Commit 2499ee84 authored by Kishon Vijay Abraham I's avatar Kishon Vijay Abraham I Committed by Lorenzo Pieralisi
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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: default avatarKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
parent 07301c98

drivers/pci/endpoint/pci-ep-cfs.c

+5 −22
Original line number Diff line number Diff line
@@ -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)
@@ -89,39 +88,24 @@ 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;



	return 0;



err_epf_bind:

	if (ret) {

		pci_epc_remove_epf(epc, epf);



err_add_epf:

	clear_bit(func_no, &epc_group->function_num_map);



		return ret;

	}



	return 0;

}



static void pci_epc_epf_unlink(struct config_item *epc_item,

			       struct config_item *epf_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);

}

drivers/pci/endpoint/pci-epc-core.c

+22 −4
Original line number Diff line number Diff line
@@ -471,22 +471,39 @@ EXPORT_SYMBOL_GPL(pci_epc_write_header); 
 */

int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)

{

	u32 func_no;

	int ret = 0;



	if (epf->epc)

		return -EBUSY;



	if (IS_ERR(epc))

		return -EINVAL;



	if (epf->func_no > epc->max_functions - 1)

		return -EINVAL;

	mutex_lock(&epc->lock);

	func_no = find_first_zero_bit(&epc->function_num_map,

				      BITS_PER_LONG);

	if (func_no >= BITS_PER_LONG) {

		ret = -EINVAL;

		goto ret;

	}



	if (func_no > epc->max_functions - 1) {

		dev_err(&epc->dev, "Exceeding max supported Function Number\n");

		ret = -EINVAL;

		goto ret;

	}



	set_bit(func_no, &epc->function_num_map);

	epf->func_no = func_no;

	epf->epc = epc;



	mutex_lock(&epc->lock);

	list_add_tail(&epf->list, &epc->pci_epf);



ret:

	mutex_unlock(&epc->lock);



	return 0;

	return ret;

}

EXPORT_SYMBOL_GPL(pci_epc_add_epf);
@@ -503,6 +520,7 @@ void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf) 
		return;



	mutex_lock(&epc->lock);

	clear_bit(epf->func_no, &epc->function_num_map);

	list_del(&epf->list);

	epf->epc = NULL;

	mutex_unlock(&epc->lock);

include/linux/pci-epc.h

+2 −0
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ struct pci_epc_mem { 
 * @max_functions: max number of functions that can be configured in this EPC

 * @group: configfs group representing the PCI EPC device

 * @lock: mutex to protect pci_epc ops

 * @function_num_map: bitmap to manage physical function number

 * @notifier: used to notify EPF of any EPC events (like linkup)

 */

struct pci_epc {
@@ -103,6 +104,7 @@ struct pci_epc { 
	struct config_group		*group;

	/* mutex to protect against concurrent access of EP controller */

	struct mutex			lock;

	unsigned long			function_num_map;

	struct atomic_notifier_head	notifier;

};