Commit f646c2a0 authored by Puranjay Mohan's avatar Puranjay Mohan Committed by Bjorn Helgaas
Browse files

PCI: Return u8 from pci_find_capability() and similar 

PCI Capabilities are linked in a list that must appear in the first 256
bytes of config space.  Each capabilities list pointer is 8 bits.

Change the return type of pci_find_capability() and supporting functions
from int to u8 to match the specification.

[bhelgaas: change other related interfaces, fix HyperTransport typos]
Link: https://lore.kernel.org/r/20201129164626.12887-1-puranjay12@gmail.com


Signed-off-by: default avatarPuranjay Mohan <puranjay12@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 3853f912

drivers/pci/pci.c

+21 −21
Original line number Diff line number Diff line
@@ -399,7 +399,7 @@ found: 
	return 1;

}



static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,

static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,

				  u8 pos, int cap, int *ttl)

{

	u8 id;
@@ -423,7 +423,7 @@ static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, 
	return 0;

}



static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,

static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,

			      u8 pos, int cap)

{

	int ttl = PCI_FIND_CAP_TTL;
@@ -431,14 +431,14 @@ static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, 
	return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);

}



int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)

u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)

{

	return __pci_find_next_cap(dev->bus, dev->devfn,

				   pos + PCI_CAP_LIST_NEXT, cap);

}

EXPORT_SYMBOL_GPL(pci_find_next_capability);



static int __pci_bus_find_cap_start(struct pci_bus *bus,

static u8 __pci_bus_find_cap_start(struct pci_bus *bus,

				    unsigned int devfn, u8 hdr_type)

{

	u16 status;
@@ -477,9 +477,9 @@ static int __pci_bus_find_cap_start(struct pci_bus *bus, 
 *  %PCI_CAP_ID_PCIX         PCI-X

 *  %PCI_CAP_ID_EXP          PCI Express

 */

int pci_find_capability(struct pci_dev *dev, int cap)

u8 pci_find_capability(struct pci_dev *dev, int cap)

{

	int pos;

	u8 pos;



	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);

	if (pos)
@@ -502,10 +502,9 @@ EXPORT_SYMBOL(pci_find_capability); 
 * device's PCI configuration space or 0 in case the device does not

 * support it.

 */

int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)

u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)

{

	int pos;

	u8 hdr_type;

	u8 hdr_type, pos;



	pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
@@ -623,7 +622,7 @@ u64 pci_get_dsn(struct pci_dev *dev) 
}

EXPORT_SYMBOL_GPL(pci_get_dsn);



static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)

static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap)

{

	int rc, ttl = PCI_FIND_CAP_TTL;

	u8 cap, mask;
@@ -650,11 +649,12 @@ static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) 


	return 0;

}



/**

 * pci_find_next_ht_capability - query a device's Hypertransport capabilities

 * pci_find_next_ht_capability - query a device's HyperTransport capabilities

 * @dev: PCI device to query

 * @pos: Position from which to continue searching

 * @ht_cap: Hypertransport capability code

 * @ht_cap: HyperTransport capability code

 *

 * To be used in conjunction with pci_find_ht_capability() to search for

 * all capabilities matching @ht_cap. @pos should always be a value returned
@@ -663,26 +663,26 @@ static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) 
 * NB. To be 100% safe against broken PCI devices, the caller should take

 * steps to avoid an infinite loop.

 */

int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)

u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap)

{

	return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);

}

EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);



/**

 * pci_find_ht_capability - query a device's Hypertransport capabilities

 * pci_find_ht_capability - query a device's HyperTransport capabilities

 * @dev: PCI device to query

 * @ht_cap: Hypertransport capability code

 * @ht_cap: HyperTransport capability code

 *

 * Tell if a device supports a given Hypertransport capability.

 * Tell if a device supports a given HyperTransport capability.

 * Returns an address within the device's PCI configuration space

 * or 0 in case the device does not support the request capability.

 * The address points to the PCI capability, of type PCI_CAP_ID_HT,

 * which has a Hypertransport capability matching @ht_cap.

 * which has a HyperTransport capability matching @ht_cap.

 */

int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)

u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap)

{

	int pos;

	u8 pos;



	pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);

	if (pos)

include/linux/pci.h

+6 −6
Original line number Diff line number Diff line
@@ -1064,12 +1064,13 @@ void pci_sort_breadthfirst(void); 


/* Generic PCI functions exported to card drivers */



int pci_find_capability(struct pci_dev *dev, int cap);

int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);

u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap);

u8 pci_find_capability(struct pci_dev *dev, int cap);

u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);

u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap);

u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap);

int pci_find_ext_capability(struct pci_dev *dev, int cap);

int pci_find_next_ext_capability(struct pci_dev *dev, int pos, int cap);

int pci_find_ht_capability(struct pci_dev *dev, int ht_cap);

int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap);

struct pci_bus *pci_find_next_bus(const struct pci_bus *from);



u64 pci_get_dsn(struct pci_dev *dev);
@@ -1280,7 +1281,6 @@ void set_pcie_port_type(struct pci_dev *pdev); 
void set_pcie_hotplug_bridge(struct pci_dev *pdev);



/* Functions for PCI Hotplug drivers to use */

int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap);

unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge);

unsigned int pci_rescan_bus(struct pci_bus *bus);

void pci_lock_rescan_remove(void);
@@ -1720,7 +1720,7 @@ static inline int __pci_register_driver(struct pci_driver *drv, 
static inline int pci_register_driver(struct pci_driver *drv)

{ return 0; }

static inline void pci_unregister_driver(struct pci_driver *drv) { }

static inline int pci_find_capability(struct pci_dev *dev, int cap)

static inline u8 pci_find_capability(struct pci_dev *dev, int cap)

{ return 0; }

static inline int pci_find_next_capability(struct pci_dev *dev, u8 post,

					   int cap)

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