[PATCH v6 1/2] ethdev: remove get_reg_length callback

[Zyta Szpak <zr@semihalf.com>]

From: Zyta Szpak <zr@semihalf.com>

Removes hard-coded assumption that device registers
are always 32 bits wide. The rte_eth_dev_get_reg_length
and rte_eth_dev_get_reg_info callbacks did not
provide register size to the app in any way while is
needed to allocate correct number of bytes before
retrieving registers using rte_eth_dev_get_reg.

This commit changes rte_eth_dev_get_reg_info so that
it can be used to retrieve both the number of registers
and their width, and removes the now-redundant
rte_eth_dev_get_reg_length.

Signed-off-by: Zyta Szpak <zr@semihalf.com>
---
 drivers/net/cxgbe/cxgbe_ethdev.c       | 14 ++++++++++----
 drivers/net/e1000/igb_ethdev.c         | 14 ++++++++++++--
 drivers/net/i40e/i40e_ethdev.c         | 15 ++++++---------
 drivers/net/ixgbe/ixgbe_ethdev.c       | 14 ++++++++++++--
 drivers/net/thunderx/nicvf_ethdev.c    | 14 +++++---------
 drivers/net/thunderx/nicvf_ethdev.h    |  1 +
 lib/librte_ether/rte_dev_info.h        |  1 +
 lib/librte_ether/rte_ethdev.c          | 12 ------------
 lib/librte_ether/rte_ethdev.h          | 25 +++++--------------------
 lib/librte_ether/rte_ether_version.map |  1 -
 10 files changed, 52 insertions(+), 59 deletions(-)

diff --git a/drivers/net/cxgbe/cxgbe_ethdev.c b/drivers/net/cxgbe/cxgbe_ethdev.c
index 6c130ed..f822d8f 100644
--- a/drivers/net/cxgbe/cxgbe_ethdev.c
+++ b/drivers/net/cxgbe/cxgbe_ethdev.c
@@ -934,10 +934,17 @@ static int cxgbe_get_regs(struct rte_eth_dev *eth_dev,
 	struct port_info *pi = (struct port_info *)(eth_dev->data->dev_private);
 	struct adapter *adapter = pi->adapter;
 
-	regs->length = cxgbe_get_regs_len(eth_dev);
 	regs->version = CHELSIO_CHIP_VERSION(adapter->params.chip) |
-			(CHELSIO_CHIP_RELEASE(adapter->params.chip) << 10) |
-			(1 << 16);
+		(CHELSIO_CHIP_RELEASE(adapter->params.chip) << 10) |
+		(1 << 16);
+
+	if (regs->data == NULL) {
+		regs->length = cxgbe_get_regs_len(eth_dev);
+		regs->width = sizeof(uint32_t);
+
+		return 0;
+	}
+
 	t4_get_regs(adapter, regs->data, (regs->length * sizeof(uint32_t)));
 
 	return 0;
@@ -971,7 +978,6 @@ static const struct eth_dev_ops cxgbe_eth_dev_ops = {
 	.get_eeprom_length	= cxgbe_get_eeprom_length,
 	.get_eeprom		= cxgbe_get_eeprom,
 	.set_eeprom		= cxgbe_set_eeprom,
-	.get_reg_length		= cxgbe_get_regs_len,
 	.get_reg		= cxgbe_get_regs,
 };
 
diff --git a/drivers/net/e1000/igb_ethdev.c b/drivers/net/e1000/igb_ethdev.c
index dea50f3..594655d 100644
--- a/drivers/net/e1000/igb_ethdev.c
+++ b/drivers/net/e1000/igb_ethdev.c
@@ -386,7 +386,6 @@ static const struct eth_dev_ops eth_igb_ops = {
 	.timesync_disable     = igb_timesync_disable,
 	.timesync_read_rx_timestamp = igb_timesync_read_rx_timestamp,
 	.timesync_read_tx_timestamp = igb_timesync_read_tx_timestamp,
-	.get_reg_length       = eth_igb_get_reg_length,
 	.get_reg              = eth_igb_get_regs,
 	.get_eeprom_length    = eth_igb_get_eeprom_length,
 	.get_eeprom           = eth_igb_get_eeprom,
@@ -426,7 +425,6 @@ static const struct eth_dev_ops igbvf_eth_dev_ops = {
 	.rxq_info_get         = igb_rxq_info_get,
 	.txq_info_get         = igb_txq_info_get,
 	.mac_addr_set         = igbvf_default_mac_addr_set,
-	.get_reg_length       = igbvf_get_reg_length,
 	.get_reg              = igbvf_get_regs,
 };
 
