If we evict enough pages to completely fill the backing store,
through APIs like k_mem_map(), z_page_frame_evict(), or
z_mem_page_out(), this will produce a crash the next time we
try to handle a page fault.
The backing store now always reserves a free storage location
for actual page faults.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This will enable testing of the implementation until the
critical set of pages is identified and known to the
kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Implement runtime APIs for pinning, paging in, and evicting
memory, as well as the page fault hook called from architecture
code.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Page tables created at build time may not include the
gperf data at the very end of RAM. Ensure this is mapped
properly at runtime to work around this.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Pre-allocation of paging structures is now required, such that
no allocations are ever needed when mapping memory.
Instantiation of new memory domains may still require allocations
unless a common page table is used.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Allows applications to increase the data space available to Zephyr
via anonymous memory mappings. Loosely based on mmap().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If we evict enough pages to completely fill the backing store,
through APIs like k_mem_map(), z_page_frame_evict(), or
z_mem_page_out(), this will produce a crash the next time we
try to handle a page fault.
The backing store now always reserves a free storage location
for actual page faults.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This will enable testing of the implementation until the
critical set of pages is identified and known to the
kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Implement runtime APIs for pinning, paging in, and evicting
memory, as well as the page fault hook called from architecture
code.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Page tables created at build time may not include the
gperf data at the very end of RAM. Ensure this is mapped
properly at runtime to work around this.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Pre-allocation of paging structures is now required, such that
no allocations are ever needed when mapping memory.
Instantiation of new memory domains may still require allocations
unless a common page table is used.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Allows applications to increase the data space available to Zephyr
via anonymous memory mappings. Loosely based on mmap().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Renamed to make its semantics clearer; this function maps
*physical* memory addresses and is not equivalent to
posix mmap(), which might confuse people.
mem_map test case remains the same name as other memory
mapping scenarios will be added in the fullness of time.
Parameter names to z_phys_map adjusted slightly to be more
consistent with names used in other memory mapping functions.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Most of kernel files where declaring os module without providing
log level. Because of that default log level was used instead of
CONFIG_KERNEL_LOG_LEVEL.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Some platforms may have multiple RAM regions which are
dis-continuous in the physical memory map. We really want
these to be in a continuous virtual region, and we need to
stop assuming that there is just one SRAM region that is
identity-mapped.
We no longer use CONFIG_SRAM_BASE_ADDRESS and CONFIG_SRAM_SIZE
as the bounds of kernel RAM, and no longer assume in the core
kernel that these are identity mapped at boot.
Two new Kconfigs, CONFIG_KERNEL_VM_BASE and
CONFIG_KERNEL_RAM_SIZE now indicate the bounds of this region
in virtual memory.
We are currently only memory-mapping physical device driver
MMIO regions so we do not need virtual-to-physical calculations
to re-map RAM yet. When the time comes an architecture interface
will be defined for this.
Platforms which just have one RAM region may continue to
identity-map it.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
In the MMU code mapping_pos is miscalculated when for example
SRAM_BASE_ADDRESS==0x40000000 and KERNEL_VM_SIZE==0xc0000000 getting a
mapping_pos of 0x0.
The problem is that we must cast the two values to uintptr_t before
casting the result to avoid the rollover to 0.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Memory mapping, for now, will be a private kernel API
and is not intended to be application-facing at this time.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We no longer plan to support a split address space with
the kernel in high memory and per-process address spaces.
Because of this, we can simplify some things. System RAM
is now always identity mapped at boot.
We no longer require any virtual-to-physical translation
for page tables, and can remove the dual-mapping logic
from the page table generation script since we won't need
to transition the instruction point off of physical
addresses.
CONFIG_KERNEL_VM_BASE and CONFIG_KERNEL_VM_LIMIT
have been removed. The kernel's address space always
starts at CONFIG_SRAM_BASE_ADDRESS, of a fixed size
specified by CONFIG_KERNEL_VM_SIZE.
Driver MMIOs and other uses of k_mem_map() are still
virtually mapped, and the later introduction of demand
paging will result in only a subset of system RAM being
a fixed identity mapping instead of all of it.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This will be the interface for mapping memory in the kernel's
part of the address space, which is guaranteed to be persistent
regardless of what thread is scheduled.
Further code for specifically managing virtual memory will end up in
kernel/mmu.c.
Further defintions for memory management in general will end up
in sys/mem_manage.h.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
