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kernel-ark/drivers/s390/net/qeth_eddp.c
Herbert Xu 7967168cef [NET]: Merge TSO/UFO fields in sk_buff 
Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 02:07:29 -07:00

632 lines
17 KiB
C
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/*
* linux/drivers/s390/net/qeth_eddp.c
*
* Enhanced Device Driver Packing (EDDP) support for the qeth driver.
*
* Copyright 2004 IBM Corporation
*
* Author(s): Thomas Spatzier <tspat@de.ibm.com>
*
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/ip.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/kernel.h>
#include <linux/tcp.h>
#include <net/tcp.h>
#include <linux/skbuff.h>
#include <net/ip.h>
#include "qeth.h"
#include "qeth_mpc.h"
#include "qeth_eddp.h"
int
qeth_eddp_check_buffers_for_context(struct qeth_qdio_out_q *queue,
struct qeth_eddp_context *ctx)
{
int index = queue->next_buf_to_fill;
int elements_needed = ctx->num_elements;
int elements_in_buffer;
int skbs_in_buffer;
int buffers_needed = 0;
QETH_DBF_TEXT(trace, 5, "eddpcbfc");
while(elements_needed > 0) {
buffers_needed++;
if (atomic_read(&queue->bufs[index].state) !=
QETH_QDIO_BUF_EMPTY)
return -EBUSY;
elements_in_buffer = QETH_MAX_BUFFER_ELEMENTS(queue->card) -
queue->bufs[index].next_element_to_fill;
skbs_in_buffer = elements_in_buffer / ctx->elements_per_skb;
elements_needed -= skbs_in_buffer * ctx->elements_per_skb;
index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
}
return buffers_needed;
}
static inline void
qeth_eddp_free_context(struct qeth_eddp_context *ctx)
{
int i;
QETH_DBF_TEXT(trace, 5, "eddpfctx");
for (i = 0; i < ctx->num_pages; ++i)
free_page((unsigned long)ctx->pages[i]);
kfree(ctx->pages);
kfree(ctx->elements);
kfree(ctx);
}
static inline void
qeth_eddp_get_context(struct qeth_eddp_context *ctx)
{
atomic_inc(&ctx->refcnt);
}
void
qeth_eddp_put_context(struct qeth_eddp_context *ctx)
{
if (atomic_dec_return(&ctx->refcnt) == 0)
qeth_eddp_free_context(ctx);
}
void
qeth_eddp_buf_release_contexts(struct qeth_qdio_out_buffer *buf)
{
struct qeth_eddp_context_reference *ref;
QETH_DBF_TEXT(trace, 6, "eddprctx");
while (!list_empty(&buf->ctx_list)){
ref = list_entry(buf->ctx_list.next,
struct qeth_eddp_context_reference, list);
qeth_eddp_put_context(ref->ctx);
list_del(&ref->list);
kfree(ref);
}
}
static inline int
qeth_eddp_buf_ref_context(struct qeth_qdio_out_buffer *buf,
struct qeth_eddp_context *ctx)
{
struct qeth_eddp_context_reference *ref;
QETH_DBF_TEXT(trace, 6, "eddprfcx");
ref = kmalloc(sizeof(struct qeth_eddp_context_reference), GFP_ATOMIC);
if (ref == NULL)
return -ENOMEM;
qeth_eddp_get_context(ctx);
ref->ctx = ctx;
list_add_tail(&ref->list, &buf->ctx_list);
return 0;
}
int
qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
struct qeth_eddp_context *ctx,
int index)
{
struct qeth_qdio_out_buffer *buf = NULL;
struct qdio_buffer *buffer;
int elements = ctx->num_elements;
int element = 0;
int flush_cnt = 0;
int must_refcnt = 1;
int i;
QETH_DBF_TEXT(trace, 5, "eddpfibu");
while (elements > 0) {
buf = &queue->bufs[index];
if (atomic_read(&buf->state) != QETH_QDIO_BUF_EMPTY){
/* normally this should not happen since we checked for
* available elements in qeth_check_elements_for_context
*/
if (element == 0)
return -EBUSY;
else {
PRINT_WARN("could only partially fill eddp "
"buffer!\n");
goto out;
}
}