@@ -4947,6 +4945,12 @@ eth_igb_get_regs(struct rte_eth_dev *dev,
 	int count = 0;
 	const struct reg_info *reg_group;
 
+	if (data == NULL) {
+		regs->length = eth_igb_get_reg_length(dev);
+		regs->width = sizeof(uint32_t);
+		return 0;
+	}
+
 	/* Support only full register dump */
 	if ((regs->length == 0) ||
 	    (regs->length == (uint32_t)eth_igb_get_reg_length(dev))) {
@@ -4971,6 +4975,12 @@ igbvf_get_regs(struct rte_eth_dev *dev,
 	int count = 0;
 	const struct reg_info *reg_group;
 
+	if (data == NULL) {
+		regs->length = igbvf_get_reg_length(dev);
+		regs->width = sizeof(uint32_t);
+		return 0;
+	}
+
 	/* Support only full register dump */
 	if ((regs->length == 0) ||
 	    (regs->length == (uint32_t)igbvf_get_reg_length(dev))) {
diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index c07da1b..8e3e27d 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -440,8 +440,6 @@ static int i40e_dev_rx_queue_intr_enable(struct rte_eth_dev *dev,
 static int i40e_dev_rx_queue_intr_disable(struct rte_eth_dev *dev,
 					  uint16_t queue_id);
 
-static int i40e_get_reg_length(struct rte_eth_dev *dev);
-
 static int i40e_get_regs(struct rte_eth_dev *dev,
 			 struct rte_dev_reg_info *regs);
 
@@ -524,7 +522,6 @@ static const struct eth_dev_ops i40e_eth_dev_ops = {
 	.timesync_adjust_time         = i40e_timesync_adjust_time,
 	.timesync_read_time           = i40e_timesync_read_time,
 	.timesync_write_time          = i40e_timesync_write_time,
-	.get_reg_length	              = i40e_get_reg_length,
 	.get_reg                      = i40e_get_regs,
 	.get_eeprom_length            = i40e_get_eeprom_length,
 	.get_eeprom                   = i40e_get_eeprom,
@@ -9350,12 +9347,6 @@ i40e_dev_rx_queue_intr_disable(struct rte_eth_dev *dev, uint16_t queue_id)
 	return 0;
 }
 
-static int i40e_get_reg_length(__rte_unused struct rte_eth_dev *dev)
-{
-	/* Highest base addr + 32-bit word */
-	return I40E_GLGEN_STAT_CLEAR + 4;
-}
-
 static int i40e_get_regs(struct rte_eth_dev *dev,
 			 struct rte_dev_reg_info *regs)
 {
@@ -9364,6 +9355,12 @@ static int i40e_get_regs(struct rte_eth_dev *dev,
 	uint32_t reg_idx, arr_idx, arr_idx2, reg_offset;
 	const struct i40e_reg_info *reg_info;
 
