Linux-2.6.33.2/drivers/staging/octeon/ethernet-rx.c
/**********************************************************************
* Author: Cavium Networks
*
* Contact: support@caviumnetworks.com
* This file is part of the OCTEON SDK
*
* Copyright (c) 2003-2007 Cavium Networks
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, Version 2, as
* published by the Free Software Foundation.
*
* This file is distributed in the hope that it will be useful, but
* AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
* NONINFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this file; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
* or visit http://www.gnu.org/licenses/.
*
* This file may also be available under a different license from Cavium.
* Contact Cavium Networks for more information
**********************************************************************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/cache.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/etherdevice.h>
#include <linux/ip.h>
#include <linux/string.h>
#include <linux/prefetch.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <net/dst.h>
#ifdef CONFIG_XFRM
#include <linux/xfrm.h>
#include <net/xfrm.h>
#endif /* CONFIG_XFRM */
#include <asm/atomic.h>
#include <asm/octeon/octeon.h>
#include "ethernet-defines.h"
#include "octeon-ethernet.h"
#include "ethernet-mem.h"
#include "ethernet-util.h"
#include "cvmx-helper.h"
#include "cvmx-wqe.h"
#include "cvmx-fau.h"
#include "cvmx-pow.h"
#include "cvmx-pip.h"
#include "cvmx-scratch.h"
#include "cvmx-gmxx-defs.h"
struct cvm_tasklet_wrapper {
struct tasklet_struct t;
};
/*
* Aligning the tasklet_struct on cachline boundries seems to decrease
* throughput even though in theory it would reduce contantion on the
* cache lines containing the locks.
*/
static struct cvm_tasklet_wrapper cvm_oct_tasklet[NR_CPUS];
/**
* Interrupt handler. The interrupt occurs whenever the POW
* transitions from 0->1 packets in our group.
*
* @cpl:
* @dev_id:
* @regs:
* Returns
*/
irqreturn_t cvm_oct_do_interrupt(int cpl, void *dev_id)
{
/* Acknowledge the interrupt */
if (INTERRUPT_LIMIT)
cvmx_write_csr(CVMX_POW_WQ_INT, 1 << pow_receive_group);
else
cvmx_write_csr(CVMX_POW_WQ_INT, 0x10001 << pow_receive_group);
preempt_disable();
tasklet_schedule(&cvm_oct_tasklet[smp_processor_id()].t);
preempt_enable();
return IRQ_HANDLED;
}
#ifdef CONFIG_NET_POLL_CONTROLLER
/**
* This is called when the kernel needs to manually poll the
* device. For Octeon, this is simply calling the interrupt
* handler. We actually poll all the devices, not just the
* one supplied.
*
* @dev: Device to poll. Unused
*/
void cvm_oct_poll_controller(struct net_device *dev)
{
preempt_disable();
tasklet_schedule(&cvm_oct_tasklet[smp_processor_id()].t);
preempt_enable();
}
#endif
/**
* This is called on receive errors, and determines if the packet
* can be dropped early-on in cvm_oct_tasklet_rx().
*
* @work: Work queue entry pointing to the packet.
* Returns Non-zero if the packet can be dropped, zero otherwise.
*/
static inline int cvm_oct_check_rcv_error(cvmx_wqe_t *work)
{
if ((work->word2.snoip.err_code == 10) && (work->len <= 64)) {
/*
* Ignore length errors on min size packets. Some
* equipment incorrectly pads packets to 64+4FCS
* instead of 60+4FCS. Note these packets still get
* counted as frame errors.
*/
} else
if (USE_10MBPS_PREAMBLE_WORKAROUND
&& ((work->word2.snoip.err_code == 5)
|| (work->word2.snoip.err_code == 7))) {
/*
* We received a packet with either an alignment error
* or a FCS error. This may be signalling that we are
* running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK}
* off. If this is the case we need to parse the
* packet to determine if we can remove a non spec
* preamble and generate a correct packet.
