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RDMA/siw: Pass a pointer to virt_to_page()

Message ID 20220829132547.115499-1-linus.walleij@linaro.org (mailing list archive)
State Superseded
Headers show
Series RDMA/siw: Pass a pointer to virt_to_page() | expand

Commit Message

Linus Walleij Aug. 29, 2022, 1:25 p.m. UTC
Functions that work on a pointer to virtual memory such as
virt_to_pfn() and users of that function such as
virt_to_page() are supposed to pass a pointer to virtual
memory, ideally a (void *) or other pointer. However since
many architectures implement virt_to_pfn() as a macro,
this function becomes polymorphic and accepts both a
(unsigned long) and a (void *).

If we instead implement a proper virt_to_pfn(void *addr)
function the following happens (occurred on arch/arm):

drivers/infiniband/sw/siw/siw_qp_tx.c:32:23: warning: incompatible
  integer to pointer conversion passing 'dma_addr_t' (aka 'unsigned int')
  to parameter of type 'const void *' [-Wint-conversion]
drivers/infiniband/sw/siw/siw_qp_tx.c:32:37: warning: passing argument
  1 of 'virt_to_pfn' makes pointer from integer without a cast
  [-Wint-conversion]
drivers/infiniband/sw/siw/siw_qp_tx.c:538:36: warning: incompatible
  integer to pointer conversion passing 'unsigned long long'
  to parameter of type 'const void *' [-Wint-conversion]

Fix this with an explicit cast. In one case where the SIW
SGE uses an unaligned u64 we need a double cast to get to
a (void *).

Cc: linux-rdma@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/infiniband/sw/siw/siw_qp_tx.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
index 1f4e60257700..5c7853ba8831 100644
--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
@@ -29,7 +29,7 @@  static struct page *siw_get_pblpage(struct siw_mem *mem, u64 addr, int *idx)
 	dma_addr_t paddr = siw_pbl_get_buffer(pbl, offset, NULL, idx);
 
 	if (paddr)
-		return virt_to_page(paddr);
+		return virt_to_page((void *)paddr);
 
 	return NULL;
 }
@@ -535,7 +535,17 @@  static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
 			} else {
 				u64 va = sge->laddr + sge_off;
 
-				page_array[seg] = virt_to_page(va & PAGE_MASK);
+				/*
+				 * virt_to_page() takes a (void *) pointer, and
+				 * the va being uint64 creates a special
+				 * problem here needing a double cast to
+				 * resolve the situation: first to (uintptr_t)
+				 * to preserve all the 64 bits and from there
+				 * to a (void *) meaning it will be 64 bits on
+				 * a 64 bit platform and 32 bits on a 32 bit
+				 * platform.
+				 */
+				page_array[seg] = virt_to_page((void *)(uintptr_t)(va & PAGE_MASK));
 				if (do_crc)
 					crypto_shash_update(
 						c_tx->mpa_crc_hd,