+	if (ptr_data == NULL) {
+		regs->length = I40E_GLGEN_STAT_CLEAR + 4;
+		regs->width = sizeof(uint32_t);
+		return 0;
+	}
+
 	/* The first few registers have to be read using AQ operations */
 	reg_idx = 0;
 	while (i40e_regs_adminq[reg_idx].name) {
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index d61af37..09109ed 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -538,7 +538,6 @@ static const struct eth_dev_ops ixgbe_eth_dev_ops = {
 	.timesync_disable     = ixgbe_timesync_disable,
 	.timesync_read_rx_timestamp = ixgbe_timesync_read_rx_timestamp,
 	.timesync_read_tx_timestamp = ixgbe_timesync_read_tx_timestamp,
-	.get_reg_length       = ixgbe_get_reg_length,
 	.get_reg              = ixgbe_get_regs,
 	.get_eeprom_length    = ixgbe_get_eeprom_length,
 	.get_eeprom           = ixgbe_get_eeprom,
@@ -589,7 +588,6 @@ static const struct eth_dev_ops ixgbevf_eth_dev_ops = {
 	.rxq_info_get         = ixgbe_rxq_info_get,
 	.txq_info_get         = ixgbe_txq_info_get,
 	.mac_addr_set         = ixgbevf_set_default_mac_addr,
-	.get_reg_length       = ixgbevf_get_reg_length,
 	.get_reg              = ixgbevf_get_regs,
 	.reta_update          = ixgbe_dev_rss_reta_update,
 	.reta_query           = ixgbe_dev_rss_reta_query,
@@ -6323,6 +6321,12 @@ ixgbe_get_regs(struct rte_eth_dev *dev,
 	const struct reg_info **reg_set = (hw->mac.type == ixgbe_mac_82598EB) ?
 				    ixgbe_regs_mac_82598EB : ixgbe_regs_others;
 
+	if (data == NULL) {
+		regs->length = ixgbe_get_reg_length(dev);
+		regs->width = sizeof(uint32_t);
+		return 0;
+	}
+
 	/* Support only full register dump */
 	if ((regs->length == 0) ||
 	    (regs->length == (uint32_t)ixgbe_get_reg_length(dev))) {
@@ -6347,6 +6351,12 @@ ixgbevf_get_regs(struct rte_eth_dev *dev,
 	int count = 0;
 	const struct reg_info *reg_group;
 
+	if (data == NULL) {
+		regs->length = ixgbevf_get_reg_length(dev);
+		regs->width = sizeof(uint32_t);
+		return 0;
+	}
+
 	/* Support only full register dump */
 	if ((regs->length == 0) ||
 	    (regs->length == (uint32_t)ixgbevf_get_reg_length(dev))) {
diff --git a/drivers/net/thunderx/nicvf_ethdev.c b/drivers/net/thunderx/nicvf_ethdev.c
index d534312..5b2c605 100644
--- a/drivers/net/thunderx/nicvf_ethdev.c
+++ b/drivers/net/thunderx/nicvf_ethdev.c
@@ -189,19 +189,16 @@ nicvf_dev_set_mtu(struct rte_eth_dev *dev, uint16_t mtu)
 }
 
 static int
-nicvf_dev_get_reg_length(struct rte_eth_dev *dev  __rte_unused)
-{
-	return nicvf_reg_get_count();
-}
-
-static int
 nicvf_dev_get_regs(struct rte_eth_dev *dev, struct rte_dev_reg_info *regs)
 {
 	uint64_t *data = regs->data;
 	struct nicvf *nic = nicvf_pmd_priv(dev);
 
-	if (data == NULL)
-		return -EINVAL;
+	if (data == NULL) {
+		regs->length = nicvf_reg_get_count();
+		regs->width = THUNDERX_REG_BYTES;
+		return 0;
+	}
 
 	/* Support only full register dump */
 	if ((regs->length == 0) ||
@@ -1623,7 +1620,6 @@ static const struct eth_dev_ops nicvf_eth_dev_ops = {
 	.rx_queue_count           = nicvf_dev_rx_queue_count,
 	.tx_queue_setup           = nicvf_dev_tx_queue_setup,
 	.tx_queue_release         = nicvf_dev_tx_queue_release,
-	.get_reg_length           = nicvf_dev_get_reg_length,
 	.get_reg                  = nicvf_dev_get_regs,
 };
 
diff --git a/drivers/net/thunderx/nicvf_ethdev.h b/drivers/net/thunderx/nicvf_ethdev.h
index 59fa19c..34447e0 100644
--- a/drivers/net/thunderx/nicvf_ethdev.h
+++ b/drivers/net/thunderx/nicvf_ethdev.h
@@ -36,6 +36,7 @@
 #include <rte_ethdev.h>
 
