[PATCH v2 1/2] ethdev: add callback to get register size in bytes

[PATCH v2 1/2] ethdev: add callback to get register size in bytes

[zr]

From: Zyta Szpak <zr@semihalf.com>

Version 2 of fixing the fixed register width assumption.
rte_eth_dev_get_reg_length and rte_eth_dev_get_reg callbacks
do not provide register size to the app in any way. It is
needed to allocate proper number of bytes before retrieving
registers content with rte_eth_dev_get_reg.

Signed-off-by: Zyta Szpak <zr@semihalf.com>
---
 lib/librte_ether/rte_ethdev.c          | 12 ++++++++++++
 lib/librte_ether/rte_ethdev.h          | 18 ++++++++++++++++++
 lib/librte_ether/rte_ether_version.map |  1 +
 3 files changed, 31 insertions(+)

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index a31018e..e0765f8 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -3231,6 +3231,18 @@ rte_eth_dev_get_reg_length(uint8_t port_id)
 }
 
 int
+rte_eth_dev_get_reg_width(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_width, -ENOTSUP);
+	return (*dev->dev_ops->get_reg_width)(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 2757510..552eaed 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -1292,6 +1292,9 @@ typedef int (*eth_timesync_write_time)(struct rte_eth_dev *dev,
 typedef int (*eth_get_reg_length_t)(struct rte_eth_dev *dev);
 /**< @internal Retrieve device register count  */
 
+typedef int (*eth_get_reg_width_t)(struct rte_eth_dev *dev);
+/**< @internal Retrieve device register byte number */
+
 typedef int (*eth_get_reg_t)(struct rte_eth_dev *dev,
 				struct rte_dev_reg_info *info);
 /**< @internal Retrieve registers  */
@@ -1455,6 +1458,8 @@ struct eth_dev_ops {
 
 	eth_get_reg_length_t get_reg_length;
 	/**< Get # of registers */
+	eth_get_reg_width_t get_reg_width;
+	/**< Get # of bytes in register */
 	eth_get_reg_t get_reg;
 	/**< Get registers */
 	eth_get_eeprom_length_t get_eeprom_length;
@@ -3971,6 +3976,19 @@ int rte_eth_tx_queue_info_get(uint8_t port_id, uint16_t queue_id,
  */
 int rte_eth_dev_get_reg_length(uint8_t port_id);
 
+/*
+ * Retrieve the number of bytes in register for a specific device
+ *
+ * @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_width(uint8_t port_id);
+
 /**
  * Retrieve device registers and register attributes
  *
diff --git a/lib/librte_ether/rte_ether_version.map b/lib/librte_ether/rte_ether_version.map
index 214ecc7..288bc63 100644
--- a/lib/librte_ether/rte_ether_version.map
+++ b/lib/librte_ether/rte_ether_version.map
@@ -130,5 +130,6 @@ DPDK_16.04 {
 	rte_eth_tx_buffer_drop_callback;
 	rte_eth_tx_buffer_init;
 	rte_eth_tx_buffer_set_err_callback;
+	rte_eth_dev_get_reg_width;
 
 } DPDK_2.2;
-- 
1.9.1

[PATCH v2 2/2] examples/ethtool: get reg width to allocate memory

[zr]

From: Zyta Szpak <zr@semihalf.com>

Version 2 of fixing the fixed register width assumption.
Not every device uses 32-bit wide register. The app was allocating too
little space for 64-bit registers which resulted in memory corruption.
This commit resolves this by getting the size of register in bytes for
a specific device. If the device does not implement this function, it
fallsback to sizeof(uint32_t)

Signed-off-by: Zyta Szpak <zr@semihalf.com>
---
 examples/ethtool/lib/rte_ethtool.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/examples/ethtool/lib/rte_ethtool.c b/examples/ethtool/lib/rte_ethtool.c
index 42e05f1..59191ca 100644
--- a/examples/ethtool/lib/rte_ethtool.c
+++ b/examples/ethtool/lib/rte_ethtool.c
@@ -88,10 +88,14 @@ int
 rte_ethtool_get_regs_len(uint8_t port_id)
 {
 	int count_regs;
+	int reg_width;
 
 	count_regs = rte_eth_dev_get_reg_length(port_id);
+	reg_width = rte_eth_dev_get_reg_width(port_id);
+	if (reg_width < 0)
+		reg_width = sizeof(uint32_t);
 	if (count_regs > 0)
-		return count_regs * sizeof(uint32_t);
+		return count_regs * reg_width;
 	return count_regs;
 }
 
-- 
1.9.1