Hello,
Motioned to the memory aligned, now there is such requirement:
When the driver send an packet to hardware, the skb's address passed by
stack do a dma map into hardware, the skb's dma address must be 64-byte
aligned.
My method:
Allocate a new skb which is 64-byte aligned, then copy the passed skb to
new one
After test, the driver can work and overcome this issue.
But I eager to get a perfect solution about that, could you offer me a nice
one? Thanks so much~~
Code：
static struct sk_buff * skb_align_copy(const struct sk_buff *skb, gfp_t
gfp_mask)
{
if((skb->len + LEN_INFO_BYTES) > 2000 ){
atomic_inc(&proc_stat[PROC_STAT_JUMBO_CNT]);
return NULL;
}
struct sk_buff *n;
n = alloc_skb(2048, gfp_mask); //0 headroom
if(!n)
return NULL;
atomic_inc(&proc_stat[PROC_STAT_SKB_ALLOC]);
skb_put(n, skb->len + LEN_INFO_BYTES);
if((skb->data - LEN_INFO_BYTES) == NULL){
c_err("skb->data - LEN_INFO_BYTES is NULL!\n");
return NULL;
}
memcpy(n->data, skb->data - LEN_INFO_BYTES, skb->len + LEN_INFO_BYTES);
return n;
}
static int ne_pcie_tx_map(struct ne_pcie_ring* tx_ring, struct sk_buff* skb)
{
struct ne_pcie_buff* buff;
struct sk_buff* align_skb;
int i = tx_ring->next_to_use;
int len = skb->len;
int count = 0;
align_skb = skb_align_copy(skb, GFP_ATOMIC);
if(!align_skb){
goto dma_map_error;
}
buff = &tx_ring->buffer[i];
buff->length = len+LEN_INFO_BYTES;
buff->dma = pci_map_single(tx_ring->pci_dev, align_skb->data,
len+LEN_INFO_BYTES, PCI_DMA_TODEVICE);
if (pci_dma_mapping_error(tx_ring->pci_dev, buff->dma)) {
goto dma_map_error;
}
-----邮件原件-----
发件人: [email protected] [mailto:[email protected]]
代表 Holger Brunck
发送时间: 2011年6月17日 16:31
收件人: [email protected]
抄送: Clive Stubbings; Holger Brunck; Pantelis Antoniou; Vitaly Bordug;
[email protected]
主题: [PATCH] fs_enet: fix freescale FCC ethernet dp buffer alignment
From: Clive Stubbings <[email protected]>
The RIPTR and TIPTR (receive/transmit internal temporary data pointer),
used by microcode as a temporary buffer for data, must be 32-byte aligned
according to the RM for MPC8247.
Tested on mgcoge.
Signed-off-by: Clive Stubbings <[email protected]>
Signed-off-by: Holger Brunck <[email protected]>
cc: Pantelis Antoniou <[email protected]>
cc: Vitaly Bordug <[email protected]>
cc: [email protected]
---
This fixes a kernel crash on mgcoge when using SPI on CPM2 and
ethernet over FCC. Now fixed because the fcc driver now allocates
the space he really needs.
drivers/net/fs_enet/mac-fcc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/net/fs_enet/mac-fcc.c b/drivers/net/fs_enet/mac-fcc.c
index 7a84e45..7583a95 100644
--- a/drivers/net/fs_enet/mac-fcc.c
+++ b/drivers/net/fs_enet/mac-fcc.c
@@ -105,7 +105,7 @@ static int do_pd_setup(struct fs_enet_private *fep)
goto out_ep;
fep->fcc.mem = (void __iomem *)cpm2_immr;
- fpi->dpram_offset = cpm_dpalloc(128, 8);
+ fpi->dpram_offset = cpm_dpalloc(128, 32);
if (IS_ERR_VALUE(fpi->dpram_offset)) {
ret = fpi->dpram_offset;
goto out_fcccp;
--
1.7.1
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