sfc: support VI strides other than 8k

Medford2 can also have 16k or 64k VI stride.  This is reported by MCDI in
 GET_CAPABILITIES, which fortunately is called before the driver does
 anything sensitive to the VI stride (such as accessing or even allocating
 VIs past the zeroth).
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/ef10.c

@@ -233,7 +233,7 @@ static int efx_ef10_get_vf_index(struct efx_nic *efx)
 
 static int efx_ef10_init_datapath_caps(struct efx_nic *efx)
 {
-	MCDI_DECLARE_BUF(outbuf, MC_CMD_GET_CAPABILITIES_V2_OUT_LEN);
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_GET_CAPABILITIES_V3_OUT_LEN);
 	struct efx_ef10_nic_data *nic_data = efx->nic_data;
 	size_t outlen;
 	int rc;
@@ -277,6 +277,35 @@ static int efx_ef10_init_datapath_caps(struct efx_nic *efx)
 		return -ENODEV;
 	}
 
+	if (outlen >= MC_CMD_GET_CAPABILITIES_V3_OUT_LEN) {
+		u8 vi_window_mode = MCDI_BYTE(outbuf,
+				GET_CAPABILITIES_V3_OUT_VI_WINDOW_MODE);
+
+		switch (vi_window_mode) {
+		case MC_CMD_GET_CAPABILITIES_V3_OUT_VI_WINDOW_MODE_8K:
+			efx->vi_stride = 8192;
+			break;
+		case MC_CMD_GET_CAPABILITIES_V3_OUT_VI_WINDOW_MODE_16K:
+			efx->vi_stride = 16384;
+			break;
+		case MC_CMD_GET_CAPABILITIES_V3_OUT_VI_WINDOW_MODE_64K:
+			efx->vi_stride = 65536;
+			break;
+		default:
+			netif_err(efx, probe, efx->net_dev,
+				  "Unrecognised VI window mode %d\n",
+				  vi_window_mode);
+			return -EIO;
+		}
+		netif_dbg(efx, probe, efx->net_dev, "vi_stride = %u\n",
+			  efx->vi_stride);
+	} else {
+		/* keep default VI stride */
+		netif_dbg(efx, probe, efx->net_dev,
+			  "firmware did not report VI window mode, assuming vi_stride = %u\n",
+			  efx->vi_stride);
+	}
+
 	return 0;
 }
 
@@ -609,17 +638,6 @@ static int efx_ef10_probe(struct efx_nic *efx)
 	struct efx_ef10_nic_data *nic_data;
 	int i, rc;
 
-	/* We can have one VI for each 8K region.  However, until we
-	 * use TX option descriptors we need two TX queues per channel.
-	 */
-	efx->max_channels = min_t(unsigned int,
-				  EFX_MAX_CHANNELS,
-				  efx_ef10_mem_map_size(efx) /
-				  (EFX_VI_PAGE_SIZE * EFX_TXQ_TYPES));
-	efx->max_tx_channels = efx->max_channels;
-	if (WARN_ON(efx->max_channels == 0))
-		return -EIO;
-
 	nic_data = kzalloc(sizeof(*nic_data), GFP_KERNEL);
 	if (!nic_data)
 		return -ENOMEM;
@@ -691,6 +709,20 @@ static int efx_ef10_probe(struct efx_nic *efx)
 	if (rc < 0)
 		goto fail5;
 
+	/* We can have one VI for each vi_stride-byte region.
+	 * However, until we use TX option descriptors we need two TX queues
+	 * per channel.
+	 */
+	efx->max_channels = min_t(unsigned int,
+				  EFX_MAX_CHANNELS,
+				  efx_ef10_mem_map_size(efx) /
+				  (efx->vi_stride * EFX_TXQ_TYPES));
+	efx->max_tx_channels = efx->max_channels;
+	if (WARN_ON(efx->max_channels == 0)) {
+		rc = -EIO;
+		goto fail5;
+	}
+
 	efx->rx_packet_len_offset =
 		ES_DZ_RX_PREFIX_PKTLEN_OFST - ES_DZ_RX_PREFIX_SIZE;
 
