PCI: endpoint: Assign function number for each PF in EPC core

The PCIe endpoint core relies on the drivers that invoke the
pci_epc_add_epf() API to allocate and assign a function number
to each physical function (PF). Since endpoint function device can
be created by multiple mechanisms (configfs, devicetree, etc..),
allowing each of these mechanisms to assign a function number
would result in mutliple endpoint function devices having the
same function number. In order to avoid this, let EPC core assign
a function number to the endpoint device.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

1 files changed, 5 insertions, 22 deletions

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index d1288a0bd530..e7e8367eead1 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -29,7 +29,6 @@ struct pci_epc_group {
 	struct config_group group;
 	struct pci_epc *epc;
 	bool start;
-	unsigned long function_num_map;
 };
 
 static inline struct pci_epf_group *to_pci_epf_group(struct config_item *item)
@@ -89,37 +88,22 @@ static int pci_epc_epf_link(struct config_item *epc_item,
 			    struct config_item *epf_item)
 {
 	int ret;
-	u32 func_no = 0;
 	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);
 	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
 	struct pci_epc *epc = epc_group->epc;
 	struct pci_epf *epf = epf_group->epf;
 
-	func_no = find_first_zero_bit(&epc_group->function_num_map,
-				      BITS_PER_LONG);
-	if (func_no >= BITS_PER_LONG)
-		return -EINVAL;
-
-	set_bit(func_no, &epc_group->function_num_map);
-	epf->func_no = func_no;
-
 	ret = pci_epc_add_epf(epc, epf);
 	if (ret)
-		goto err_add_epf;
+		return ret;
 
 	ret = pci_epf_bind(epf);
-	if (ret)
-		goto err_epf_bind;
+	if (ret) {
+		pci_epc_remove_epf(epc, epf);
+		return ret;
+	}
 
 	return 0;
-
-err_epf_bind:
-	pci_epc_remove_epf(epc, epf);
-
-err_add_epf:
-	clear_bit(func_no, &epc_group->function_num_map);
-
-	return ret;
 }
 
 static void pci_epc_epf_unlink(struct config_item *epc_item,
@@ -134,7 +118,6 @@ static void pci_epc_epf_unlink(struct config_item *epc_item,
 
 	epc = epc_group->epc;
 	epf = epf_group->epf;
-	clear_bit(epf->func_no, &epc_group->function_num_map);
 	pci_epf_unbind(epf);
 	pci_epc_remove_epf(epc, epf);
 }