*/
int interface = cvmx_helper_get_interface_num(work->ipprt);
int index = cvmx_helper_get_interface_index_num(work->ipprt);
union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
gmxx_rxx_frm_ctl.u64 =
cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
uint8_t *ptr =
cvmx_phys_to_ptr(work->packet_ptr.s.addr);
int i = 0;
while (i < work->len - 1) {
if (*ptr != 0x55)
break;
ptr++;
i++;
}
if (*ptr == 0xd5) {
/*
DEBUGPRINT("Port %d received 0xd5 preamble\n", work->ipprt);
*/
work->packet_ptr.s.addr += i + 1;
work->len -= i + 5;
} else if ((*ptr & 0xf) == 0xd) {
/*
DEBUGPRINT("Port %d received 0x?d preamble\n", work->ipprt);
*/
work->packet_ptr.s.addr += i;
work->len -= i + 4;
for (i = 0; i < work->len; i++) {
*ptr =
((*ptr & 0xf0) >> 4) |
((*(ptr + 1) & 0xf) << 4);
ptr++;
}
} else {
DEBUGPRINT("Port %d unknown preamble, packet "
"dropped\n",
work->ipprt);
/*
cvmx_helper_dump_packet(work);
*/
cvm_oct_free_work(work);
return 1;
}
}
} else {
DEBUGPRINT("Port %d receive error code %d, packet dropped\n",
work->ipprt, work->word2.snoip.err_code);
cvm_oct_free_work(work);
return 1;
}
return 0;
}
/**
* Tasklet function that is scheduled on a core when an interrupt occurs.
*
* @unused:
*/
void cvm_oct_tasklet_rx(unsigned long unused)
{
const int coreid = cvmx_get_core_num();
uint64_t old_group_mask;
uint64_t old_scratch;
int rx_count = 0;
int number_to_free;
int num_freed;
int packet_not_copied;
/* Prefetch cvm_oct_device since we know we need it soon */
prefetch(cvm_oct_device);
if (USE_ASYNC_IOBDMA) {
/* Save scratch in case userspace is using it */
CVMX_SYNCIOBDMA;
old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
}
/* Only allow work for our group (and preserve priorities) */
old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
(old_group_mask & ~0xFFFFull) | 1 << pow_receive_group);
if (USE_ASYNC_IOBDMA)
cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
while (1) {
struct sk_buff *skb = NULL;
int skb_in_hw;
cvmx_wqe_t *work;
if (USE_ASYNC_IOBDMA) {
work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
} else {
if ((INTERRUPT_LIMIT == 0)
|| likely(rx_count < MAX_RX_PACKETS))
work =
cvmx_pow_work_request_sync
(CVMX_POW_NO_WAIT);
else
work = NULL;
}
prefetch(work);
if (work == NULL)
break;
/*
* Limit each core to processing MAX_RX_PACKETS
* packets without a break. This way the RX can't
* starve the TX task.
*/
if (USE_ASYNC_IOBDMA) {
if ((INTERRUPT_LIMIT == 0)
|| likely(rx_count < MAX_RX_PACKETS))
cvmx_pow_work_request_async_nocheck
(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
else {
cvmx_scratch_write64(CVMX_SCR_SCRATCH,
0x8000000000000000ull);
cvmx_pow_tag_sw_null_nocheck();
}
}
skb_in_hw = USE_SKBUFFS_IN_HW && work->word2.s.bufs == 1;
if (likely(skb_in_hw)) {
skb =
*(struct sk_buff
**)(cvm_oct_get_buffer_ptr(work->packet_ptr) -
sizeof(void *));
prefetch(&skb->head);
prefetch(&skb->len);
}
prefetch(cvm_oct_device[work->ipprt]);
rx_count++;
/* Immediately throw away all packets with receive errors */
if (unlikely(work->word2.snoip.rcv_error)) {
if (cvm_oct_check_rcv_error(work))
continue;
}
/*
* We can only use the zero copy path if skbuffs are
* in the FPA pool and the packet fits in a single
* buffer.
*/
if (likely(skb_in_hw)) {
/*
* This calculation was changed in case the
* skb header is using a different address
* aliasing type than the buffer. It doesn't
* make any differnece now, but the new one is
* more correct.
*/
skb->data =
skb->head + work->packet_ptr.s.addr -
cvmx_ptr_to_phys(skb->head);
prefetch(skb->data);
skb->len = work->len;
skb_set_tail_pointer(skb, skb->len);
packet_not_copied = 1;
} else {
/*
* We have to copy the packet. First allocate
* an skbuff for it.
*/
skb = dev_alloc_skb(work->len);
if (!skb) {
DEBUGPRINT("Port %d failed to allocate "
"skbuff, packet dropped\n",
work->ipprt);
cvm_oct_free_work(work);
continue;
}
/*
* Check if we've received a packet that was
* entirely stored in the work entry. This is
* untested.
*/
if (unlikely(work->word2.s.bufs == 0)) {
uint8_t *ptr = work->packet_data;
if (likely(!work->word2.s.not_IP)) {
/*
* The beginning of the packet
* moves for IP packets.