@@ -927,7 +959,7 @@ static int efx_ef10_link_piobufs(struct efx_nic *efx)
 			} else {
 				tx_queue->piobuf =
 					nic_data->pio_write_base +
-					index * EFX_VI_PAGE_SIZE + offset;
+					index * efx->vi_stride + offset;
 				tx_queue->piobuf_offset = offset;
 				netif_dbg(efx, probe, efx->net_dev,
 					  "linked VI %u to PIO buffer %u offset %x addr %p\n",
@@ -1273,19 +1305,19 @@ static int efx_ef10_dimension_resources(struct efx_nic *efx)
 	 * for writing PIO buffers through.
 	 *
 	 * The UC mapping contains (channel_vis - 1) complete VIs and the
-	 * first half of the next VI.  Then the WC mapping begins with
-	 * the second half of this last VI.
+	 * first 4K of the next VI.  Then the WC mapping begins with
+	 * the remainder of this last VI.
 	 */
-	uc_mem_map_size = PAGE_ALIGN((channel_vis - 1) * EFX_VI_PAGE_SIZE +
+	uc_mem_map_size = PAGE_ALIGN((channel_vis - 1) * efx->vi_stride +
 				     ER_DZ_TX_PIOBUF);
 	if (nic_data->n_piobufs) {
 		/* pio_write_vi_base rounds down to give the number of complete
 		 * VIs inside the UC mapping.
 		 */
-		pio_write_vi_base = uc_mem_map_size / EFX_VI_PAGE_SIZE;
+		pio_write_vi_base = uc_mem_map_size / efx->vi_stride;
 		wc_mem_map_size = (PAGE_ALIGN((pio_write_vi_base +
 					       nic_data->n_piobufs) *
-					      EFX_VI_PAGE_SIZE) -
+					      efx->vi_stride) -
 				   uc_mem_map_size);
 		max_vis = pio_write_vi_base + nic_data->n_piobufs;
 	} else {
@@ -1357,7 +1389,7 @@ static int efx_ef10_dimension_resources(struct efx_nic *efx)
 		nic_data->pio_write_vi_base = pio_write_vi_base;
 		nic_data->pio_write_base =
 			nic_data->wc_membase +
-			(pio_write_vi_base * EFX_VI_PAGE_SIZE + ER_DZ_TX_PIOBUF -
+			(pio_write_vi_base * efx->vi_stride + ER_DZ_TX_PIOBUF -
 			 uc_mem_map_size);
 
 		rc = efx_ef10_link_piobufs(efx);

drivers/net/ethernet/sfc/efx.c

@@ -27,6 +27,7 @@
 #include <net/udp_tunnel.h>
 #include "efx.h"
 #include "nic.h"
+#include "io.h"
 #include "selftest.h"
 #include "sriov.h"
 
@@ -2977,6 +2978,7 @@ static int efx_init_struct(struct efx_nic *efx,
 	efx->rx_packet_ts_offset =
 		efx->type->rx_ts_offset - efx->type->rx_prefix_size;
 	spin_lock_init(&efx->stats_lock);
+	efx->vi_stride = EFX_DEFAULT_VI_STRIDE;
 	mutex_init(&efx->mac_lock);
 	efx->phy_op = &efx_dummy_phy_operations;
 	efx->mdio.dev = net_dev;

drivers/net/ethernet/sfc/io.h

@@ -222,18 +222,21 @@ static inline void efx_reado_table(struct efx_nic *efx, efx_oword_t *value,
 	efx_reado(efx, value, reg + index * sizeof(efx_oword_t));
 }
 
