From 1f94a94f67e1083e19fb7b436dd7ca7a4ba03f2b Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Fri, 9 Jan 2015 20:34:39 -0600 Subject: [PATCH] PCI: Add generic config accessors Many PCI controllers' configuration space accesses are memory-mapped and vary only in address calculation and access checks. There are 2 main access methods: a decoded address space such as ECAM or a single address and data register similar to x86. This implementation can support both cases as well as be used in cases that need additional pre- or post-access handling. Add a new pci_ops member, map_bus, which can do access checks and any necessary setup. It returns the address to use for the configuration space access. The access types supported are 32-bit only accesses or correct byte, word, or dword sized accesses. Tested-by: Thierry Reding Signed-off-by: Rob Herring Signed-off-by: Bjorn Helgaas Reviewed-by: Thierry Reding --- drivers/pci/access.c | 87 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 11 ++++++ 2 files changed, 98 insertions(+) diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 49dd766852ba..d9b64a175990 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -67,6 +67,93 @@ EXPORT_SYMBOL(pci_bus_write_config_byte); EXPORT_SYMBOL(pci_bus_write_config_word); EXPORT_SYMBOL(pci_bus_write_config_dword); +int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + void __iomem *addr; + + addr = bus->ops->map_bus(bus, devfn, where); + if (!addr) { + *val = ~0; + return PCIBIOS_DEVICE_NOT_FOUND; + } + + if (size == 1) + *val = readb(addr); + else if (size == 2) + *val = readw(addr); + else + *val = readl(addr); + + return PCIBIOS_SUCCESSFUL; +} +EXPORT_SYMBOL_GPL(pci_generic_config_read); + +int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + void __iomem *addr; + + addr = bus->ops->map_bus(bus, devfn, where); + if (!addr) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (size == 1) + writeb(val, addr); + else if (size == 2) + writew(val, addr); + else + writel(val, addr); + + return PCIBIOS_SUCCESSFUL; +} +EXPORT_SYMBOL_GPL(pci_generic_config_write); + +int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + void __iomem *addr; + + addr = bus->ops->map_bus(bus, devfn, where & ~0x3); + if (!addr) { + *val = ~0; + return PCIBIOS_DEVICE_NOT_FOUND; + } + + *val = readl(addr); + + if (size <= 2) + *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); + + return PCIBIOS_SUCCESSFUL; +} +EXPORT_SYMBOL_GPL(pci_generic_config_read32); + +int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + void __iomem *addr; + u32 mask, tmp; + + addr = bus->ops->map_bus(bus, devfn, where & ~0x3); + if (!addr) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (size == 4) { + writel(val, addr); + return PCIBIOS_SUCCESSFUL; + } else { + mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8)); + } + + tmp = readl(addr) & mask; + tmp |= val << ((where & 0x3) * 8); + writel(tmp, addr); + + return PCIBIOS_SUCCESSFUL; +} +EXPORT_SYMBOL_GPL(pci_generic_config_write32); + /** * pci_bus_set_ops - Set raw operations of pci bus * @bus: pci bus struct diff --git a/include/linux/pci.h b/include/linux/pci.h index 360a966a97a5..e7fd51900182 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -560,6 +560,7 @@ static inline int pcibios_err_to_errno(int err) /* Low-level architecture-dependent routines */ struct pci_ops { + void __iomem *(*map_bus)(struct pci_bus *bus, unsigned int devfn, int where); int (*read)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val); int (*write)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val); }; @@ -857,6 +858,16 @@ int pci_bus_write_config_word(struct pci_bus *bus, unsigned int devfn, int where, u16 val); int pci_bus_write_config_dword(struct pci_bus *bus, unsigned int devfn, int where, u32 val); + +int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val); +int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val); +int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val); +int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val); + struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops); static inline int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)