sfc: split up nic.h

The new nic_common.h contains the inlines for NIC-type function dispatch,
 declarations for NIC-generic functions in nic.c, and other similar NIC-
 generic functionality.  Retained in nic.h are NIC-specific declarations
 such as the siena and ef10 nic_data structs and various farch functions.

The EF100 driver will thus include nic_common.h but not nic.h.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 273 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/nic_common.h b/drivers/net/ethernet/sfc/nic_common.h
new file mode 100644
index 000000000000..e90ce85359cb
--- /dev/null
+++ b/drivers/net/ethernet/sfc/nic_common.h
@@ -0,0 +1,273 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2005-2006 Fen Systems Ltd.
+ * Copyright 2006-2013 Solarflare Communications Inc.
+ * Copyright 2019-2020 Xilinx Inc.
+ */
+
+#ifndef EFX_NIC_COMMON_H
+#define EFX_NIC_COMMON_H
+
+#include "net_driver.h"
+#include "efx_common.h"
+#include "mcdi.h"
+#include "ptp.h"
+
+enum {
+	/* Revisions 0-2 were Falcon A0, A1 and B0 respectively.
+	 * They are not supported by this driver but these revision numbers
+	 * form part of the ethtool API for register dumping.
+	 */
+	EFX_REV_SIENA_A0 = 3,
+	EFX_REV_HUNT_A0 = 4,
+};
+
+static inline int efx_nic_rev(struct efx_nic *efx)
+{
+	return efx->type->revision;
+}
+
+/* Read the current event from the event queue */
+static inline efx_qword_t *efx_event(struct efx_channel *channel,
+				     unsigned int index)
+{
+	return ((efx_qword_t *) (channel->eventq.buf.addr)) +
+		(index & channel->eventq_mask);
+}
+
+/* See if an event is present
+ *
+ * We check both the high and low dword of the event for all ones.  We
+ * wrote all ones when we cleared the event, and no valid event can
+ * have all ones in either its high or low dwords.  This approach is
+ * robust against reordering.
+ *
+ * Note that using a single 64-bit comparison is incorrect; even
+ * though the CPU read will be atomic, the DMA write may not be.
+ */
+static inline int efx_event_present(efx_qword_t *event)
+{
+	return !(EFX_DWORD_IS_ALL_ONES(event->dword[0]) |
+		  EFX_DWORD_IS_ALL_ONES(event->dword[1]));
+}
+
+/* Returns a pointer to the specified transmit descriptor in the TX
+ * descriptor queue belonging to the specified channel.
+ */
+static inline efx_qword_t *
+efx_tx_desc(struct efx_tx_queue *tx_queue, unsigned int index)
+{
+	return ((efx_qword_t *) (tx_queue->txd.buf.addr)) + index;
+}
+
+/* Report whether this TX queue would be empty for the given write_count.
+ * May return false negative.
+ */
+static inline bool __efx_nic_tx_is_empty(struct efx_tx_queue *tx_queue,
+					 unsigned int write_count)
+{
+	unsigned int empty_read_count = READ_ONCE(tx_queue->empty_read_count);
+
+	if (empty_read_count == 0)
+		return false;
+
+	return ((empty_read_count ^ write_count) & ~EFX_EMPTY_COUNT_VALID) == 0;
+}
+
+/* Report whether the NIC considers this TX queue empty, using
+ * packet_write_count (the write count recorded for the last completable
+ * doorbell push).  May return false negative.  EF10 only, which is OK
+ * because only EF10 supports PIO.
+ */
+static inline bool efx_nic_tx_is_empty(struct efx_tx_queue *tx_queue)
+{
+	EFX_WARN_ON_ONCE_PARANOID(!tx_queue->efx->type->option_descriptors);
+	return __efx_nic_tx_is_empty(tx_queue, tx_queue->packet_write_count);
+}
+
+/* Get partner of a TX queue, seen as part of the same net core queue */
+/* XXX is this a thing on EF100? */
+static inline struct efx_tx_queue *efx_tx_queue_partner(struct efx_tx_queue *tx_queue)
+{
+	if (tx_queue->queue & EFX_TXQ_TYPE_OFFLOAD)
+		return tx_queue - EFX_TXQ_TYPE_OFFLOAD;
+	else
+		return tx_queue + EFX_TXQ_TYPE_OFFLOAD;
+}
+
+/* Decide whether we can use TX PIO, ie. write packet data directly into
+ * a buffer on the device.  This can reduce latency at the expense of
+ * throughput, so we only do this if both hardware and software TX rings
+ * are empty.  This also ensures that only one packet at a time can be
+ * using the PIO buffer.
+ */
+static inline bool efx_nic_may_tx_pio(struct efx_tx_queue *tx_queue)
+{
+	struct efx_tx_queue *partner = efx_tx_queue_partner(tx_queue);
+
+	return tx_queue->piobuf && efx_nic_tx_is_empty(tx_queue) &&
+	       efx_nic_tx_is_empty(partner);
+}
+
+/* Decide whether to push a TX descriptor to the NIC vs merely writing
+ * the doorbell.  This can reduce latency when we are adding a single
+ * descriptor to an empty queue, but is otherwise pointless.  Further,
+ * Falcon and Siena have hardware bugs (SF bug 33851) that may be
+ * triggered if we don't check this.
+ * We use the write_count used for the last doorbell push, to get the
+ * NIC's view of the tx queue.
