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Address PR kern/148307 - fix if_ath TX mbuf alignment/size constraint checks

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The existing code only checked the alignment of the first mbuf and
didn't enforce the size constraints.

This commit introduces a simple function to check the alignment and
size of all mbufs in the list. This fixes the initial issue in the
PR.

PR: kern/148307
Reviewed by: gonzo@
This commit is contained in:
Adrian Chadd 2010-07-08 14:59:32 +00:00
parent 76780f208c
commit ef54d27641
1 changed files with 23 additions and 1 deletions
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24
sys/mips/atheros/if_arge.c
View File

@ -833,6 +833,28 @@ arge_init_locked(struct arge_softc *sc)
ARGE_WRITE(sc, AR71XX_DMA_INTR, DMA_INTR_ALL);
}
/*
* Return whether the mbuf chain is correctly aligned
* for the arge TX engine.
*
* The TX engine requires each fragment to be aligned to a
* 4 byte boundary and the size of each fragment except
* the last to be a multiple of 4 bytes.
*/
static int
arge_mbuf_chain_is_tx_aligned(struct mbuf *m0)
{
struct mbuf *m;
for (m = m0; m != NULL; m = m->m_next) {
if((mtod(m, intptr_t) & 3) != 0)
return 0;
if ((m->m_next != NULL) && ((m->m_len & 0x03) != 0))
return 0;
}
return 1;
}
/*
* Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
* pointers to the fragment pointers.
@ -853,7 +875,7 @@ arge_encap(struct arge_softc *sc, struct mbuf **m_head)
* even 4 bytes
*/
m = *m_head;
if((mtod(m, intptr_t) & 3) != 0) {
if (! arge_mbuf_chain_is_tx_aligned(m)) {
m = m_defrag(*m_head, M_DONTWAIT);
if (m == NULL) {
*m_head = NULL;