>Consider network drivers (most PCI ones) that keep track of:
>
> struct sk_buff *skb;
> dma_addr_t mapping;
>
>pairs for each transmit packet. With your suggested change,
>their structures will increase 32-bits in size for each entry
>when CONFIG_HIGHMEM on x86 or on a 64-bit platform.
They already increase by 32bits on IA64. A driver should use a
fixed sized type for a fixed sized address that corresponds to its
capabilities. There is no guarantee of the size of dma_addr_t.
It is opaque and should be able to represent all dma (or I would prefer
bus) addresses in the system. The examples I've seen where people
assume it to be 32bits in size are, well, broken.
-- Justin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Aug 23 2001 - 21:00:52 EST