From: Matthew Wilcox

Sent: 16 April 2021 16:28

On Thu, Apr 15, 2021 at 08:08:32PM +0200, Jesper Dangaard Brouer wrote:

quoted

See below patch.  Where I swap32 the dma address to satisfy
page->compound having bit zero cleared. (It is the simplest fix I could
come up with).

I think this is slightly simpler, and as a bonus code that assumes the
old layout won't compile.

Always a good plan.

...

 static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
 {
-	return page->dma_addr;
+	dma_addr_t ret = page->dma_addr[0];
+	if (sizeof(dma_addr_t) > sizeof(unsigned long))
+		ret |= (dma_addr_t)page->dma_addr[1] << 32;
+	return ret;
+}

Won't some compiler/option combinations generate an
error for the '<< 32' when dma_addr_t is 32bit?

You might need to use a (u64) cast.

	David

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