Hi Matthew,
On Wed, Aug 02, 2023 at 04:13:49PM +0100, Matthew Wilcox (Oracle) wrote:
> Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio().
> Change the PG_arch_1 (aka PG_dcache_dirty) flag from being per-page to
> per-folio.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
...
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index d16d80ad2ae4..b4da8514af43 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -894,7 +894,7 @@ void kvmppc_init_lpid(unsigned long nr_lpids);
>
> static inline void kvmppc_mmu_flush_icache(kvm_pfn_t pfn)
> {
> - struct page *page;
> + struct folio *folio;
> /*
> * We can only access pages that the kernel maps
> * as memory. Bail out for unmapped ones.
> @@ -903,10 +903,10 @@ static inline void kvmppc_mmu_flush_icache(kvm_pfn_t pfn)
> return;
>
> /* Clear i-cache for new pages */
> - page = pfn_to_page(pfn);
> - if (!test_bit(PG_dcache_clean, &page->flags)) {
> - flush_dcache_icache_page(page);
> - set_bit(PG_dcache_clean, &page->flags);
> + folio = page_folio(pfn_to_page(pfn));
> + if (!test_bit(PG_dcache_clean, &folio->flags)) {
> + flush_dcache_icache_folio(folio);
> + set_bit(PG_dcache_clean, &folio->flags);
> }
> }
...
> diff --git a/arch/powerpc/mm/cacheflush.c b/arch/powerpc/mm/cacheflush.c
> index 0e9b4879c0f9..8760d2223abe 100644
> --- a/arch/powerpc/mm/cacheflush.c
> +++ b/arch/powerpc/mm/cacheflush.c
> @@ -148,44 +148,30 @@ static void __flush_dcache_icache(void *p)
> invalidate_icache_range(addr, addr + PAGE_SIZE);
> }
>
> -static void flush_dcache_icache_hugepage(struct page *page)
> +void flush_dcache_icache_folio(struct folio *folio)
> {
> - int i;
> - int nr = compound_nr(page);
> + unsigned int i, nr = folio_nr_pages(folio);
>
> - if (!PageHighMem(page)) {
> + if (flush_coherent_icache())
> + return;
> +
> + if (!folio_test_highmem(folio)) {
> + void *addr = folio_address(folio);
> for (i = 0; i < nr; i++)
> - __flush_dcache_icache(lowmem_page_address(page + i));
> - } else {
> + __flush_dcache_icache(addr + i * PAGE_SIZE);
> + } else if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
> for (i = 0; i < nr; i++) {
> - void *start = kmap_local_page(page + i);
> + void *start = kmap_local_folio(folio, i * PAGE_SIZE);
>
> __flush_dcache_icache(start);
> kunmap_local(start);
> }
> - }
> -}
> -
> -void flush_dcache_icache_page(struct page *page)
> -{
> - if (flush_coherent_icache())
> - return;
> -
> - if (PageCompound(page))
> - return flush_dcache_icache_hugepage(page);
> -
> - if (!PageHighMem(page)) {
> - __flush_dcache_icache(lowmem_page_address(page));
> - } else if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
> - void *start = kmap_local_page(page);
> -
> - __flush_dcache_icache(start);
> - kunmap_local(start);
> } else {
> - flush_dcache_icache_phys(page_to_phys(page));
> + unsigned long pfn = folio_pfn(folio);
> + for (i = 0; i < nr; i++)
> + flush_dcache_icache_phys((pfn + i) * PAGE_SIZE);
> }
> }
> -EXPORT_SYMBOL(flush_dcache_icache_page);
Apologies if this has already been fixed or reported, I searched lore
and did not find anything. The dropping of this export in combination
with the conversion above appears to cause ARCH=powerpc allmodconfig to
fail with:
ERROR: modpost: "flush_dcache_icache_folio" [arch/powerpc/kvm/kvm-pr.ko] undefined!
I don't know if this should be re-exported or not but that does
obviously resolve the issue.
Cheers,
Nathan
