diff options
Diffstat (limited to 'drivers/pci/setup-bus.c')
| -rw-r--r-- | drivers/pci/setup-bus.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c new file mode 100644 index 000000000..401185890 --- /dev/null +++ b/drivers/pci/setup-bus.c @@ -0,0 +1,156 @@ +/* + * drivers/pci/setup-bus.c + * + * Extruded from code written by + * Dave Rusling (david.rusling@reo.mts.dec.com) + * David Mosberger (davidm@cs.arizona.edu) + * David Miller (davem@redhat.com) + * + * Support routines for initializing a PCI subsystem. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/errno.h> +#include <linux/ioport.h> +#include <linux/cache.h> + + +#define DEBUG_CONFIG 0 +#if DEBUG_CONFIG +# define DBGC(args) printk args +#else +# define DBGC(args) +#endif + + +#define ROUND_UP(x, a) (((x) + (a) - 1) & ~((a) - 1)) +#define ROUND_DOWN(x, a) ((x) & ~((a) - 1)) + +static void __init +pbus_set_ranges(struct pci_bus *bus, struct pbus_set_ranges_data *outer) +{ + struct pbus_set_ranges_data inner; + struct pci_dev *dev; + struct list_head *ln; + + inner.found_vga = 0; + inner.mem_start = inner.io_start = ~0UL; + inner.mem_end = inner.io_end = 0; + + /* Collect information about how our direct children are layed out. */ + for (ln=bus->devices.next; ln != &bus->devices; ln=ln->next) { + int i; + dev = pci_dev_b(ln); + for (i = 0; i < PCI_NUM_RESOURCES; i++) { + struct resource *res = &dev->resource[i]; + if (res->flags & IORESOURCE_IO) { + if (res->start < inner.io_start) + inner.io_start = res->start; + if (res->end > inner.io_end) + inner.io_end = res->end; + } else if (res->flags & IORESOURCE_MEM) { + if (res->start < inner.mem_start) + inner.mem_start = res->start; + if (res->end > inner.mem_end) + inner.mem_end = res->end; + } + } + if ((dev->class >> 8) == PCI_CLASS_DISPLAY_VGA) + inner.found_vga = 1; + } + + /* And for all of the sub-busses. */ + for (ln=bus->children.next; ln != &bus->children; ln=ln->next) + pbus_set_ranges(pci_bus_b(ln), &inner); + + /* Align the values. */ + inner.io_start = ROUND_DOWN(inner.io_start, 4*1024); + inner.io_end = ROUND_UP(inner.io_end, 4*1024); + + inner.mem_start = ROUND_DOWN(inner.mem_start, 1*1024*1024); + inner.mem_end = ROUND_UP(inner.mem_end, 1*1024*1024); + + pcibios_fixup_pbus_ranges(bus, &inner); + + /* Configure the bridge, if possible. */ + if (bus->self) { + struct pci_dev *bridge = bus->self; + u32 l; + + /* Set up the top and bottom of the PCI I/O segment + for this bus. */ + pci_read_config_dword(bridge, PCI_IO_BASE, &l); + l &= 0xffff0000; + l |= (inner.io_start >> 8) & 0x00f0; + l |= (inner.io_end - 1) & 0xf000; + pci_write_config_dword(bridge, PCI_IO_BASE, l); + + /* + * Clear out the upper 16 bits of IO base/limit. + * Clear out the upper 32 bits of PREF base/limit. + */ + pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0); + pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 0); + pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0); + + /* Set up the top and bottom of the PCI Memory segment + for this bus. */ + l = (inner.mem_start & 0xfff00000) >> 16; + l |= (inner.mem_end - 1) & 0xfff00000; + pci_write_config_dword(bridge, PCI_MEMORY_BASE, l); + + /* + * Turn off downstream PF memory address range, unless + * there is a VGA behind this bridge, in which case, we + * enable the PREFETCH range to include BIOS ROM at C0000. + * + * NOTE: this is a bit of a hack, done with PREFETCH for + * simplicity, rather than having to add it into the above + * non-PREFETCH range, which could then be bigger than we want. + * We might assume that we could relocate the BIOS ROM, but + * that would depend on having it found by those who need it + * (the DEC BIOS emulator would find it, but I do not know + * about the Xservers). So, we do it this way for now... ;-) + */ + l = (inner.found_vga) ? 0 : 0x0000ffff; + pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l); + + /* + * Tell bridge that there is an ISA bus in the system, + * and (possibly) a VGA as well. + */ + l = (inner.found_vga) ? 0x0c : 0x04; + pci_write_config_byte(bridge, PCI_BRIDGE_CONTROL, l); + + /* + * Clear status bits, + * turn on I/O enable (for downstream I/O), + * turn on memory enable (for downstream memory), + * turn on master enable (for upstream memory and I/O). + */ + pci_write_config_dword(bridge, PCI_COMMAND, 0xffff0007); + } + + if (outer) { + outer->found_vga |= inner.found_vga; + if (inner.io_start < outer->io_start) + outer->io_start = inner.io_start; + if (inner.io_end > outer->io_end) + outer->io_end = inner.io_end; + if (inner.mem_start < outer->mem_start) + outer->mem_start = inner.mem_start; + if (inner.mem_end > outer->mem_end) + outer->mem_end = inner.mem_end; + } +} + +void __init +pci_set_bus_ranges(void) +{ + struct list_head *ln; + + for(ln=pci_root_buses.next; ln != &pci_root_buses; ln=ln->next) + pbus_set_ranges(pci_bus_b(ln), NULL); +} |