[dpdk-dev] [PATCH v3 3/3] igb_uio: deprecate extended tag

[Thomas Monjalon <thomas.monjalon@6wind.com>]

From: Helin Zhang <helin.zhang@intel.com>

It deprecates sys files of 'extended_tag' and
'max_read_request_size' which was not documented.

Signed-off-by: Helin Zhang <helin.zhang@intel.com>
---
 doc/guides/linux_gsg/enable_func.rst      | 26 ++++-------
 doc/guides/rel_notes/deprecation.rst      |  2 +
 lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 72 ++++---------------------------
 3 files changed, 18 insertions(+), 82 deletions(-)

diff --git a/doc/guides/linux_gsg/enable_func.rst b/doc/guides/linux_gsg/enable_func.rst
index 8cb3d79..076770f 100644
--- a/doc/guides/linux_gsg/enable_func.rst
+++ b/doc/guides/linux_gsg/enable_func.rst
@@ -186,27 +186,17 @@ Check with the local Intel's Network Division application engineers for firmware
 The base driver to support firmware version of FVL3E will be integrated in the next
 DPDK release, so currently the validated firmware version is 4.2.6.
 
-Enabling Extended Tag and Setting Max Read Request Size
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Enabling Extended Tag
+~~~~~~~~~~~~~~~~~~~~~
 
-PCI configurations of ``extended_tag`` and max _read_requ st_size have big impacts on performance of small packets on 40G NIC.
-Enabling extended_tag and setting ``max_read_request_size`` to small size such as 128 bytes provide great helps to high performance of small packets.
+PCI configuration of ``extended_tag`` has big impact on small packet size
+performance of 40G ports. Enabling ``extended_tag`` can help 40G port to
+achieve the best performance, especially for small packet size.
 
-*   These can be done in some BIOS implementations.
+* Disabling/enabling ``extended_tag`` can be done in some BIOS implementations.
 
-*   For other BIOS implementations, PCI configurations can be changed by using command of ``setpci``, or special configurations in DPDK config file of ``common_linux``.
-
-    *   Bits 7:5 at address of 0xA8 of each PCI device is used for setting the max_read_request_size,
-        and bit 8 of 0xA8 of each PCI device is used for enabling/disabling the extended_tag.
-        lspci and setpci can be used to read the values of 0xA8 and then write it back after being changed.
-
-    *   In config file of common_linux, below three configurations can be changed for the same purpose.
-
-        ``CONFIG_RTE_PCI_CONFIG``
-
-        ``CONFIG_RTE_PCI_EXTENDED_TAG``
-
-        ``CONFIG_RTE_PCI_MAX_READ_REQUEST_SIZE``
+* If BIOS does not enable it, and does not support changing it, tools
+  (e.g. ``setpci`` on Linux) can be used to enable or disable ``extended_tag``.
 
 * From release 16.04, ``extended_tag`` is enabled by default during port
   initialization, users don't need to care about that anymore.
diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 9979982..5287811 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -12,6 +12,8 @@ Deprecation Notices
   and will be removed from 16.07.
   Macros CONFIG_RTE_PCI_CONFIG, CONFIG_RTE_PCI_EXTENDED_TAG and
   CONFIG_RTE_PCI_MAX_READ_REQUEST_SIZE will be removed.
+  The /sys entries extended_tag and max_read_request_size created by igb_uio
+  will be removed.
 
 * The following fields have been deprecated in rte_eth_stats:
   ibadcrc, ibadlen, imcasts, fdirmatch, fdirmiss,
diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
index a3ad912..72b2692 100644
--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
@@ -40,15 +40,6 @@
 
 #include "compat.h"
 
