Re: [PATCH 2/2] ofnet: implement a receive buffer

[Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>]

Hi.

I still believe this series may be useful for the community. So here is
one more ping.

Thanks.

On 07/13/2016 05:35 PM, Stanislav Kholmanskikh wrote:
> Hi.
> 
> On 05/10/2016 01:45 PM, Stanislav Kholmanskikh wrote:
>> Hi.
>>
>> Could anybody have a look at this series, please?
> 
> Ping.
> 
>>
>> Thanks.
>>
>> On 04/12/2016 03:39 PM, Stanislav Kholmanskikh wrote:
>>> get_card_packet() from ofnet.c allocates a netbuff based on the
>>> device's MTU:
>>>
>>>    nb = grub_netbuff_alloc (dev->mtu + 64 + 2);
>>>
>>> In the case when the MTU is large, and the received packet is
>>> relatively small, this leads to allocation of significantly more memory,
>>> than it's required. An example could be transmission of TFTP packets
>>> with 0x400 blksize via a network card with 0x10000 MTU.
>>>
>>> This patch implements a per-card receive buffer in a way similar to
>>> efinet.c,
>>> and makes get_card_packet() allocate a netbuff of the received data
>>> size.
>>>
>>> Signed-off-by: Stanislav Kholmanskikh
>>> <stanislav.kholmanskikh@oracle.com>
>>> ---
>>>   grub-core/net/drivers/ieee1275/ofnet.c |  100
>>> ++++++++++++++++++-------------
>>>   1 files changed, 58 insertions(+), 42 deletions(-)
>>>
>>> diff --git a/grub-core/net/drivers/ieee1275/ofnet.c
>>> b/grub-core/net/drivers/ieee1275/ofnet.c
>>> index 6bd3b92..09ec77e 100644
>>> --- a/grub-core/net/drivers/ieee1275/ofnet.c
>>> +++ b/grub-core/net/drivers/ieee1275/ofnet.c
>>> @@ -85,24 +85,35 @@ get_card_packet (struct grub_net_card *dev)
>>>     grub_uint64_t start_time;
>>>     struct grub_net_buff *nb;
>>>
>>> -  nb = grub_netbuff_alloc (dev->mtu + 64 + 2);
>>> +  start_time = grub_get_time_ms ();
>>> +  do
>>> +    rc = grub_ieee1275_read (data->handle, dev->rcvbuf,
>>> dev->rcvbufsize, &actual);
>>> +  while ((actual <= 0 || rc < 0) && (grub_get_time_ms () - start_time
>>> < 200));
>>> +
>>> +  if (actual <= 0)
>>> +    return NULL;
>>> +
>>> +  nb = grub_netbuff_alloc (actual + 2);
>>>     if (!nb)
>>>       return NULL;
>>> +
>>>     /* Reserve 2 bytes so that 2 + 14/18 bytes of ethernet header is
>>> divisible
>>>        by 4. So that IP header is aligned on 4 bytes. */
>>> -  grub_netbuff_reserve (nb, 2);
>>> +  if (grub_netbuff_reserve (nb, 2))
>>> +    {
>>> +      grub_netbuff_free (nb);
>>> +      return NULL;
>>> +    }
>>>
>>> -  start_time = grub_get_time_ms ();
>>> -  do
>>> -    rc = grub_ieee1275_read (data->handle, nb->data, dev->mtu + 64,
>>> &actual);
>>> -  while ((actual <= 0 || rc < 0) && (grub_get_time_ms () - start_time
>>> < 200));
>>> -  if (actual > 0)
>>> +  grub_memcpy (nb->data, dev->rcvbuf, actual);
>>> +
>>> +  if (grub_netbuff_put (nb, actual))
>>>       {
>>> -      grub_netbuff_put (nb, actual);
>>> -      return nb;
>>> +      grub_netbuff_free (nb);
>>> +      return NULL;
>>>       }
>>> -  grub_netbuff_free (nb);