+ */
+static inline bool efx_nic_may_push_tx_desc(struct efx_tx_queue *tx_queue,
+					    unsigned int write_count)
+{
+	bool was_empty = __efx_nic_tx_is_empty(tx_queue, write_count);
+
+	tx_queue->empty_read_count = 0;
+	return was_empty && tx_queue->write_count - write_count == 1;
+}
+
+/* Returns a pointer to the specified descriptor in the RX descriptor queue */
+static inline efx_qword_t *
+efx_rx_desc(struct efx_rx_queue *rx_queue, unsigned int index)
+{
+	return ((efx_qword_t *) (rx_queue->rxd.buf.addr)) + index;
+}
+
+/* Alignment of PCIe DMA boundaries (4KB) */
+#define EFX_PAGE_SIZE	4096
+/* Size and alignment of buffer table entries (same) */
+#define EFX_BUF_SIZE	EFX_PAGE_SIZE
+
+/* NIC-generic software stats */
+enum {
+	GENERIC_STAT_rx_noskb_drops,
+	GENERIC_STAT_rx_nodesc_trunc,
+	GENERIC_STAT_COUNT
+};
+
+#define EFX_GENERIC_SW_STAT(ext_name)				\
+	[GENERIC_STAT_ ## ext_name] = { #ext_name, 0, 0 }
+
+/* TX data path */
+static inline int efx_nic_probe_tx(struct efx_tx_queue *tx_queue)
+{
+	return tx_queue->efx->type->tx_probe(tx_queue);
+}
+static inline void efx_nic_init_tx(struct efx_tx_queue *tx_queue)
+{
+	tx_queue->efx->type->tx_init(tx_queue);
+}
+static inline void efx_nic_remove_tx(struct efx_tx_queue *tx_queue)
+{
+	tx_queue->efx->type->tx_remove(tx_queue);
+}
+static inline void efx_nic_push_buffers(struct efx_tx_queue *tx_queue)
+{
+	tx_queue->efx->type->tx_write(tx_queue);
+}
+
+/* RX data path */
+static inline int efx_nic_probe_rx(struct efx_rx_queue *rx_queue)
+{
+	return rx_queue->efx->type->rx_probe(rx_queue);
+}
+static inline void efx_nic_init_rx(struct efx_rx_queue *rx_queue)
+{
+	rx_queue->efx->type->rx_init(rx_queue);
+}
+static inline void efx_nic_remove_rx(struct efx_rx_queue *rx_queue)
+{
+	rx_queue->efx->type->rx_remove(rx_queue);
+}
+static inline void efx_nic_notify_rx_desc(struct efx_rx_queue *rx_queue)
+{
+	rx_queue->efx->type->rx_write(rx_queue);
+}
+static inline void efx_nic_generate_fill_event(struct efx_rx_queue *rx_queue)
+{
+	rx_queue->efx->type->rx_defer_refill(rx_queue);
+}
+
+/* Event data path */
+static inline int efx_nic_probe_eventq(struct efx_channel *channel)
+{
+	return channel->efx->type->ev_probe(channel);
+}
+static inline int efx_nic_init_eventq(struct efx_channel *channel)
+{
+	return channel->efx->type->ev_init(channel);
+}
+static inline void efx_nic_fini_eventq(struct efx_channel *channel)
+{
+	channel->efx->type->ev_fini(channel);
+}
+static inline void efx_nic_remove_eventq(struct efx_channel *channel)
+{
+	channel->efx->type->ev_remove(channel);
+}
+static inline int
+efx_nic_process_eventq(struct efx_channel *channel, int quota)
+{
+	return channel->efx->type->ev_process(channel, quota);
+}
+static inline void efx_nic_eventq_read_ack(struct efx_channel *channel)
+{
+	channel->efx->type->ev_read_ack(channel);
+}
+
+void efx_nic_event_test_start(struct efx_channel *channel);
+
+bool efx_nic_event_present(struct efx_channel *channel);
+
+/* Some statistics are computed as A - B where A and B each increase
+ * linearly with some hardware counter(s) and the counters are read
+ * asynchronously.  If the counters contributing to B are always read
+ * after those contributing to A, the computed value may be lower than
+ * the true value by some variable amount, and may decrease between
+ * subsequent computations.
+ *
+ * We should never allow statistics to decrease or to exceed the true
+ * value.  Since the computed value will never be greater than the
+ * true value, we can achieve this by only storing the computed value
+ * when it increases.
+ */
+static inline void efx_update_diff_stat(u64 *stat, u64 diff)
+{
+	if ((s64)(diff - *stat) > 0)
+		*stat = diff;
+}
+
+/* Interrupts */
+int efx_nic_init_interrupt(struct efx_nic *efx);
+int efx_nic_irq_test_start(struct efx_nic *efx);
+void efx_nic_fini_interrupt(struct efx_nic *efx);
+
+static inline int efx_nic_event_test_irq_cpu(struct efx_channel *channel)
+{
+	return READ_ONCE(channel->event_test_cpu);
+}
+static inline int efx_nic_irq_test_irq_cpu(struct efx_nic *efx)
+{
+	return READ_ONCE(efx->last_irq_cpu);
+}
+
+/* Global Resources */
+int efx_nic_alloc_buffer(struct efx_nic *efx, struct efx_buffer *buffer,
+			 unsigned int len, gfp_t gfp_flags);
+void efx_nic_free_buffer(struct efx_nic *efx, struct efx_buffer *buffer);
+
+size_t efx_nic_get_regs_len(struct efx_nic *efx);
+void efx_nic_get_regs(struct efx_nic *efx, void *buf);
+
+size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
+			      const unsigned long *mask, u8 *names);
+int efx_nic_copy_stats(struct efx_nic *efx, __le64 *dest);
+void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count,
+			  const unsigned long *mask, u64 *stats,
+			  const void *dma_buf, bool accumulate);
+void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *stat);
+
+#define EFX_MAX_FLUSH_TIME 5000
+
+#endif /* EFX_NIC_COMMON_H */