netcp: try to reduce type confusion in descriptors
The netcp driver produces tons of warnings when CONFIG_LPAE is enabled
on ARM:
drivers/net/ethernet/ti/netcp_core.c: In function 'netcp_tx_map_skb':
drivers/net/ethernet/ti/netcp_core.c:1084:13: warning: passing argument 1 of 'set_words' from incompatible pointer type [-Wincompatible-pointer-types]
This is the result of trying to pass a pointer to a dma_addr_t to
a function that expects a u32 pointer to copy that into a DMA descriptor.
Looking at that code in more detail to fix the warnings, I see multiple
related problems:
* The conversion functions are not endian-safe, as the DMA descriptors
are almost certainly fixed-endian, but the CPU is not.
* On 64-bit machines, passing a pointer through a u32 variable is a
bug, accessing an indirect pointer as a u32 pointer even more so.
* The handling of epib and psdata mixes native-endian and device-endian
data.
In this patch, I try to sort out the types for most accesses here,
adding le32_to_cpu/cpu_to_le32 where appropriate, and passing pointers
through two 32-bit words in the descriptor padding, to make it plausible
that the driver does the right thing if compiled for big-endian or
64-bit systems.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed