From 12ea6cad1c7d046e21decc18b0e2170c6794dc51 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 11 Jun 2012 05:26:55 +0000 Subject: PCI: add PCI DMA source ID quirk DMA transactions are tagged with the source ID of the device making the request. Occasionally hardware screws this up and uses the source ID of a different device (often the wrong function number of a multifunction device). A specific Ricoh multifunction device is a prime example of this problem and included in this patch. Given a pci_dev, this function returns the pci_dev to use as the source ID for DMA. When hardware works correctly, this returns the input device. For the components of the Ricoh multifunction device, it returns the pci_dev for function 0. This will be used by IOMMU drivers for determining the boundaries of IOMMU groups as multiple devices using the same source ID must be contained within the same group. This can also be used by existing streaming DMA paths for the same purpose. [bhelgaas: fold in pci_dev_get() for !CONFIG_PCI] Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- include/linux/pci.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/pci.h') diff --git a/include/linux/pci.h b/include/linux/pci.h index d8c379dba6ad..39983be7b25b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1332,6 +1332,9 @@ static inline struct pci_dev *pci_get_bus_and_slot(unsigned int bus, static inline int pci_domain_nr(struct pci_bus *bus) { return 0; } +static inline struct pci_dev *pci_dev_get(struct pci_dev *dev) +{ return NULL; } + #define dev_is_pci(d) (false) #define dev_is_pf(d) (false) #define dev_num_vf(d) (0) @@ -1486,9 +1489,14 @@ enum pci_fixup_pass { #ifdef CONFIG_PCI_QUIRKS void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev); +struct pci_dev *pci_get_dma_source(struct pci_dev *dev); #else static inline void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) {} +static inline struct pci_dev *pci_get_dma_source(struct pci_dev *dev) +{ + return pci_dev_get(dev); +} #endif void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen); -- cgit v1.2.3 From ad805758c0eb25bce7b2e3b298d63dc62a1bc71c Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 11 Jun 2012 05:27:07 +0000 Subject: PCI: add ACS validation utility In a PCI environment, transactions aren't always required to reach the root bus before being re-routed. Intermediate switches between an endpoint and the root bus can redirect DMA back downstream before things like IOMMUs have a chance to intervene. Legacy PCI is always susceptible to this as it operates on a shared bus. PCIe added a new capability to describe and control this behavior, Access Control Services, or ACS. The utility function pci_acs_enabled() allows us to test the ACS capabilities of an individual devices against a set of flags while pci_acs_path_enabled() tests a complete path from a given downstream device up to the specified upstream device. We also include the ability to add device specific tests as it's likely we'll see devices that do not implement ACS, but want to indicate support for various capabilities in this space. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/pci/quirks.c | 33 +++++++++++++++++++++++++ include/linux/pci.h | 10 +++++++- 3 files changed, 111 insertions(+), 1 deletion(-) (limited to 'include/linux/pci.h') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 447e83472c01..1ccf7d49f522 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2359,6 +2359,75 @@ void pci_enable_acs(struct pci_dev *dev) pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl); } +/** + * pci_acs_enabled - test ACS against required flags for a given device + * @pdev: device to test + * @acs_flags: required PCI ACS flags + * + * Return true if the device supports the provided flags. Automatically + * filters out flags that are not implemented on multifunction devices. + */ +bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags) +{ + int pos, ret; + u16 ctrl; + + ret = pci_dev_specific_acs_enabled(pdev, acs_flags); + if (ret >= 0) + return ret > 0; + + if (!pci_is_pcie(pdev)) + return false; + + /* Filter out flags not applicable to multifunction */ + if (pdev->multifunction) + acs_flags &= (PCI_ACS_RR | PCI_ACS_CR | + PCI_ACS_EC | PCI_ACS_DT); + + if (pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM || + pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT || + pdev->multifunction) { + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS); + if (!pos) + return false; + + pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl); + if ((ctrl & acs_flags) != acs_flags) + return false; + } + + return true; +} + +/** + * pci_acs_path_enable - test ACS flags from start to end in a hierarchy + * @start: starting downstream device + * @end: ending upstream device or NULL to search to the root bus + * @acs_flags: required flags + * + * Walk up a device tree from start to end testing PCI ACS support. If + * any step along the way does not support the required flags, return false. + */ +bool pci_acs_path_enabled(struct pci_dev *start, + struct pci_dev *end, u16 acs_flags) +{ + struct pci_dev *pdev, *parent = start; + + do { + pdev = parent; + + if (!pci_acs_enabled(pdev, acs_flags)) + return false; + + if (pci_is_root_bus(pdev->bus)) + return (end == NULL); + + parent = pdev->bus->self; + } while (pdev != end); + + return true; +} + /** * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge * @dev: the PCI device diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index acd3956b44bd..27e2c8f4ec73 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3230,3 +3230,36 @@ struct pci_dev *pci_get_dma_source(struct pci_dev *dev) return pci_dev_get(dev); } + +static const struct pci_dev_acs_enabled { + u16 vendor; + u16 device; + int (*acs_enabled)(struct pci_dev *dev, u16 acs_flags); +} pci_dev_acs_enabled[] = { + { 0 } +}; + +int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags) +{ + const struct pci_dev_acs_enabled *i; + int ret; + + /* + * Allow devices that do not expose standard PCIe ACS capabilities + * or control to indicate their support here. Multi-function express + * devices which do not allow internal peer-to-peer between functions, + * but do not implement PCIe ACS may wish to return true here. + */ + for (i = pci_dev_acs_enabled; i->acs_enabled; i++) { + if ((i->vendor == dev->vendor || + i->vendor == (u16)PCI_ANY_ID) && + (i->device == dev->device || + i->device == (u16)PCI_ANY_ID)) { + ret = i->acs_enabled(dev, acs_flags); + if (ret >= 0) + return ret; + } + } + + return -ENOTTY; +} diff --git a/include/linux/pci.h b/include/linux/pci.h index 39983be7b25b..dd7af0f37b3a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1490,6 +1490,7 @@ enum pci_fixup_pass { #ifdef CONFIG_PCI_QUIRKS void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev); struct pci_dev *pci_get_dma_source(struct pci_dev *dev); +int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags); #else static inline void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) {} @@ -1497,6 +1498,11 @@ static inline struct pci_dev *pci_get_dma_source(struct pci_dev *dev) { return pci_dev_get(dev); } +static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev, + u16 acs_flags) +{ + return -ENOTTY; +} #endif void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen); @@ -1599,7 +1605,9 @@ static inline bool pci_is_pcie(struct pci_dev *dev) } void pci_request_acs(void); - +bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags); +bool pci_acs_path_enabled(struct pci_dev *start, + struct pci_dev *end, u16 acs_flags); #define PCI_VPD_LRDT 0x80 /* Large Resource Data Type */ #define PCI_VPD_LRDT_ID(x) (x | PCI_VPD_LRDT) -- cgit v1.2.3 From c63587d7f5b9db84e71daf5962dc0394eb657da2 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 11 Jun 2012 05:27:19 +0000 Subject: PCI: export pci_user functions for use by other drivers VFIO PCI support will make use of these for user-initiated PCI config accesses. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/access.c | 6 ++++-- drivers/pci/pci.h | 7 ------- include/linux/pci.h | 8 ++++++++ 3 files changed, 12 insertions(+), 9 deletions(-) (limited to 'include/linux/pci.h') diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 2a581642c237..ba91a7e17519 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -162,7 +162,8 @@ int pci_user_read_config_##size \ if (ret > 0) \ ret = -EINVAL; \ return ret; \ -} +} \ +EXPORT_SYMBOL_GPL(pci_user_read_config_##size); /* Returns 0 on success, negative values indicate error. */ #define PCI_USER_WRITE_CONFIG(size,type) \ @@ -181,7 +182,8 @@ int pci_user_write_config_##size \ if (ret > 0) \ ret = -EINVAL; \ return ret; \ -} +} \ +EXPORT_SYMBOL_GPL(pci_user_write_config_##size); PCI_USER_READ_CONFIG(byte, u8) PCI_USER_READ_CONFIG(word, u16) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index e4943479b234..f2dcc46bdece 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -86,13 +86,6 @@ static inline bool pci_is_bridge(struct pci_dev *pci_dev) return !!