* Implement both RawSPU and threaded SPU page fault recovery
* Guard page_fault_notification_entries access with a mutex
* Add missing lock in sys_ppu_thread_recover_page_fault/get_page_fault_context
* Fix EINVAL check in sys_ppu_thread_recover_page_fault, previously when the event was not found begin() was erased and
CELL_OK was returned.
* Fixed page fault recovery waiting logic:
- Do not rely on a single thread_ctrl notification (unsafe)
- Avoided a race where ::awake(ppu) can be called before ::sleep(ppu) therefore nop-ing out the notification
* Avoid inconsistencies with vm flags on page fault cause detection
* Fix sys_mmapper_enable_page_fault_notification EBUSY check
from RE it's allowed to register the same queue twice (on a different area) but not to enable page fault notifications twice
TODO: From hw testing, it seems like sys_memory_get_page_attribute and sys_rsx_context_iomap check page size a little differently
get_page_attribute() always go by area flags, sys_rsx_context_iomap checks page by the page granularity
This means that if the area page size 64k, but shared memory is mapped with SYS_MEMORY_GRANULARITY_1M
It can be mapped for rsxio, but the page attribute will indicate 64k page size :thonk:
rsxio memory is verified to need 1m pages.
* Fix 0 vm page flags to behave like 1m flags, follows c8a681e60
* check if address exists and valid for rsx io allcations (must be allocated on 1m pages)
