1 files changed, 538 insertions, 0 deletions

diff --git a/drivers/staging/octeon/ethernet-rx.c b/drivers/staging/octeon/ethernet-rx.c
new file mode 100644
index 000000000000..2c16230f993c
--- /dev/null
+++ b/drivers/staging/octeon/ethernet-rx.c
@@ -0,0 +1,538 @@
+// 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.
+		 */
+	} else 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;
+			} else 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++;
+				}
+			} else {
+				printk_ratelimited("Port %d unknown preamble, packet dropped\n",
+						   port);
+				cvm_oct_free_work(work);
+				return 1;
+			}
+		}
+	} else {
+		printk_ratelimited("Port %d receive error code %d, packet dropped\n",
+				   port, work->word2.snoip.err_code);
+		cvm_oct_free_work(work);
+		return 1;
+	}
+
+	return 0;
+}
+
+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(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);
+	}
+}