-/* Page size used as step between per-VI registers */
-#define EFX_VI_PAGE_SIZE 0x2000
+/* default VI stride (step between per-VI registers) is 8K */
+#define EFX_DEFAULT_VI_STRIDE 0x2000
 
 /* Calculate offset to page-mapped register */
-#define EFX_PAGED_REG(page, reg) \
-	((page) * EFX_VI_PAGE_SIZE + (reg))
+static inline unsigned int efx_paged_reg(struct efx_nic *efx, unsigned int page,
+					 unsigned int reg)
+{
+	return page * efx->vi_stride + reg;
+}
 
 /* Write the whole of RX_DESC_UPD or TX_DESC_UPD */
 static inline void _efx_writeo_page(struct efx_nic *efx, efx_oword_t *value,
 				    unsigned int reg, unsigned int page)
 {
-	reg = EFX_PAGED_REG(page, reg);
+	reg = efx_paged_reg(efx, page, reg);
 
 	netif_vdbg(efx, hw, efx->net_dev,
 		   "writing register %x with " EFX_OWORD_FMT "\n", reg,
@@ -262,7 +265,7 @@ static inline void
 _efx_writed_page(struct efx_nic *efx, const efx_dword_t *value,
 		 unsigned int reg, unsigned int page)
 {
-	efx_writed(efx, value, EFX_PAGED_REG(page, reg));
+	efx_writed(efx, value, efx_paged_reg(efx, page, reg));
 }
 #define efx_writed_page(efx, value, reg, page)				\
 	_efx_writed_page(efx, value,					\
@@ -288,10 +291,10 @@ static inline void _efx_writed_page_locked(struct efx_nic *efx,
 
 	if (page == 0) {
 		spin_lock_irqsave(&efx->biu_lock, flags);
-		efx_writed(efx, value, EFX_PAGED_REG(page, reg));
+		efx_writed(efx, value, efx_paged_reg(efx, page, reg));
 		spin_unlock_irqrestore(&efx->biu_lock, flags);
 	} else {
-		efx_writed(efx, value, EFX_PAGED_REG(page, reg));
+		efx_writed(efx, value, efx_paged_reg(efx, page, reg));
 	}
 }
 #define efx_writed_page_locked(efx, value, reg, page)			\

drivers/net/ethernet/sfc/mcdi.h

@@ -208,6 +208,9 @@ void efx_mcdi_sensor_event(struct efx_nic *efx, efx_qword_t *ev);
 #define _MCDI_DWORD(_buf, _field)					\
 	((_buf) + (_MCDI_CHECK_ALIGN(MC_CMD_ ## _field ## _OFST, 4) >> 2))
 
+#define MCDI_BYTE(_buf, _field)						\
+	((void)BUILD_BUG_ON_ZERO(MC_CMD_ ## _field ## _LEN != 1),	\
+	 *MCDI_PTR(_buf, _field))
 #define MCDI_WORD(_buf, _field)						\
 	((u16)BUILD_BUG_ON_ZERO(MC_CMD_ ## _field ## _LEN != 2) +	\
 	 le16_to_cpu(*(__force const __le16 *)MCDI_PTR(_buf, _field)))

drivers/net/ethernet/sfc/net_driver.h

@@ -708,6 +708,7 @@ struct vfdi_status;
  * @reset_work: Scheduled reset workitem
  * @membase_phys: Memory BAR value as physical address
  * @membase: Memory BAR value
+ * @vi_stride: step between per-VI registers / memory regions
  * @interrupt_mode: Interrupt mode
  * @timer_quantum_ns: Interrupt timer quantum, in nanoseconds
  * @timer_max_ns: Interrupt timer maximum value, in nanoseconds
@@ -842,6 +843,8 @@ struct efx_nic {
 	resource_size_t membase_phys;
 	void __iomem *membase;
 
+	unsigned int vi_stride;
+
 	enum efx_int_mode interrupt_mode;
 	unsigned int timer_quantum_ns;
 	unsigned int timer_max_ns;