/**********************************************************************
* Author: Cavium Networks
*
* Contact: support@caviumnetworks.com
* This file is part of the OCTEON SDK
*
* Copyright (c) 2003-2010 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/cpumask.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/ratelimit.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <net/dst.h>
#ifdef CONFIG_XFRM
#include <linux/xfrm.h>
#include <net/xfrm.h>
#endif /* CONFIG_XFRM */
#include <linux/atomic.h>
#include <asm/octeon/octeon.h>
#include "ethernet-defines.h"
#include "ethernet-mem.h"
#include "ethernet-rx.h"
#include "octeon-ethernet.h"
#include "ethernet-util.h"
#include <asm/octeon/cvmx-helper.h>
#include <asm/octeon/cvmx-wqe.h>
#include <asm/octeon/cvmx-fau.h>
#include <asm/octeon/cvmx-pow.h>
#include <asm/octeon/cvmx-pip.h>
#include <asm/octeon/cvmx-scratch.h>
#include <asm/octeon/cvmx-gmxx-defs.h>
struct cvm_napi_wrapper {
struct napi_struct napi;
} ____cacheline_aligned_in_smp;
static struct cvm_napi_wrapper cvm_oct_napi[NR_CPUS] __cacheline_aligned_in_smp;
struct cvm_oct_core_state {
int baseline_cores;
/*
* The number of additional cores that could be processing
* input packtes.
*/
atomic_t available_cores;
cpumask_t cpu_state;
} ____cacheline_aligned_in_smp;
static struct cvm_oct_core_state core_state __cacheline_aligned_in_smp;
static void cvm_oct_enable_napi(void *_)
{
int cpu = smp_processor_id();
napi_schedule(&cvm_oct_napi[cpu].napi);
}
static void cvm_oct_enable_one_cpu(void)
{
int v;
int cpu;
/* Check to see if more CPUs are available for receive processing... */
v = atomic_sub_if_positive(1, &core_state.available_cores);
if (v < 0)
return;
/* ... if a CPU is available, Turn on NAPI polling for that CPU. */
for_each_online_cpu(cpu) {
if (!cpu_test_and_set(cpu, core_state.cpu_state)) {
v = smp_call_function_single(cpu, cvm_oct_enable_napi,
NULL, 0);
if (v)
panic("Can't enable NAPI.");
break;
}
}
}
static void cvm_oct_no_more_work(void)
{
int cpu = smp_processor_id();
/*
* CPU zero is special. It always has the irq enabled when
* waiting for incoming packets.
*/
if (cpu == 0) {
enable_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group);
return;
}
cpu_clear(cpu, core_state.cpu_state);
atomic_add(1, &core_state.available_cores);
}
/**
* cvm_oct_do_interrupt - interrupt handler.
*
* The interrupt occurs whenever the POW has packets in our group.
*
*/
static irqreturn_t cvm_oct_do_interrupt(int cpl, void *dev_id)
{
/* Disable the IRQ and start napi_poll. */
disable_irq_nosync(OCTEON_IRQ_WORKQ0 + pow_receive_group);
cvm_oct_enable_napi(NULL);
return IRQ_HANDLED;
}
/**
* cvm_oct_check_rcv_error - process receive errors
* @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) {
/*
printk_ratelimited("Port %d received 0xd5 preamble\n", work->ipprt);
*/
work->packet_ptr.s.addr += i + 1;
work->len -= i + 5;
} else if ((*ptr & 0xf) == 0xd) {
/*
printk_ratelimited("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 {
printk_ratelimited("Port %d unknown preamble, packet "
"dropped\n",
work->ipprt);
/*
cvmx_helper_dump_packet(work);
*/
cvm_oct_free_work(work);
return 1;
}
}
} else {
printk_ratelimited("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;
}
/**
* cvm_oct_napi_poll - the NAPI poll function.
* @napi: The NAPI instance, or null if called from cvm_oct_poll_controller
* @budget: Maximum number of packets to receive.
*
* Returns the number of packets processed.