 #define THUNDERX_NICVF_PMD_VERSION      "1.0"
+#define THUNDERX_REG_BYTES		8
 
 #define NICVF_INTR_POLL_INTERVAL_MS	50
 #define NICVF_HALF_DUPLEX		0x00
diff --git a/lib/librte_ether/rte_dev_info.h b/lib/librte_ether/rte_dev_info.h
index 291bd4d..574683d 100644
--- a/lib/librte_ether/rte_dev_info.h
+++ b/lib/librte_ether/rte_dev_info.h
@@ -41,6 +41,7 @@ struct rte_dev_reg_info {
 	void *data; /**< Buffer for return registers */
 	uint32_t offset; /**< Start register table location for access */
 	uint32_t length; /**< Number of registers to fetch */
+	uint32_t width; /**< Size of device register */
 	uint32_t version; /**< Device version */
 };
 
diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 42aaef7..2d73758 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -3308,18 +3308,6 @@ rte_eth_timesync_write_time(uint8_t port_id, const struct timespec *timestamp)
 }
 
 int
-rte_eth_dev_get_reg_length(uint8_t port_id)
-{
-	struct rte_eth_dev *dev;
-
-	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
-
-	dev = &rte_eth_devices[port_id];
-	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->get_reg_length, -ENOTSUP);
-	return (*dev->dev_ops->get_reg_length)(dev);
-}
-
-int
 rte_eth_dev_get_reg_info(uint8_t port_id, struct rte_dev_reg_info *info)
 {
 	struct rte_eth_dev *dev;
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index ebe6578..2ad7de5 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -1322,9 +1322,6 @@ typedef int (*eth_timesync_write_time)(struct rte_eth_dev *dev,
 				       const struct timespec *timestamp);
 /**< @internal Function used to get time from the device clock */
 
-typedef int (*eth_get_reg_length_t)(struct rte_eth_dev *dev);
-/**< @internal Retrieve device register count  */
-
 typedef int (*eth_get_reg_t)(struct rte_eth_dev *dev,
 				struct rte_dev_reg_info *info);
 /**< @internal Retrieve registers  */
@@ -1488,8 +1485,6 @@ struct eth_dev_ops {
 	/** Query redirection table. */
 	reta_query_t reta_query;
 
-	eth_get_reg_length_t get_reg_length;
-	/**< Get # of registers */
 	eth_get_reg_t get_reg;
 	/**< Get registers */
 	eth_get_eeprom_length_t get_eeprom_length;
@@ -4047,25 +4042,15 @@ int rte_eth_tx_queue_info_get(uint8_t port_id, uint16_t queue_id,
 	struct rte_eth_txq_info *qinfo);
 
 /**
- * Retrieve number of available registers for access
- *
- * @param port_id
- *   The port identifier of the Ethernet device.
- * @return
- *   - (>=0) number of registers if successful.
- *   - (-ENOTSUP) if hardware doesn't support.
- *   - (-ENODEV) if *port_id* invalid.
- *   - others depends on the specific operations implementation.
- */
-int rte_eth_dev_get_reg_length(uint8_t port_id);
-
-/**
- * Retrieve device registers and register attributes
+ * Retrieve device registers and register attributes (number of registers and
+ * register size)
  *
  * @param port_id
  *   The port identifier of the Ethernet device.
  * @param info
- *   The template includes buffer for register data and attribute to be filled.
+ *   Pointer to rte_dev_reg_info structure to fill in. If info->data is
+ *   NULL the function fills in the width and length fields. If non-NULL
+ *   the registers are put into the buffer pointed at by the data field.
  * @return
  *   - (0) if successful.
  *   - (-ENOTSUP) if hardware doesn't support.
diff --git a/lib/librte_ether/rte_ether_version.map b/lib/librte_ether/rte_ether_version.map
index 97ed0b0..bbc50d1 100644
--- a/lib/librte_ether/rte_ether_version.map
+++ b/lib/librte_ether/rte_ether_version.map
@@ -36,7 +36,6 @@ DPDK_2.2 {
 	rte_eth_dev_get_eeprom_length;
 	rte_eth_dev_get_mtu;
 	rte_eth_dev_get_reg_info;
-	rte_eth_dev_get_reg_length;
 	rte_eth_dev_get_vlan_offload;
 	rte_eth_devices;
 	rte_eth_dev_info_get;
-- 
2.7.4