(pci_dev->subordinate); } -extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val); -extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val); -extern int pci_user_read_config_dword(struct pci_dev *dev, int where, u32 *val); -extern int pci_user_write_config_byte(struct pci_dev *dev, int where, u8 val); -extern int pci_user_write_config_word(struct pci_dev *dev, int where, u16 val); -extern int pci_user_write_config_dword(struct pci_dev *dev, int where, u32 val); - struct pci_vpd_ops { ssize_t (*read)(struct pci_dev *dev, loff_t pos, size_t count, void *buf); ssize_t (*write)(struct pci_dev *dev, loff_t pos, size_t count, const void *buf); diff --git a/include/linux/pci.h b/include/linux/pci.h index dd7af0f37b3a..9d04599c6bd9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -777,6 +777,14 @@ static inline int pci_write_config_dword(const struct pci_dev *dev, int where, return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val); } +/* user-space driven config access */ +int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val); +int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val); +int pci_user_read_config_dword(struct pci_dev *dev, int where, u32 *val); +int pci_user_write_config_byte(struct pci_dev *dev, int where, u8 val); +int pci_user_write_config_word(struct pci_dev *dev, int where, u16 val); +int pci_user_write_config_dword(struct pci_dev *dev, int where, u32 val); + int __must_check pci_enable_device(struct pci_dev *dev); int __must_check pci_enable_device_io(struct pci_dev *dev); int __must_check pci_enable_device_mem(struct pci_dev *dev); -- cgit v1.2.3 From a6961651408afa9387d6df43c4a1dc4fd35dcb1b Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 11 Jun 2012 05:27:33 +0000 Subject: PCI: create common pcibios_err_to_errno For returning errors out to non-PCI code. Re-name xen's version. Acked-by: Konrad Rzeszutek Wilk Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/xen/xen-pciback/conf_space.c | 6 +++--- include/linux/pci.h | 26 ++++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 3 deletions(-) (limited to 'include/linux/pci.h') diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c index 30d7be026c18..46ae0f9f02ad 100644 --- a/drivers/xen/xen-pciback/conf_space.c +++ b/drivers/xen/xen-pciback/conf_space.c @@ -124,7 +124,7 @@ static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask, return val; } -static int pcibios_err_to_errno(int err) +static int xen_pcibios_err_to_errno(int err) { switch (err) { case PCIBIOS_SUCCESSFUL: @@ -202,7 +202,7 @@ out: pci_name(dev), size, offset, value); *ret_val = value; - return pcibios_err_to_errno(err); + return xen_pcibios_err_to_errno(err); } int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value) @@ -290,7 +290,7 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value) } } - return pcibios_err_to_errno(err); + return xen_pcibios_err_to_errno(err); } void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev) diff --git a/include/linux/pci.h b/include/linux/pci.h index 9d04599c6bd9..a691f62bcf89 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -474,6 +474,32 @@ static inline bool pci_dev_msi_enabled(struct pci_dev *pci_dev) { return false; #define PCIBIOS_SET_FAILED 0x88 #define PCIBIOS_BUFFER_TOO_SMALL 0x89 +/* + * Translate above to generic errno for passing back through non-pci. + */ +static inline int pcibios_err_to_errno(int err) +{ + if (err <= PCIBIOS_SUCCESSFUL) + return err; /* Assume already errno */ + + switch (err) { + case PCIBIOS_FUNC_NOT_SUPPORTED: + return -ENOENT; + case PCIBIOS_BAD_VENDOR_ID: + return -EINVAL; + case PCIBIOS_DEVICE_NOT_FOUND: + return -ENODEV; + case PCIBIOS_BAD_REGISTER_NUMBER: + return -EFAULT; + case PCIBIOS_SET_FAILED: + return -EIO; + case PCIBIOS_BUFFER_TOO_SMALL: + return -ENOSPC; + } + + return -ENOTTY; +} + /* Low-level architecture-dependent routines */ struct pci_ops { -- cgit v1.2.3