On Thu, Feb 16, 2023 at 01:59:44PM +1300, Michael Schmitz wrote:
Matthew,
On 16/02/23 09:09, Matthew Wilcox (Oracle) wrote:
Add set_ptes(), update_mmu_cache_range(), flush_icache_pages() and
flush_dcache_folio(). I'm not entirely certain that the 040/060 case
in __flush_pages_to_ram() is correct.
I'm pretty sure you need to iterate to hit each of the pages - the code as
is will only push cache entries for the first page.
Quoting the 040 UM:
"Both instructions [cinv, cpush] allow operation on a single cache line, all
cache lines in a specific page, or an entire cache, and can select one or
both caches for the operation. For line and page operations, a physical
address in an address register specifies the memory address."
I actually found that! What I didn't find was how to tell if this
cpush insn is the one which is operating on a single cache line,
a single page, or the entire cache.
So I should do a loop around this asm and call it once for each page
we're flushing?
