On 3/29/23 09:23, Linus Walleij wrote: > Like the other calls in this function virt_to_page() expects > a pointer, not an integer. > > However since many architectures implement virt_to_pfn() as > a macro, this function becomes polymorphic and accepts both a > (unsigned long) and a (void *). > > Fix this up with an explicit cast. > > Then we need a second cast to (uintptr_t). This is because > the kernel robot builds this driver also for the PARISC, > yielding the following build error on PARISC when casting > (void *) to virt_to_page(): > > drivers/infiniband/sw/rxe/rxe_mr.c: In function 'rxe_set_page': >>> drivers/infiniband/sw/rxe/rxe_mr.c:216:42: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] > 216 | struct page *page = virt_to_page((void *)(iova & mr->page_mask)); > | ^ > include/asm-generic/memory_model.h:18:46: note: in definition of macro '__pfn_to_page' > 18 | #define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET)) > | ^~~ > arch/parisc/include/asm/page.h:179:45: note: in expansion of macro '__pa' > 179 | #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) > | ^~~~ > drivers/infiniband/sw/rxe/rxe_mr.c:216:29: note: in expansion of macro 'virt_to_page' > 216 | struct page *page = virt_to_page((void *)(iova & mr->page_mask)); > | ^~~~~~~~~~~~ > > First: I think this happens because iova is u64 by design and > (void *) on PARISC is sometimes 32 bit. > > Second: compilation of the SW RXE driver on PARISC is made possible > because it fulfills depends on INFINIBAND_VIRT_DMA since that is just > def_bool !HIGHMEM and PARISC does not have HIGHMEM. > > By first casting iova to (uintptr_t) it is turned into a u32 on PARISC > or any other 32bit system and u64 on any 64BIT system. > > Link: https://lore.kernel.org/linux-rdma/202303242000.HmTaa6yB-lkp@xxxxxxxxx/ > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > --- > ChangeLog v1->v2: > - Fix up confusion between virtual and physical addresses found > by Jason in a separate patch. > - Fix up compilation on PARISC by additional cast. > I don't know if this is the right solution, perhaps RDMA should > rather depend on 64BIT if the subsystem is only for 64BIT > systems? > --- > drivers/infiniband/sw/rxe/rxe_mr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c > index 8e8250652f9d..a5efb0575956 100644 > --- a/drivers/infiniband/sw/rxe/rxe_mr.c > +++ b/drivers/infiniband/sw/rxe/rxe_mr.c > @@ -213,7 +213,7 @@ int rxe_mr_init_fast(int max_pages, struct rxe_mr *mr) > static int rxe_set_page(struct ib_mr *ibmr, u64 iova) > { > struct rxe_mr *mr = to_rmr(ibmr); > - struct page *page = virt_to_page(iova & mr->page_mask); > + struct page *page = virt_to_page((void *)(uintptr_t)(iova & mr->page_mask)); > bool persistent = !!(mr->access & IB_ACCESS_FLUSH_PERSISTENT); > int err; > Linus, Thanks for these. AFAIK these are just fine. I am not aware of any interest in 32 bit support for the rxe driver. My testing has been limited to IA64 architectures but I would be interested in going further with emulated hardware. Reviewed-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
