arm: implement the new page table range API

Add set_ptes(), update_mmu_cache_range(), flush_dcache_folio() and
flush_icache_pages().  Change the PG_dcache_clear flag from being per-page
to per-folio which makes __dma_page_dev_to_cpu() a bit more exciting. 
Also add flush_cache_pages(), even though this isn't used by generic code
(yet?)

[m.szyprowski@samsung.com: fix potential endless loop in __dma_page_dev_to_cpu()]
  Link: https://lkml.kernel.org/r/20230809172737.3574190-1-m.szyprowski@samsung.com
[willy@infradead.org: fix folio conversion in __dma_page_dev_to_cpu()]
  Link: https://lkml.kernel.org/r/20230823191852.1556561-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 15 insertions, 13 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 033a1bce2b17..5409225b4abc 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -709,19 +709,21 @@ static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
 	 * Mark the D-cache clean for these pages to avoid extra flushing.
 	 */
 	if (dir != DMA_TO_DEVICE && size >= PAGE_SIZE) {
-		unsigned long pfn;
-		size_t left = size;
-
-		pfn = page_to_pfn(page) + off / PAGE_SIZE;
-		off %= PAGE_SIZE;
-		if (off) {
-			pfn++;
-			left -= PAGE_SIZE - off;
-		}
-		while (left >= PAGE_SIZE) {
-			page = pfn_to_page(pfn++);
-			set_bit(PG_dcache_clean, &page->flags);
-			left -= PAGE_SIZE;
+		struct folio *folio = pfn_folio(paddr / PAGE_SIZE);
+		size_t offset = offset_in_folio(folio, paddr);
+
+		for (;;) {
+			size_t sz = folio_size(folio) - offset;
+
+			if (size < sz)
+				break;
+			if (!offset)
+				set_bit(PG_dcache_clean, &folio->flags);
+			offset = 0;
+			size -= sz;
+			if (!size)
+				break;
+			folio = folio_next(folio);
 		}
 	}
 }