-#ifdef RTE_PCI_CONFIG
-#define PCI_SYS_FILE_BUF_SIZE      10
-#define PCI_DEV_CAP_REG            0xA4
-#define PCI_DEV_CTRL_REG           0xA8
-#define PCI_DEV_CAP_EXT_TAG_MASK   0x20
-#define PCI_DEV_CTRL_EXT_TAG_SHIFT 8
-#define PCI_DEV_CTRL_EXT_TAG_MASK  (1 << PCI_DEV_CTRL_EXT_TAG_SHIFT)
-#endif
-
 /**
  * A structure describing the private information for a uio device.
  */
@@ -94,19 +85,9 @@ store_max_vfs(struct device *dev, struct device_attribute *attr,
 static ssize_t
 show_extended_tag(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct pci_dev *pci_dev = to_pci_dev(dev);
-	uint32_t val = 0;
+	dev_info(dev, "Deprecated\n");
 
-	pci_read_config_dword(pci_dev, PCI_DEV_CAP_REG, &val);
-	if (!(val & PCI_DEV_CAP_EXT_TAG_MASK)) /* Not supported */
-		return snprintf(buf, PCI_SYS_FILE_BUF_SIZE, "%s\n", "invalid");
-
-	val = 0;
-	pci_bus_read_config_dword(pci_dev->bus, pci_dev->devfn,
-					PCI_DEV_CTRL_REG, &val);
-
-	return snprintf(buf, PCI_SYS_FILE_BUF_SIZE, "%s\n",
-		(val & PCI_DEV_CTRL_EXT_TAG_MASK) ? "on" : "off");
+	return 0;
 }
 
 static ssize_t
@@ -115,36 +96,9 @@ store_extended_tag(struct device *dev,
 		   const char *buf,
 		   size_t count)
 {
-	struct pci_dev *pci_dev = to_pci_dev(dev);
-	uint32_t val = 0, enable;
-
-	if (strncmp(buf, "on", 2) == 0)
-		enable = 1;
-	else if (strncmp(buf, "off", 3) == 0)
-		enable = 0;
-	else
-		return -EINVAL;
-
-	pci_cfg_access_lock(pci_dev);
-	pci_bus_read_config_dword(pci_dev->bus, pci_dev->devfn,
-					PCI_DEV_CAP_REG, &val);
-	if (!(val & PCI_DEV_CAP_EXT_TAG_MASK)) { /* Not supported */
-		pci_cfg_access_unlock(pci_dev);
-		return -EPERM;
-	}
+	dev_info(dev, "Deprecated\n");
 
-	val = 0;
-	pci_bus_read_config_dword(pci_dev->bus, pci_dev->devfn,
-					PCI_DEV_CTRL_REG, &val);
-	if (enable)
-		val |= PCI_DEV_CTRL_EXT_TAG_MASK;
-	else
-		val &= ~PCI_DEV_CTRL_EXT_TAG_MASK;
-	pci_bus_write_config_dword(pci_dev->bus, pci_dev->devfn,
-					PCI_DEV_CTRL_REG, val);
-	pci_cfg_access_unlock(pci_dev);
-
-	return count;
+	return 0;
 }
 
 static ssize_t
@@ -152,10 +106,9 @@ show_max_read_request_size(struct device *dev,
 			   struct device_attribute *attr,
 			   char *buf)
 {
-	struct pci_dev *pci_dev = to_pci_dev(dev);
-	int val = pcie_get_readrq(pci_dev);
+	dev_info(dev, "Deprecated\n");
 
-	return snprintf(buf, PCI_SYS_FILE_BUF_SIZE, "%d\n", val);
+	return 0;
 }
 
 static ssize_t
@@ -164,18 +117,9 @@ store_max_read_request_size(struct device *dev,
 			    const char *buf,
 			    size_t count)
 {
-	struct pci_dev *pci_dev = to_pci_dev(dev);
-	unsigned long size = 0;
-	int ret;
+	dev_info(dev, "Deprecated\n");
 
-	if (0 != kstrtoul(buf, 0, &size))
-		return -EINVAL;
-
-	ret = pcie_set_readrq(pci_dev, (int)size);
-	if (ret < 0)
-		return ret;
-
-	return count;
+	return 0;
 }
 #endif
 
-- 
2.7.0