[PATCH v2 0/3] enable MMU for RISC-V

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

The patch series is based on top of  'RISCV basic exception handling
implementation' patch series. [1]

The patch series introduces the following things:
1. Functionality to build the page tables for Xen that map
   link-time to physical-time location.
2. Check that Xen is less then page size.
3. Check that load addresses don't overlap with linker addresses.
4. Prepare things for proper switch to virtual memory world.
5. Load the built page table into the SATP
6. Enable MMU.

[1] 
https://lore.kernel.org/xen-devel/cover.1678976127.git.oleksii.kurochko@xxxxxxxxx/T/#t

---
Changes in V2:
  * Remove {ZEROETH,FIRST,...}_{SHIFT,MASK, SIZE,...} and
    introduce instead of them XEN_PT_LEVEL_*() and LEVEL_*
  * Rework pt_linear_offset() and pt_index based on  XEN_PT_LEVEL_*()
  * Remove clear_pagetables() functions as pagetables were zeroed during
    .bss initialization
  * Rename _setup_initial_pagetables() to setup_initial_mapping()
  * Make PTE_DEFAULT equal to RX.
  * Update prototype of setup_initial_mapping(..., bool writable) -> 
    setup_initial_mapping(..., UL flags)  
  * Update calls of setup_initial_mapping according to new prototype
  * Remove unnecessary call of:
    _setup_initial_pagetables(..., load_addr_start, load_addr_end, 
load_addr_start, ...)
  * Define index* in the loop of setup_initial_mapping
  * Remove attribute "__attribute__((section(".entry")))" for 
setup_initial_pagetables()
    as we don't have such section
  * make arguments of paddr_to_pte() and pte_is_valid() as const.
  * use <xen/kernel.h> instead of declaring extern unsigned long _stext, 
0etext, _srodata, _erodata
  * update  'extern unsigned long __init_begin' to 'extern unsigned long 
__init_begin[]'
  * use aligned() instead of "__attribute__((__aligned__(PAGE_SIZE)))"
  * set __section(".bss.page_aligned") for page tables arrays
  * fix identatations
  * Change '__attribute__((section(".entry")))' to '__init'
  * Remove alignment  of {map, pa}_start &= XEN_PT_LEVEL_MAP_MASK(0); in
    setup_inital_mapping() as they should be already aligned.
  * Remove clear_pagetables() as initial pagetables will be
    zeroed during bss initialization
  * Remove __attribute__((section(".entry")) for setup_initial_pagetables()
    as there is no such section in xen.lds.S
  * Update the argument of pte_is_valid() to "const pte_t *p"
  * Remove patch "[PATCH v1 3/3] automation: update RISC-V smoke test" from the 
patch series
    as it was introduced simplified approach for RISC-V smoke test by Andrew 
Cooper
  * Add patch [[xen/riscv: remove dummy_bss variable] as there is no any sense 
in
    dummy_bss variable after introduction of inittial page tables.
---
Oleksii Kurochko (3):
  xen/riscv: introduce setup_initial_pages
  xen/riscv: setup initial pagetables
  xen/riscv: remove dummy_bss variable

 xen/arch/riscv/Makefile           |   1 +
 xen/arch/riscv/include/asm/mm.h   |   8 ++
 xen/arch/riscv/include/asm/page.h |  67 +++++++++++++++++
 xen/arch/riscv/mm.c               | 121 ++++++++++++++++++++++++++++++
 xen/arch/riscv/riscv64/head.S     |  65 ++++++++++++++++
 xen/arch/riscv/setup.c            |  13 ++--
 xen/arch/riscv/xen.lds.S          |   2 +
 7 files changed, 269 insertions(+), 8 deletions(-)
 create mode 100644 xen/arch/riscv/include/asm/mm.h
 create mode 100644 xen/arch/riscv/include/asm/page.h
 create mode 100644 xen/arch/riscv/mm.c

-- 
2.39.2