sfc: Move and rename Falcon/Siena common NIC operations

Add efx_nic_type operations for the many efx_nic functions that need
to be implemented different on EF10.  For now, change most of the
existing efx_nic_*() functions into inline wrappers.  As a later step,
we may be able to improve branch prediction for operations used on the
fast path by copying the pointers into each queue/channel structure.

Move the Falcon/Siena implementations to new file farch.c and rename
the functions and static data to use a prefix of 'efx_farch_'.

Move efx_may_push_tx_desc() to nic.h, as the EF10 TX code will also
use it.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

1 files changed, 167 insertions, 33 deletions

diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h
index 21f662cc39a4..25e25b635798 100644
--- a/drivers/net/ethernet/sfc/nic.h
+++ b/drivers/net/ethernet/sfc/nic.h
@@ -34,7 +34,7 @@ static inline int efx_nic_rev(struct efx_nic *efx)
 	return efx->type->revision;
 }
 
-extern u32 efx_nic_fpga_ver(struct efx_nic *efx);
+extern u32 efx_farch_fpga_ver(struct efx_nic *efx);
 
 /* NIC has two interlinked PCI functions for the same port. */
 static inline bool efx_nic_is_dual_func(struct efx_nic *efx)
@@ -42,6 +42,65 @@ static inline bool efx_nic_is_dual_func(struct efx_nic *efx)
 	return efx_nic_rev(efx) < EFX_REV_FALCON_B0;
 }
 
+/* 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;
+}
+
+/* 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.
+ */
+static inline bool efx_nic_may_push_tx_desc(struct efx_tx_queue *tx_queue,
+					    unsigned int write_count)
+{
+	unsigned empty_read_count = ACCESS_ONCE(tx_queue->empty_read_count);
+
+	if (empty_read_count == 0)
+		return false;
+
+	tx_queue->empty_read_count = 0;
+	return ((empty_read_count ^ write_count) & ~EFX_EMPTY_COUNT_VALID) == 0
+		&& 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;
+}
+
 enum {
 	PHY_TYPE_NONE = 0,
 	PHY_TYPE_TXC43128 = 1,
@@ -258,25 +317,93 @@ extern const struct efx_nic_type siena_a0_nic_type;
 extern int falcon_probe_board(struct efx_nic *efx, u16 revision_info);
 
 /* TX data path */
-extern int efx_nic_probe_tx(struct efx_tx_queue *tx_queue);
-extern void efx_nic_init_tx(struct efx_tx_queue *tx_queue);
-extern void efx_nic_remove_tx(struct efx_tx_queue *tx_queue);
-extern void efx_nic_push_buffers(struct efx_tx_queue *tx_queue);
+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 */
-extern int efx_nic_probe_rx(struct efx_rx_queue *rx_queue);
-extern void efx_nic_init_rx(struct efx_rx_queue *rx_queue);
-extern void efx_nic_remove_rx(struct efx_rx_queue *rx_queue);
-extern void efx_nic_notify_rx_desc(struct efx_rx_queue *rx_queue);
-extern void efx_nic_generate_fill_event(struct efx_rx_queue *rx_queue);
+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 */
-extern int efx_nic_probe_eventq(struct efx_channel *channel);
-extern void efx_nic_init_eventq(struct efx_channel *channel);
-extern void efx_nic_fini_eventq(struct efx_channel *channel);
-extern void efx_nic_remove_eventq(struct efx_channel *channel);
-extern int efx_nic_process_eventq(struct efx_channel *channel, int rx_quota);
-extern void efx_nic_eventq_read_ack(struct efx_channel *channel);
+static inline int efx_nic_probe_eventq(struct efx_channel *channel)
+{
+	return channel->efx->type->ev_probe(channel);
+}
+static inline void efx_nic_init_eventq(struct efx_channel *channel)
+{
+	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);
+}
+extern void efx_nic_event_test_start(struct efx_channel *channel);
+
+/* Falcon/Siena queue operations */
+extern int efx_farch_tx_probe(struct efx_tx_queue *tx_queue);
+extern void efx_farch_tx_init(struct efx_tx_queue *tx_queue);
+extern void efx_farch_tx_fini(struct efx_tx_queue *tx_queue);
+extern void efx_farch_tx_remove(struct efx_tx_queue *tx_queue);
+extern void efx_farch_tx_write(struct efx_tx_queue *tx_queue);
+extern int efx_farch_rx_probe(struct efx_rx_queue *rx_queue);
+extern void efx_farch_rx_init(struct efx_rx_queue *rx_queue);
+extern void efx_farch_rx_fini(struct efx_rx_queue *rx_queue);
+extern void efx_farch_rx_remove(struct efx_rx_queue *rx_queue);
+extern void efx_farch_rx_write(struct efx_rx_queue *rx_queue);
+extern void efx_farch_rx_defer_refill(struct efx_rx_queue *rx_queue);
+extern int efx_farch_ev_probe(struct efx_channel *channel);
+extern void efx_farch_ev_init(struct efx_channel *channel);
+extern void efx_farch_ev_fini(struct efx_channel *channel);
+extern void efx_farch_ev_remove(struct efx_channel *channel);
+extern int efx_farch_ev_process(struct efx_channel *channel, int quota);
+extern void efx_farch_ev_read_ack(struct efx_channel *channel);
+extern void efx_farch_ev_test_generate(struct efx_channel *channel);
+
 extern bool efx_nic_event_present(struct efx_channel *channel);
 
