2017-11-03 4:00 GMT+01:00 Willem de Bruijn <willemdebruijn.ker...@gmail.com>:
> On Tue, Oct 31, 2017 at 9:41 PM, Björn Töpel <bjorn.to...@gmail.com> wrote:
>> From: Björn Töpel <bjorn.to...@intel.com>
>>
>> Here, the PACKET_MEMREG setsockopt is implemented for the AF_PACKET
>> protocol family. PACKET_MEMREG allows the user to register memory
>> regions that can be used by AF_PACKET V4 as packet data buffers.
>>
>> Signed-off-by: Björn Töpel <bjorn.to...@intel.com>
>> ---
>> +/*************** V4 QUEUE OPERATIONS *******************************/
>> +
>> +/**
>> + * tp4q_umem_new - Creates a new umem (packet buffer)
>> + *
>> + * @addr: The address to the umem
>> + * @size: The size of the umem
>> + * @frame_size: The size of each frame, between 2K and PAGE_SIZE
>> + * @data_headroom: The desired data headroom before start of the packet
>> + *
>> + * Returns a pointer to the new umem or NULL for failure
>> + **/
>> +static inline struct tp4_umem *tp4q_umem_new(unsigned long addr, size_t
>> size,
>> + unsigned int frame_size,
>> + unsigned int data_headroom)
>> +{
>> + struct tp4_umem *umem;
>> + unsigned int nframes;
>> +
>> + if (frame_size < TP4_UMEM_MIN_FRAME_SIZE || frame_size > PAGE_SIZE) {
>> + /* Strictly speaking we could support this, if:
>> + * - huge pages, or*
>> + * - using an IOMMU, or
>> + * - making sure the memory area is consecutive
>> + * but for now, we simply say "computer says no".
>> + */
>> + return ERR_PTR(-EINVAL);
>> + }
>> +
>> + if (!is_power_of_2(frame_size))
>> + return ERR_PTR(-EINVAL);
>> +
>> + if (!PAGE_ALIGNED(addr)) {
>> + /* Memory area has to be page size aligned. For
>> + * simplicity, this might change.
>> + */
>> + return ERR_PTR(-EINVAL);
>> + }
>> +
>> + if ((addr + size) < addr)
>> + return ERR_PTR(-EINVAL);
>> +
>> + nframes = size / frame_size;
>> + if (nframes == 0)
>> + return ERR_PTR(-EINVAL);
>> +
>> + data_headroom = ALIGN(data_headroom, 64);
>> +
>> + if (frame_size - data_headroom - TP4_KERNEL_HEADROOM < 0)
>> + return ERR_PTR(-EINVAL);
>
> signed comparison on unsigned int
Thanks, will address in next revision!