/* check if the whole next skb fits into current buffer */
if ((QETH_MAX_BUFFER_ELEMENTS(queue->card) -
buf->next_element_to_fill)
< ctx->elements_per_skb){
/* no -> go to next buffer */
atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
flush_cnt++;
/* new buffer, so we have to add ctx to buffer'ctx_list
* and increment ctx's refcnt */
must_refcnt = 1;
continue;
}
if (must_refcnt){
must_refcnt = 0;
if (qeth_eddp_buf_ref_context(buf, ctx)){
PRINT_WARN("no memory to create eddp context "
"reference\n");
goto out_check;
}
}
buffer = buf->buffer;
/* fill one skb into buffer */
for (i = 0; i < ctx->elements_per_skb; ++i){
buffer->element[buf->next_element_to_fill].addr =
ctx->elements[element].addr;
buffer->element[buf->next_element_to_fill].length =
ctx->elements[element].length;
buffer->element[buf->next_element_to_fill].flags =
ctx->elements[element].flags;
buf->next_element_to_fill++;
element++;
elements--;
}
}
out_check:
if (!queue->do_pack) {
QETH_DBF_TEXT(trace, 6, "fillbfnp");
/* set state to PRIMED -> will be flushed */
if (buf->next_element_to_fill > 0){
atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
flush_cnt++;
}
} else {
#ifdef CONFIG_QETH_PERF_STATS
queue->card->perf_stats.skbs_sent_pack++;
#endif
QETH_DBF_TEXT(trace, 6, "fillbfpa");
if (buf->next_element_to_fill >=
QETH_MAX_BUFFER_ELEMENTS(queue->card)) {
/*
* packed buffer if full -> set state PRIMED
* -> will be flushed
*/
atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
flush_cnt++;
}
}
out:
return flush_cnt;
}
static inline void
qeth_eddp_create_segment_hdrs(struct qeth_eddp_context *ctx,
struct qeth_eddp_data *eddp, int data_len)
{
u8 *page;
int page_remainder;
int page_offset;
int pkt_len;
struct qeth_eddp_element *element;
QETH_DBF_TEXT(trace, 5, "eddpcrsh");
page = ctx->pages[ctx->offset >> PAGE_SHIFT];
page_offset = ctx->offset % PAGE_SIZE;
element = &ctx->elements[ctx->num_elements];
pkt_len = eddp->nhl + eddp->thl + data_len;
/* FIXME: layer2 and VLAN !!! */
if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2)
pkt_len += ETH_HLEN;
if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
pkt_len += VLAN_HLEN;
/* does complete packet fit in current page ? */
page_remainder = PAGE_SIZE - page_offset;
if (page_remainder < (sizeof(struct qeth_hdr) + pkt_len)){
/* no -> go to start of next page */
ctx->offset += page_remainder;
page = ctx->pages[ctx->offset >> PAGE_SHIFT];
page_offset = 0;
}
memcpy(page + page_offset, &eddp->qh, sizeof(struct qeth_hdr));
element->addr = page + page_offset;
element->length = sizeof(struct qeth_hdr);
ctx->offset += sizeof(struct qeth_hdr);
page_offset += sizeof(struct qeth_hdr);
/* add mac header (?) */
if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
memcpy(page + page_offset, &eddp->mac, ETH_HLEN);
element->length += ETH_HLEN;
ctx->offset += ETH_HLEN;
page_offset += ETH_HLEN;
}
/* add VLAN tag */
if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)){
memcpy(page + page_offset, &eddp->vlan, VLAN_HLEN);
element->length += VLAN_HLEN;
ctx->offset += VLAN_HLEN;
page_offset += VLAN_HLEN;
}
/* add network header */
memcpy(page + page_offset, (u8 *)&eddp->nh, eddp->nhl);
element->length += eddp->nhl;
eddp->nh_in_ctx = page + page_offset;
ctx->offset += eddp->nhl;
page_offset += eddp->nhl;
/* add transport header */
memcpy(page + page_offset, (u8 *)&eddp->th, eddp->thl);
element->length += eddp->thl;
