[dpdk-dev] [PATCH v15 05/13] eal/pci: Consolidate pci address comparison APIs

[Tetsuya Mukawa <mukawa@igel.co.jp>]

This patch replaces pci_addr_comparison() and memcmp() of pci addresses by
rte_eal_compare_pci_addr().

To compare PCI addresses, rte_eal_compare_pci_addr() doesn't use memcmp().
This is because sizeof(struct rte_pci_addr) returns 6, but actually
this structure is like below.

struct rte_pci_addr {
        uint16_t domain;                /**< Device domain */
        uint8_t bus;                    /**< Device bus */
        uint8_t devid;                  /**< Device ID */
        uint8_t function;               /**< Device function. */
};

If the structure is dynamically allocated in a function without bzero,
last 1 byte may have value. As a result, memcmp may not work.
To avoid such a case, rte_eal_compare_pci_addr() compare following values.

        dev_addr = (addr->domain << 24) | (addr->bus << 16) |
                                (addr->devid << 8) | addr->function;

v9:
- eal_compare_pci_addr() is replaced by rte_eal_compare_pci_addr().
- Fix commit log.
  (Thanks to Thomas Monjalon)
v8:
- Fix pci_scan_one() to update sysfs values.
  (Thanks to Qiu, Michael and Iremonger, Bernard)
v5:
- Fix pci_scan_one to handle pt_driver correctly.
v4:
- Fix calculation method of eal_compare_pci_addr().
- Add parameter checking.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 lib/librte_eal/bsdapp/eal/eal_pci.c       | 29 ++++++++++++--------------
 lib/librte_eal/common/eal_common_pci.c    |  2 +-
 lib/librte_eal/common/include/rte_pci.h   | 34 +++++++++++++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci.c     | 30 +++++++++++++--------------
 lib/librte_eal/linuxapp/eal/eal_pci_uio.c |  2 +-
 5 files changed, 63 insertions(+), 34 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
index 74ecce7..9193f80 100644
--- a/lib/librte_eal/bsdapp/eal/eal_pci.c
+++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
@@ -270,20 +270,6 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 	return (0);
 }
 
-/* Compare two PCI device addresses. */
-static int
-pci_addr_comparison(struct rte_pci_addr *addr, struct rte_pci_addr *addr2)
-{
-	uint64_t dev_addr = (addr->domain << 24) + (addr->bus << 16) + (addr->devid << 8) + addr->function;
-	uint64_t dev_addr2 = (addr2->domain << 24) + (addr2->bus << 16) + (addr2->devid << 8) + addr2->function;
-
-	if (dev_addr > dev_addr2)
-		return 1;
-	else
-		return 0;
-}
-
-
 /* Scan one pci sysfs entry, and fill the devices list from it. */
 static int
 pci_scan_one(int dev_pci_fd, struct pci_conf *conf)
@@ -356,13 +342,24 @@ pci_scan_one(int dev_pci_fd, struct pci_conf *conf)
 	}
 	else {
 		struct rte_pci_device *dev2 = NULL;
+		int ret;
 
 		TAILQ_FOREACH(dev2, &pci_device_list, next) {
-			if (pci_addr_comparison(&dev->addr, &dev2->addr))
+			ret = rte_eal_compare_pci_addr(&dev->addr, &dev2->addr);
+			if (ret > 0)
 				continue;
-			else {
+			else if (ret < 0) {
 				TAILQ_INSERT_BEFORE(dev2, dev, next);
 				return 0;
+			} else { /* already registered */
+				/* update pt_driver */
+				dev2->pt_driver = dev->pt_driver;
+				dev2->max_vfs = dev->max_vfs;
+				memmove(dev2->mem_resource,
+					dev->mem_resource,
+					sizeof(dev->mem_resource));
+				free(dev);
+				return 0;
 			}
 		}
 		TAILQ_INSERT_TAIL(&pci_device_list, dev, next);
diff --git a/lib/librte_eal/common/eal_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
index f3c7f71..bf2793f 100644
--- a/lib/librte_eal/common/eal_common_pci.c
+++ b/lib/librte_eal/common/eal_common_pci.c
@@ -93,7 +93,7 @@ static struct rte_devargs *pci_devargs_lookup(struct rte_pci_device *dev)
 		if (devargs->type != RTE_DEVTYPE_BLACKLISTED_PCI &&
 			devargs->type != RTE_DEVTYPE_WHITELISTED_PCI)
 			continue;
-		if (!memcmp(&dev->addr, &devargs->pci.addr, sizeof(dev->addr)))
+		if (!rte_eal_compare_pci_addr(&dev->addr, &devargs->pci.addr))
 			return devargs;
 	}
 	return NULL;
diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
index 255a77b..dcf9c81 100644
--- a/lib/librte_eal/common/include/rte_pci.h
+++ b/lib/librte_eal/common/include/rte_pci.h
@@ -272,6 +272,40 @@ eal_parse_pci_DomBDF(const char *input, struct rte_pci_addr *dev_addr)
 }
 #undef GET_PCIADDR_FIELD
 
