linux/drivers/s390/net/qeth_eddp.c
Frank Pavlic 05e08a2a29 [PATCH] s390: qeth bug fixes
[patch 10/10] s390: qeth bug fixes.

From: Frank Pavlic <pavlic@de.ibm.com>

qeth network driver related changes:
 - due to OSA hardware changes in TCP Segmentation Offload
   support we are able now to pack TSO packets too.
   This fits perfectly in design of qeth buffer handling and
   sending data respectively.
 - remove skb_realloc_headroom from the sending path since
   hard_header_len value provides enough headroom now.
 - device recovery behaviour improvement
 - bug fixed in Enhanced Device Driver Packing functionality

Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>
2005-05-15 18:06:17 -04:00

633 lines
17 KiB
C

/*
*
* linux/drivers/s390/net/qeth_eddp.c ($Revision: 1.13 $)
*
* Enhanced Device Driver Packing (EDDP) support for the qeth driver.
*
* Copyright 2004 IBM Corporation
*
* Author(s): Thomas Spatzier <tspat@de.ibm.com>
*
* $Revision: 1.13 $ $Date: 2005/05/04 20:19:18 $
*
*/
#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);
if (ctx->elements != NULL)
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 = kmalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
if (eddp){
memset(eddp, 0, sizeof(struct qeth_eddp_data));
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;
tcph = eddp->skb->h.th;
while (eddp->skb_offset < eddp->skb->len) {
data_len = min((int)skb_shinfo(eddp->skb)->tso_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) {
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)->tso_size + hdr_len);
if (skbs_per_page > 1){
ctx->num_pages = (skb_shinfo(skb)->tso_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)->tso_size + hdr_len +
PAGE_SIZE) >> PAGE_SHIFT;
ctx->num_pages = ctx->elements_per_skb *
(skb_shinfo(skb)->tso_segs + 1);
}
ctx->num_elements = ctx->elements_per_skb *
(skb_shinfo(skb)->tso_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 = kmalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
if (ctx == NULL){
QETH_DBF_TEXT(trace, 2, "ceddpcn1");
return NULL;
}
memset(ctx, 0, sizeof(struct qeth_eddp_context));
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 = kmalloc(ctx->num_pages * sizeof(u8 *), GFP_ATOMIC);
if (ctx->pages == NULL){
QETH_DBF_TEXT(trace, 2, "ceddpcn2");
kfree(ctx);
return NULL;
}
memset(ctx->pages, 0, ctx->num_pages * sizeof(u8 *));
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 = kmalloc(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;
}
memset(ctx->elements, 0,
ctx->num_elements * sizeof(struct qeth_eddp_element));
/* 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;
}