The current patch series introduces the relocation of the host device tree file
to free up low memory and also it is expected that discard_initial_modules()
will be called sooner or later, it will discard the FDT boot module,
and remove_early_mappings() will destroy the early mappings.
In addition to relocation, unflattening is introduced to create the tree of
struct device_node for the host device tree.
To implement this, several things have been introduced:
- destroy_xen_mappings() function, which removes page mappings from Xen's
page tables. This is necessary for clear_fixmap().
- {set,clear}_fixmap() functions to manage mappings in the fixmap region,
which are expected to be used in copy_from_paddr() to copy the FDT to Xen's
heap.
- A new config HAS_CMO is introduced (in anticipation of future use). This is
despite the fact that hardware ( "available" to me ) with the hypervisor
extension is generally I/O-coherent ( and it is preferred way mentioned in
the RISC-V spec ) and should not be an issue in QEMU as it doesn't emulate
caches.
This config introduces stubs for clean_and_invalidate_dcache_va_range()
and clean_dcache_va_range(), which are expected to be used in
copy_from_paddr() and flush_page_to_ram(), which in turn are expected to be
used during the call to xmalloc_bytes() in relocate_fdt().
- The introduction of copy_from_paddr() to copy the FDT to an address
allocated in Xen's heap.
Oleksii Kurochko (6):
xen/riscv: add destroy_xen_mappings() to remove mappings in Xen page
tables
xen/riscv: reorder includes in asm/page.h alphabetically
xen/riscv: add {set,clear}_fixmap() functions for managing fixmap
entries
xen/riscv: introduce cache management operations (CMO)
xen/riscv: implement relocate_fdt()
xen/riscv: relocating and unflattening host device tree
xen/arch/riscv/Kconfig | 3 ++
xen/arch/riscv/include/asm/fixmap.h | 5 +++
xen/arch/riscv/include/asm/mm.h | 10 ++++-
xen/arch/riscv/include/asm/page.h | 30 +++++++++++++--
xen/arch/riscv/mm.c | 9 ++---
xen/arch/riscv/pt.c | 27 ++++++++++++++
xen/arch/riscv/setup.c | 57 ++++++++++++++++++++++++++++-
7 files changed, 128 insertions(+), 13 deletions(-)
--
2.47.0
