From 44a9a36f6be43636ac2342c06d9feb60db77826a Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 13 Jul 2012 14:24:59 -0600 Subject: PCI: Add pci_find_next_ext_capability() Some extended capabilities, e.g., the vendor-specific capability, can occur several times. The existing pci_find_ext_capability() only finds the first occurrence. This adds pci_find_next_ext_capability(), which can iterate through all of them. Signed-off-by: Bjorn Helgaas diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f3ea977..d34415b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -286,20 +286,17 @@ static int pci_pcie_cap2(struct pci_dev *dev) } /** - * pci_find_ext_capability - Find an extended capability + * pci_find_next_ext_capability - Find an extended capability * @dev: PCI device to query + * @start: address at which to start looking (0 to start at beginning of list) * @cap: capability code * - * Returns the address of the requested extended capability structure + * Returns the address of the next matching extended capability structure * within the device's PCI configuration space or 0 if the device does - * not support it. Possible values for @cap: - * - * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting - * %PCI_EXT_CAP_ID_VC Virtual Channel - * %PCI_EXT_CAP_ID_DSN Device Serial Number - * %PCI_EXT_CAP_ID_PWR Power Budgeting + * not support it. Some capabilities can occur several times, e.g., the + * vendor-specific capability, and this provides a way to find them all. */ -int pci_find_ext_capability(struct pci_dev *dev, int cap) +int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap) { u32 header; int ttl; @@ -311,6 +308,9 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) if (dev->cfg_size <= PCI_CFG_SPACE_SIZE) return 0; + if (start) + pos = start; + if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) return 0; @@ -322,7 +322,7 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) return 0; while (ttl-- > 0) { - if (PCI_EXT_CAP_ID(header) == cap) + if (PCI_EXT_CAP_ID(header) == cap && pos != start) return pos; pos = PCI_EXT_CAP_NEXT(header); @@ -335,6 +335,26 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) return 0; } +EXPORT_SYMBOL_GPL(pci_find_next_ext_capability); + +/** + * pci_find_ext_capability - Find an extended capability + * @dev: PCI device to query + * @cap: capability code + * + * Returns the address of the requested extended capability structure + * within the device's PCI configuration space or 0 if the device does + * not support it. Possible values for @cap: + * + * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting + * %PCI_EXT_CAP_ID_VC Virtual Channel + * %PCI_EXT_CAP_ID_DSN Device Serial Number + * %PCI_EXT_CAP_ID_PWR Power Budgeting + */ +int pci_find_ext_capability(struct pci_dev *dev, int cap) +{ + return pci_find_next_ext_capability(dev, 0, cap); +} EXPORT_SYMBOL_GPL(pci_find_ext_capability); static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) diff --git a/include/linux/pci.h b/include/linux/pci.h index 5faa831..65c503c 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -755,6 +755,7 @@ enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *dev); int pci_find_capability(struct pci_dev *dev, int cap); int pci_find_next_capability(struct pci_dev *dev, u8 pos, int 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); -- cgit v0.10.2 From defb9446fe417f72855bc8bf97aa5d8af076bdf8 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 13 Jul 2012 14:30:21 -0600 Subject: PCI: Add Vendor-Specific Extended Capability header info This adds the fields in the Vendor-Specific Header: ID, Rev, and Length. There may be multiple Vendor-Specific capabilities, so drivers should use the VSEC ID to identify the one of interest. Signed-off-by: Bjorn Helgaas diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h index 7fb75b1..02448b1 100644 --- a/include/linux/pci_regs.h +++ b/include/linux/pci_regs.h @@ -677,6 +677,12 @@ #define PCI_PWR_CAP_BUDGET(x) ((x) & 1) /* Included in system budget */ #define PCI_EXT_CAP_PWR_SIZEOF 16 +/* Vendor-Specific (VSEC, PCI_EXT_CAP_ID_VNDR) */ +#define PCI_VNDR_HEADER 4 /* Vendor-Specific Header */ +#define PCI_VNDR_HEADER_ID(x) ((x) & 0xffff) +#define PCI_VNDR_HEADER_REV(x) (((x) >> 16) & 0xf) +#define PCI_VNDR_HEADER_LEN(x) (((x) >> 20) & 0xfff) + /* * Hypertransport sub capability types * -- cgit v0.10.2