+/* Compare two PCI device addresses. */
+/**
+ * Utility function to compare two PCI device addresses.
+ *
+ * @param addr
+ *	The PCI Bus-Device-Function address to compare
+ * @param addr2
+ *	The PCI Bus-Device-Function address to compare
+ * @return
+ *	0 on equal PCI address.
+ *	Positive on addr is greater than addr2.
+ *	Negative on addr is less than addr2, or error.
+ */
+static inline int
+rte_eal_compare_pci_addr(struct rte_pci_addr *addr, struct rte_pci_addr *addr2)
+{
+	uint64_t dev_addr, dev_addr2;
+
+	if ((addr == NULL) || (addr2 == NULL))
+		return -1;
+
+	dev_addr = (addr->domain << 24) | (addr->bus << 16) |
+				(addr->devid << 8) | addr->function;
+	dev_addr2 = (addr2->domain << 24) | (addr2->bus << 16) |
+				(addr2->devid << 8) | addr2->function;
+
+	if (dev_addr > dev_addr2)
+		return 1;
+	else if (dev_addr < dev_addr2)
+		return -1;
+	else
+		return 0;
+}
+
 /**
  * Probe the PCI bus for registered drivers.
  *
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index 3291c68..06bfc1a 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -41,6 +41,7 @@
 #include <rte_eal_memconfig.h>
 #include <rte_malloc.h>
 #include <rte_devargs.h>
+#include <rte_memcpy.h>
 
 #include "rte_pci_dev_ids.h"
 #include "eal_filesystem.h"
@@ -228,20 +229,6 @@ error:
 	return -1;
 }
 
-/* Compare two PCI device addresses. */
-static int
-pci_addr_comparison(struct rte_pci_addr *addr, struct rte_pci_addr *addr2)
-{
-	uint64_t dev_addr = (addr->domain << 24) + (addr->bus << 16) + (addr->devid << 8) + addr->function;
-	uint64_t dev_addr2 = (addr2->domain << 24) + (addr2->bus << 16) + (addr2->devid << 8) + addr2->function;
-
-	if (dev_addr > dev_addr2)
-		return 1;
-	else
-		return 0;
-}
-
-
 /* Scan one pci sysfs entry, and fill the devices list from it. */
 static int
 pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
@@ -359,13 +346,24 @@ pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
 	}
 	else {
 		struct rte_pci_device *dev2 = NULL;
+		int ret;
 
 		TAILQ_FOREACH(dev2, &pci_device_list, next) {
-			if (pci_addr_comparison(&dev->addr, &dev2->addr))
+			ret = rte_eal_compare_pci_addr(&dev->addr, &dev2->addr);
+			if (ret > 0)
 				continue;
-			else {
+			else if (ret < 0) {
 				TAILQ_INSERT_BEFORE(dev2, dev, next);
 				return 0;
+			} else { /* already registered */
+				/* update pt_driver */
+				dev2->pt_driver = dev->pt_driver;
+				dev2->max_vfs = dev->max_vfs;
+				memmove(dev2->mem_resource,
+					dev->mem_resource,
+					sizeof(dev->mem_resource));
+				free(dev);
+				return 0;
 			}
 		}
 		TAILQ_INSERT_TAIL(&pci_device_list, dev, next);
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
index 0a95376..c5e0cf3 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
@@ -91,7 +91,7 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
 	TAILQ_FOREACH(uio_res, pci_res_list, next) {
 
 		/* skip this element if it doesn't match our PCI address */
-		if (memcmp(&uio_res->pci_addr, &dev->addr, sizeof(dev->addr)))
+		if (rte_eal_compare_pci_addr(&uio_res->pci_addr, &dev->addr))
 			continue;
 
 		for (i = 0; i != uio_res->nb_maps; i++) {
-- 
1.9.1