code,
since the presence of the system heap is no longer detected using a
non-zero CONFIG_HEAP_MEM_POOL_SIZE value, rather it's now detected using
a new K_HEAP_MEM_POOL_SIZE value that's evaluated at build.
Signed-off-by: Johan Hedberg <johan.hedberg@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>
Fix the way we read the current l1 page table set in the mmu.
We use it check if the current page table is different from the
running thread.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
The ring field in the pte mapping a memory partition should
be based in the partition attribute and not in the domain
asid that is used only to set the ASID (in RASID) position for
user ring.
Signed-off-by: Flavio Ceolin <flavio.ceolin@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>