eddp->th_in_ctx = page + page_offset;
ctx->offset += eddp->thl;
}
static inline void
qeth_eddp_copy_data_tcp(char *dst, struct qeth_eddp_data *eddp, int len,
u32 *hcsum)
{
struct skb_frag_struct *frag;
int left_in_frag;
int copy_len;
u8 *src;
QETH_DBF_TEXT(trace, 5, "eddpcdtc");
if (skb_shinfo(eddp->skb)->nr_frags == 0) {
memcpy(dst, eddp->skb->data + eddp->skb_offset, len);
*hcsum = csum_partial(eddp->skb->data + eddp->skb_offset, len,
*hcsum);
eddp->skb_offset += len;
} else {
while (len > 0) {
if (eddp->frag < 0) {
/* we're in skb->data */
left_in_frag = (eddp->skb->len - eddp->skb->data_len)
- eddp->skb_offset;
src = eddp->skb->data + eddp->skb_offset;
} else {
frag = &skb_shinfo(eddp->skb)->
frags[eddp->frag];
left_in_frag = frag->size - eddp->frag_offset;
src = (u8 *)(
(page_to_pfn(frag->page) << PAGE_SHIFT)+
frag->page_offset + eddp->frag_offset);
}
if (left_in_frag <= 0) {
eddp->frag++;
eddp->frag_offset = 0;
continue;
}
copy_len = min(left_in_frag, len);
memcpy(dst, src, copy_len);
*hcsum = csum_partial(src, copy_len, *hcsum);
dst += copy_len;
eddp->frag_offset += copy_len;
eddp->skb_offset += copy_len;
len -= copy_len;
}
}
}
static inline void
qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
struct qeth_eddp_data *eddp, int data_len,
u32 hcsum)
{
u8 *page;
int page_remainder;
int page_offset;
struct qeth_eddp_element *element;
int first_lap = 1;
QETH_DBF_TEXT(trace, 5, "eddpcsdt");
page = ctx->pages[ctx->offset >> PAGE_SHIFT];
page_offset = ctx->offset % PAGE_SIZE;
element = &ctx->elements[ctx->num_elements];
while (data_len){
page_remainder = PAGE_SIZE - page_offset;
if (page_remainder < data_len){
qeth_eddp_copy_data_tcp(page + page_offset, eddp,
page_remainder, &hcsum);
element->length += page_remainder;
if (first_lap)
element->flags = SBAL_FLAGS_FIRST_FRAG;
else
element->flags = SBAL_FLAGS_MIDDLE_FRAG;
ctx->num_elements++;
element++;
data_len -= page_remainder;
ctx->offset += page_remainder;
page = ctx->pages[ctx->offset >> PAGE_SHIFT];
page_offset = 0;
element->addr = page + page_offset;
} else {
qeth_eddp_copy_data_tcp(page + page_offset, eddp,
data_len, &hcsum);
element->length += data_len;
if (!first_lap)
element->flags = SBAL_FLAGS_LAST_FRAG;
ctx->num_elements++;
ctx->offset += data_len;
data_len = 0;
}
first_lap = 0;
}
((struct tcphdr *)eddp->th_in_ctx)->check = csum_fold(hcsum);
}
static inline u32
qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
{
u32 phcsum; /* pseudo header checksum */
QETH_DBF_TEXT(trace, 5, "eddpckt4");
eddp->th.tcp.h.check = 0;
/* compute pseudo header checksum */
phcsum = csum_tcpudp_nofold(eddp->nh.ip4.h.saddr, eddp->nh.ip4.h.daddr,
eddp->thl + data_len, IPPROTO_TCP, 0);
/* compute checksum of tcp header */
return csum_partial((u8 *)&eddp->th, eddp->thl, phcsum);
}
static inline u32
qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
{
u32 proto;
u32 phcsum; /* pseudo header checksum */
QETH_DBF_TEXT(trace, 5, "eddpckt6");
eddp->th.tcp.h.check = 0;
/* compute pseudo header checksum */
phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.saddr,
sizeof(struct in6_addr), 0);
phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.daddr,
sizeof(struct in6_addr), phcsum);
proto = htonl(IPPROTO_TCP);
phcsum = csum_partial((u8 *)&proto, sizeof(u32), phcsum);
return phcsum;
}
static inline struct qeth_eddp_data *
qeth_eddp_create_eddp_data(struct qeth_hdr *qh, u8 *nh, u8 nhl, u8 *th, u8 thl)
