[PATCH 5.4 101/108] RDMA/siw: Pass a pointer to virt_to_page()

Greg Kroah-Hartman
2022-09-13T15:05:22Z

From: Linus Walleij <linus.walleij@linaro.org>

[ Upstream commit 0d1b756acf60da5004c1e20ca4462f0c257bf6e1 ]

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 modifying the
virtual address (va) to a platform-specific uintptr_t before
casting to a (void *).

Fixes: b9be6f18cf9e ("rdma/siw: transmit path")
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220902215918.603761-1-linus.walleij@linaro.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/sw/siw/siw_qp_tx.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
index 424918eb1cd4a..5e6d96bd2eb12 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;
}
@@ -523,13 +523,23 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
kunmap(p);
}
} else {
- u64 va = sge->laddr + sge_off;
+ /*
+ * Cast to an uintptr_t to preserve all 64 bits
+ * in sge->laddr.
+ */
+ uintptr_t va = (uintptr_t)(sge->laddr + sge_off);

- page_array[seg] = virt_to_page(va & PAGE_MASK);
+ /*
+ * virt_to_page() takes a (void *) pointer
+ * so cast 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 *)(va & PAGE_MASK));
if (do_crc)
crypto_shash_update(
c_tx->mpa_crc_hd,
- (void *)(uintptr_t)va,
+ (void *)va,
plen);
}

--
2.35.1