env: clean up PCI address comparison function

- Split the part that gets a PCI device's address into its own function,
  spdk_pci_device_get_addr(). This is useful outside of the comparison
  function and is orthogonal to comparing addresses.
- Make the comparison function take two addresses instead of a device
  and an address.  The more general form will be useful with addresses
  that are not directly associated with a device.  Because of this, also
  rename the function from spdk_pci_device_compare_addr() to
  spdk_pci_addr_compare().
- Return a signed value similar to strcmp() so that addresses can be
  ordered, not just compared for equality.

Change-Id: Idf304454af09ea57f1e1d5dc3a39b077378cecad
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>

include/spdk/env.h

@@ -173,6 +173,9 @@ uint16_t spdk_pci_device_get_domain(struct spdk_pci_device *dev);
 uint8_t spdk_pci_device_get_bus(struct spdk_pci_device *dev);
 uint8_t spdk_pci_device_get_dev(struct spdk_pci_device *dev);
 uint8_t spdk_pci_device_get_func(struct spdk_pci_device *dev);
+
+struct spdk_pci_addr spdk_pci_device_get_addr(struct spdk_pci_device *dev);
+
 uint16_t spdk_pci_device_get_vendor_id(struct spdk_pci_device *dev);
 uint16_t spdk_pci_device_get_device_id(struct spdk_pci_device *dev);
 uint16_t spdk_pci_device_get_subvendor_id(struct spdk_pci_device *dev);
@@ -189,7 +192,12 @@ int spdk_pci_device_cfg_write16(struct spdk_pci_device *dev, uint16_t value, uin
 int spdk_pci_device_cfg_read32(struct spdk_pci_device *dev, uint32_t *value, uint32_t offset);
 int spdk_pci_device_cfg_write32(struct spdk_pci_device *dev, uint32_t value, uint32_t offset);
 
-bool spdk_pci_device_compare_addr(struct spdk_pci_device *dev, struct spdk_pci_addr *addr);
+/**
+ * Compare two PCI addresses.
+ *
+ * \return 0 if a1 == a2, less than 0 if a1 < a2, greater than 0 if a1 > a2
+ */
+int spdk_pci_addr_compare(const struct spdk_pci_addr *a1, const struct spdk_pci_addr *a2);
 
 #ifdef __cplusplus
 }

lib/bdev/nvme/blockdev_nvme.c

@@ -414,10 +414,12 @@ blockdev_nvme_exist(struct nvme_probe_ctx *ctx)
 {
 	int i;
 	struct nvme_device *nvme_dev;
+	struct spdk_pci_addr dev_addr;
 
 	for (i = 0; i < ctx->num_whitelist_controllers; i++) {
 		TAILQ_FOREACH(nvme_dev, &g_nvme_devices, tailq) {
-			if (spdk_pci_device_compare_addr(nvme_dev->pci_dev, &ctx->whitelist[i])) {
+			dev_addr = spdk_pci_device_get_addr(nvme_dev->pci_dev);
+			if (spdk_pci_addr_compare(&dev_addr, &ctx->whitelist[i]) == 0) {
 				return true;
 			}
 		}

lib/env/pci.c

@@ -394,13 +394,41 @@ spdk_pci_device_get_serial_number(struct spdk_pci_device *dev, char *sn, size_t
 	return -1;
 }
 
