diff options
| -rw-r--r-- | drivers/pci/setup-bus.c | 32 | ||||
| -rw-r--r-- | include/linux/pci.h | 2 |
2 files changed, 34 insertions, 0 deletions
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index fb506137aaee..896f06e3e793 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -697,6 +697,38 @@ static resource_size_t calculate_memsize(resource_size_t size, return size; } +resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus, + unsigned long type) +{ + return 1; +} + +#define PCI_P2P_DEFAULT_MEM_ALIGN 0x100000 /* 1MiB */ +#define PCI_P2P_DEFAULT_IO_ALIGN 0x1000 /* 4KiB */ +#define PCI_P2P_DEFAULT_IO_ALIGN_1K 0x400 /* 1KiB */ + +static resource_size_t window_alignment(struct pci_bus *bus, + unsigned long type) +{ + resource_size_t align = 1, arch_align; + + if (type & IORESOURCE_MEM) + align = PCI_P2P_DEFAULT_MEM_ALIGN; + else if (type & IORESOURCE_IO) { + /* + * Per spec, I/O windows are 4K-aligned, but some + * bridges have an extension to support 1K alignment. + */ + if (bus->self->io_window_1k) + align = PCI_P2P_DEFAULT_IO_ALIGN_1K; + else + align = PCI_P2P_DEFAULT_IO_ALIGN; + } + + arch_align = pcibios_window_alignment(bus, type); + return max(align, arch_align); +} + /** * pbus_size_io() - size the io window of a given bus * diff --git a/include/linux/pci.h b/include/linux/pci.h index b8667e0548e0..2c755243eef2 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1064,6 +1064,8 @@ int pci_cfg_space_size_ext(struct pci_dev *dev); int pci_cfg_space_size(struct pci_dev *dev); unsigned char pci_bus_max_busnr(struct pci_bus *bus); void pci_setup_bridge(struct pci_bus *bus); +resource_size_t pcibios_window_alignment(struct pci_bus *bus, + unsigned long type); #define PCI_VGA_STATE_CHANGE_BRIDGE (1 << 0) #define PCI_VGA_STATE_CHANGE_DECODES (1 << 1) |