2 #include <console/console.h>
4 #include <arch/pciconf.h>
5 #include <device/pci.h>
6 #include <device/pci_ids.h>
7 #include <device/pci_ops.h>
10 * Before we decide to use direct hardware access mechanisms, we try to do some
11 * trivial checks to ensure it at least _seems_ to be working -- we just test
12 * whether bus 00 contains a host bridge (this is similar to checking
13 * techniques used in XFree86, but ours should be more reliable since we
14 * attempt to make use of direct access hints provided by the PCI BIOS).
16 * This should be close to trivial, but it isn't, because there are buggy
17 * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
19 static int pci_sanity_check(const struct pci_bus_operations *o)
21 uint16_t class, vendor;
24 struct bus pbus; /* Dummy device */
25 #define PCI_CLASS_BRIDGE_HOST 0x0600
26 #define PCI_CLASS_DISPLAY_VGA 0x0300
27 #define PCI_VENDOR_ID_COMPAQ 0x0e11
28 #define PCI_VENDOR_ID_INTEL 0x8086
29 #define PCI_VENDOR_ID_MOTOROLA 0x1057
31 for (bus = 0, devfn = 0; devfn < 0x100; devfn++) {
32 class = o->read16(&pbus, bus, devfn, PCI_CLASS_DEVICE);
33 vendor = o->read16(&pbus, bus, devfn, PCI_VENDOR_ID);
34 if (((class == PCI_CLASS_BRIDGE_HOST) || (class == PCI_CLASS_DISPLAY_VGA)) ||
35 ((vendor == PCI_VENDOR_ID_INTEL) || (vendor == PCI_VENDOR_ID_COMPAQ) ||
36 (vendor == PCI_VENDOR_ID_MOTOROLA))) {
40 printk(BIOS_ERR, "PCI: Sanity check failed\n");
44 struct pci_bus_operations *pci_bus_fallback_ops = NULL;
46 static const struct pci_bus_operations *pci_check_direct(void)
51 * Check if configuration type 1 works.
56 outl(0x80000000, 0xCF8);
57 if ((inl(0xCF8) == 0x80000000) &&
58 pci_sanity_check(&pci_cf8_conf1))
61 printk(BIOS_DEBUG, "PCI: Using configuration type 1\n");
62 return &pci_cf8_conf1;
68 * Check if configuration type 2 works.
74 if ((inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00) &&
75 pci_sanity_check(&pci_cf8_conf2))
77 printk(BIOS_DEBUG, "PCI: Using configuration type 2\n");
78 return &pci_cf8_conf2;
82 die("pci_check_direct failed\n");
86 const struct pci_bus_operations *pci_remember_direct(void)
88 if (!pci_bus_fallback_ops)
89 pci_bus_fallback_ops = (struct pci_bus_operations *)pci_check_direct();
90 return pci_bus_fallback_ops;
93 /** Set the method to be used for PCI, type I or type II
95 void pci_set_method(device_t dev)
97 printk(BIOS_INFO, "Finding PCI configuration type.\n");
98 dev->ops->ops_pci_bus = pci_remember_direct();