 /* Some statistics are computed as A - B where A and B each increase
@@ -297,15 +424,18 @@ static inline void efx_update_diff_stat(u64 *stat, u64 diff)
 		*stat = diff;
 }
 
-/* Interrupts and test events */
+/* Interrupts */
 extern int efx_nic_init_interrupt(struct efx_nic *efx);
-extern void efx_nic_enable_interrupts(struct efx_nic *efx);
-extern void efx_nic_event_test_start(struct efx_channel *channel);
 extern void efx_nic_irq_test_start(struct efx_nic *efx);
-extern void efx_nic_disable_interrupts(struct efx_nic *efx);
 extern void efx_nic_fini_interrupt(struct efx_nic *efx);
-extern irqreturn_t efx_nic_fatal_interrupt(struct efx_nic *efx);
-extern irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id);
+
+/* Falcon/Siena interrupts */
+extern void efx_farch_irq_enable_master(struct efx_nic *efx);
+extern void efx_farch_irq_test_generate(struct efx_nic *efx);
+extern void efx_farch_irq_disable_master(struct efx_nic *efx);
+extern irqreturn_t efx_farch_msi_interrupt(int irq, void *dev_id);
+extern irqreturn_t efx_farch_legacy_interrupt(int irq, void *dev_id);
+extern irqreturn_t efx_farch_fatal_interrupt(struct efx_nic *efx);
 
 static inline int efx_nic_event_test_irq_cpu(struct efx_channel *channel)
 {
@@ -317,36 +447,40 @@ static inline int efx_nic_irq_test_irq_cpu(struct efx_nic *efx)
 }
 
 /* Global Resources */
-extern int efx_farch_fini_dmaq(struct efx_nic *efx);
+extern int efx_nic_flush_queues(struct efx_nic *efx);
 extern void siena_prepare_flush(struct efx_nic *efx);
+extern int efx_farch_fini_dmaq(struct efx_nic *efx);
 extern void siena_finish_flush(struct efx_nic *efx);
 extern void falcon_start_nic_stats(struct efx_nic *efx);
 extern void falcon_stop_nic_stats(struct efx_nic *efx);
 extern int falcon_reset_xaui(struct efx_nic *efx);
-extern void
-efx_nic_dimension_resources(struct efx_nic *efx, unsigned sram_lim_qw);
-extern void efx_nic_init_common(struct efx_nic *efx);
-extern void efx_nic_push_rx_indir_table(struct efx_nic *efx);
+extern void efx_farch_dimension_resources(struct efx_nic *efx, unsigned sram_lim_qw);
+extern void efx_farch_init_common(struct efx_nic *efx);
+static inline void efx_nic_push_rx_indir_table(struct efx_nic *efx)
+{
+	efx->type->rx_push_indir_table(efx);
+}
+extern void efx_farch_rx_push_indir_table(struct efx_nic *efx);
 
 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);
 
 /* Tests */
-struct efx_nic_register_test {
+struct efx_farch_register_test {
 	unsigned address;
 	efx_oword_t mask;
 };
-extern int efx_nic_test_registers(struct efx_nic *efx,
-				  const struct efx_nic_register_test *regs,
-				  size_t n_regs);
+extern int efx_farch_test_registers(struct efx_nic *efx,
+				    const struct efx_farch_register_test *regs,
+				    size_t n_regs);
 
 extern size_t efx_nic_get_regs_len(struct efx_nic *efx);
 extern void efx_nic_get_regs(struct efx_nic *efx, void *buf);
 
 #define EFX_MAX_FLUSH_TIME 5000
 
-extern void efx_generate_event(struct efx_nic *efx, unsigned int evq,
-			       efx_qword_t *event);
+extern void efx_farch_generate_event(struct efx_nic *efx, unsigned int evq,
+				     efx_qword_t *event);
 
 #endif /* EFX_NIC_H */