diff options
| -rw-r--r-- | sys/dev/pci/pci.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c index 295e68d..a027e99 100644 --- a/sys/dev/pci/pci.c +++ b/sys/dev/pci/pci.c @@ -2291,9 +2291,27 @@ pci_add_map(device_t pcib, device_t bus, device_t dev, struct resource *res; map = PCIB_READ_CONFIG(pcib, b, s, f, reg, 4); + + /* + * Disable decoding via the command register before + * determining the BARs length since we will be placing them + * in a weird state. + */ + cmd = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_COMMAND, 2); + PCIB_WRITE_CONFIG(pcib, b, s, f, PCIR_COMMAND, + cmd & ~(PCI_BAR_MEM(map) ? PCIM_CMD_MEMEN : PCIM_CMD_PORTEN), 2); + + /* + * Determine the BAR's length by writing all 1's. The bottom + * log_2(size) bits of the BAR will stick as 0 when we read + * the value back. + */ PCIB_WRITE_CONFIG(pcib, b, s, f, reg, 0xffffffff, 4); testval = PCIB_READ_CONFIG(pcib, b, s, f, reg, 4); + + /* Restore the BAR and command register. */ PCIB_WRITE_CONFIG(pcib, b, s, f, reg, map, 4); + PCIB_WRITE_CONFIG(pcib, b, s, f, PCIR_COMMAND, cmd, 2); if (PCI_BAR_MEM(map)) type = SYS_RES_MEMORY; |
