diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/staging/octeon/ethernet-rx.c | 542 |
1 files changed, 542 insertions, 0 deletions
diff --git a/drivers/staging/octeon/ethernet-rx.c b/drivers/staging/octeon/ethernet-rx.c new file mode 100644 index 000000000..965330eec --- /dev/null +++ b/drivers/staging/octeon/ethernet-rx.c @@ -0,0 +1,542 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This file is based on code from OCTEON SDK by Cavium Networks. + * + * Copyright (c) 2003-2010 Cavium Networks + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/cache.h> +#include <linux/cpumask.h> +#include <linux/netdevice.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 "octeon-ethernet.h" +#include "ethernet-defines.h" +#include "ethernet-mem.h" +#include "ethernet-rx.h" +#include "ethernet-util.h" + +static atomic_t oct_rx_ready = ATOMIC_INIT(0); + +static struct oct_rx_group { + int irq; + int group; + struct napi_struct napi; +} oct_rx_group[16]; + +/** + * cvm_oct_do_interrupt - interrupt handler. + * @irq: Interrupt number. + * @napi_id: Cookie to identify the NAPI instance. + * + * The interrupt occurs whenever the POW has packets in our group. + * + */ +static irqreturn_t cvm_oct_do_interrupt(int irq, void *napi_id) +{ + /* Disable the IRQ and start napi_poll. */ + disable_irq_nosync(irq); + napi_schedule(napi_id); + + 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(struct cvmx_wqe *work) +{ + int port; + + if (octeon_has_feature(OCTEON_FEATURE_PKND)) + port = work->word0.pip.cn68xx.pknd; + else + port = work->word1.cn38xx.ipprt; + + if ((work->word2.snoip.err_code == 10) && (work->word1.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. + */ + return 0; + + if (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(port); + int index = cvmx_helper_get_interface_index_num(port); + 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) { + u8 *ptr = + cvmx_phys_to_ptr(work->packet_ptr.s.addr); + int i = 0; + + while (i < work->word1.len - 1) { + if (*ptr != 0x55) + break; + ptr++; + i++; + } + + if (*ptr == 0xd5) { + /* Port received 0xd5 preamble */ + work->packet_ptr.s.addr += i + 1; + work->word1.len -= i + 5; + return 0; + } + + if ((*ptr & 0xf) == 0xd) { + /* Port received 0xd preamble */ + work->packet_ptr.s.addr += i; + work->word1.len -= i + 4; + for (i = 0; i < work->word1.len; i++) { + *ptr = + ((*ptr & 0xf0) >> 4) | + ((*(ptr + 1) & 0xf) << 4); + ptr++; + } + return 0; + } + + printk_ratelimited("Port %d unknown preamble, packet dropped\n", + port); + cvm_oct_free_work(work); + return 1; + } + } + + printk_ratelimited("Port %d receive error code %d, packet dropped\n", + port, work->word2.snoip.err_code); + cvm_oct_free_work(work); + return 1; +} + +static void copy_segments_to_skb(struct cvmx_wqe *work, struct sk_buff *skb) +{ + int segments = work->word2.s.bufs; + union cvmx_buf_ptr segment_ptr = work->packet_ptr; + int len = work->word1.len; + int segment_size; + + while (segments--) { + union cvmx_buf_ptr next_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; + */ + 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 */ + skb_put_data(skb, cvmx_phys_to_ptr(segment_ptr.s.addr), + segment_size); + len -= segment_size; + segment_ptr = next_ptr; + } +} + +static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget) +{ + const int coreid = cvmx_get_core_num(); + u64 old_group_mask; + u64 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) */ + if (OCTEON_IS_MODEL(OCTEON_CN68XX)) { + old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); + cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), + BIT(rx_group->group)); + cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */ + } else { + 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) | + BIT(rx_group->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; + struct cvmx_wqe *work; + int port; + + 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) { + if (OCTEON_IS_MODEL(OCTEON_CN68XX)) { + cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS, + BIT(rx_group->group)); + cvmx_write_csr(CVMX_SSO_WQ_INT, + BIT(rx_group->group)); + } else { + union cvmx_pow_wq_int wq_int; + + wq_int.u64 = 0; + wq_int.s.iq_dis = BIT(rx_group->group); + wq_int.s.wq_int = BIT(rx_group->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; + } + rx_count++; + + skb_in_hw = work->word2.s.bufs == 1; + if (likely(skb_in_hw)) { + skb = *pskb; + prefetch(&skb->head); + prefetch(&skb->len); + } + + if (octeon_has_feature(OCTEON_FEATURE_PKND)) + port = work->word0.pip.cn68xx.pknd; + else + port = work->word1.cn38xx.ipprt; + + prefetch(cvm_oct_device[port]); + + /* 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->word1.