-bool
-spdk_pci_device_compare_addr(struct spdk_pci_device *dev, struct spdk_pci_addr *addr)
+struct spdk_pci_addr
+spdk_pci_device_get_addr(struct spdk_pci_device *pci_dev)
 {
-	return ((spdk_pci_device_get_domain(dev) == addr->domain) &&
-		(spdk_pci_device_get_bus(dev) == addr->bus) &&
-		(spdk_pci_device_get_dev(dev) == addr->dev) &&
-		(spdk_pci_device_get_func(dev) == addr->func));
+	struct spdk_pci_addr pci_addr;
+
+	pci_addr.domain = spdk_pci_device_get_domain(pci_dev);
+	pci_addr.bus = spdk_pci_device_get_bus(pci_dev);
+	pci_addr.dev = spdk_pci_device_get_dev(pci_dev);
+	pci_addr.func = spdk_pci_device_get_func(pci_dev);
+
+	return pci_addr;
+}
+
+int
+spdk_pci_addr_compare(const struct spdk_pci_addr *a1, const struct spdk_pci_addr *a2)
+{
+	if (a1->domain > a2->domain) {
+		return 1;
+	} else if (a1->domain < a2->domain) {
+		return -1;
+	} else if (a1->bus > a2->bus) {
+		return 1;
+	} else if (a1->bus < a2->bus) {
+		return -1;
+	} else if (a1->dev > a2->dev) {
+		return 1;
+	} else if (a1->dev < a2->dev) {
+		return -1;
+	} else if (a1->func > a2->func) {
+		return 1;
+	} else if (a1->func < a2->func) {
+		return -1;
+	}
+
+	return 0;
 }
 
 #ifdef __linux__

lib/nvme/nvme.c

@@ -229,6 +229,9 @@ nvme_enum_cb(void *ctx, struct spdk_pci_device *pci_dev)
 	struct nvme_enum_ctx *enum_ctx = ctx;
 	struct spdk_nvme_ctrlr *ctrlr;
 	struct spdk_nvme_ctrlr_opts opts;
+	struct spdk_pci_addr dev_addr;
+
+	dev_addr = spdk_pci_device_get_addr(pci_dev);
 
 	/* Verify that this controller is not already attached */
 	TAILQ_FOREACH(ctrlr, &g_spdk_nvme_driver->attached_ctrlrs, tailq) {
@@ -236,7 +239,7 @@ nvme_enum_cb(void *ctx, struct spdk_pci_device *pci_dev)
 		 * different per each process, we compare by BDF to determine whether it is the
 		 * same controller.
 		 */
-		if (spdk_pci_device_compare_addr(pci_dev, &ctrlr->pci_addr)) {
+		if (spdk_pci_addr_compare(&dev_addr, &ctrlr->pci_addr) == 0) {
 			return 0;
 		}
 	}

test/lib/nvme/unit/nvme_c/nvme_ut.c

@@ -73,8 +73,17 @@ spdk_nvme_ctrlr_opts_set_defaults(struct spdk_nvme_ctrlr_opts *opts)
 	memset(opts, 0, sizeof(*opts));
 }
 
-bool
-spdk_pci_device_compare_addr(struct spdk_pci_device *dev, struct spdk_pci_addr *addr)
+struct spdk_pci_addr
+spdk_pci_device_get_addr(struct spdk_pci_device *pci_dev)
+{
+	struct spdk_pci_addr pci_addr;
+
+	memset(&pci_addr, 0, sizeof(pci_addr));
+	return pci_addr;
+}
+
+int
+spdk_pci_addr_compare(const struct spdk_pci_addr *a1, const struct spdk_pci_addr *a2)
 {
 	return true;
 }

test/lib/nvme/unit/nvme_ns_cmd_c/nvme_ns_cmd_ut.c

@@ -77,8 +77,17 @@ nvme_ctrlr_start(struct spdk_nvme_ctrlr *ctrlr)
 	return 0;
 }
 
-bool
-spdk_pci_device_compare_addr(struct spdk_pci_device *dev, struct spdk_pci_addr *addr)
+struct spdk_pci_addr
+spdk_pci_device_get_addr(struct spdk_pci_device *pci_dev)
+{
+	struct spdk_pci_addr pci_addr;
+
+	memset(&pci_addr, 0, sizeof(pci_addr));
+	return pci_addr;
+}
+
+int
+spdk_pci_addr_compare(const struct spdk_pci_addr *a1, const struct spdk_pci_addr *a2)
 {
 	return true;
 }