PCI: support PCIe ARI capability

This patch adds support for PCI Express Alternative Routing-ID
Interpretation (ARI) capability.

The ARI capability extends the Function Number field of the PCI Express
Endpoint by reusing the Device Number which is otherwise hardwired to 0.
With ARI, an Endpoint can have up to 256 functions.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Yu Zhao 2008-10-14 14:02:53 +08:00 committed by Jesse Barnes
parent 201de56eb2
commit 58c3a727cb
5 changed files with 62 additions and 0 deletions

View File

@ -1299,6 +1299,38 @@ void pci_pm_init(struct pci_dev *dev)
}
}
/**
* pci_enable_ari - enable ARI forwarding if hardware support it
* @dev: the PCI device
*/
void pci_enable_ari(struct pci_dev *dev)
{
int pos;
u32 cap;
u16 ctrl;
if (!dev->is_pcie)
return;
if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
dev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
return;
pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (!pos)
return;
pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_ARI))
return;
pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
ctrl |= PCI_EXP_DEVCTL2_ARI;
pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
dev->ari_enabled = 1;
}
int
pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
{

View File

@ -151,4 +151,16 @@ struct pci_slot_attribute {
};
#define to_pci_slot_attr(s) container_of(s, struct pci_slot_attribute, attr)
extern void pci_enable_ari(struct pci_dev *dev);
/**
* pci_ari_enabled - query ARI forwarding status
* @dev: the PCI device
*
* Returns 1 if ARI forwarding is enabled, or 0 if not enabled;
*/
static inline int pci_ari_enabled(struct pci_dev *dev)
{
return dev->ari_enabled;
}
#endif /* DRIVERS_PCI_H */

View File

@ -1025,6 +1025,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
/* Vital Product Data */
pci_vpd_pci22_init(dev);
/* Alternative Routing-ID Forwarding */
pci_enable_ari(dev);
}
void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)

View File

@ -214,6 +214,7 @@ struct pci_dev {
unsigned int broken_parity_status:1; /* Device generates false positive parity */
unsigned int msi_enabled:1;
unsigned int msix_enabled:1;
unsigned int ari_enabled:1; /* ARI forwarding */
unsigned int is_managed:1;
unsigned int is_pcie:1;
pci_dev_flags_t dev_flags;

View File

@ -419,6 +419,10 @@
#define PCI_EXP_RTCTL_CRSSVE 0x10 /* CRS Software Visibility Enable */
#define PCI_EXP_RTCAP 30 /* Root Capabilities */
#define PCI_EXP_RTSTA 32 /* Root Status */
#define PCI_EXP_DEVCAP2 36 /* Device Capabilities 2 */
#define PCI_EXP_DEVCAP2_ARI 0x20 /* Alternative Routing-ID */
#define PCI_EXP_DEVCTL2 40 /* Device Control 2 */
#define PCI_EXP_DEVCTL2_ARI 0x20 /* Alternative Routing-ID */
/* Extended Capabilities (PCI-X 2.0 and Express) */
#define PCI_EXT_CAP_ID(header) (header & 0x0000ffff)
@ -429,6 +433,7 @@
#define PCI_EXT_CAP_ID_VC 2
#define PCI_EXT_CAP_ID_DSN 3
#define PCI_EXT_CAP_ID_PWR 4
#define PCI_EXT_CAP_ID_ARI 14
/* Advanced Error Reporting */
#define PCI_ERR_UNCOR_STATUS 4 /* Uncorrectable Error Status */
@ -536,5 +541,14 @@
#define HT_CAPTYPE_GEN3 0xD0 /* Generation 3 hypertransport configuration */
#define HT_CAPTYPE_PM 0xE0 /* Hypertransport powermanagement configuration */
/* Alternative Routing-ID Interpretation */
#define PCI_ARI_CAP 0x04 /* ARI Capability Register */
#define PCI_ARI_CAP_MFVC 0x0001 /* MFVC Function Groups Capability */
#define PCI_ARI_CAP_ACS 0x0002 /* ACS Function Groups Capability */
#define PCI_ARI_CAP_NFN(x) (((x) >> 8) & 0xff) /* Next Function Number */
#define PCI_ARI_CTRL 0x06 /* ARI Control Register */
#define PCI_ARI_CTRL_MFVC 0x0001 /* MFVC Function Groups Enable */
#define PCI_ARI_CTRL_ACS 0x0002 /* ACS Function Groups Enable */
#define PCI_ARI_CTRL_FG(x) (((x) >> 4) & 7) /* Function Group */
#endif /* LINUX_PCI_REGS_H */