Date: Thu, 8 Jul 2010 14:59:32 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r209807 - head/sys/mips/atheros Message-ID: <201007081459.o68ExWgO044025@svn.freebsd.org>
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Author: adrian Date: Thu Jul 8 14:59:32 2010 New Revision: 209807 URL: http://svn.freebsd.org/changeset/base/209807 Log: Address PR kern/148307 - fix if_ath TX mbuf alignment/size constraint checks 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@ Modified: head/sys/mips/atheros/if_arge.c Modified: head/sys/mips/atheros/if_arge.c ============================================================================== --- head/sys/mips/atheros/if_arge.c Thu Jul 8 14:56:42 2010 (r209806) +++ head/sys/mips/atheros/if_arge.c Thu Jul 8 14:59:32 2010 (r209807) @@ -834,6 +834,28 @@ arge_init_locked(struct arge_softc *sc) } /* + * 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 * 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;
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