{
struct qeth_eddp_data *eddp;
QETH_DBF_TEXT(trace, 5, "eddpcrda");
eddp = kzalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
if (eddp){
eddp->nhl = nhl;
eddp->thl = thl;
memcpy(&eddp->qh, qh, sizeof(struct qeth_hdr));
memcpy(&eddp->nh, nh, nhl);
memcpy(&eddp->th, th, thl);
eddp->frag = -1; /* initially we're in skb->data */
}
return eddp;
}
static inline void
__qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
struct qeth_eddp_data *eddp)
{
struct tcphdr *tcph;
int data_len;
u32 hcsum;
QETH_DBF_TEXT(trace, 5, "eddpftcp");
eddp->skb_offset = sizeof(struct qeth_hdr) + eddp->nhl + eddp->thl;
if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
eddp->skb_offset += sizeof(struct ethhdr);
#ifdef CONFIG_QETH_VLAN
if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
eddp->skb_offset += VLAN_HLEN;
#endif /* CONFIG_QETH_VLAN */
}
tcph = eddp->skb->h.th;
while (eddp->skb_offset < eddp->skb->len) {
data_len = min((int)skb_shinfo(eddp->skb)->gso_size,
(int)(eddp->skb->len - eddp->skb_offset));
/* prepare qdio hdr */
if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
eddp->nhl + eddp->thl -
sizeof(struct qeth_hdr);
#ifdef CONFIG_QETH_VLAN
if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;
#endif /* CONFIG_QETH_VLAN */
} else
eddp->qh.hdr.l3.length = data_len + eddp->nhl +
eddp->thl;
/* prepare ip hdr */
if (eddp->skb->protocol == ETH_P_IP){
eddp->nh.ip4.h.tot_len = data_len + eddp->nhl +
eddp->thl;
eddp->nh.ip4.h.check = 0;
eddp->nh.ip4.h.check =
ip_fast_csum((u8 *)&eddp->nh.ip4.h,
eddp->nh.ip4.h.ihl);
} else
eddp->nh.ip6.h.payload_len = data_len + eddp->thl;
/* prepare tcp hdr */
if (data_len == (eddp->skb->len - eddp->skb_offset)){
/* last segment -> set FIN and PSH flags */
eddp->th.tcp.h.fin = tcph->fin;
eddp->th.tcp.h.psh = tcph->psh;
}
if (eddp->skb->protocol == ETH_P_IP)
hcsum = qeth_eddp_check_tcp4_hdr(eddp, data_len);
else
hcsum = qeth_eddp_check_tcp6_hdr(eddp, data_len);
/* fill the next segment into the context */
qeth_eddp_create_segment_hdrs(ctx, eddp, data_len);
qeth_eddp_create_segment_data_tcp(ctx, eddp, data_len, hcsum);
if (eddp->skb_offset >= eddp->skb->len)
break;
/* prepare headers for next round */
if (eddp->skb->protocol == ETH_P_IP)
eddp->nh.ip4.h.id++;
eddp->th.tcp.h.seq += data_len;
}
}
static inline int
qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
struct sk_buff *skb, struct qeth_hdr *qhdr)
{
struct qeth_eddp_data *eddp = NULL;
QETH_DBF_TEXT(trace, 5, "eddpficx");
/* create our segmentation headers and copy original headers */
if (skb->protocol == ETH_P_IP)
eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.iph,
skb->nh.iph->ihl*4,
(u8 *)skb->h.th, skb->h.th->doff*4);
else
eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.ipv6h,
sizeof(struct ipv6hdr),
(u8 *)skb->h.th, skb->h.th->doff*4);
if (eddp == NULL) {
QETH_DBF_TEXT(trace, 2, "eddpfcnm");
return -ENOMEM;
}
if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
skb->mac.raw = (skb->data) + sizeof(struct qeth_hdr);
memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
#ifdef CONFIG_QETH_VLAN
if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
eddp->vlan[0] = __constant_htons(skb->protocol);
eddp->vlan[1] = htons(vlan_tx_tag_get(skb));
}
#endif /* CONFIG_QETH_VLAN */
}
/* the next flags will only be set on the last segment */
eddp->th.tcp.h.fin = 0;
eddp->th.tcp.h.psh = 0;