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->word1.len); + if (!skb) { + 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)) { + u8 *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; + } + skb_put_data(skb, ptr, work->word1.len); + /* No packet buffers to free */ + } else { + copy_segments_to_skb(work, skb); + } + packet_not_copied = 0; + } + if (likely((port < TOTAL_NUMBER_OF_PORTS) && + cvm_oct_device[port])) { + struct net_device *dev = cvm_oct_device[port]; + + /* + * 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 (port >= CVMX_PIP_NUM_INPUT_PORTS) { + dev->stats.rx_packets++; + dev->stats.rx_bytes += skb->len; + } + netif_receive_skb(skb); + } else { + /* + * Drop any packet received for a device that + * isn't up. + */ + dev->stats.rx_dropped++; + 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", + port); + dev_kfree_skb_irq(skb); + } + /* + * Check to see if the skbuff and work share the same + * packet buffer. + */ + if (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, 1); + } else { + cvm_oct_free_work(work); + } + } + /* Restore the original POW group mask */ + if (OCTEON_IS_MODEL(OCTEON_CN68XX)) { + cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), old_group_mask); + cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */ + } else { + 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); + + return rx_count; +} + +/** + * cvm_oct_napi_poll - the NAPI poll function. + * @napi: The NAPI instance. + * @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) +{ + struct oct_rx_group *rx_group = container_of(napi, struct oct_rx_group, + napi); + int rx_count; + + rx_count = cvm_oct_poll(rx_group, budget); + + if (rx_count < budget) { + /* No more work */ + napi_complete_done(napi, rx_count); + enable_irq(rx_group->irq); + } + 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) +{ + int i; + + if (!atomic_read(&oct_rx_ready)) + return; + + for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) { + if (!(pow_receive_groups & BIT(i))) + continue; + + cvm_oct_poll(&oct_rx_group[i], 16); + } +} +#endif + +void cvm_oct_rx_initialize(void) +{ + int i; + struct net_device *dev_for_napi = NULL; + + for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) { + if (cvm_oct_device[i]) { + dev_for_napi = cvm_oct_device[i]; + break; + } + } + + if (!dev_for_napi) + panic("No net_devices were allocated."); + + for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) { + int ret; + + if (!(pow_receive_groups & BIT(i))) + continue; + + netif_napi_add_weight(dev_for_napi, &oct_rx_group[i].napi, + cvm_oct_napi_poll, rx_napi_weight); + napi_enable(&oct_rx_group[i].napi); + + oct_rx_group[i].irq = OCTEON_IRQ_WORKQ0 + i; + oct_rx_group[i].group = i; + + /* Register an IRQ handler to receive POW interrupts */ + ret = request_irq(oct_rx_group[i].irq, cvm_oct_do_interrupt, 0, + "Ethernet", &oct_rx_group[i].napi); + if (ret) + panic("Could not acquire Ethernet IRQ %d\n", + oct_rx_group[i].irq); + + disable_irq_nosync(oct_rx_group[i].irq); + + /* Enable POW interrupt when our port has at least one packet */ + if (OCTEON_IS_MODEL(OCTEON_CN68XX)) { + union cvmx_sso_wq_int_thrx int_thr; + union cvmx_pow_wq_int_pc int_pc; + + int_thr.u64 = 0; + int_thr.s.tc_en = 1; + int_thr.s.tc_thr = 1; + cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), int_thr.u64); + + int_pc.u64 = 0; + int_pc.s.pc_thr = 5; + cvmx_write_csr(CVMX_SSO_WQ_INT_PC, int_pc.u64); + } else { + union cvmx_pow_wq_int_thrx int_thr; + union cvmx_pow_wq_int_pc int_pc; + + int_thr.u64 = 0; + int_thr.s.tc_en = 1; + int_thr.s.tc_thr = 1; + cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), int_thr.u64); + + int_pc.u64 = 0; + int_pc.s.pc_thr = 5; + cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64); + } + + /* Schedule NAPI now. This will indirectly enable the + * interrupt. + */ + napi_schedule(&oct_rx_group[i].napi); + } + atomic_inc(&oct_rx_ready); +} + +void cvm_oct_rx_shutdown(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) { + if (!(pow_receive_groups & BIT(i))) + continue; + + /* Disable POW interrupt */ + if (OCTEON_IS_MODEL(OCTEON_CN68XX)) + cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), 0); + else + cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0); + + /* Free the interrupt handler */ + free_irq(oct_rx_group[i].irq, cvm_oct_device); + + netif_napi_del(&oct_rx_group[i].napi); + } +} |