*/
static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
{
const int coreid = cvmx_get_core_num();
uint64_t old_group_mask;
uint64_t old_scratch;
int rx_count = 0;
int did_work_request = 0;
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);
did_work_request = 1;
}
while (rx_count < budget) {
struct sk_buff *skb = NULL;
struct sk_buff **pskb = NULL;
int skb_in_hw;
cvmx_wqe_t *work;
if (USE_ASYNC_IOBDMA && did_work_request)
work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
else
work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
prefetch(work);
did_work_request = 0;
if (work == NULL) {
union cvmx_pow_wq_int wq_int;
wq_int.u64 = 0;
wq_int.s.iq_dis = 1 << pow_receive_group;
wq_int.s.wq_int = 1 << pow_receive_group;
cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
break;
}
pskb = (struct sk_buff **)(cvm_oct_get_buffer_ptr(work->packet_ptr) - sizeof(void *));
prefetch(pskb);
if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
did_work_request = 1;
}
if (rx_count == 0) {
/*
* First time through, see if there is enough
* work waiting to merit waking another
* CPU.
*/
union cvmx_pow_wq_int_cntx counts;
int backlog;
int cores_in_use = core_state.baseline_cores - atomic_read(&core_state.available_cores);
counts.u64 = cvmx_read_csr(CVMX_POW_WQ_INT_CNTX(pow_receive_group));
backlog = counts.s.iq_cnt + counts.s.ds_cnt;
if (backlog > budget * cores_in_use && napi != NULL)
cvm_oct_enable_one_cpu();
}
skb_in_hw = USE_SKBUFFS_IN_HW && work->word2.s.bufs == 1;
if (likely(skb_in_hw)) {
skb = *pskb;
prefetch(&skb->head);
prefetch(&skb->len);
}
prefetch(cvm_oct_device[work->ipprt]);
/* 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)) {
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) {
printk_ratelimited("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.
*/
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);
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 || !work->word2.s.tcp_or_udp))
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);
rx_count++;
} else {
/* Drop any packet received for a device that isn't up */
/*
printk_ratelimited("%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.
*/
printk_ratelimited("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);
}
cvm_oct_rx_refill_pool(0);
if (rx_count < budget && napi != NULL) {
/* No more work */
napi_complete(napi);
cvm_oct_no_more_work();
}
return rx_count;
}
#ifdef CONFIG_NET_POLL_CONTROLLER
/**
* cvm_oct_poll_controller - poll for receive packets
* device.
*
* @dev: Device to poll. Unused
*/
void cvm_oct_poll_controller(struct net_device *dev)
{
cvm_oct_napi_poll(NULL, 16);
}
#endif
void cvm_oct_rx_initialize(void)
{
int i;
struct net_device *dev_for_napi = NULL;
union cvmx_pow_wq_int_thrx int_thr;
union cvmx_pow_wq_int_pc int_pc;
for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
if (cvm_oct_device[i]) {
dev_for_napi = cvm_oct_device[i];
break;
}
}
if (NULL == dev_for_napi)
panic("No net_devices were allocated.");
if (max_rx_cpus > 1 && max_rx_cpus < num_online_cpus())
atomic_set(&core_state.available_cores, max_rx_cpus);
else
atomic_set(&core_state.available_cores, num_online_cpus());
core_state.baseline_cores = atomic_read(&core_state.available_cores);
core_state.cpu_state = CPU_MASK_NONE;
for_each_possible_cpu(i) {
netif_napi_add(dev_for_napi, &cvm_oct_napi[i].napi,
cvm_oct_napi_poll, rx_napi_weight);
napi_enable(&cvm_oct_napi[i].napi);
}
/* Register an IRQ hander for to receive POW interrupts */
i = request_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group,
cvm_oct_do_interrupt, 0, "Ethernet", cvm_oct_device);
if (i)
panic("Could not acquire Ethernet IRQ %d\n",
OCTEON_IRQ_WORKQ0 + pow_receive_group);
disable_irq_nosync(OCTEON_IRQ_WORKQ0 + pow_receive_group);
int_thr.u64 = 0;
int_thr.s.tc_en = 1;
int_thr.s.tc_thr = 1;
/* Enable POW interrupt when our port has at least one packet */
cvmx_write_csr(CVMX_POW_WQ_INT_THRX(pow_receive_group), int_thr.u64);
int_pc.u64 = 0;
int_pc.s.pc_thr = 5;
cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
/* Scheduld NAPI now. This will indirectly enable interrupts. */
cvm_oct_enable_one_cpu();
}
void cvm_oct_rx_shutdown(void)
{
int i;
/* Shutdown all of the NAPIs */
for_each_possible_cpu(i)
netif_napi_del(&cvm_oct_napi[i].napi);
}