eddp->skb = skb;
/* begin segmentation and fill context */
__qeth_eddp_fill_context_tcp(ctx, eddp);
kfree(eddp);
return 0;
}
static inline void
qeth_eddp_calc_num_pages(struct qeth_eddp_context *ctx, struct sk_buff *skb,
int hdr_len)
{
int skbs_per_page;
QETH_DBF_TEXT(trace, 5, "eddpcanp");
/* can we put multiple skbs in one page? */
skbs_per_page = PAGE_SIZE / (skb_shinfo(skb)->gso_size + hdr_len);
if (skbs_per_page > 1){
ctx->num_pages = (skb_shinfo(skb)->gso_segs + 1) /
skbs_per_page + 1;
ctx->elements_per_skb = 1;
} else {
/* no -> how many elements per skb? */
ctx->elements_per_skb = (skb_shinfo(skb)->gso_size + hdr_len +
PAGE_SIZE) >> PAGE_SHIFT;
ctx->num_pages = ctx->elements_per_skb *
(skb_shinfo(skb)->gso_segs + 1);
}
ctx->num_elements = ctx->elements_per_skb *
(skb_shinfo(skb)->gso_segs + 1);
}
static inline struct qeth_eddp_context *
qeth_eddp_create_context_generic(struct qeth_card *card, struct sk_buff *skb,
int hdr_len)
{
struct qeth_eddp_context *ctx = NULL;
u8 *addr;
int i;
QETH_DBF_TEXT(trace, 5, "creddpcg");
/* create the context and allocate pages */
ctx = kzalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
if (ctx == NULL){
QETH_DBF_TEXT(trace, 2, "ceddpcn1");
return NULL;
}
ctx->type = QETH_LARGE_SEND_EDDP;
qeth_eddp_calc_num_pages(ctx, skb, hdr_len);
if (ctx->elements_per_skb > QETH_MAX_BUFFER_ELEMENTS(card)){
QETH_DBF_TEXT(trace, 2, "ceddpcis");
kfree(ctx);
return NULL;
}
ctx->pages = kcalloc(ctx->num_pages, sizeof(u8 *), GFP_ATOMIC);
if (ctx->pages == NULL){
QETH_DBF_TEXT(trace, 2, "ceddpcn2");
kfree(ctx);
return NULL;
}
for (i = 0; i < ctx->num_pages; ++i){
addr = (u8 *)__get_free_page(GFP_ATOMIC);
if (addr == NULL){
QETH_DBF_TEXT(trace, 2, "ceddpcn3");
ctx->num_pages = i;
qeth_eddp_free_context(ctx);
return NULL;
}
memset(addr, 0, PAGE_SIZE);
ctx->pages[i] = addr;
}
ctx->elements = kcalloc(ctx->num_elements,
sizeof(struct qeth_eddp_element), GFP_ATOMIC);
if (ctx->elements == NULL){
QETH_DBF_TEXT(trace, 2, "ceddpcn4");
qeth_eddp_free_context(ctx);
return NULL;
}
/* reset num_elements; will be incremented again in fill_buffer to
* reflect number of actually used elements */
ctx->num_elements = 0;
return ctx;
}
static inline struct qeth_eddp_context *
qeth_eddp_create_context_tcp(struct qeth_card *card, struct sk_buff *skb,
struct qeth_hdr *qhdr)
{
struct qeth_eddp_context *ctx = NULL;
QETH_DBF_TEXT(trace, 5, "creddpct");
if (skb->protocol == ETH_P_IP)
ctx = qeth_eddp_create_context_generic(card, skb,
sizeof(struct qeth_hdr) + skb->nh.iph->ihl*4 +
skb->h.th->doff*4);
else if (skb->protocol == ETH_P_IPV6)
ctx = qeth_eddp_create_context_generic(card, skb,
sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
skb->h.th->doff*4);
else
QETH_DBF_TEXT(trace, 2, "cetcpinv");
if (ctx == NULL) {
QETH_DBF_TEXT(trace, 2, "creddpnl");
return NULL;
}
if (qeth_eddp_fill_context_tcp(ctx, skb, qhdr)){
QETH_DBF_TEXT(trace, 2, "ceddptfe");
qeth_eddp_free_context(ctx);
return NULL;
}
atomic_set(&ctx->refcnt, 1);
return ctx;
}
struct qeth_eddp_context *
qeth_eddp_create_context(struct qeth_card *card, struct sk_buff *skb,
struct qeth_hdr *qhdr)
{
QETH_DBF_TEXT(trace, 5, "creddpc");
switch (skb->sk->sk_protocol){
case IPPROTO_TCP:
return qeth_eddp_create_context_tcp(card, skb, qhdr);
default:
QETH_DBF_TEXT(trace, 2, "eddpinvp");
}
return NULL;
}
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