*/
if (work->word2.s.is_v6)
ptr += 2;
else
ptr += 6;
}
memcpy(skb_put(skb, work->len), ptr, work->len);
/* No packet buffers to free */
} else {
int segments = work->word2.s.bufs;
union cvmx_buf_ptr segment_ptr =
work->packet_ptr;
int len = work->len;
while (segments--) {
union cvmx_buf_ptr next_ptr =
*(union cvmx_buf_ptr *)
cvmx_phys_to_ptr(segment_ptr.s.
addr - 8);
/*
* Octeon Errata PKI-100: The segment size is
* wrong. Until it is fixed, calculate the
* segment size based on the packet pool
* buffer size. When it is fixed, the
* following line should be replaced with this
* one: int segment_size =
* segment_ptr.s.size;
*/
int segment_size =
CVMX_FPA_PACKET_POOL_SIZE -
(segment_ptr.s.addr -
(((segment_ptr.s.addr >> 7) -
segment_ptr.s.back) << 7));
/* Don't copy more than what is left
in the packet */
if (segment_size > len)
segment_size = len;
/* Copy the data into the packet */
memcpy(skb_put(skb, segment_size),
cvmx_phys_to_ptr(segment_ptr.s.
addr),
segment_size);
/* Reduce the amount of bytes left
to copy */
len -= segment_size;
segment_ptr = next_ptr;
}
}
packet_not_copied = 0;
}
if (likely((work->ipprt < TOTAL_NUMBER_OF_PORTS) &&
cvm_oct_device[work->ipprt])) {
struct net_device *dev = cvm_oct_device[work->ipprt];
struct octeon_ethernet *priv = netdev_priv(dev);
/* Only accept packets for devices
that are currently up */
if (likely(dev->flags & IFF_UP)) {
skb->protocol = eth_type_trans(skb, dev);
skb->dev = dev;
if (unlikely
(work->word2.s.not_IP
|| work->word2.s.IP_exc
|| work->word2.s.L4_error))
skb->ip_summed = CHECKSUM_NONE;
else
skb->ip_summed = CHECKSUM_UNNECESSARY;
/* Increment RX stats for virtual ports */
if (work->ipprt >= CVMX_PIP_NUM_INPUT_PORTS) {
#ifdef CONFIG_64BIT
atomic64_add(1, (atomic64_t *)&priv->stats.rx_packets);
atomic64_add(skb->len, (atomic64_t *)&priv->stats.rx_bytes);
#else
atomic_add(1, (atomic_t *)&priv->stats.rx_packets);
atomic_add(skb->len, (atomic_t *)&priv->stats.rx_bytes);
#endif
}
netif_receive_skb(skb);
} else {
/*
* Drop any packet received for a
* device that isn't up.
*/
/*
DEBUGPRINT("%s: Device not up, packet dropped\n",
dev->name);
*/
#ifdef CONFIG_64BIT
atomic64_add(1, (atomic64_t *)&priv->stats.rx_dropped);
#else
atomic_add(1, (atomic_t *)&priv->stats.rx_dropped);
#endif
dev_kfree_skb_irq(skb);
}
} else {
/*
* Drop any packet received for a device that
* doesn't exist.
*/
DEBUGPRINT("Port %d not controlled by Linux, packet "
"dropped\n",
work->ipprt);
dev_kfree_skb_irq(skb);
}
/*
* Check to see if the skbuff and work share the same
* packet buffer.
*/
if (USE_SKBUFFS_IN_HW && likely(packet_not_copied)) {
/*
* This buffer needs to be replaced, increment
* the number of buffers we need to free by
* one.
*/
cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
1);
cvmx_fpa_free(work, CVMX_FPA_WQE_POOL,
DONT_WRITEBACK(1));
} else {
cvm_oct_free_work(work);
}
}
/* Restore the original POW group mask */
cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
if (USE_ASYNC_IOBDMA) {
/* Restore the scratch area */
cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
}
if (USE_SKBUFFS_IN_HW) {
/* Refill the packet buffer pool */
number_to_free =
cvmx_fau_fetch_and_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, 0);
if (number_to_free > 0) {
cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
-number_to_free);
num_freed =
cvm_oct_mem_fill_fpa(CVMX_FPA_PACKET_POOL,
CVMX_FPA_PACKET_POOL_SIZE,
number_to_free);
if (num_freed != number_to_free) {
cvmx_fau_atomic_add32
(FAU_NUM_PACKET_BUFFERS_TO_FREE,
number_to_free - num_freed);
}
}
}
}
void cvm_oct_rx_initialize(void)
{
int i;
/* Initialize all of the tasklets */
for (i = 0; i < NR_CPUS; i++)
tasklet_init(&cvm_oct_tasklet[i].t, cvm_oct_tasklet_rx, 0);
}
void cvm_oct_rx_shutdown(void)
{
int i;
/* Shutdown all of the tasklets */
for (i = 0; i < NR_CPUS; i++)
tasklet_kill(&cvm_oct_tasklet[i].t);
}