Re: [PATCH v8 01/23] dma-direct: return struct page from dma_direct_alloc_from_pool()

On Thu, Jul 23, 2026 at 10:57:04AM +0300, Leon Romanovsky wrote:

On Wed, Jul 22, 2026 at 04:59:12PM -0300, Jason Gunthorpe wrote:

quoted

On Tue, Jul 21, 2026 at 06:33:21PM +0300, Leon Romanovsky wrote:

quoted

Something like, but probably void* needs to be phys_addr_t:

static inline struct page *dma_phys_to_page(void *addr)
{
#ifdef CONFIG_DMA_DIRECT_REMAP
	return vmalloc_to_page(addr);
#else
	return virt_to_page(addr);
#endif
}

I don't like this, we don't know for sure the addr will be in a vmap
and this will fail if it isn't.

Of course we know. The existing "#ifdef CONFIG_DMA_DIRECT_REMAP" is
relevant for addresses acquired from pool.

Yeah, but I still don't like it :) It is hard to follow if you make
those kinds of leaps, someone will call this new helper on something
they shouldn't

dma_phys_to_page() is a bad name for some low-level conversion function.
It needs to be internal to DMA logic, in the level when we convert from
phys to page.

I think we should not convert from phys to page, that's also easy to
do wrong

Jason