>>> -  return NULL;
>>> +
>>> +  return nb;
>>>   }
>>>
>>>   static struct grub_net_card_driver ofdriver =
>>> @@ -294,6 +305,24 @@ grub_ieee1275_net_config_real (const char
>>> *devpath, char **device, char **path,
>>>     }
>>>   }
>>>
>>> +static void *
>>> +ofnet_alloc_netbuf (grub_size_t len)
>>> +{
>>> +  if (grub_ieee1275_test_flag (GRUB_IEEE1275_FLAG_VIRT_TO_REAL_BROKEN))
>>> +    return grub_ieee1275_alloc_mem (len);
>>> +  else
>>> +    return grub_malloc (len);
>>> +}
>>> +
>>> +static void
>>> +ofnet_free_netbuf (void *addr, grub_size_t len)
>>> +{
>>> +  if (grub_ieee1275_test_flag (GRUB_IEEE1275_FLAG_VIRT_TO_REAL_BROKEN))
>>> +    grub_ieee1275_free_mem (addr, len);
>>> +  else
>>> +    grub_free (addr);
>>> +}
>>> +
>>>   static int
>>>   search_net_devices (struct grub_ieee1275_devalias *alias)
>>>   {
>>> @@ -409,41 +438,21 @@ search_net_devices (struct
>>> grub_ieee1275_devalias *alias)
>>>     card->default_address = lla;
>>>
>>>     card->txbufsize = ALIGN_UP (card->mtu, 64) + 256;
>>> +  card->rcvbufsize = ALIGN_UP (card->mtu, 64) + 256;
>>>
>>> -  if (grub_ieee1275_test_flag (GRUB_IEEE1275_FLAG_VIRT_TO_REAL_BROKEN))
>>> -    {
>>> -      struct alloc_args
>>> -      {
>>> -    struct grub_ieee1275_common_hdr common;
>>> -    grub_ieee1275_cell_t method;
>>> -    grub_ieee1275_cell_t len;
>>> -    grub_ieee1275_cell_t catch;
>>> -    grub_ieee1275_cell_t result;
>>> -      }
>>> -      args;
>>> -      INIT_IEEE1275_COMMON (&args.common, "interpret", 2, 2);
>>> -      args.len = card->txbufsize;
>>> -      args.method = (grub_ieee1275_cell_t) "alloc-mem";
>>> -
>>> -      if (IEEE1275_CALL_ENTRY_FN (&args) == -1
>>> -      || args.catch)
>>> -    {
>>> -      card->txbuf = 0;
>>> -      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
>>> -    }
>>> -      else
>>> -    card->txbuf = (void *) args.result;
>>> -    }
>>> -  else
>>> -    card->txbuf = grub_zalloc (card->txbufsize);
>>> +  card->txbuf = ofnet_alloc_netbuf (card->txbufsize);
>>>     if (!card->txbuf)
>>> +    goto fail;
>>> +
>>> +  card->rcvbuf = ofnet_alloc_netbuf (card->rcvbufsize);
>>> +  if (!card->rcvbuf)
>>>       {
>>> -      grub_free (ofdata->path);
>>> -      grub_free (ofdata);
>>> -      grub_free (card);
>>> -      grub_print_error ();
>>> -      return 0;
>>> +      grub_error_push ();
>>> +      ofnet_free_netbuf(card->txbuf, card->txbufsize);
>>> +      grub_error_pop ();
>>> +      goto fail;
>>>       }
>>> +
>>>     card->driver = NULL;
>>>     card->data = ofdata;
>>>     card->flags = 0;
>>> @@ -455,6 +464,13 @@ search_net_devices (struct grub_ieee1275_devalias
>>> *alias)
>>>     card->driver = &ofdriver;
>>>     grub_net_card_register (card);
>>>     return 0;
>>> +
>>> + fail:
>>> +  grub_free (ofdata->path);
>>> +  grub_free (ofdata);
>>> +  grub_free (card);
>>> +  grub_print_error ();
>>> +  return 1;
>>>   }
>>>
>>>   static void
>>>
>>
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